Quick Search:

uzh logo
Browse by:
bullet
bullet
bullet
bullet

Zurich Open Repository and Archive

Kumar, P; Ohana, O (2008). Inter- and intralaminar subcircuits of excitatory and inhibitory neurons in layer 6a of the rat barrel cortex. Journal of Neurophysiology, 100(4):1909-1922.

Full text not available from this repository.

View at publisher

Abstract

Approximately half the excitatory neurons in layer 6 (L6) of the rat barrel cortex project to the thalamus with axon collaterals ramifying in the granular L4; the remaining project within cortex with collaterals restricted to infragranular laminae. In analogy, L6 inhibitory neurons also include locally arborizing and inter-laminar projecting neurons. We examined whether L6 neurons participating in different laminar interactions were also morphologically and electrically distinct. Corticothalamic (CT) neurons were labeled by in vivo injections of a retrogradely transported fluorescent tracer into the primary thalamic nucleus. Whole cell current-clamp recordings were performed from labeled and unlabeled L6 neurons in brain slices of juvenile rats; the morphology of cells was subsequently recovered and reconstructed. Corticocortical (CC) neurons were distinguished from CT cells based on the absence of a subcortical projection and the predominantly infragranular arborization of their axon collaterals. Two morphological CC subtypes could be further distinguished based on the structure of their apical dendrite. Electrically, CT neurons had shorter membrane time-constants and action potential (AP) durations and higher rheobase currents. CC neurons fired high-frequency spike doublets or triplets on sustained depolarization; the burst frequency also distinguished the two morphological CC subtypes. Among inhibitory L6 cells, the L4-projecting (L6iL4) and local (L6iL6) inhibitory neurons also had contrasting firing properties; L6iL4 neurons had broader APs and lower maximal firing rates. We propose that L6 excitatory and inhibitory neurons projecting to L4 constitute specialized subcircuits distinct from the infragranular network in their connectivity and firing patterns.

Citations

22 citations in Web of Science®
21 citations in Scopus®
Google Scholar™

Altmetrics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Institute of Neuroinformatics
DDC:570 Life sciences; biology
Language:English
Date:October 2008
Deposited On:08 Mar 2009 18:52
Last Modified:23 Nov 2012 15:50
Publisher:American Physiological Society
ISSN:0022-3077
Publisher DOI:10.1152/jn.90684.2008
PubMed ID:18650305

Users (please log in): suggest update or correction for this item

Repository Staff Only: item control page