PROJECT SUMMARY/ABSTRACT Autism spectrum disorder (ASD) is a prevalent and disabling neurodevelopmental disorder that takes a significant toll on patients, their families, and the national economy. There are no targeted treatments for the dysregulated autonomic responses, or dysautonomia, that affect and disable over 70% of autistic children. Most current medical approaches are non-selective, ineffective, and associated with side effects. Thus, a novel and targeted therapy is urgently needed for refractory dysautonomia in ASD. Given dysautonomia is thought to arise from a problem in how the brain regulates peripheral autonomic organs, a major barrier to progress has been an incomplete understanding of the neural networks that influence peripheral autonomic output. Recently, I identified the sites of the cerebellum that are major sources of descending control over the adrenal medulla, an autonomic organ that releases adrenaline and initiates the body-wide sympathetic response. Cerebellar involvement is clinically relevant because dysautonomia and cerebellar abnormalities are both present in ASD and the superficial location of the cerebellum makes it an attractive target for non-invasive trans-cranial magnetic stimulation (TMS). Yet, two remaining knowledge gaps prevent clinical translation: we do not know which sites of the ‘autonomic cerebellum’ influence the physiologic responses perturbed in dysautonomia and how these sites are affected in conditions like ASD where dysautonomia and cerebellar abnormalities are present. The goals of this project are to fill these gaps by defining the regions of the autonomic cerebellum that selectively control physiologic responses and by testing how these cerebellar networks are altered in a model of autism. Specifically, Aim 1 is to test if modulating the adrenal-related cerebellum alters autonomic physiologic responses. Aim 2 is to test if autonomic responses are abnormal in a marmoset model of ASD. Aim 3 is to test if the cerebellar sites that control the adrenal’s sympathetic output are altered in a marmoset model of ASD. I will employ in vivo recording of autonomic physiologic responses and trans-neuronal transport of rabies virus to establish the behavioral and systems neuroscience foundations for how the autonomic cerebellum is affected in ASD. These studies have the potential to identify specific cerebellar regions to target with a new treatment approach (e.g., cerebellar TMS) that aims to normalize refractory dysautonomia in ASD. Thus, the results of the proposed work may ultimately transform how we manage dysautonomia in ASD and other disorders associated with cerebellar abnormalities.

PROJECT NARRATIVE There are no targeted treatments for the dysregulated autonomic responses (‘dysautonomia’) of autism; yet, these disruptive physiologic responses that consist of alterations in heart rate, blood pressure, and perspiration affect over 70% of autistic individuals and contribute to significant disability. Building on a novel finding that the cerebellum, a brain region affected in autism, contains specific sites that control autonomic output, the proposed research will determine which cerebellar sites selectively influence autonomic physiologic responses and identify which sites are altered in a model of autism. Results are likely to advance our knowledge of the autonomic cerebellum and identify specific regions to therapeutically target for the dysautonomia prevalent in autism.