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Differential Translaminar Inhibition in Neocortical Circuits
Dennis Kaetzel, University of Oxford, UK
Abstract
The cytoarchitectonic similarities of different neocortical regions have given rise
to the idea of “canonical” connectivity between excitatory neurons of different
layers. It is unclear whether similarly general organizational principles also exist
for inhibitory neocortical circuits. Here, we delineate and compare patterns of
local inhibitory-to-excitatory connectivity in all principal layers of primary motor
(M1), somatosensory (S1), and visual cortex (V1), using genetically targeted
photostimulation in a mouse knock-in line that conditionally expresses
channelrhodopsin-2 in GABAergic interneurons. We find that neocortical areas
as well as cells within them display significant differences with respect to
inhibition received from other layers. Most importantly some pyramidal cells in
layers 2/3, 4 and 5B in sensory cortices receive extensive translaminar inhibition
from their direct or indirect target layers, potentially providing inhibitory feedback
and allowing for functional specialisation.
Recent publications
a) Kätzel, D; Zemelman BV; Buetfering C; Wölfel, M; Miesenböck, G: The
columnar and laminar organization of inhibitory connections to neocortical
excitatory cells. Nat Neurosci, 2011.