[Morphometrical-statistical structure analysis of human striatum, pallidus and subthalamic nucleus. II. Globus pallidus].

1. The pallidum of 13 hemispheres of 11 human brains of normal adults was studied by morphometric-statistical methods. 2. The values obtained on paraffin-embedded frontal serial sections were corrected individually for shrinkage in order to get comparable fresh values. 3. The mean fresh volume of the pallidum laterale of males (1220 mm3) was 13% higher than that of females (1065 mm3). The corresponding mean values of the pallidum mediale were 520 mm3 (male) and 430 mm3 (female), the difference being 17%. The difference between sexes failed to be significant. The lateral segment accounted for about 70% of the total volume of the pallidum. 4. The pallidum occupied 0,32% or ca. 1 over 300 of the volume of the hemisphere. 5. The numeric cell densities showed no significant age or sex differences. The mean value of the lateral pallidum was 437 nerve cells/mm3 and of the medial part 327 nerve cells/mm3, the difference being highly significant (p less than 0,001). 6. The pallidum laterale showed a numerical density of 66000 glial cells/mm3, the medial segment had 62000 glial cells/mm3, the difference just reaching the 5% -- level of significance. 7. On the average the ratio of glial cells to nerve cells was 158:1 in the lateral pallidum, and 159:1 in the medial part. The difference was statistically significant (p less than 0,01). 8. The mean of the total number of nerve cells in the pallidum laterale amounted to 540000 for males and 465000 for females. The corresponding values of the medial part were 171000 (male) and 143000 (female). The total number of pallidal nerve cells is just about as high as the number of large striatal nerve cells (670000 (male) and 570000 (female). 9. In the pallidum laterale we calculated the total number of glial cells to be 82 million for males and 63 million for females. In the medial pallidum we found 32 million (male) and 26 million (female). 10. The total numbers of nerve and glial cells were well correlated in the lateral as well as in the medial segment (r = 0,636 and r = 0,734, respectively). 11. The volumetric nerve cell densities showed no significant differences between sexes. The values were 0,36 Vol.-% lateral and 0,31 Vol.-% medial. This difference failed to be significant. 12. The volumetric densities of the glial cell nuclei were equal in both segments, the value being 0,43 Vol.-%. They were strictly correlated (r = 0,830). 13. The mean volume of a nerve cell in the medial segment (9600 mum3) was 19% higher (p less than 0,05) than in the lateral segment (8100 mum). 14. The mean volume of a nucleus of a glial cell showed only insignificant differences, being lateral 65 mum3 and medial 70 mum3. 15. The various morphometric data indicated a closer correlation between striatum and pallidum laterale than between striatum and pallidum mediale. Within the striatum, the putamen showed a better correlation with the pallidum than the nucleus caudatus.