RT Journal Article
SR Electronic
T1 Neuromodulators Produce Distinct Activated States in Neocortex
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 12353
OP 12367
DO 10.1523/JNEUROSCI.1858-14.2014
VO 34
IS 37
A1 Manuel A. Castro-Alamancos
A1 Tanuj Gulati
YR 2014
UL http://www.jneurosci.org/content/34/37/12353.abstract
AB Neocortical population activity varies between deactivated and activated states marked by the presence and absence of slow oscillations, respectively. Neocortex activation occurs during waking and vigilance and is readily induced in anesthetized animals by stimulating the brainstem reticular formation, basal forebrain, or thalamus. Neuromodulators are thought to be responsible for these changes in cortical activity, but their selective cortical effects (i.e., without actions in other brain areas) on neocortical population activity in vivo are not well defined. We found that selective cholinergic and noradrenergic stimulation of the barrel cortex produces well differentiated activated states in rats. Cholinergic cortical stimulation activates the cortex by abolishing synchronous slow oscillations and shifting firing to a tonic mode, which increases in rate at high doses. This shift causes the sensory thalamus itself to become activated. In contrast, noradrenergic cortical stimulation activates the cortex by abolishing synchronous slow oscillations but suppresses overall cortical firing rate, which deactivates the thalamus. Cortical activation produced by either of these neuromodulators leads to suppressed sensory responses and more focused receptive fields. High-frequency sensory stimuli are best relayed to barrel cortex during cortical cholinergic activation because this also activates the thalamus. Cortical neuromodulation sets different cortical and thalamic states that may serve to control sensory information processing according to behavioral contingencies.