Wiegand, Hauke F.; Beed, Prateep; Bendels, Michael H. K.; Leibold, Christian; Schmitz, Dietmar; Johenning, Friedrich W.
(24. August 2011):
Complementary Sensory and Associative Microcircuitry in Primary Olfactory Cortex.
In: Journal of Neuroscience, Vol. 31, Nr. 34: S. 12149-12158
The three-layered primary olfactory (piriform) cortex is the largest component of the olfactory cortex. Sensory and intracortical inputs
converge on principal cells in the anterior piriform cortex (aPC).Wecharacterize organization principles of the sensory and intracortical
microcircuitry of layer II and III principal cells in acute slices of rat aPC using laser-scanning photostimulation and fast two-photon
population Ca²⁺ imaging. Layer II and III principal cells are set up on a superficial-to-deep vertical axis. We found that the position on
this axis correlates with input resistance and bursting behavior. These parameters scale with distinct patterns of incorporation into
sensory and associative microcircuits, resulting in a converse gradient of sensory and intracortical inputs. In layer II, sensory circuits
dominate superficial cells, whereas incorporation in intracortical circuits increases with depth. Layer III pyramidal cells receive more
intracortical inputs than layer II pyramidal cells, but with an asymmetric dorsal offset. This microcircuit organization results in a diverse
hybrid feedforward/recurrent network of neurons integrating varying ratios of intracortical and sensory input depending on a cell’s
position on the superficial-to-deep vertical axis. Since burstiness of spiking correlates with both the cell’s location on this axis and its
incorporation in intracortical microcircuitry, the neuronal output mode may encode a given cell’s involvement in sensory versus associative