Neocortex-cerebellum Circuitry Unit

National Institute Of Neurological Disorders And Stroke

Investigators

Linked publications & trials

Abstract

Trainees and lab staffing: My lab is currently training 3 postdoctoral fellows and 2 PhD students in the Brown-NIH neuroscience program, each of whom are leading research projects described below, as well as two postbaccalaureate fellows assisting with several of these projects. In the past year, two postbaccalaureate fellows completed their time in the lab and were accepted and matriculated into M.D.-Ph.D. programs in neuroscience. Scientific projects and progress: Cerebellar anticipation of dopamine rewards – we have demonstrated that expectation of a predictable dopamine reward after an action triggers widespread anticipatory neural activity across the cerebellum, using multi-color two-photon Ca2+ imaging during dopamine self-stimulation. This provides a concrete neural substrate that could link the cerebellum to a host of dopamine-dependent processes, including aberrant conditions like compulsive behaviors and substance use. Task separation and generalization in cortico-cerebellar circuits – we have obtained initial evidence that neural circuits in the neocortex versus those in the cerebellum employ distinct approaches to learning two different skills with overlapping elements. With this data we aim to determine how these two centers of learning differentially contribute to generalizing skills across domains versus separating similar domains to avoid confusion – a key capability disrupted in many neurological conditions. Information transmission through cortico-ponto-cerebellar pathways – We have established a novel multisite two photon imaging and optogenetics approach to chronically probe causal transmission from the cortical pyramidal tract into pontine mossy fibers and cerebellar granule cells. By activating a variety of neocortical neural dynamics and measuring the downstream effects across the cerebellum, we aim to identify general principles of information transmission through this universal mammalian neural pathway. Neural mechanisms to reject external disturbances – Our preliminary data indicates that suppression of excitatory neural transmission in the neocortex and cerebellum predict more effective rejection of external perturbations to the hand during grasp-and-hold control, which patients with a variety of movement control conditions struggle to perform.