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ORIGINAL RESEARCH article

Front. Neurosci.

Sec. Neuroendocrine Science

Volume 19 - 2025 | doi: 10.3389/fnins.2025.1614819

This article is part of the Research TopicNeuromodulation of mood and eating behaviorView all 5 articles

Homeostatic-related peptides injected into the rat nucleus accumbens alter palatable eating and impact the binge-like intake of a sweetened fat diet during simultaneous µ-opioid receptor stimulation

Provisionally accepted
Wayne  E. PrattWayne E. Pratt*Cardinal  DoCardinal DoAlexandra  M. GroomeAlexandra M. GroomeAlana  J. SmithAlana J. SmithAllison  C. SiegfriedAllison C. SiegfriedCami  J. CalafioriCami J. Calafiori
  • Wake Forest University, Winston-Salem, United States

The final, formatted version of the article will be published soon.

The nucleus accumbens is central for directing motivated behavior and is a key node in the neural circuitry that promotes eating in response to palatable diets. We examined the impact of intra-accumbens injections of a variety of homeostatic peptides (HRPs) on eating elicited by a sweetened fat diet, with or without co-administration of the prophagic mu-opioid agonist [D-Ala2, N-MePhe4, Gly-ol]-enkephalin (DAMGO).Methods: Rats received surgical placement of guide cannulas above the anterior medial nucleus accumbens. Non-restricted animals were then accustomed to 2-hr daily access to a sweetened fat diet. Palatable eating was examined following intra-accumbens injections of one hypothalamic HRP, alone or with co-infusions of DAMGO.Results: Nucleus accumbens injections of neuropeptide Y (NPY) and orexin-A significantly increased palatable eating. Cocaine-and amphetamine-related transcript (CART) reduced intake. When rats received co-stimulation of µ-opioid receptors, NPY and DAMGO had a synergistic effect on food intake, whereas orexin-A initially disrupted eating on the palatable diet and had no additive effect with DAMGO by the end of the session. Neither agouti-related protein (AGRP), melanin concentrating hormone (MCH), alpha-melanocyte stimulating hormone (αMSH), nor the stress-related peptides corticotropin-releasing factor (CRF) or urocortin impacted intake, although MCH and CRF both affected eating in response to mu-opioid receptor stimulation dependent upon the dose.These experiments offer insight into the regulation of hedonically motivated feeding by homeostatic-and stress-related inputs to the nucleus accumbens. This systematic examination suggests that the nucleus accumbens' role in promoting palatable eating is not independent of the homeostatic signals that reach it from the hypothalamus and other brain regions.

Keywords: Motivation, Eating, food intake, Palatable eating, hedonic eating, Nucleus Accumbens, Peptides, Opioids

Received: 19 Apr 2025; Accepted: 12 Jun 2025.

Copyright: © 2025 Pratt, Do, Groome, Smith, Siegfried and Calafiori. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Wayne E. Pratt, Wake Forest University, Winston-Salem, United States

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