Cell Type-Specific Modulation of Layer 6A Excitatory Microcircuits by Acetylcholine in Rat Barrel Cortex [article]

Danqing Yang, Robert Günter, Guanxiao Qi, Gabriele Radnikow, Dirk Feldmeyer
2019 bioRxiv   pre-print
AbstractAcetylcholine (ACh) is known to regulate cortical activity during different behavioral states, e.g. wakefulness and attention. Here we show a differential expression of muscarinic ACh receptors (mAChRs) and nicotinic AChRs (nAChRs) in different layer 6A (L6A) pyramidal cell (PC) types of somatosensory cortex. At low concentrations, ACh induced a persistent hyperpolarization in corticocortical (CC) but a depolarization in corticothalamic (CT) L6A PCs via M4 and M1 mAChRs, respectively.
more » ... Rs, respectively. At ∼1 mM ACh depolarized exclusively CT PCs via α4β2 subunit-containing nAChRs without affecting CC PCs. Miniature EPSC frequency in CC PCs was decreased by ACh but increased in CT PCs. In synaptic connections with a presynaptic CC PC, glutamate release was suppressed via M4 mAChR activation but enhanced by nAChRs when the presynaptic neuron was a CT PC. Thus, in layer 6A the interaction of mAChRs and nAChRs results in an altered excitability and synaptic release, effectively strengthening corticothalamic while weakening corticocortical synaptic signaling.
doi:10.1101/701318 fatcat:qre7rms54rcjrn6rdkhrng5w2q