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The circuit mechanisms underlying fear-induced suppression of feeding are poorly understood. To help fill this gap, mice were fear conditioned, and the resulting changes in synaptic connectivity among the locus coeruleus (LC), the parabrachial nucleus (PBN), and the central nucleus of amygdala (CeA)-all of which are implicated in fear and feeding-were studied. LC neurons co-released noradrenaline and glutamate to excite PBN neurons and suppress feeding. LC neurons also suppressed inhibitory input to PBN neurons by inducing heterosynaptic, endocannabinoid-dependent, long-term depression of CeA synapses. Blocking or knocking down endocannabinoid receptors in CeA neurons prevented fear-induced depression of CeA synaptic transmission and fear-induced suppression of feeding. Altogether, these studies demonstrate that LC neurons play a pivotal role in modulating the circuitry that underlies fear-induced suppression of feeding, pointing to new ways of alleviating stress-induced eating disorders.
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http://dx.doi.org/10.1016/j.neuron.2020.12.023 | DOI Listing |
Transl Psychiatry
July 2025
Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong-Hong Kong Joint Laboratory for Psychiatric Disorders, Guangdong Province Key Laboratory of Psychiatric Disorders, Guangdong Bas
Many psychiatric disorders, such as anxiety disorders, are characterized by abnormal processing of fear-related information. Parvalbumin (PV) neurons in the prelimbic cortex (PL) are critically involved in fear expression. However, the role of plasticity of the local PV neuron network in the regulation of remote fear memory remains unknown.
View Article and Find Full Text PDFNeurosci Biobehav Rev
January 2025
Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Gualtar Campus, Braga 4710-057, Portugal; ICVS/3B's-PT Government Associate Laboratory, Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Guimarães, Po
Fear-induced antinociception (FIA), an instinctive defensive response producing pain suppression in stressful and/or dangerous situations, has been the subject of extensive research to elucidate the mechanisms involved in triggering and controlling pain during emotional disorders. In this systematic review, we synthesized pre-clinical studies that demonstrated the neural hodology and the neurochemical bases of FIA in laboratory animals. The literature search in PubMed, Web of Science, Science Direct, and Scopus, from inception up to July 2022, retrieved 797 articles from which 50 studies were included in this review.
View Article and Find Full Text PDFProg Neuropsychopharmacol Biol Psychiatry
August 2024
Department of Psychology, Federal University of São Carlos (UFSCar), São Carlos, Brazil; Institute of Neuroscience and Behavior (INeC), Ribeirão Preto, Brazil. Electronic address:
Growing evidence supports dopamine's role in aversive states, yet systematic reviews focusing on dopamine receptors in defensive behaviors are lacking. This study presents a systematic review of the literature examining the influence of drugs acting on dopamine D2-like receptors on unconditioned and conditioned fear in rodents. The review reveals a predominant use of adult male rats in the studies, with limited inclusion of female rodents.
View Article and Find Full Text PDFInt J Mol Sci
June 2024
Institute for Advanced Brain Studies, Lomonosov Moscow State University, 119991 Moscow, Russia.
Posttraumatic stress disorder (PTSD) is a debilitating psychosomatic condition characterized by impairment of brain fear circuits and persistence of exceptionally strong associative memories resistant to extinction. In this study, we investigated the neural and behavioral consequences of inhibiting protein synthesis, a process known to suppress the formation of conventional aversive memories, in an established PTSD animal model based on contextual fear conditioning in mice. Control animals were subjected to the conventional fear conditioning task.
View Article and Find Full Text PDFNeuropharmacology
March 2024
Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (USP), Av. Bandeirantes 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil; Behavioural Neurosciences Institute (INeC), Psychobiology Division, Av. Bandeira
The anterior cingulate cortex (ACC) Cg1 (24b) area modulates glutamate-mediated unconditioned fear and antinociception organised by hypothalamus. However, it remains unknown whether 24b area also modulates these latter defensive responses through connections with the dorsal periaqueductal grey matter (dPAG), a midbrain structure implicated in the genesis of innate fear-induced defence. The aim of this work is to examine the correlation between the behavioural effects of intra-ACC microinjections of vehicle, NMDA (1 nmol) or lidocaine (2%) with Fos protein expression and nitrergic activity in the dPAG of male C57BL/6 mice that were threatened by snakes.
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