TABLE 2.
Distribution of neurons expressing VGluT2 or TH mRNAs in the rostro-caudal sub-regions of the VTA
| Neurons expressing VGluT2 mRNA* |
(n) | Neurons expressing TH mRNA† |
(n) | |
|---|---|---|---|---|
| Rostral VTA‡ | 100 | (1204) | 100 | (2314) |
| Ventral tegmental area rostral | 84.8 ± 0.7 | (1032) | 26.9 ± 1.1 | (584) |
| Parabrachial pigmental area | 15.2 ± 0.7 | (172) | 73.1 ± 1.1 | (1730) |
| Medial VTA§ | 100 | (1278) | 100 | (2498) |
| Parabrachial pigmental area | 44.5 ± 1.5 | (531) | 82.9 ± 1.3 | (2070) |
| Paranigral nucleus | 55.5 ± 1.5 | (747) | 17.1 ± 1.3 | (428) |
| Caudal VTA¶ | 100 | (216) | 100 | (141) |
| Parabrachial pigmental area | 24.6 ± 3.1 | (54) | 38.8 ± 2.1 | (522) |
| Parainterfasicular nucleus | 40.9 ± 2.6 | (88) | 41.7 ± 1.0 | (599) |
| Paranigral nucleus | 35.5 ± 1.4 | (74) | 19.4 ± 1.8 | (294) |
Data are presented as mean percentages ±SEM. Quantitative analysis at three levels of the VTA (rostral, medial and caudal) was conducted to determine the rostro-caudal distribution of neurons expressing VGluT2 mRNA or TH mRNA within the different subregions of the VTA (ventral tegmental area rostral, parabrachial pigmental area, parainterfasicular nucleus and paranigral nucleus). Density of cells expressing VGluT2 mRNA and density of cells expressing TH mRNA were calculated at the
rostral (ten sections, six rats),
medial (nine sections, five rats) and
caudal (four sections, three rats) levels of the VTA. Rostral VTA = −4.68 mm to −5.15 mm from Bregma; medial VTA, −5.16 mm to −5.51 mm from Bregma; caudal, −5.52 mm to −5.75 mm from Bregma.
At each VTA level, the percentage of neurons expressing VGluT2 mRNA within each VTA subregion was calculated from the total population of cells expressing VGluT2 mRNA.
At each VTA level, the percentage of neurons expressing TH mRNA within each VTA subregion was calculated from the total population of cells expressing TH mRNA.