INIBIOMA   20415
INSTITUTO DE INVESTIGACIONES EN BIODIVERSIDAD Y MEDIOAMBIENTE
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Mature and immature hippocampal granule cells activation profiles are dictated by local inhibitory circuits
Autor/es:
M BELEN PARDI; MONGIAT LA; SCHINDER AF; MARIN-BURGIN A
Lugar:
Huerta Grande, Cordoba
Reunión:
Congreso; Reunión Anual Sociedad Argentina de Investigación en Neurociencias; 2013
Institución organizadora:
Sociedad Argentina de Investigación en Neurociencias
Resumen:
Neurogenesis in the adulthood provides the dentate gyrus (DG) of thehippocampus with pools of granule cells (GC) which integrate into the preexisting network. It has been widely shown that newly born GC are necessary for many types of memory, but how these neurons contribute to the hippocampal function is unknown. In this work, we propose that it is when they are still immature that newly born GC provide the network with a specific processing function. We injected a retrovirus in the adult mice DG to label new GC by the expression of fluorescent markers. We performed calcium imaging and elecrophysiological recordings from immature newly born GC (iGC) and mature GC (mGC) on acute hippocampal slices. Upon stimulation of the afferent pathway, iGC require weaker input strengths to be activated than mGC. This difference is due to the fact that iGC receive a slower and weaker inhibition. In addition, we showed that iGC could respond to independent inputs, acting as good integrators of afferent information, while mGC are more specific in their responses. Last, we evaluated the responses of iGC and mGC to stimulation at different frequencies. While both populations differentially responded to distinct frequencies, iGC showed higher activationlevels. Inhibitory circuits play a main role in generating these differences. Our results show iGC emerge as a population of GC with different activation properties since they escape from the generalized high levels of inhibition of the DG.