The gross studies on the hippocampus were made on 10 specimens each of calves and adults of the Indian buffalo. The hippocampus was a curved elevation, lying immediately ventral to the splenium of the corpus callosum, dorsal to the lateral aspect of the thalamus. It occupied the floor of the inferior horn of the lateral ventricle. The ventricular surface of the hippocampus was covered by a thin layer of white matter, the alveus. Rostrolaterally the alveus joined a thick fibrous band, the hippocampal fimbria which connected the alveus to the fornix. On the ventromedial aspect, a deep groove, the hippocampal sulcus, separated this surface into lateral and medial portions. 

The brain samples were collected from 10 calves and 10 adult Indian buffaloes. Routine histological and histochemical processing and sectioning were done. The hippocampus was a curved elevation, lying immediately ventral to the splenium of the thalamus. Longitudinal section showed the ependyma, the alveus, the stratum oriens, the stratum pyramidale, the stratum radiatum, the stratum lacunosum and the stratum moleculare from above downwards. The prominent layer was the stratum pyramidale, composed of pyramidal cells in 2-3 rows. The four fields of the cornu ammonis, (CA1, CA2, CA3 and CA4) were identified based on the sizes of the pyramidal cells and their dendritic arborizations, both in the calf and in the adult. The presence of mucopolysaccharides was recorded. 

The gross studies on the hippocampus were made on 10 specimens each of calves and adults of the Indian buffalo. The hippocampus was a curved elevation, lying immediately ventral to the splenium of the corpus callosum, dorsal to the lateral aspect of the thalamus. It occupied the floor of the inferior horn of the lateral ventricle. The ventricular surface of the hippocampus was covered by a thin layer of white matter, the alveus. Rostrolaterally the alveus joined a thick fibrous band, the hippocampal fimbria which connected the alveus to the fornix. On the ventromedial aspect, a deep groove, the hippocampal sulcus, separated this surface into lateral and medial portions. 

The brain samples were collected from 10 calves and 10 adult Indian buffaloes. Routine histological and histochemical processing and sectioning were done. The hippocampus was a curved elevation, lying immediately ventral to the splenium of the thalamus. Longitudinal section showed the ependyma, the alveus, the stratum oriens, the stratum pyramidale, the stratum radiatum, the stratum lacunosum and the stratum moleculare from above downwards. The prominent layer was the stratum pyramidale, composed of pyramidal cells in 2-3 rows. The four fields of the cornu ammonis, (CA1, CA2, CA3 and CA4) were identified based on the sizes of the pyramidal cells and their dendritic arborizations, both in the calf and in the adult. The presence of mucopolysaccharides was recorded. 

OBJECTIVE To investigate epilepsy-related neuropathologic changes in cats of a familial spontaneous epileptic strain (ie, familial spontaneous epileptic cats [FSECs]). ANIMALS 6 FSECs, 9 age-matched unrelated healthy control cats, and 2 nonaffected (without clinical seizures)dams and 1 nonaffected sire of FSECs. PROCEDURES Immunohistochemical analyses were used to evaluate hippocampal sclerosis, amygdaloid sclerosis, mossy fiber sprouting, and granule cell pathological changes. Values were compared between FSECs and control cats. RESULTS Significantly fewer neurons without gliosis were detected in the third subregion of the cornu ammonis (CA) of the dorsal and ventral aspects of the hippocampus as well as the central nucleus of the amygdala in FSECs versus control cats. Gliosis without neuronal loss was also observed in the CA4 subregion of the ventral aspect of the hippocampus. No changes in mossy fiber sprouting and granule cell pathological changes were detected. Moreover, similar changes were observed in the dams and sire without clinical seizures, although to a lesser extent. CONCLUSIONS AND CLINICAL RELEVANCE Findings suggested that the lower numbers of neurons in the CA3 subregion of the hippocampus and the central nucleus of the amygdala were endophenotypes of familial spontaneous epilepsy in cats. In contrast to results of other veterinary medicine reports, severe epilepsy-related neuropathologic changes (eg, hippocampal sclerosis, amygdaloid sclerosis, mossy fiber sprouting, and granule cell pathological changes) were not detected in FSECs. Despite the use of a small number of cats with infrequent seizures, these findings contributed new insights on the pathophysiologic mechanisms of genetic-related epilepsy in cats.

Meadow voles (Microtus pennsylvanicus) are permissive to chronic wasting disease (CWD) infection, but their susceptibility to other transmissible spongiform encephalopathies (TSEs) is poorly characterized. In this initial study, we intracerebrally challenged 6 meadow voles with 2 isolates of sheep scrapie. Three meadow voles acquired a TSE after the scrapie challenge and an extended incubation period. The glycoform profile of proteinase K-resistant prion protein (PrPres) in scrapie-sick voles remained similar to the sheep inocula, but differed from that of voles clinically affected by CWD. Vacuolization patterns and disease-associated prion protein (PrPSc) deposition were generally similar in all scrapie-affected voles, except in the hippocampus, where PrPSc staining varied markedly among the animals. Our results demonstrate that meadow voles can acquire a TSE after intracerebral scrapie challenge and that this species could therefore prove useful for characterizing scrapie isolates.

Objective: To isolate and characterize neural stem and progenitor cell populations in the brain of adult dogs. Animals: 7 healthy adult dogs. Procedures: Dogs (age, 10 to 60 months) were euthanized for reasons unrelated to the study. The subventricular zone (SVZ) adjacent to the lateral ventricles and subgranular zone (SGZ) of the hippocampus were isolated and used to generate single cell suspensions for nonadherent culture. The resulting primary neurospheres were serially passaged to assess self-renewal capacity. Neurospheres were differentiated by the withdrawal of growth factors and the addition of serum. Differentiated and undifferentiated neurospheres were analyzed via reverse transcriptase PCR assay or immunocytochemical staining for markers of pluripotency and neural lineage. Results: Neurospheres were generated from the SVZ and SGZ in all dogs. The SVZ generated more primary neurospheres than did the SGZ. Serial passage was successful, although few neurospheres could be generated after the fifth passage. Undifferentiated neurospheres were positive for SOX2, nestin, and glial fibrillary acidic protein (GFAP) and negative for OCT4 and NANOG. After differentiation, GFAP, neuronal class III β-tubulin, and 2′, 3′-cyclic nucleotide 3′-phosphodiesterase–positive progeny were noted migrating out of the neurospheres. Conclusions and Clinical Relevance: Results suggested the persistence of SOX2-positive, nestin-positive, GFAP-positive, OCT4-negative, and NANOG-negative neural progenitor cells in the SVZ and SGZ regions of mature canine brains, which are capable of producing multiple cell lineages. This study may serve as a basis for future studies investigating the role of these cells in various disease processes, such as neoplasia, or for regenerative purposes.