PT  - JOURNAL ARTICLE
AU  - Stephanie C. Seeman
AU  - Luke Campagnola
AU  - Pasha A. Davoudian
AU  - Alex Hoggarth
AU  - Travis A. Hage
AU  - Alice Bosma-Moody
AU  - Christopher A. Baker
AU  - Jung Hoon Lee
AU  - Stefan Mihalas
AU  - Corinne Teeter
AU  - Andrew L. Ko
AU  - Jeffrey G. Ojemann
AU  - Ryder P. Gwinn
AU  - Daniel L. Silbergeld
AU  - Charles Cobbs
AU  - John Phillips
AU  - Ed Lein
AU  - Gabe J. Murphy
AU  - Christof Koch
AU  - Hongkui Zeng
AU  - Tim Jarsky
TI  - Sparse recurrent excitatory connectivity in the cortical microcircuit of the adult mouse and human
AID  - 10.1101/292706
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 292706
4099  - http://biorxiv.org/content/early/2018/04/02/292706.short
4100  - http://biorxiv.org/content/early/2018/04/02/292706.full
AB  - Understanding cortical function will require a detailed and comprehensive knowledge of local circuit properties. The Allen Institute for Brain Science is beginning a large-scale project using multipatch electrophysiology, supplemented with 2-photon optogenetics, to characterize local connectivity and synaptic signaling between major classes of neurons in the adult mouse primary visual cortex and neurosurgical samples from human frontal and temporal cortex. We focus on generating results that are detailed enough for the generation of computational models and enable rigorous comparison with future studies. Here we report our examination of the intralaminar connectivity within each of several classes of excitatory neurons. We find that connections are sparse but present among all excitatory cell types and layers we sampled, with the most sparse connections in layers 5 and 6. Almost all synapses in mouse exhibited short-term depression with similar dynamics. Synaptic signaling between a subset of layer 2/3 neurons, however, exhibited facilitation. These results contribute to a body of evidence describing recurrent excitatory connectivity as a conserved feature of cortical microcircuits.