The ability of animals to mount adaptive responses to emotional and physiological stress is mediated by central neural pathways that control neuroendocrine secretion, autonomic function, and motivated behavior. The long-term objective of Dr. Rinaman's research program is to characterize the functional multisynaptic organization of these neural systems. We also study how early life adversity modifies gene expression and synaptic connectivity within these neural systems to shape emotional responses across the lifespan. Transectional viral and genetic tools are applied in wildtype and genetically modified rats and mice to assess neuroanatomical, physiological, and behavioral endpoints. Our research program offers unique opportunities to test hypotheses about brain structure-function relationships to understand the basis of emotional responses to physiological and cognitive stress, and to reveal mechanisms through which these responses are shaped by early life experience.
Our NIH-funded projects focus on (1) the functional organization of neural pathways from caudal brainstem to limbic forebrain that contribute to anxiety-like behavior and threat responses, and (2) how early life adversity induces neural circuit adaptations in vagal sensory and motor “gut-brain” circuits that control these responses. We characterize the axonal projections, synaptic connectivity, chemical phenotypes, and activation profiles of neurons within these circuits to reveal how visceral control systems intersect with hypothalamic and limbic forebrain functions. We use neurotropic and Cre-conditional viruses, chemogenetics, fluorescent in situ hybridization, advanced confocal microscopy, and an array of sophisticated behavioral analyses in our multidisciplinary studies.