Whole-cell recordings and optogenetic manipulation of GABAergic neurons in the barrel cortex of behaving mice

• Applicant: Professor Dr. Carl Petersen
• Subject Area: Molecular Biology and Physiology of Neurons and Glial Cells
• Term: from 2010 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 141272880

• Final Report Year: 2016

Final Report Abstract

There were two major goals of this project: i) to characterize mouse lines expressing Crerecombinase in subsets of GABAergic neurons in the mouse barrel cortex; and ii) to record and manipulate these neurons using electrophysiological recordings and optogenetics. Over the course of the three year funding period, we made relatively careful characterizations of mice expressing Cre-recombinase from the parvalbumin gene locus (PV-Cre mice) and from the somatostatin gene locus (Sst-Cre mice). We made optogenetic manipulations combined with electrophysiological recordings from these neurons during anesthesia and during performance of a simple goal-directed sensorimotor task. We found that PV neurons are the most active cells, receiving strong inputs from surrounding excitatory neurons and, apparently, contributing causally to gating sensorimotor transformation in primary somatosensory barrel cortex. Although originally planned, we did not in detail characterise mice expressing Cre-recombinase from the vasoactive intestinal peptide locus (VIP-Cre) or from the neuronal nitric oxide synthase locus (nNOS-CreER). We were thus only partially successful in achieving our original aims.

Publications

• (2013) Barrel cortex function. Prog Neurobiol 103:3-27
  Feldmeyer D, Brecht M, Helmchen F, Petersen CCH, Poulet JFA, Staiger JF, Luhmann HJ, Schwarz C
  (See online at https://doi.org/10.1016/j.pneurobio.2012.11.002)
• (2014) Cell-type specific function of GABAergic neurons in layers 2 and 3 of mouse barrel cortex. Curr Opin Neurobiol 26:1-6
  Petersen CCH
  (See online at https://doi.org/10.1016/j.conb.2013.10.004)
• (2015) In vivo measurement of cell-type-specific synaptic connectivity and synaptic transmission in layer 2/3 mouse barrel cortex. Neuron 85:68-75
  Pala A, Petersen CCH
  (See online at https://doi.org/10.1016/j.neuron.2014.11.025)
• (2016) Parvalbumin-expressing GABAergic neurons in mouse barrel cortex contribute to gating a goal-directed sensorimotor transformation. Cell Reports 15:700-706
  Sachidhanandam S, Sermet BS, Petersen CCH
  (See online at https://doi.org/10.1016/j.celrep.2016.03.063)