Leucine changes reward-related gene expression and neuronal activity in the hypothalamus and nucleus accumbens
(English)Manuscript (preprint) (Other academic)
The branched-chain amino acid leucine has been shown to have satiating effects when administered centrally. However, studies on how oral administration of leucine affects appetite shown disparate effects ranging from orexigenic to anorexigenic. To shed more light on the effects of ingested leucine on the components of the forebrain circuitry that govern feeding for hunger versus reward, we studied changes in c-Fos immunoreactivity (IR) immediately after 2-h 1.5 w/v % leucine vs water exposure and used qPCR to analyze relevant feeding-related gene transcripts in mice consuming leucine for 48 h.Leucine caused an increase in c-Fos IR in the arcuate nucleus and a decrease in the paraventricular nucleus whereas a trend towards an increase was detected in the nucleus accumbens shell. We found an increased expression of the µ-opioid receptor (MOR) in the Acb and δ-opioid receptor mRNA in the hypothalamus. Furthermore, expression of anorexigenic genes cocaine- and amphetamine-regulated transcript (CART), oxytocin (OXY) and arginine vasopressin (AVP) was downregulated in the Acb, and CRH expression was elevated in the hypothalamus of mice fed with leucine. Our results indicate that ingested leucine affects both the hunger- and reward-related circuits, which likely underlies the mixed orexigenic and anorexigenic outcomes of this amino acid’s consumption.
Research subject Medical Science
IdentifiersURN: urn:nbn:se:uu:diva-223807OAI: oai:DiVA.org:uu-223807DiVA: diva2:714276