A gradual depth-dependent change of connectivity features of supragranular pyramidal cells in rat barrel cortex

Staiger, J. F., Bojak, I. ORCID: https://orcid.org/0000-0003-1765-3502, Miceli, S. and Schubert, D. (2015) A gradual depth-dependent change of connectivity features of supragranular pyramidal cells in rat barrel cortex. Brain Structure and Function, 220 (3). pp. 1317-1337. ISSN 1863-2653 doi: 10.1007/s00429-014-0726-8

Abstract/Summary

Recent experimental evidence suggests a finer genetic, structural and functional subdivision of the layers which form a cortical column. The classical layer II/III (LII/III) of rodent neocortex integrates ascending sensory information with contextual cortical information for behavioral read-out. We systematically investigated to which extent regular-spiking supragranular pyramidal neurons, located at different depths within the cortex, show different input-output connectivity patterns. Combining glutamate-uncaging with whole-cell recordings and biocytin filling, we revealed a novel cellular organization of LII/III: (i) “Lower LII/III” pyramidal cells receive a very strong excitatory input from lemniscal LIV and much fewer inputs from paralemniscal LVa. They project to all layers of the home column, including a feedback projection to LIV whereas transcolumnar projections are relatively sparse. (ii) “Upper LII/III” pyramidal cells also receive their strongest input from LIV, but in addition, a very strong and dense excitatory input from LVa. They project extensively to LII/III as well as LVa and Vb of their home and neighboring columns, (iii) “Middle LII/III” pyramidal cell show an intermediate connectivity phenotype that stands in many ways in-between the features described for lower versus upper LII/III. “Lower LII/III” intracolumnarly segregates and transcolumnarly integrates lemniscal information whereas “upper LII/III” seems to integrate lemniscal with paralemniscal information. This suggests a finegrained functional subdivision of the supragranular compartment containing multiple circuits without any obvious cytoarchitectonic, other structural or functional correlate of a laminar border in rodent barrel cortex.

Item Type	Article
URI	https://reading-pure-test.eprints-hosting.org/id/eprint/36570
Identification Number/DOI	10.1007/s00429-014-0726-8
Refereed	Yes
Divisions	Life Sciences > School of Psychology and Clinical Language Sciences > Department of Psychology Central Services
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