AUTHOR=McGarry Laura M., Packer Adam M., Fino Elodie , Nikolenko Volodymyr , Sippy Tanya , Yuste Rafael TITLE=Quantitative classification of somatostatin-positive neocortical interneurons identifies three interneuron subtypes JOURNAL=Frontiers in Neural Circuits VOLUME=Volume 4 - 2010 YEAR=2010 URL=https://www.frontiersin.org/journals/neural-circuits/articles/10.3389/fncir.2010.00012 DOI=10.3389/fncir.2010.00012 ISSN=1662-5110 ABSTRACT=

Deciphering the circuitry of the neocortex requires knowledge of its components, making a systematic classification of neocortical neurons necessary. GABAergic interneurons contribute most of the morphological, electrophysiological and molecular diversity of the cortex, yet interneuron subtypes are still not well defined. To quantitatively identify classes of interneurons, 59 GFP-positive interneurons from a somatostatin-positive mouse line were characterized by whole-cell recordings and anatomical reconstructions. For each neuron, we measured a series of physiological and morphological variables and analyzed these data using unsupervised classification methods. PCA and cluster analysis of morphological variables revealed three groups of cells: one comprised of Martinotti cells, and two other groups of interneurons with short asymmetric axons targeting layers 2/3 and bending medially. PCA and cluster analysis of electrophysiological variables also revealed the existence of these three groups of neurons, particularly with respect to action potential time course. These different morphological and electrophysiological characteristics could make each of these three interneuron subtypes particularly suited for a different function within the cortical circuit.