{
 "version": "1.0.0",
 "about": "Brain Energy - region titles, descriptions, neuron counts and energy resilience. Midsagittal (inside) view. Neuron counts are for an average adult and cover BOTH hemispheres unless the text says otherwise. 'refs' point at ids in references.json. Order = paint order (later siblings are drawn on top). 'open': shown split into its subsections when the page loads. 'group': a heading with no shape of its own.",
 "regions": [
  {
   "id": "cerebrum",
   "parent": null,
   "open": true,
   "title": "Cerebrum",
   "subtitle": "Cerebral hemispheres",
   "color": "#e9a3a6",
   "summary": "The largest part of the brain: a wrinkled sheet of grey matter (the cerebral cortex) over white-matter wiring. Cut down the middle, you see the inner (medial) face of one hemisphere and the bridge of fibres - the corpus callosum - that joins it to the other.",
   "facts": [
    "The cortex is only 2-4 mm thick, but folding gives it about 1,800-2,500 cm2 of surface per brain.",
    "The cerebral cortex holds about 19% of the brain's neurons but uses a larger share of its energy."
   ],
   "neurons": {
    "count": 16300000000,
    "text": "16.3 billion (cerebral cortex)",
    "basis": "measured",
    "note": "Isotropic fractionator; includes white matter. Stereology gives ~19 billion (women) to ~23 billion (men) for the neocortex alone.",
    "refs": [
     "azevedo2009",
     "pakkenberg1997"
    ]
   },
   "energy": {
    "resilience": 0.35,
    "evidence": "moderate"
   }
  },
  {
   "id": "frontal",
   "parent": "cerebrum",
   "title": "Frontal lobe",
   "color": "#e8414b",
   "summary": "The front of the brain, reaching back to the central sulcus. On the inner face it holds the medial prefrontal cortex, the supplementary motor area and the front half of the paracentral lobule (leg area of the motor strip).",
   "facts": [
    "Last region to finish maturing - myelination continues into the mid-20s."
   ],
   "neurons": {
    "count": 4000000000,
    "text": "~3-5.5 billion (estimate)",
    "basis": "estimate",
    "note": "No direct lobe count exists. Estimate = prefrontal share plus most of the 'dorsal' slice in Ribeiro et al. 2013, times 16.3 billion.",
    "refs": [
     "ribeiro2013",
     "azevedo2009"
    ]
   },
   "energy": {
    "resilience": 0.3,
    "evidence": "mixed",
    "note": "Largest drop in glucose use at high altitude; cortex is vulnerable in severe hypoglycemia. Against: frontal blood flow rises most in insulin hypoglycemia.",
    "refs": [
     "hochachka1994",
     "hochachka1999",
     "auer2004",
     "tallroth1992"
    ]
   }
  },
  {
   "id": "prefrontal",
   "parent": "frontal",
   "title": "Prefrontal cortex",
   "subtitle": "PFC",
   "color": "#e8414b",
   "summary": "The front of the frontal lobe, ahead of the motor areas. It holds goals in mind, weighs options, holds back impulses and tunes emotional reactions - the 'executive' functions.",
   "facts": [
    "Executive tasks are among the first to fail when blood glucose falls or after a night without sleep."
   ],
   "neurons": {
    "count": 1240000000,
    "text": "~1.2 billion (about 8% of cortical neurons)",
    "basis": "measured",
    "note": "Cortex in front of the corpus callosum; Ribeiro 2013 (7.6%), Gabi 2016 (~8%).",
    "refs": [
     "ribeiro2013",
     "gabi2016"
    ]
   },
   "energy": {
    "resilience": 0.3,
    "evidence": "mixed",
    "note": "Behaviour (executive function) fails first in hypoglycemia and sleep loss; glucose use drops after 24 h awake. Against: medial PFC is activated during hypoglycemia.",
    "refs": [
     "thomas2000",
     "harrison2000",
     "warren2005",
     "teves2004",
     "teh2010"
    ]
   }
  },
  {
   "id": "dmpfc",
   "parent": "prefrontal",
   "title": "Dorsomedial prefrontal cortex",
   "subtitle": "dmPFC - medial superior frontal gyrus",
   "color": "#ef5a63",
   "summary": "The upper inner face of the prefrontal cortex. Active when you think about yourself and other people's minds, and when monitoring your own performance.",
   "neurons": {
    "count": null,
    "text": "Part of the ~1.2 billion prefrontal neurons",
    "basis": "none",
    "note": "No separate count published.",
    "refs": []
   },
   "energy": {
    "resilience": 0.3,
    "evidence": "weak",
    "note": "Inherits the prefrontal estimate.",
    "refs": [
     "thomas2000"
    ]
   }
  },
  {
   "id": "vmpfc",
   "parent": "prefrontal",
   "title": "Ventromedial prefrontal cortex",
   "subtitle": "vmPFC, with the frontal pole",
   "color": "#d6303a",
   "summary": "The lower inner face of the frontal lobe and the frontal pole. It attaches value and feeling to choices and links the cortex to the limbic system and hypothalamus.",
   "facts": [
    "Damage here (as in Phineas Gage) leaves intelligence intact but wrecks judgment and social conduct."
   ],
   "neurons": {
    "count": null,
    "text": "Part of the ~1.2 billion prefrontal neurons",
    "basis": "none",
    "note": "No separate count published.",
    "refs": []
   },
   "energy": {
    "resilience": 0.4,
    "evidence": "mixed",
    "note": "Medial PFC (areas 24/32 border) is ACTIVATED during hypoglycemia as it drives the autonomic response - so it is not simply switched off.",
    "refs": [
     "teves2004",
     "teh2010"
    ]
   }
  },
  {
   "id": "ofc",
   "parent": "prefrontal",
   "title": "Orbitofrontal cortex",
   "subtitle": "OFC - above the eye sockets",
   "color": "#b8242d",
   "summary": "The underside of the frontal lobe, resting on the orbits. It tracks reward and punishment, smell and taste value, and updates choices when outcomes change.",
   "neurons": {
    "count": null,
    "text": "Part of the ~1.2 billion prefrontal neurons",
    "basis": "none",
    "note": "No separate count published.",
    "refs": []
   },
   "energy": {
    "resilience": 0.3,
    "evidence": "weak",
    "note": "Lateral orbitofrontal cortex was deactivated at 2.6 mmol/L glucose in type 1 diabetes.",
    "refs": [
     "dunn2007"
    ]
   }
  },
  {
   "id": "sma",
   "parent": "frontal",
   "title": "Supplementary motor area",
   "subtitle": "SMA / premotor (medial area 6)",
   "color": "#f07a6a",
   "summary": "Just in front of the leg area of the motor strip. It prepares and sequences movements - especially self-started ones - before the primary motor cortex sends the command.",
   "neurons": {
    "count": null,
    "text": "No published count",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.45,
    "evidence": "placeholder",
    "note": "No region-specific data; placeholder.",
    "refs": []
   }
  },
  {
   "id": "motor",
   "parent": "frontal",
   "title": "Primary motor cortex",
   "subtitle": "M1 - paracentral lobule (front)",
   "color": "#c7362f",
   "summary": "The motor strip, in front of the central sulcus. On the inner face it controls the leg and foot. Its giant Betz cells send axons all the way down the spinal cord.",
   "facts": [
    "Mapped as the 'motor homunculus' by Wilder Penfield."
   ],
   "neurons": {
    "count": 400000000,
    "text": "~0.3-0.5 billion (estimate)",
    "basis": "estimate",
    "note": "No total count published; estimate from area 4 being ~2-3% of the cortex.",
    "refs": [
     "rivara2003"
    ]
   },
   "energy": {
    "resilience": 0.5,
    "evidence": "placeholder",
    "note": "No region-specific data; placeholder (simple motor tasks hold up better than complex ones in hypoglycemia).",
    "refs": [
     "warren2005"
    ]
   }
  },
  {
   "id": "parietal",
   "parent": "cerebrum",
   "title": "Parietal lobe",
   "color": "#f5b731",
   "summary": "Behind the central sulcus, in front of the parieto-occipital sulcus. It builds the body's sense of touch and position and a map of space; on the inner face it holds the precuneus.",
   "neurons": {
    "count": 3100000000,
    "text": "~3.1 billion (19% of cortical neurons)",
    "basis": "measured",
    "note": "Ribeiro 2013 share x 16.3 billion; one brain, and the 'lobes' there are front-to-back slices.",
    "refs": [
     "ribeiro2013"
    ]
   },
   "energy": {
    "resilience": 0.35,
    "evidence": "mixed",
    "note": "Posterior parietal glucose use drops after 24 h awake; watershed zone in hypoxia. Against: blood flow rises in insulin hypoglycemia.",
    "refs": [
     "thomas2000",
     "miller2005",
     "tallroth1992"
    ]
   }
  },
  {
   "id": "precuneus",
   "parent": "parietal",
   "title": "Precuneus",
   "subtitle": "medial parietal cortex",
   "color": "#f5b731",
   "summary": "A hub of the brain's 'default mode network': most active when you are awake but not focused outward - remembering, imagining, thinking about yourself.",
   "facts": [
    "One of the most energy-hungry parts of the cortex at rest."
   ],
   "neurons": {
    "count": null,
    "text": "No separate count",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.35,
    "evidence": "weak",
    "refs": [
     "thomas2000"
    ]
   }
  },
  {
   "id": "s1",
   "parent": "parietal",
   "title": "Primary somatosensory cortex",
   "subtitle": "S1 - paracentral lobule (back)",
   "color": "#e39a12",
   "summary": "Just behind the central sulcus. On the inner face it receives touch, pain, temperature and position signals from the leg and foot.",
   "neurons": {
    "count": null,
    "text": "No separate count",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.4,
    "evidence": "weak",
    "refs": []
   }
  },
  {
   "id": "occipital",
   "parent": "cerebrum",
   "title": "Occipital lobe",
   "color": "#3a8fd0",
   "summary": "The back of the brain, behind the parieto-occipital sulcus - the visual cortex. The calcarine sulcus cuts across its inner face; primary visual cortex lines it.",
   "facts": [
    "Has the highest neuron density in the cortex."
   ],
   "neurons": {
    "count": 5400000000,
    "text": "~5.4 billion (33% of cortical neurons)",
    "basis": "measured",
    "note": "Ribeiro 2013 share x 16.3 billion.",
    "refs": [
     "ribeiro2013"
    ]
   },
   "energy": {
    "resilience": 0.5,
    "evidence": "weak",
    "note": "Mixed: relatively up after sleep loss, down after weeks at altitude.",
    "refs": [
     "wu1991",
     "hochachka1999"
    ]
   }
  },
  {
   "id": "cuneus",
   "parent": "occipital",
   "title": "Cuneus",
   "subtitle": "above the calcarine sulcus",
   "color": "#5aa4dc",
   "summary": "The wedge between the parieto-occipital and calcarine sulci. It processes the lower half of the visual field.",
   "neurons": {
    "count": null,
    "text": "No separate count",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.5,
    "evidence": "weak",
    "refs": []
   }
  },
  {
   "id": "lingual",
   "parent": "occipital",
   "title": "Lingual gyrus",
   "subtitle": "below the calcarine sulcus",
   "color": "#2f79b5",
   "summary": "Below the calcarine sulcus. It handles the upper visual field and plays a part in recognising letters and in visual memory.",
   "neurons": {
    "count": null,
    "text": "No separate count",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.5,
    "evidence": "weak",
    "refs": []
   }
  },
  {
   "id": "v1",
   "parent": "occipital",
   "title": "Primary visual cortex",
   "subtitle": "V1 - striate cortex, area 17",
   "color": "#1d5f9a",
   "summary": "Lines the calcarine sulcus. Every signal from the eyes (via the thalamus) arrives here first, laid out as a map of the visual field.",
   "facts": [
    "Named 'striate' for the white stripe (line of Gennari) visible to the naked eye."
   ],
   "neurons": {
    "count": 280000000,
    "text": "~280 million (about 140 million per hemisphere)",
    "basis": "measured",
    "note": "Varies a lot between people: 90-200 million per hemisphere.",
    "refs": [
     "leuba1994"
    ]
   },
   "energy": {
    "resilience": 0.5,
    "evidence": "weak",
    "refs": [
     "wu1991"
    ]
   }
  },
  {
   "id": "temporal",
   "parent": "cerebrum",
   "title": "Temporal lobe",
   "subtitle": "medial and inferior surface",
   "color": "#6cc5b0",
   "summary": "Mostly on the outside of the brain, so only its inner edge shows in this view - the parahippocampal gyrus and the temporal pole. Deep inside lie the hippocampus and amygdala (drawn see-through).",
   "neurons": {
    "count": 1900000000,
    "text": "~1.9 billion (12% of cortical neurons)",
    "basis": "measured",
    "note": "Ribeiro 2013 share x 16.3 billion; the insula adds ~0.2 billion.",
    "refs": [
     "ribeiro2013"
    ]
   },
   "energy": {
    "resilience": 0.35,
    "evidence": "moderate",
    "note": "Relative drop after sleep loss; cortex is vulnerable in severe hypoglycemia.",
    "refs": [
     "wu1991",
     "auer2004"
    ]
   }
  },
  {
   "id": "parahippocampal",
   "parent": "temporal",
   "title": "Parahippocampal gyrus",
   "color": "#6cc5b0",
   "summary": "The ridge alongside the hippocampus. Its front part (entorhinal cortex) is the main gateway of information into the hippocampus; its back part recognises places and scenes.",
   "facts": [
    "The entorhinal cortex is one of the first places affected in Alzheimer's disease."
   ],
   "neurons": {
    "count": null,
    "text": "No separate count",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.25,
    "evidence": "weak",
    "note": "Posterior parahippocampal gyrus was deactivated during induced hypoglycemia.",
    "refs": [
     "teh2010"
    ]
   }
  },
  {
   "id": "temporal_pole",
   "parent": "temporal",
   "title": "Temporal pole",
   "color": "#4fae98",
   "summary": "The front tip of the temporal lobe. It links names and facts about people and things to their emotional meaning.",
   "neurons": {
    "count": null,
    "text": "No separate count",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.35,
    "evidence": "weak",
    "refs": []
   }
  },
  {
   "id": "hippocampus",
   "parent": "temporal",
   "always": true,
   "title": "Hippocampus",
   "subtitle": "deep in the temporal lobe (projected)",
   "color": "#2f6fe0",
   "summary": "A curled ridge of cortex inside the temporal lobe, off the midline - shown see-through. It turns experiences into lasting memories and builds maps of places.",
   "facts": [
    "One of the few places where new neurons may be added in adults (dentate gyrus).",
    "Among the most vulnerable parts of the brain to low glucose and low oxygen."
   ],
   "neurons": {
    "count": 80000000,
    "text": "~80 million (about 40 million per side)",
    "basis": "measured",
    "note": "Per side: dentate granule cells 15 M, CA1 16 M, CA3-2 2.7 M, hilus 2.0 M, subiculum 4.5 M.",
    "refs": [
     "west1990"
    ]
   },
   "energy": {
    "resilience": 0.2,
    "evidence": "moderate",
    "note": "Dentate gyrus necrosis is a hallmark of severe hypoglycemic damage.",
    "refs": [
     "auer2004",
     "teh2010"
    ]
   }
  },
  {
   "id": "amygdala",
   "parent": "temporal",
   "always": true,
   "title": "Amygdala",
   "subtitle": "deep in the temporal lobe (projected)",
   "color": "#e0439b",
   "summary": "An almond-shaped group of nuclei in front of the hippocampus, off the midline. It detects threat and emotional significance and tags memories with feeling.",
   "neurons": {
    "count": 24000000,
    "text": "~24 million (12.2 million per hemisphere)",
    "basis": "measured",
    "note": "Lateral nucleus 4.0 M, basal 3.2 M, accessory basal 1.3 M, central 0.36 M (per hemisphere).",
    "refs": [
     "schumann2005"
    ]
   },
   "energy": {
    "resilience": 0.55,
    "evidence": "weak",
    "note": "Activated when hypoglycemia is felt.",
    "refs": [
     "dunn2007"
    ]
   }
  },
  {
   "id": "cingulate",
   "parent": "cerebrum",
   "title": "Cingulate gyrus",
   "subtitle": "limbic lobe",
   "color": "#7cc36a",
   "summary": "The belt ('cingulum') of cortex wrapped around the corpus callosum. A core part of the limbic system, linking emotion to action and attention.",
   "neurons": {
    "count": null,
    "text": "No reliable total",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.55,
    "evidence": "mixed"
   }
  },
  {
   "id": "cingulate_post",
   "parent": "cingulate",
   "title": "Posterior cingulate cortex",
   "subtitle": "PCC",
   "color": "#8fcf7c",
   "summary": "The back half of the cingulate. With the precuneus it is a hub of the default mode network - memory, self-reflection and mind-wandering.",
   "neurons": {
    "count": null,
    "text": "No separate count",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.45,
    "evidence": "placeholder",
    "note": "No verified region-specific data; placeholder.",
    "refs": []
   }
  },
  {
   "id": "cingulate_ant",
   "parent": "cingulate",
   "title": "Anterior cingulate cortex",
   "subtitle": "ACC - areas 24, 32, 25",
   "color": "#5aa94a",
   "summary": "The front of the cingulate. It notices errors and conflict, feels the unpleasantness of pain, and drives the body's autonomic responses.",
   "neurons": {
    "count": 250000000,
    "text": "~0.15-0.35 billion (estimate)",
    "basis": "estimate",
    "note": "No reliable count; estimate from its share of cortical area.",
    "refs": []
   },
   "energy": {
    "resilience": 0.6,
    "evidence": "moderate",
    "note": "Activated early in hypoglycemia and stays engaged - it helps drive the counter-regulatory response.",
    "refs": [
     "teves2004",
     "teh2010"
    ]
   }
  },
  {
   "id": "white",
   "parent": "cerebrum",
   "group": true,
   "open": true,
   "title": "White matter tracts",
   "color": "#efe3c8",
   "summary": "Bundles of myelinated axons - the cables between regions. They carry signals but hold no neuron cell bodies.",
   "neurons": {
    "count": 0,
    "text": "No neuron cell bodies (axons only)",
    "basis": "measured",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "corpus_callosum",
   "parent": "white",
   "title": "Corpus callosum",
   "color": "#efe3c8",
   "summary": "The great bridge of about 200 million axons joining the left and right hemispheres. Cut down the middle it has the shape of a C lying on its side.",
   "neurons": {
    "count": 0,
    "text": "0 neurons - about 200 million axons",
    "basis": "measured",
    "refs": [
     "aboitiz1992"
    ]
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "cc_body",
   "parent": "corpus_callosum",
   "title": "Body of the corpus callosum",
   "color": "#efe3c8",
   "summary": "The long middle part. Connects the motor, sensory and parietal cortex of the two sides.",
   "neurons": {
    "count": 0,
    "text": "Axons only",
    "basis": "measured",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "cc_genu",
   "parent": "corpus_callosum",
   "title": "Genu",
   "subtitle": "the 'knee'",
   "color": "#e6d4ae",
   "summary": "The front bend. Its axons join the two prefrontal cortices.",
   "neurons": {
    "count": 0,
    "text": "Axons only",
    "basis": "measured",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "cc_rostrum",
   "parent": "corpus_callosum",
   "title": "Rostrum",
   "subtitle": "the 'beak'",
   "color": "#dcc79c",
   "summary": "The thin tip curving back under the genu. Joins the orbital surfaces of the frontal lobes.",
   "neurons": {
    "count": 0,
    "text": "Axons only",
    "basis": "measured",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "cc_splenium",
   "parent": "corpus_callosum",
   "title": "Splenium",
   "color": "#e6d4ae",
   "summary": "The thick back end. Carries visual and temporal-parietal connections between the hemispheres.",
   "neurons": {
    "count": 0,
    "text": "Axons only",
    "basis": "measured",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "septal",
   "parent": "cerebrum",
   "title": "Septal area",
   "subtitle": "septal nuclei, below the rostrum",
   "color": "#22b3b3",
   "summary": "A small region under the front of the corpus callosum. It links the hippocampus with the hypothalamus and is part of the brain's reward and pleasure circuitry.",
   "neurons": {
    "count": null,
    "text": "No count found",
    "basis": "none",
    "note": "Nearest figure: the cholinergic basal forebrain (Ch1-Ch4) has ~0.79 million neurons per hemisphere.",
    "refs": [
     "wegiel2014"
    ]
   },
   "energy": {
    "resilience": 0.5,
    "evidence": "weak",
    "refs": []
   }
  },
  {
   "id": "olfactory_bulb",
   "parent": "cerebrum",
   "title": "Olfactory bulb and tract",
   "color": "#c9a36a",
   "summary": "Lies under the frontal lobe. Smell receptors in the nose connect straight into it - the only sense that reaches the cortex without first passing through the thalamus.",
   "neurons": {
    "count": 80000,
    "text": "~40,000 mitral cells per bulb (young adults)",
    "basis": "measured",
    "note": "Only the main output cells were counted; falls ~10% per decade.",
    "refs": [
     "meisami1998"
    ]
   },
   "energy": {
    "resilience": 0.5,
    "evidence": "weak",
    "refs": []
   }
  },
  {
   "id": "cerebellum",
   "parent": null,
   "title": "Cerebellum",
   "subtitle": "'little brain' - vermis in this cut",
   "color": "#3f3f94",
   "summary": "Tucked under the back of the cerebrum. It fine-tunes movement, balance and timing, and helps with some thinking and learning. Cut down the middle, its white matter shows as a tree - the arbor vitae.",
   "facts": [
    "About 10% of brain volume but about 80% of its neurons - mostly tiny granule cells.",
    "About 30 million Purkinje cells, each receiving up to 200,000 inputs."
   ],
   "neurons": {
    "count": 69000000000,
    "text": "69 billion (80% of all neurons)",
    "basis": "measured",
    "note": "Stereology of granule cells alone gives ~101 billion (Andersen 1992); Purkinje cells ~30.5 million.",
    "refs": [
     "azevedo2009",
     "andersen1992"
    ]
   },
   "energy": {
    "resilience": 0.82,
    "evidence": "moderate",
    "note": "Spared in hypoglycemic brain damage; least reduced (or even increased) in chronic hypoxia. Against: reduced after 32 h without sleep.",
    "refs": [
     "auer2004",
     "hochachka1994",
     "hochachka1999",
     "cranston1998",
     "wu1991"
    ]
   }
  },
  {
   "id": "cb_posterior",
   "parent": "cerebellum",
   "title": "Posterior lobe",
   "color": "#3f3f94",
   "summary": "The largest part, behind the primary fissure. Coordinates skilled movement and connects with the prefrontal cortex for planning and thinking.",
   "neurons": {
    "count": null,
    "text": "Most of the 69 billion",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.82,
    "evidence": "moderate",
    "refs": [
     "auer2004"
    ]
   }
  },
  {
   "id": "cb_anterior",
   "parent": "cerebellum",
   "title": "Anterior lobe",
   "color": "#5959b8",
   "summary": "In front of the primary fissure. Controls muscle tone and posture of the limbs and trunk.",
   "neurons": {
    "count": null,
    "text": "No separate count",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.82,
    "evidence": "moderate",
    "refs": [
     "auer2004"
    ]
   }
  },
  {
   "id": "cb_flocculonodular",
   "parent": "cerebellum",
   "title": "Flocculonodular lobe",
   "subtitle": "nodulus in this cut",
   "color": "#7474cc",
   "summary": "The oldest part, next to the fourth ventricle. Works with the inner-ear balance organs to keep balance and steady the eyes.",
   "neurons": {
    "count": null,
    "text": "No separate count",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.82,
    "evidence": "moderate",
    "refs": [
     "auer2004"
    ]
   }
  },
  {
   "id": "brainstem",
   "parent": null,
   "open": true,
   "title": "Brainstem",
   "color": "#ee7a3a",
   "summary": "The stalk joining the brain to the spinal cord: midbrain, pons and medulla. It runs the automatic functions that keep you alive and carries every pathway between brain and body.",
   "neurons": {
    "count": null,
    "text": "No total count (brainstem + hypothalamus ~0.3 billion, estimate)",
    "basis": "estimate",
    "note": "Azevedo's 'rest of brain' (0.69 billion) minus thalamus and striatum.",
    "refs": [
     "azevedo2009",
     "wegiel2014"
    ]
   },
   "energy": {
    "resilience": 0.85,
    "evidence": "moderate"
   }
  },
  {
   "id": "midbrain",
   "parent": "brainstem",
   "title": "Midbrain",
   "subtitle": "mesencephalon",
   "color": "#f28c50",
   "summary": "The top of the brainstem. Holds visual and auditory reflex centres, the dopamine neurons of the substantia nigra and ventral tegmental area, and the cerebral aqueduct.",
   "neurons": {
    "count": null,
    "text": "No total; substantia nigra ~0.55 million pigmented neurons",
    "basis": "measured",
    "refs": [
     "pakkenberg1991"
    ]
   },
   "energy": {
    "resilience": 0.75,
    "evidence": "weak",
    "note": "Part of the spared brainstem in hypoglycemia; keeps its glucose use in ketosis.",
    "refs": [
     "auer2004",
     "hasselbalch1996"
    ]
   }
  },
  {
   "id": "tegmentum",
   "parent": "midbrain",
   "title": "Tegmentum",
   "color": "#f28c50",
   "summary": "The front 'floor' of the midbrain: red nucleus, substantia nigra, ventral tegmental area, eye-movement nuclei and part of the reticular formation.",
   "neurons": {
    "count": null,
    "text": "SN ~0.55 M pigmented + 0.26 M non-pigmented",
    "basis": "measured",
    "refs": [
     "pakkenberg1991"
    ]
   },
   "energy": {
    "resilience": 0.75,
    "evidence": "weak",
    "refs": [
     "auer2004"
    ]
   }
  },
  {
   "id": "substantia_nigra",
   "parent": "tegmentum",
   "always": true,
   "title": "Substantia nigra",
   "subtitle": "in the midbrain, off the midline (projected)",
   "color": "#5a4a3a",
   "summary": "The 'black substance': a band of dark, pigmented dopamine neurons in the midbrain. Their axons run to the caudate and putamen and set the tone for movement; losing them causes Parkinson's disease.",
   "neurons": {
    "count": 810000,
    "text": "~0.81 million (550,000 pigmented + 260,000 non-pigmented, both sides)",
    "basis": "measured",
    "refs": [
     "pakkenberg1991"
    ]
   },
   "energy": {
    "resilience": 0.75,
    "evidence": "weak",
    "note": "Brainstem structures are spared in hypoglycemia, but these neurons have very long, branched axons and a high energy cost, which is thought to make them fragile in Parkinson's disease.",
    "refs": [
     "auer2004"
    ]
   }
  },
  {
   "id": "tectum",
   "parent": "midbrain",
   "title": "Tectum",
   "subtitle": "superior and inferior colliculi",
   "color": "#f7a676",
   "summary": "The 'roof' of the midbrain behind the aqueduct. The superior colliculi turn the eyes and head toward things you see; the inferior colliculi relay hearing.",
   "neurons": {
    "count": null,
    "text": "No separate count",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.75,
    "evidence": "weak",
    "refs": []
   }
  },
  {
   "id": "pons",
   "parent": "brainstem",
   "title": "Pons",
   "color": "#ee7a3a",
   "summary": "The bulge of the brainstem. A bridge of fibres to the cerebellum plus centres for breathing rhythm, sleep (REM) and alertness - including the locus coeruleus, the brain's main noradrenaline source.",
   "neurons": {
    "count": null,
    "text": "No total; locus coeruleus ~31,000 neurons",
    "basis": "measured",
    "refs": [
     "ohm1997"
    ]
   },
   "energy": {
    "resilience": 0.88,
    "evidence": "moderate",
    "note": "Brainstem is universally spared in hypoglycemic damage; smallest blood-flow change.",
    "refs": [
     "auer2004",
     "tallroth1992"
    ]
   }
  },
  {
   "id": "locus_coeruleus",
   "parent": "pons",
   "always": true,
   "title": "Locus coeruleus",
   "subtitle": "in the pons, beside the fourth ventricle (projected)",
   "color": "#3d7fb8",
   "summary": "The 'blue spot': a tiny nucleus in the upper pons that is the brain's main source of noradrenaline. Its axons reach almost the whole brain and set alertness, attention and the response to stress.",
   "neurons": {
    "count": 31400,
    "text": "~31,000 (about 15,700 per side)",
    "basis": "measured",
    "refs": [
     "ohm1997"
    ]
   },
   "energy": {
    "resilience": 0.88,
    "evidence": "weak",
    "note": "Inherits the brainstem's resilience (spared in hypoglycemia).",
    "refs": [
     "auer2004"
    ]
   }
  },
  {
   "id": "medulla",
   "parent": "brainstem",
   "title": "Medulla oblongata",
   "color": "#d9632a",
   "summary": "The lowest part of the brainstem, continuous with the spinal cord. It keeps the heart beating and the lungs breathing without any conscious effort.",
   "neurons": {
    "count": null,
    "text": "No total; inferior olive ~0.72 million per side",
    "basis": "measured",
    "refs": [
     "wegiel2014"
    ]
   },
   "energy": {
    "resilience": 0.92,
    "evidence": "moderate",
    "note": "Spared in hypoglycemic damage; controls breathing and circulation.",
    "refs": [
     "auer2004"
    ]
   }
  },
  {
   "id": "ventricles",
   "parent": null,
   "group": true,
   "open": true,
   "title": "Ventricles",
   "color": "#bcd7f0",
   "summary": "Fluid-filled spaces inside the brain. They make cerebrospinal fluid (about 500 ml a day), which cushions the brain and clears waste.",
   "neurons": {
    "count": 0,
    "text": "No neurons (fluid space)",
    "basis": "measured",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "lateral_ventricle",
   "parent": "ventricles",
   "title": "Lateral ventricle",
   "color": "#bcd7f0",
   "summary": "One in each hemisphere, curving under the corpus callosum. The largest of the ventricles; its choroid plexus makes most of the CSF.",
   "neurons": {
    "count": 0,
    "text": "No neurons",
    "basis": "measured",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "third_ventricle",
   "parent": "ventricles",
   "title": "Third ventricle",
   "color": "#cfe1f3",
   "summary": "A thin slit of fluid in the midline between the left and right thalamus and hypothalamus. In a cut down the middle you look straight into it; its side walls are the thalamus and hypothalamus.",
   "neurons": {
    "count": 0,
    "text": "No neurons",
    "basis": "measured",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "aqueduct",
   "parent": "ventricles",
   "title": "Cerebral aqueduct",
   "color": "#9fc4ea",
   "summary": "A narrow canal through the midbrain from the third to the fourth ventricle. If it narrows, fluid backs up (hydrocephalus).",
   "neurons": {
    "count": 0,
    "text": "No neurons",
    "basis": "measured",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "fourth_ventricle",
   "parent": "ventricles",
   "title": "Fourth ventricle",
   "color": "#9fc4ea",
   "summary": "A tent-shaped space between the pons, medulla and cerebellum. CSF leaves the ventricles from here to bathe the brain and spinal cord.",
   "neurons": {
    "count": 0,
    "text": "No neurons",
    "basis": "measured",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "diencephalon",
   "parent": null,
   "group": true,
   "open": true,
   "title": "Diencephalon",
   "subtitle": "'between-brain'",
   "color": "#f3c34a",
   "summary": "The core at the centre of the brain, above the brainstem: thalamus, hypothalamus and their attachments (pituitary stalk, pineal gland, mammillary bodies).",
   "neurons": {
    "count": null,
    "text": "Thalamus ~99 million + hypothalamus",
    "basis": "measured",
    "refs": [
     "wegiel2014"
    ]
   },
   "energy": {
    "resilience": 0.65,
    "evidence": "mixed"
   }
  },
  {
   "id": "thalamus",
   "parent": "diencephalon",
   "title": "Thalamus",
   "color": "#f3c34a",
   "summary": "An egg-shaped relay station at the centre of the brain. Almost every sense (except smell) passes through it on the way to the cortex, and it helps set alertness and consciousness.",
   "neurons": {
    "count": 99000000,
    "text": "~99 million (49 million per hemisphere)",
    "basis": "measured",
    "note": "Mediodorsal nucleus ~6.4 million; lateral geniculate ~1.4 million per side. Wegiel's subjects were aged 4-60.",
    "refs": [
     "wegiel2014",
     "abitz2007"
    ]
   },
   "energy": {
    "resilience": 0.55,
    "evidence": "mixed",
    "note": "Activated in hypoglycemia (dorsal midline), but its glucose use falls in sleep loss and hypoxia, and it is a damage site in newborn asphyxia.",
    "refs": [
     "arbelaez2012",
     "arbelaez2008",
     "teves2004",
     "thomas2000",
     "hochachka1999",
     "miller2005"
    ]
   }
  },
  {
   "id": "hypothalamus",
   "parent": "diencephalon",
   "title": "Hypothalamus",
   "color": "#7fbf6a",
   "summary": "Below the thalamus, the size of an almond. It keeps the body in balance - temperature, hunger, thirst, sleep, stress - and runs the pituitary gland. It also senses blood glucose.",
   "facts": [
    "About 70,000 orexin (hypocretin) neurons here keep you awake; their loss causes narcolepsy."
   ],
   "neurons": {
    "count": 20000000,
    "text": "~10-30 million (estimate)",
    "basis": "estimate",
    "note": "No total count published. Orexin neurons ~70,000; suprachiasmatic nucleus ~8,600 counted (one side).",
    "refs": [
     "thannickal2000",
     "hofman1996"
    ]
   },
   "energy": {
    "resilience": 0.85,
    "evidence": "moderate",
    "note": "The glucose sensor: its blood flow rises at the first small fall in glucose, and its activity is kept.",
    "refs": [
     "page2009",
     "cranston2001",
     "teh2010"
    ]
   }
  },
  {
   "id": "mammillary",
   "parent": "diencephalon",
   "title": "Mammillary body",
   "color": "#e57db0",
   "summary": "A small round bump on the underside of the hypothalamus where the fornix ends. A relay in the memory (Papez) circuit.",
   "facts": [
    "Damaged in thiamine deficiency (Wernicke-Korsakoff syndrome)."
   ],
   "neurons": {
    "count": null,
    "text": "Not verified",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.6,
    "evidence": "weak",
    "refs": []
   }
  },
  {
   "id": "pituitary",
   "parent": "diencephalon",
   "title": "Pituitary gland",
   "color": "#f0a0a0",
   "summary": "The 'master gland', hanging from the hypothalamus on a stalk. Its front part makes hormones; its back part releases hormones made by hypothalamic neurons.",
   "neurons": {
    "count": 0,
    "text": "No neuron cell bodies (posterior lobe = hypothalamic axon endings)",
    "basis": "measured",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "optic_chiasm",
   "parent": "diencephalon",
   "title": "Optic chiasm",
   "color": "#9aa7b4",
   "summary": "Where the two optic nerves meet and half their fibres cross, so each side of the brain sees the opposite half of the world.",
   "neurons": {
    "count": 0,
    "text": "0 neurons - ~1.2 million axons per optic nerve",
    "basis": "measured",
    "note": "Classic figure.",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "pineal",
   "parent": "diencephalon",
   "title": "Pineal gland",
   "color": "#b58ad6",
   "summary": "A pea-sized gland behind the thalamus that releases melatonin at night, timed by the hypothalamus's body clock.",
   "neurons": {
    "count": 0,
    "text": "No neurons (pinealocytes are gland cells)",
    "basis": "measured",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "fornix",
   "parent": "white",
   "title": "Fornix",
   "color": "#8e6bd1",
   "summary": "An arched cable of axons running from the hippocampus, under the corpus callosum, down to the mammillary bodies. The main output pathway of the hippocampus.",
   "neurons": {
    "count": 0,
    "text": "0 neurons - about 1.2 million fibres per side",
    "basis": "measured",
    "note": "Classic figure (Daitz 1953), not re-verified.",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "basal_ganglia",
   "parent": null,
   "group": true,
   "open": true,
   "title": "Basal ganglia",
   "color": "#8e6cc0",
   "summary": "A set of nuclei buried deep in each hemisphere, 10-40 mm off the midline, so a cut down the middle misses them: they are drawn here as see-through ghosts projected onto the view. They select and gate actions, learn habits and run on dopamine - the circuit that fails in Parkinson's disease.",
   "neurons": {
    "count": null,
    "text": "See the parts",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": null
   }
  },
  {
   "id": "caudate",
   "parent": "basal_ganglia",
   "title": "Caudate nucleus",
   "subtitle": "deep, off the midline (projected)",
   "color": "#8e6cc0",
   "summary": "A C-shaped nucleus that follows the lateral ventricle: a big head in front, a body over the thalamus and a tail curling down toward the amygdala. With the putamen it forms the striatum, the input stage of the basal ganglia. It takes part in goal-directed action, learning from feedback and (with the frontal lobe) in thinking and planning.",
   "neurons": {
    "count": null,
    "text": "tens of millions per hemisphere (roughly 50-65 million, in the same class as the thalamus and putamen)",
    "basis": "estimate",
    "refs": [
     "wegiel2014"
    ]
   },
   "energy": {
    "resilience": 0.5,
    "evidence": "weak",
    "note": "The caudate and putamen are among the regions damaged in severe hypoglycemia (with the cortex and hippocampus); the brainstem and cerebellum are spared.",
    "refs": [
     "auer2004"
    ]
   }
  },
  {
   "id": "putamen",
   "parent": "basal_ganglia",
   "title": "Putamen",
   "subtitle": "deep, off the midline (projected)",
   "color": "#a07fd0",
   "summary": "The outer part of the striatum, lateral to the thalamus. It receives from the motor and sensory cortex and is the main route for learned movements and habits - the 'autopilot' for actions you no longer have to think about.",
   "neurons": {
    "count": null,
    "text": "tens of millions per hemisphere (roughly 50-65 million)",
    "basis": "estimate",
    "refs": [
     "wegiel2014"
    ]
   },
   "energy": {
    "resilience": 0.5,
    "evidence": "weak",
    "note": "Damaged with the caudate in severe hypoglycemia.",
    "refs": [
     "auer2004"
    ]
   }
  },
  {
   "id": "globus_pallidus",
   "parent": "basal_ganglia",
   "title": "Globus pallidus",
   "subtitle": "deep, off the midline (projected)",
   "color": "#b99ddd",
   "summary": "The 'pale globe' medial to the putamen: the output stage of the basal ganglia. Its cells fire steadily and hold movements back; the striatum releases a movement by pausing them. Deep-brain stimulation for Parkinson's disease targets it (or the nearby subthalamic nucleus).",
   "neurons": {
    "count": null,
    "text": "a few hundred thousand per hemisphere (large, sparse neurons)",
    "basis": "none",
    "refs": []
   },
   "energy": {
    "resilience": 0.7,
    "evidence": "placeholder",
    "note": "Placeholder: no study of this nucleus under energy shortage was found; it is classically hit by lack of oxygen (carbon monoxide) rather than by low blood sugar.",
    "refs": []
   }
  },
  {
   "id": "nucleus_accumbens",
   "parent": "basal_ganglia",
   "title": "Nucleus accumbens",
   "subtitle": "deep, off the midline (projected)",
   "color": "#c78ad6",
   "summary": "The ventral striatum, where the caudate head meets the putamen, beside the septal area. Dopamine from the midbrain arrives here when a reward is expected: it drives wanting, motivation and the learning of what is worth working for.",
   "neurons": {
    "count": null,
    "text": "roughly 7-15 million per hemisphere",
    "basis": "estimate",
    "refs": [
     "wegiel2014"
    ]
   },
   "energy": {
    "resilience": 0.55,
    "evidence": "placeholder",
    "note": "Placeholder: no direct data; placed with the rest of the striatum.",
    "refs": []
   }
  }
 ],
 "systems": [
  {
   "id": "limbic",
   "title": "Limbic system",
   "color": "#e0439b",
   "summary": "A ring of structures around the brain's core that handles emotion, memory and motivation. Paul MacLean named the 'limbic system' in 1952; it is a functional grouping rather than a sharp anatomical one.",
   "functions": [
    "Emotion",
    "Memory",
    "Motivation and reward",
    "Smell",
    "Hormonal and autonomic responses"
   ],
   "members": [
    "cingulate",
    "cingulate_ant",
    "cingulate_post",
    "hippocampus",
    "amygdala",
    "parahippocampal",
    "fornix",
    "mammillary",
    "hypothalamus",
    "thalamus",
    "septal",
    "olfactory_bulb",
    "vmpfc",
    "ofc"
   ]
  },
  {
   "id": "motor_sys",
   "title": "Motor system",
   "color": "#c7362f",
   "summary": "The regions that plan, launch and fine-tune movement.",
   "functions": [
    "Planning movement",
    "Executing movement",
    "Coordination and balance"
   ],
   "members": [
    "motor",
    "sma",
    "cerebellum",
    "cb_anterior",
    "cb_posterior",
    "cb_flocculonodular",
    "thalamus",
    "midbrain",
    "tegmentum",
    "pons",
    "medulla",
    "caudate",
    "putamen",
    "globus_pallidus",
    "substantia_nigra"
   ]
  },
  {
   "id": "visual_sys",
   "title": "Visual system",
   "color": "#1d5f9a",
   "summary": "From the optic chiasm through the thalamus (lateral geniculate nucleus) to the visual cortex, plus the midbrain's orienting reflexes.",
   "functions": [
    "Seeing",
    "Orienting to what you see"
   ],
   "members": [
    "optic_chiasm",
    "thalamus",
    "v1",
    "cuneus",
    "lingual",
    "occipital",
    "tectum"
   ]
  },
  {
   "id": "default_mode",
   "title": "Default mode network",
   "color": "#f5b731",
   "summary": "Regions most active when the mind is at rest and turned inward: remembering, imagining the future, thinking about yourself and others.",
   "functions": [
    "Self-reflection",
    "Autobiographical memory",
    "Mind-wandering"
   ],
   "members": [
    "precuneus",
    "cingulate_post",
    "dmpfc",
    "vmpfc",
    "parahippocampal",
    "hippocampus"
   ]
  }
 ]
}