PT  - JOURNAL ARTICLE
AU  - Packer, Adam M.
AU  - Yuste, Rafael
TI  - Dense, Unspecific Connectivity of Neocortical Parvalbumin-Positive Interneurons: A Canonical Microcircuit for Inhibition?
AID  - 10.1523/JNEUROSCI.3131-11.2011
DP  - 2011 Sep 14
TA  - The Journal of Neuroscience
PG  - 13260--13271
VI  - 31
IP  - 37
4099  - http://www.jneurosci.org/content/31/37/13260.short
4100  - http://www.jneurosci.org/content/31/37/13260.full
SO  - J. Neurosci.2011 Sep 14; 31
AB  - GABAergic interneurons play a major role in the function of the mammalian neocortex, but their circuit connectivity is still poorly understood. We used two-photon RuBi-Glutamate uncaging to optically map how the largest population of cortical interneurons, the parvalbumin-positive cells (PV+), are connected to pyramidal cells (PCs) in mouse neocortex. We found locally dense connectivity from PV+ interneurons onto PCs across cortical areas and layers. In many experiments, all nearby PV+ cells were connected to every local PC sampled. In agreement with this, we found no evidence for connection specificity, as PV+ interneurons contacted PC pairs similarly regardless of whether they were synaptically connected or not. We conclude that the microcircuit architecture for PV+ interneurons, and probably neocortical inhibition in general, is an unspecific, densely homogenous matrix covering all nearby pyramidal cells.