Table 1.
Cellular composition of the African elephant brain.
| Structure | Mass, g | Neurons | Other cells | N/mg | O/mg | O/N |
|---|---|---|---|---|---|---|
| Whole brain | 4,618.62 | 257.04 B | 216.06 B | 56,071 | 47,130 | 0.841 |
| Cerebral cortex, GM + WM* | 2,847.95 | 5.59 B | 150.15 B | 1964 | 52,721 | 26.844 |
| Cerebral cortex, GM** | 1,431.50 | 5.53 B | 55.70 B | 3.661 | 38,910 | 10.628 |
| Cerebral cortex, WM | 1,382.09 | – | 91.99 B | – | 66,561 | – |
| Cerebellum | 1,171.63 | 250.71 B | 38.51 B | 213,983 | 32,866 | 0.154 |
| Rest of brain | 564.67 | 0.74 B | 27.40 B | 1314 | 48,531 | 36,948 |
| Hippocampus | 24.42 | 36.63 M | 1.73 B | 1500 | 70,714 | 47.154 |
| Amygdala | 9.94 | 28.46 M | 0.73 B | 2864 | 73,107 | 25.530 |
| Striatum | 242.38 | 330.75 M | 13.65 B | 1365 | 56,326 | 41.277 |
| Diencephalon | 91.18 | 97.20 M | 5.27 B | 1066 | 57,770 | 54.195 |
| Mesencephalon | 54.10 | 108.78 M | 2.49 B | 2011 | 45,976 | 22.867 |
| Pons | 102.00 | 123.53 M | 3.16 B | 1211 | 30,993 | 25.594 |
| Medulla | 74.99 | 81.44 M | 2.83 B | 1086 | 37,803 | 34.811 |
| Olfactory bulb | 41.88 | 908.37 M | 2.86 B | 21,687 | 68,230 | 3.146 |
All figures refer to 2 times the values obtained for one half-brain. N/mg, density of neurons per milligram of tissue. O/mg, density of other (non-neuronal) cells per milligram of tissue. B, billion cells (1 × 109). M, million cells (1 × 106). GM, gray matter. WM, white matter.
*
, includes hippocampus and amygdala.
**
, excludes hippocampus and amygdala.