Molecular programs specifying properties and plasticity of parvalbumin interneuron innervation.

Parvalbumin-positive (PV) interneurons, a class of fast-spiking GABAergic interneurons, govern gain-control and the timing of neuronal signal propagation in neuronal circuits. With remarkable temporal precision, PV-interneurons rapidly transform an excitatory input signal into a strong inhibitory output. In cortical circuits, this provides critical feedforward and feedback inhibition. Given their important roles and unique functional features in instructing neuronal circuit function, PV-interneurons have served as an excellent model system for uncovering molecular mechanisms underlying the specification of neuronal synapse properties. Moreover, studies on PV-interneurons led to the discovery of novel mechanisms of neuronal plasticity as PV-networks rapidly adapt their connectivity in response to changes in sensory experience and during learning processes. In this review, we will integrate recent work on the distinct synaptic protein complexes that instruct glutamatergic synapse formation onto PV-interneurons and discuss transcriptional programs that dynamically adjust PV-interneuron function.