Referenced in: none

Automatically associated channels: Kir6.2

Title: Serotonin 3A receptor subtype as an early and protracted marker of cortical interneuron subpopulations.

Authors: Ksenija Vucurovic, Thierry Gallopin, Isabelle Férézou, Armelle Rancillac, Pascal Chameau, Johannes A van Hooft, Hélène Geoffroy, Hannah Monyer, Jean Rossier, Tania Vitalis

Journal, date & volume: Cereb. Cortex, 2010 Oct , 20, 2333-47

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/20083553

Abstract
To identify neocortical neurons expressing the type 3 serotonergic receptor, here we used transgenic mice expressing the enhanced green fluorescent protein (GFP) under the control of the 5-HT(3A) promoter (5-HT(3A):GFP mice). By means of whole-cell patch-clamp recordings, biocytin labeling, and single-cell reversed-transcriptase polymerase chain reaction on acute brain slices of 5-HT(3A):GFP mice, we identified 2 populations of 5-HT(3A)-expressing interneurons within the somatosensory cortex. The first population was characterized by the frequent expression of the vasoactive intestinal peptide and a typical bipolar/bitufted morphology, whereas the second population expressed predominantly the neuropeptide Y and exhibited more complex dendritic arborizations. Most interneurons of this second group appeared very similar to neurogliaform cells according to their electrophysiological, molecular, and morphological properties. The combination of 5-bromo-2-deoxyuridine injections with 5-HT(3A) mRNA detection showed that cortical 5-HT(3A) interneurons are generated around embryonic day 14.5. Although at this stage the 5-HT(3A) receptor subunit is expressed in both the caudal ganglionic eminence and the entopeduncular area, homochronic in utero grafts experiments revealed that cortical 5-HT(3A) interneurons are mainly generated in the caudal ganglionic eminence. This protracted expression of the 5-HT(3A) subunit allowed us to study specific cortical interneuron populations from their birth to their final functional phenotype.