Quantification of neurons in the hippocampal formation of chimpanzees: comparison to rhesus monkeys and humans.

Quantification of neurons in the hippocampal formation of chimpanzees: comparison to rhesus monkeys and humans. Brain Struct Funct. 2020 Sep 09;: Authors: Rogers Flattery CN, Rosen RF, Farberg AS, Dooyema JM, Hof PR, Sherwood CC, Walker LC, Preuss TM Abstract The hippocampal formation is important for higher brain functions such as spatial navigation and the consolidation of memory, and it contributes to abilities thought to be uniquely human, yet little is known about how the human hippocampal formation compares to that of our closest living relatives, the chimpanzees. To gain insight into the comparative organization of the hippocampal formation in catarrhine primates, we quantified neurons stereologically in its major subdivisions-the granular layer of the dentate gyrus, CA4, CA2-3, CA1, and the subiculum-in archival brain tissue from six chimpanzees ranging from 29 to 43 years of age. We also sought evidence of Aβ deposition and hyperphosphorylated tau in the hippocampus and adjacent neocortex. A 42-year-old animal had moderate cerebral Aβ-amyloid angiopathy and tauopathy, but Aβ was absent and tauopathy was minimal in the others. Quantitatively, granule cells of the dentate gyrus were most numerous, followed by CA1, subiculum, CA4, and CA2-3. In the context of prior investigations of rhesus monkeys and humans, our findings indicate that, in the hippocampal formation as a whole, the proportions of neurons in CA1 and the...
Source: Brain Structure and Function - Category: Neuroscience Authors: Tags: Brain Struct Funct Source Type: research