Delay-dependent cholinergic modulation of visual short-term memory in rhesus macaques

Cholinergic neuromodulation is known to play a key role in visual working memory (VWM) – keeping relevant stimulus representations available for cognitive processes short time periods (up few minutes). Despite the growing body of evidence on how neural and mechanisms VWM dynamically change over retention time, there mixed cholinergic effects as function delay period non-human primates. Using delayed matching sample task rhesus macaques (N = 6), we aimed characterize maintenance terms performance changes duration (across wide range delays from 1 76 s). Then, studied influences using muscarinic receptor antagonist scopolamine administered alone transient amnestic treatment, combination with two doses acetylcholinesterase inhibitor donepezil, widely used Alzheimer’s medication probing reversal scopolamine-induced impairments. Results indicate that impairments are delay-dependent specifically affect 15?33 s range, suggesting worsens normal decay passage time. Donepezil partially rescued observed performance. These results provide strong behavioral increased tone beyond seconds, line our current knowledge acetylcholine receptors sustained activity during periods.