An anatomical study of the brains of Dipodomys (Mammalia: Rodentia: Heteromyidae).

Whole brains and Nissl-stained serial sections of 3 species of kangaroo rat (Dipodomys spectabilis, D. ordii, D. merriami) were compared for interspecific differences. Neuroanatomical variations were conservative in nature. Examination of the cerebellum revealed possible differences in locomotion and ecology. Dipodomys ordii exhibited more neurological evidence for increased specialization of the hindlimbs, while D. merriami had the least differentiated cerebellar surface, thereby suggesting more stereotyped movements of the hindlimbs. Dipodomys spectabilis had abilities that lie somewhere between those of D. ordii and D. merriami. Stereological analysis demonstrated little difference in the percent of total brain volume comprising the telencephalon, diencephalon, cerebellum, and brain stem; and it revealed the relative position of the cranial nerve nuclei.