Meeting Abstract
Astrocytes in the cerebral cortex have many functions that support neuronal integrity. One such function is maintaining ionic homeostasis of the extracellular fluid. Alterations in astrocyte function could affect the associated neuronal field, in turn, effecting neuronal activity or neuronal survival. We previously published that transgenicFGFR1Flox/Flox;NestinCre mice have a decreased number of cortical interneurons. Interneurons grown on FGFR1Flox/Flox;NestinCre mouse astrocytes presented smaller soma size and fewer dendritic processes than their littermates. The physiology underlying this morphology is unknown. One possible hypothesis is FGFR1Flox/Flox;NestinCre cortical astrocytes are unable to maintain the proper extracellular environment for proper function and/or survival of these interneurons. To investigate the role FGFR1 has in neuronal-astrocyte physiology, Gad-67 GFP+ labeled GABAergic inhibitory interneurons were grown on a feeder layer of FGFR1Flox/Flox;NestinCre knockout astrocytes. Using Fluro3AM, videos recording intracellular calcium signaling were analyzed using Image J. FGFR1Flox/Flox;NestinCre had significantly fewer calcium peaks when compared to control. (FGFR1Flox/Flox;NestinCre knockout astrocytes Mean=4.75 ± 3.38 peaks, FGFR1control astrocytes Mean=20.13 ± 3.38, p=0.0063*) To be further investigated was the observation that the calcium peaks of cocultured interneurons on the knockout astrocytes were lower amplitude than control. These results suggest that there are definitely significant differences when interneurons are applied to FGFR1Flox/Flox;NestinCre astrocytes, indicating the importance of the astrocyte-neuron interaction.
