Optogenetic Inhibition of Lateral Hypothalamic Inputs into Ventral Pallidum Amplifies Aversive ‘Disgust’
Year: 2015
Type: dissertation
Abstract: The ventral pallidum (VP) is a brain structure within the basal ganglia that is involved in the regulation of motivation, behavior, and emotions.VP has also been found to play a special role in generating the hedonic impact ('liking') of food and other rewards.However, this ability is anatomically restricted to a roughly cubic millimeter 'hedonic hotspot' in its posterior half, and has shown to be activated by opioid or orexin microinjections.Previous work has shown that selective optogenetic stimulation of lateral hypothalamic (presumably orexinergic) inputs into the VP hotspot amplifies 'liking' to sucrose solutions, demonstrating the sufficiency of this pathway to recruit the VP hotspot and alter 'liking'.Here, we explored the necessity of this LH-VP pathway in hedonic processing by infusing an inhibitory optogenetic virus (hsyn-NpHr3.0mcherry)and implanting optic fibers into the VP hotspot to selectively knock out this pathway during taste reactivity and food intake behaviors.It was found that inhibition of the LH-VP pathway caused an increase in the number of aversive 'disgust' reactions to a bitter quinine solution while leaving hedonic or aversive reactions to palatable sucrose unchanged.'Wanting' for palatable M&M candies was also not affected by LH-VP inhibition.These results indicate that LH may be involved in mediating baseline hedonic tone, such that disruption of its inputs into the hotspot may unbalance how VP processes unpalatable and disgusting stimuli.
Author: Dema Fawaz
Language: English
Subfield: Cellular and Molecular Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2755019672