The study was conducted to evaluate the sexual dimorphism in the morphometric
parameters of the whole brain and the brainstem in adult captive African
giant pouched rats. Twenty-nine brain samples, comprising 15 females and
14 males, were utilized. Following brain extraction by standard procedures, the
mean values of the weights, lengths, diameters, and volumes of the intact brains
and the brainstem structures were compared in male and female rats using quantitative
analytical statistical methods. The absolute brain weight obtained in the
male was significantly higher (p < 0.01) than that of the female while the relative
brain weight obtained in the female (0.636 ± 0.049%) was higher than that
of the male rats (0.564 ± 0.032%), although the difference in the values was
not statistically significant (p > 0.05). The lengths of the brain and myelencephalon,
as well as the weights of the myelencephalon and mesencephalon, did not
differ between the two sexes (p > 0.05). The weights and lengths of the pons
did not differ between the two sexes (p > 0.05). There was a significant difference
(p < 0.05) in the pyramidal length and a highly significant difference
(p < 0.01) in the pyramidal width between the two sexes, with the male rats
having higher values. This pioneering sexual dimorphic brain morphometry provides
information for further research. (Folia Morphol 2010; 69, 2: 69-74