The effect of nociceptin (an endogenous ligand of the ORL1 receptor) on mesolimbic dopamine release and simultaneous horizontal locomotion was studied in freely moving mice undergoing microdialysis of the nucleus accumbens. Intracerebroventricular (i.c.v.) administration of nociceptin (7 nmol) induced a long-lasting suppression of mesolimbic dopamine release and horizontal locomotion in wild-type but not ORL1 knockout mice. I.c.v. administration of the recently reported peptide nociceptin antagonist [Nphe1, Arg14, Lys15] nociceptin-NH(2) (known also as UFP-101, 5 nmol) completely abolished the suppressive effect of nociceptin on mesolimbic dopamine release. However, UFP-101 administration alone induced a mild and lasting suppression of mesolimbic dopamine release in both wild-type and ORL1 knockout mice that was magnified in ORL1 knockout mice by coadministration of nociceptin. UFP-101 administration alone suppressed locomotion in both genotypes. These results confirm that the suppressive action of nociceptin on mesolimbic dopamine release is mediated entirely by the ORL1 receptor, and that UFP-101 effectively antagonizes this action. However, the lack of a stimulatory effect of UFP-101 in wild-type mice indicates that despite being sensitive to exogenous nociceptin action, basal mesolimbic dopaminergic activity is not determined by endogenous nociceptin in mice.
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http://dx.doi.org/10.1111/j.1471-4159.2003.02322.x | DOI Listing |
Sci Adv
January 2025
Douglas Mental Health University Institute, McGill University, Montreal, QC H4H 1R3, Canada.
Infradian mood and sleep-wake rhythms with periods of 48 hours and beyond have been observed in patients with bipolar disorder (BD), which even persist in the absence of exogenous timing cues, indicating an endogenous origin. Here, we show that mice exposed to methamphetamine in drinking water develop infradian locomotor rhythms with periods of 48 hours and beyond which extend to sleep length and manic state-associated behaviors in support of a model for cycling in BD. The cycling capacity is abrogated upon genetic disruption of dopamine (DA) production in DA neurons of the ventral tegmental area (VTA) or ablation of nucleus accumbens projecting DA neurons.
View Article and Find Full Text PDFFront Hum Neurosci
December 2024
Department of Information Medicine, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan.
Accurate interoceptive processing in decision-making is essential to maintain homeostasis and overall health. Disruptions in this process have been associated with various psychiatric conditions, including depression. Recent studies have focused on nutrient homeostatic dysregulation in depression for effective subtype classification and treatment.
View Article and Find Full Text PDFTransl Psychiatry
December 2024
Center for Substance Abuse Research, Temple University, Philadelphia, PA, USA.
Recent progress in psychiatric research has highlighted neuroinflammation in the pathophysiology of opioid use disorder (OUD), suggesting that heightened immune responses in the brain may exacerbate opioid-related mechanisms. However, the molecular mechanisms resulting from neuroinflammation that impact opioid-induced behaviors and transcriptional pathways remain poorly understood. In this study, we have begun to address this critical knowledge gap by exploring the intersection between neuroinflammation and exposure to the opioid heroin, utilizing lipopolysaccharide (LPS)-induced neuroinflammation, to investigate transcriptional changes in the nucleus accumbens (NAc), an essential region in the mesolimbic dopamine system that mediates opioid reward.
View Article and Find Full Text PDFBehav Brain Res
December 2024
Human Genetics Laboratory, Oswaldo Cruz Institute, Oswaldo Cruz Foundation (Fiocruz), 4365 Brazil Avenue, Leônidas Deane Pavilion, Rio de Janeiro, RJ 21040-360, Brazil; Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Professor Rodolpho Paulo Rocco Street, 255, University City, Rio de Janeiro, RJ 21941-617, Brazil. Electronic address:
Neurosci Res
December 2024
Neuroscience Institute, New York University Langone Medical Center, New York, NY, USA; Department of Psychiatry, New York University Langone Medical Center, New York, NY, USA; Department of Neuroscience and physiology, New York University Langone Medical Center, New York, NY, USA. Electronic address:
In nearly all mammalian species, newborn pups are weak and vulnerable, relying heavily on care and protection from parents for survival. Thus, developmentally hardwired neural circuits are in place to ensure the timely expression of parental behaviors. Furthermore, several neurochemical systems, including estrogen, oxytocin, and dopamine, facilitate the emergence and expression of parental behaviors.
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