| Popis: |
As a continuation of the morphometric studies on the preceding paper, here we report on the rate of growth of the caudate nucleus (n.), thalamus, red n., and the substantia (s.) nigra using, with few exceptions, the same cohort of cats. The same previously used brains (n=64 cats) were allocated to the following age groups: fetal (E) 59 days, postnatal (P) days 1, 7, 15, 30, 45, 60, 90, 120, and 180. Sixteen additional cats, interspersed within the groups, were substituted for the red n. and s. nigra studies. There were six subjects per group (except for E59, n=4). Using a projection microscope and cytochrome oxidase-stained coronal sections, a combined (left plus right sides) total of 4693, 3822, 1636, and 1180 sections were drawn for the caudate, thalamus, s. nigra, and red n., respectively. With computer assistance, the drawings were digitized to calculate mean cross-sectional areas and then the mean volume of each structure per group. The growth time tables for the caudate n., thalamus and s. nigra were fairly synchronous. In terms of percentage of the adult volume, for the left side (both sides grew at a similar rate), the three structures grew at a fast pace between E59 and P30. Thus, at E59 their respective percentages relative to adult volume were 23.7, 29.8 and 22.6% and by P30 the percentages were within adult range (85.2, 115.1 and 87.5%, respectively). Starting at P30, for the thalamus and at P45 for the caudate n., there was a consistent tendency to an overgrow which ranged between 4.3 and 30.9% (at P180, P |
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