Adult hippocampal neurogenesis in Egyptian fruit bats from three different environments: Are interpretational variations due to the environment or methodology?. Issue 17 (6th March 2020)

• Record Type: Journal Article
• Authors: Chawana, Richard; Patzke, Nina; Bhagwandin, Adhil; Kaswera‐Kyamakya, Consolate; Gilissen, Emmanuel; Bertelsen, Mads F.; Hemingway, Jason; Manger, Paul R.
• Is Part Of: Journal of comparative neurology. Volume 528:Issue 17(2020)
• Page Start: 2994
• Page End: 3007
• Publication Date: 2020-03-06
• Subjects: doublecortin -- Ki‐67 -- maturation -- megachiroptera -- proliferation -- rainforest -- RRID AB_2088494 -- RRID AB_2142367; Comparative neurobiology -- Periodicals; Neurology -- Periodicals; 616
• DOI: 10.1002/cne.24895
• Languages: English
• ISSNs: 0021-9967

Abstract

Abstract: We quantified both proliferative (Ki‐67 immunohistochemistry) and immature (doublecortin immunohistochemistry) cells within the dentate gyrus of adult Egyptian fruit bats from three distinct environments: (a) primary rainforest, (b) subtropical woodland, and (c) fifth‐generation captive‐bred. We used four different previously reported methods to assess the effect of the environment on proliferative and immature cells: (a) the comparison of raw totals of proliferative and immature cells; (b) these totals standardized to brain mass; (c) these totals expressed as a density using the volume of the granular cell layer (GCLv) for standardization; and (d) these totals expressed as a percentage of the total number of granule cells. For all methods, the numbers of proliferative cells did not differ statistically among the three groups, indicating that the rate of proliferation, while malleable to experimental manipulation or transiently in response to events of importance in the natural habitat, appears to occur, for the most part, at a predetermined rate within a species. For the immature cells, raw numbers and standardizations to brain mass and GCLv revealed no difference between the three groups studied; however, standardization to total granule cell numbers indicated that the two groups of wild‐caught bats had significantly higher numbers of immature neurons than the captive‐bred bats. These contrasting results indicate that the interpretation of the effect of the environment on the numbers of immature neurons appears method dependent. It is possible that current methods are not sensitive enough to reveal the effect of different environments on proliferative and immature cells. Abstract : Using immunohistochemical and quantitative methods, we examined adult hippocampal neurogenesis in wild‐caught and captive‐bred Egyptian fruit bats. We find that the effect of the environment on this process is more method dependent than environment dependent, requiring a reassessment of how we interpret differences in the process of adult hippocampal neurogenesis between environments and species. This image shows doublecortin immunostained immature neurons in the dentate gyrus of an Egyptian fruit bat captured in the subtropical woodlands of South Africa.