Table 2. Stereological estimate of neuronal populations of the rat VTA.
| Density (cells/mm3)×103 | ||||
| TH-positive | α1-positive | TH-negativeα1-negative | TH-positiveα1-positive | |
| Rostral PBP | 12.5±1.3 | 5.4±0.6 | 4.0±0.6 | 0.1±0.1 |
| Middle PBP | 8.2±1.2 | 2.0±0.4 | 1.7±0.5 | 0.1±0.0 |
| Caudal PBP | 6.6±0.6 | 3.1±0.4 | 1.4±0.3 | 0.3±0.1 |
| Rostral PN | 12.1±2.5 | 5.1±1.0 | 2.6±1.1 | 0.3±0.1 |
| Middle PN | 15.3±1.1 | 2.7±0.5 | 3.1±0.1 | 0.3±0.1 |
| Caudal PN | 13.2±2.9 | 4.4±1.4 | 5.7±2.0 | 0.0±0.0 |
| RLi | 5.6±1.3 | 6.3±0.9 | 6.8±1.7 | 0.4±0.2 |
| IF | 25.0±3.1 | 2.9±0.8 | 9.7±2.0 | 0.7±0.2 |
| CLi | 25.5±2.4 | 2.6±0.9 | 6.9±0.4 | 0.5±0.3 |
| Rostral VTA | 10.4±0.5 (43%) | 6.5±0.8 (26.9%) | 7.1±0.8 (29.3%) | 0.2±0.1 (0.8%) |
| Middle VTA | 16.3±1.4 (70.3%) | 2.1±0.6 (9.1%) | 4.4±1.2 (18.9%) | 0.4±0.2 (1.7%) |
| Caudal VTA | 15.1±0.7 (64.3%) | 3.4±0.9 (14.4%) | 4.7±0.7 (20%) | 0.3±0.1 (1.3%) |
| Total VTA | 13.9±0.6 (58.9%) | 4.0±0.1 (16.9%) | 5.4±0.8 (22.9%) | 0.3±0.1 (1.3%) |
The values of rostral, middle and caudal VTA have been obtained averaging the values of all the subnuclei at each individual rostro-caudal level. Percentage values are referred to all NeuN-positive cells counted in the corresponding region. Values are means ± S.E.M. of 3 rats.