Cesar Morales, “Sex Differences in Estrogenic Regulation of Memory Consolidation within CA1 Hippocampal Interneurons in Mice”
Mentor: Karyn Frick, Psychology, Letters & Science (College of)
Poster #165
Neuronal activity within the hippocampus underlies the formation and consolidation of episodic memories. Estrogens are crucial in lowering the threshold for excitatory neuronal signaling, which triggers molecular cascade responses within hippocampal cells. The exact localization of those effects in interneurons is not entirely understood. Thus, we incorporated several methods to pinpoint the cellular targets of estrogenic regulation of memory. Male and female mice either underwent gonadectomy surgery (GDX) and or sham surgeries, allowing us to explore sex and gonadal status differences in the expression of the major estrogen receptor isoforms, ER alpha and beta, in three interneuronal subtypes, Somatostatin (SST), Parvalbumin (PV) and Vasoactive Intestinal Peptide (VIP). Following the GDX or sham surgeries, the mice were handled and lavaged daily to track the estrous cycle in females; males were handled similarly to control for the lavage procedure in female mice. Females were euthanized via isoflurane overdose when the intact females were in phases of low circulating estrogen and had their brains collected and flash frozen. Both intact and GDX males were euthanized similarly near the end of their light cycle to capture low levels of circulating androgens. Pilot immunohistochemistry and RNAscope studies were conducted to optimize antibodies for markers of different interneuronal populations and detect estrogen receptor subtypes,respectively. Having successfully optimized the initial protocol, our next step is to localize gene expression and regulation of neuronal activity within the hippocampus to explore the effects of neurodegenerative disorders on memory consolidation.