Roles of Nicotinic Acetylcholine receptors in primary visual cortex on perceptual sensitivity in macaque monkeys

Cortical cholinergic transmission is crucial for higher cognitive functions like attention, and cognitive impairments like Alzheimer’ disease coincides by abnormal cholinergic system.  Physiological and pharmacological observations suggest that acetylcholine at the thalami-cortical synapse mediates dynamic control of visual input to the cortex. In this study we investigated roles of nicotinic acetylcholine agonists on perceptual sensitivity in primary visual cortex in macaque monkeys.

Experiments performed on a male rhesus macaque (weighing 8-10 kg). After implanting a titanium head-holder, the animal trained in a detection task. First, we determined receptive location of the injection site by electrophysiological recordings. Then we injected nicotine using a microinjectrode system.

Nicotinic acetylcholine agonist, Nicotine, significantly increased detection threshold of visual stimuli.

Primary cortical nicotinic acetylcholine receptors are involved in modulating perceptual sensitivity in a detection task. Understanding roles of thalamocortical acetylcholine receptors is fundamental to understanding sensory perception in normal and cognition-impaired people.