Diversity of GABAergic interneurons and diversification of communication modules in cortical networks

The phenotypic diversity of cortical GABAergic neurons is likely necessary for their functional versatility in shaping exquisite spatiotemporal dynamics of circuit operations underlying cognitive processes. Deciphering the logic of this diversity requires overcoming the technical challenge of quantitative and comprehensive analysis of multi-modal cell features as well as the conceptual challenge of formulating a framework of neuronal identity that reflects biological mechanisms and principles. In the past few years, advances in high-throughput single cell analyses began to generate unprecedented datasets on interneuron transcriptomes, morphology and electrophysiology that drive their classification. Recent studies suggest that cardinal interneuron types can be defined by their synaptic communication properties encoded in key transcriptional signatures - a conceptual framework that integrates across phenotypic features and captures neuronal input-output properties elemental to circuit operation. This definition may further facilitate understanding the appropriate granularity of neuron types toward building a biologically-grounded and operationally useful interneuron taxonomy.