RT Journal Article
SR Electronic
T1 Cell-type specific innervation of cortical pyramidal cells at their apical tufts
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 571695
DO 10.1101/571695
A1 Ali Karimi
A1 Jan Odenthal
A1 Florian Drawitsch
A1 Kevin M. Boergens
A1 Moritz Helmstaedter
YR 2019
UL http://biorxiv.org/content/early/2019/03/15/571695.abstract
AB We investigated the synaptic innervation of apical tufts of cortical pyramidal cells in a region between layers 1 and 2 using 3-D electron microscopy (3D-EM) applied to four cortical regions in mouse. Across all cortices, we found the relative inhibitory input at the apical dendrite’s main bifurcation to be more than 3-fold stronger for layer 2 pyramidal cells than for all other pyramidal cells. Towards the distal tuft dendrites in upper layer 1, however, the relative inhibitory input was about 2-fold stronger for L5 pyramidal cells than for all others. Only L3 pyramidal cells showed homogeneous inhibitory input density. The inhibitory to excitatory synaptic balance is thus specific for the types of pyramidal cells. Inhibitory axons preferentially innervated either layer 2 or L3/5 apical dendrites, but not both. These findings describe connectomic principles for the control of pyramidal cells at their apical dendrites in the upper layers of the cerebral cortex and point to differential computational properties of layer 2, layer 3 and layer 5 pyramidal cells in cortex.