A Local Networ k Acti vated by Experience Accelerates the Integration of New Dentate Granule Cells

GIACOMINI D; ALVAREZ DD; YANG SM; TRINCHERO MF; TEMPRANA SG; BUTTNER KA; SCHINDER AF

Buenos Aires

Congreso; FALAN; 2016

Society for Research in Neuroscience

Adult-born dentate granule cells (GCs) develop and integrateinto the local networks in a process that lasts several weeks.It has been shown that the level of activity of local networkscorrelates with the speed of maturation of adult-born GCs.Here we show that developing GCs display a critical periodprevious to the onset of glutamatergic synaptogenesiswhereby they are prone to modulation by activity. Whenmice were exposed to enriched environment for two days,GCs undergoing this critical period displayed acceleratedmaturation and functional integration. Acceleratedintegration was also found upon direct activation of newGCs in vivo during the critical period using syntheticDREADDs (Designer Receptors Exclusively Activated byDesigner Drugs). In addition, activation of mature GCs bymeans of the hM3Dq receptor was used to monitor theinfluence of local circuits on developing GCs. Indeed, in vivoactivation of mature GCs by the synthetic ligand acceleratedthe integration of developing GCs. In agreement with recentworks, we propose that parvalbumin-expressing GABAinterneurons (PV) are responsible of controlling neuronalmaturation. Interestingly, activation of PV interneuronsor mature GCs in acute slices induced a postsynapticresponse in developing neurons undergoing the criticalperiod. Our results suggest that during cognitive tasks, GCsactivate PV interneurons, which, in turn, promote functionalrecruitment of new cohorts of developing GCs.