Satvik Kukreti

Astrocytes are a type of glial cell that provide supportive functions to neurons and also influence blood flow, regulate neurotransmitter balance, and are a part of the brain’s immune response. Growing evidence demonstrates that astrocytes also play a crucial role in memory. In this study, we employ a chemogenetic technique known as DREADDs (Designer Receptors Exclusivelly Activated by Designer Drugs) to specifically activate prelimbic astrocytes in rats through increased calcium signaling and test their spatial working memory in delayed spontaneous alternation tasks. The number of arm entries and sequences were recorded and quantified through calculating the percent alternation, a measure of spatial working memory. After their behavioral testing, rats were immediately perfused and histological analyses were performed to confirm virus placement. It was discovered that astrocytes play an important role in memory processes in the prelimbic cortex and may act differently by sex. It was also noticed that C21, the designer drug used, significantly impaired female spatial working memory and arm choices but not the males. Additionally, C21 may have effects beyond DREADDs activation as higher concentrations of C21 impaired male exploratory behavior. These findings support the view that astrocytes play integral roles in memory, though it was not conclusive whether DREADDs increased the rats' spatial working memory. Future work must be done on analyzing GFAP morphology to determine whether the increased calcium signaling also incited an inflammatory response, hindering the hypothesized improvements in memory.