Table 2. TH+ and TH- neuron densities in summer (top) and winter (bottom) subjects.
| Subject | Block locationa | Block size (WxHxD)b | Sections analyzed | Counting sites analyzed | TH+ neuron density (/mm2) | TH- neuron density (/mm2) | Total neuron density (/mm2) |
|---|---|---|---|---|---|---|---|
| SD030/11 | 3 | 28x21x1.9 | 4 | 88 | 41.7 | 7.1 | 48.8 |
| SD032/11 | 3 | 31x23x2.5 | 4 | 126 | 22.8 | 13.2 | 36.0 |
| SD033/11 | 2 | 32x21x3.1 | 5 | 160 | 35.2 | 9.0 | 44.2 |
| SD030/12 | 2 | 28x21x3.6 | 6 | 183 | 34.1 | 9.2 | 43.3 |
| SD037/12 | 4 | 21x24x2.2 | 4 | 53c | 34.7 | 7.3 | 42.0 |
| Summer mean (SE) | 2.8 (0.4) | 28x22x2.7 | 4.6 (0.4) | 122.0 (23.6) | 33.7 (3.1) | 9.2 (1.1) | 42.9 (2.1) |
| SD002/10 | 2 | 30x24x2.2 | 6 | 199 | 7.3 | 30.1 | 37.4 |
| SD003/10 | 2 | 32x22x2.2 | 4 | 133 | 0.6 | 35.9 | 36.5 |
| SD034/10 | 4 | 27x22x2.7 | 5 | 174 | 0.2 | 12.9 | 13.1 |
| SD001/11 | 4 | 27x22x1.2 | 3 | 57c | 4.4 | 15.4 | 19.8 |
| SD002/12 | 3 | 16x25x2.1 | 6 | 151 | 15.2 | 21.9 | 37.1 |
| Winter mean (SE) | 3.0 (0.4)d | 26x23x2.1 | 4.8 (0.6)e | 142.8 (24.1)e | 5.5 (2.7)f | 23.2 (4.3)f | 28.7 (5.2)g |
aEstimated as: 1 = rostral-most quarter, 2–4 = next three quarters moving progressively caudally.
bBlock size (mm) measured at maximum width (W = medio-lateral) and height (H = dorso-ventral). D = depth = rostro-caudal.
cNumber of counting sites is low due to a low volume of midbrain DA nuclei within the block provided.
dRostro-caudal block location is not significantly different in summer compared with winter (p>0.05, unpaired, two-tailed t-test).
eThe number of sections and number of counting sites are not significantly different in summer compared with winter (p>0.05, unpaired, two-tailed t-tests).
fTH+ neuron density is ~6-fold higher (on average) and TH- neuron density is ~2.5-fold lower in summer compared with winter. These differences are significantly different (p<0.017, unpaired, two-tailed t-tests with correction for multiple comparisons).
gTotal neuron density (TH+ & TH- combined) is not significantly different (p>0.017, unpaired two-tailed t-test with correction for multiple comparisons) in summer compared with winter.