PT  - JOURNAL ARTICLE
AU  - Rui Kimura
AU  - Mir-Shahram Safari
AU  - Javad Mirnajafi-Zadeh
AU  - Rie Kimura
AU  - Teppei Ebina
AU  - Yuchio Yanagawa
AU  - Kazuhiro Sohya
AU  - Tadaharu Tsumoto
TI  - Curtailing Effect of Awakening on Visual Responses of Cortical Neurons by Cholinergic Activation of Inhibitory Circuits
AID  - 10.1523/JNEUROSCI.0863-14.2014
DP  - 2014 Jul 23
TA  - The Journal of Neuroscience
PG  - 10122--10133
VI  - 34
IP  - 30
4099  - http://www.jneurosci.org/content/34/30/10122.short
4100  - http://www.jneurosci.org/content/34/30/10122.full
SO  - J. Neurosci.2014 Jul 23; 34
AB  - Visual responsiveness of cortical neurons changes depending on the brain state. Neural circuit mechanism underlying this change is unclear. By applying the method of in vivo two-photon functional calcium imaging to transgenic rats in which GABAergic neurons express fluorescent protein, we analyzed changes in visual response properties of cortical neurons when animals became awakened from anesthesia. In the awake state, the magnitude and reliability of visual responses of GABAergic neurons increased whereas the decay of responses of excitatory neurons became faster. To test whether the basal forebrain (BF) cholinergic projection is involved in these changes, we analyzed effects of electrical and optogenetic activation of BF on visual responses of mouse cortical neurons with in vivo imaging and whole-cell recordings. Electrical BF stimulation in anesthetized animals induced the same direction of changes in visual responses of both groups of neurons as awakening. Optogenetic activation increased the frequency of visually evoked action potentials in GABAergic neurons but induced the delayed hyperpolarization that ceased the late generation of action potentials in excitatory neurons. Pharmacological analysis in slice preparations revealed that photoactivation-induced depolarization of layer 1 GABAergic neurons was blocked by a nicotinic receptor antagonist, whereas non–fast-spiking layer 2/3 GABAergic neurons was blocked only by the application of both nicotinic and muscarinic receptor antagonists. These results suggest that the effect of awakening is mediated mainly through nicotinic activation of layer 1 GABAergic neurons and mixed nicotinic/muscarinic activation of layer 2/3 non–fast-spiking GABAergic neurons, which together curtails the visual responses of excitatory neurons.