Mapping Brain-Wide Afferent Inputs of Parvalbumin-Expressing GABAergic Neurons in Barrel Cortex Reveals Local and Long-Range Circuit Motifs

摘要

Parvalbumin (PV)-expressing GABAergic neuronsare the largest class of inhibitory neocortical cells.We visualize brain-wide, monosynaptic inputs to PVneurons in mouse barrel cortex. We develop intersectionalrabies virus tracing to specifically targetGABAergic PV cells and exclude a small fraction ofexcitatory PV cells from our starter population. Localinputs are mainly from layer (L) IV and excitatorycells. A small number of inhibitory inputs originatefrom LI neurons, which connect to LII/III PV neurons.Long-range inputs originate mainly from other sensorycortices and the thalamus. In visual cortex,most transsynaptically labeled neurons are locatedin LIV, which contains a molecularly mixed populationof projection neurons with putative functionalsimilarity to LIII neurons. This study expands ourknowledge of the brain-wide circuits in which PVneurons are embedded and introduces intersectionalrabies virus tracing as an applicable tool to dissectthe circuitry of more clearly defined cell types.