Longitudinal imaging of prefrontal cholinergic dynamics and cognitive flexibility in an alzheimer's model

The National Institute on Aging awarded $780,217 to the University of Connecticut Health Center on September 1, 2026, under the Aging Research program (CFDA 93.866) to conduct longitudinal imaging of prefrontal cholinergic dynamics and cognitive flexibility in an Alzheimer's disease model.

The research combines chronic two-photon imaging, fluorescent acetylcholine reporting, in vivo beta-amyloid labeling, and cell-type-specific chemogenetic and optogenetic control to test whether amyloid-beta pathology degrades calcium dynamics and acetylcholine tone in prefrontal-cortex projection-defined subnetworks, and whether boosting cortical cholinergic interneuron activity restores network stability and cognitive flexibility through M1-muscarinic and alpha-7-nicotinic mechanisms. Aim 1 tracks calcium and acetylcholine signals monthly in corticothalamic, corticostriatal, and corticocortical pyramidal neurons of APP^NL-G-F and wild-type mice during a head-fixed two-armed bandit task, quantifying how activity loss and cholinergic hypo-response relate to plaque accrual. Aim 2 tests circuit rescue through chronic HM3DQ activation of cortical cholinergic interneurons from months 4–8, endpoint stereologic counts, dual-color calcium imaging in glutamatergic and GABAergic populations under sustained cortical cholinergic interneuron drive, and all-optical mapping of acute cortical cholinergic interneuron stimulation with M1 and alpha-7 agonist and antagonist applications.

Performance occurs in Farmington, Connecticut, with a period of performance from September 1, 2026, through June 30, 2031. The award is classified as a Project Grant.

Abstract

Executive dysfunction emerges years before dementia in alzheimer's disease (ad) and maps to prefrontal-cortex (PFC) circuits that depend critically on acetylcholine (ACH). Sparse cortical cholinergic interneurons (ccins) remain numerically intact in prodromal ad yet show early transcriptional stress, suggesting that amplifying their output could stabilize vulnerable networks without the systemic side-effects of broad cholinergic drugs. This R01 combines chronic micro-prism two-photon imaging, the grab-ACH fluorescent reporter, in-vivo β-amyloid (AΒ) labeling, and cell-type-specific chemogenetic/optogenetic control to test two hypotheses: (i) AΒ pathology propagates preferentially through projection-defined PFC subnetworks, degrading calcium dynamics and ACH tone; and (II) boosting ccin activity restores network stability and cognitive flexibility via M1-muscarinic and Α7-nicotinic mechanisms. Aim 1 tracks calcium and ACH signals monthly in corticothalamic, corticostriatal, and corticocortical pyramidal neurons of APP^NL-g-f and wild-type mice during a head-fixed two-armed bandit task, quantifying how activity loss and cholinergic hypo-response relate to plaque accrual. Aim 2 tests circuit rescue: (2.1) chronic HM3DQ activation of ccins from 4-8 months and endpoint stereologic counts of ccins, basal-forebrain cholinergic neurons, and plaques; (2.2) dual-color calcium imaging in glutamatergic and gabaergic populations under sustained ccin drive; (2.3) all-optical mapping of acute ccin stimulation with M1 and Α7 agonist/antagonist wash-INS. Mixed- effects models handle the unbalanced longitudinal panel of repeatedly imaged cells. Successful completion will deliver multiscale evidence that endogenous, circuit-delimited cholinergic reinforcement can blunt prefrontal network decay and preserve decision flexibility, providing a mechanistic foundation for precision neuromodulation in early ad.