Parvalbumin interneurons mediate neuronal circuitry–neurogenesis coupling in the adult hippocampus

Abstract

Using immunohistology, electron microscopy, electrophysiology and optogenetics, we show that proliferating adult hippocampal neural precursors receive immature GABAergic synaptic inputs from parvalbumin-expressing interneurons. Recently shown to suppress quiescent neural stem cell activation, parvalbumin interneuron activation promotes newborn neuronal progeny survival and development. Our study suggests a niche mechanism involving parvalbumin interneurons that couples local circuit activity to diametric regulation of two critical initial phases of adult hippocampal neurogenesis.

Daily access to sucrose impairs aspects of spatial memory tasks reliant on pattern separation and neural proliferation in rats

“…Neuronal excitability is thought to decrease from the time that spinogenesis begins; a time which overlaps with the development of gamma-aminobutyric acid (GABA) receptors (Esposito et al 2005). Fast-spiking parvalbuminpositive GABAergic interneurons regulate early phases of adult hippocampal neurogenesis (Song et al 2013). Previously, we observed a reduction in parvalbumin neuron immunoreactivity within the dorsal hippocampus of rats that consumed sucrose on a daily basis (Reichelt et al 2015a), which may have contributed to the reduced neuroproliferation markers observed here.…”

Interaction between Neurogenesis and Hippocampal Memory System: New Vistas

“…The activity dependence could also implicate g-aminobutyric acid (GABA) interneurons, which also innervate newborn neurons (Vivar et al 2012). The newborn cells expressed GABA A receptors (Mayo et al 2005) and GABA regulates adult neurogenesis (Song et al 2012(Song et al , 2013. Through enhanced network activity, inputs sculpt den-dritic development by turning on the necessary molecular pathways (Libersat and Duch 2004).…”

Neurogenesis in Cancun: where science meets the sea

“…Juan Song (University of North Carolina, Chapel Hill, USA) described the role of interneurons in the niche, in particular the role of cholecystokinin (CCK)-expressing interneurons and their regulation of quiescent neural stem cells. Using a chemogenetics approach to activate dentate CCK-expressing interneurons, Song found increased activation of quiescent neural stem cells, which is in sharp contrast to the role of parvalbumin-expressing interneurons in maintaining quiescence of neural stem cells (Song et al, 2013). Song's more recent data support the idea that multiple interneuron subtypes are involved in the complex circuit regulation of adult neural stem cells.…”