To establish whether chronic opiate exposure might impair brain dopaminergic or serotonergic function in humans, we assessed biochemical indices of monoaminergic neurotransmitter activity and integrity in post mortem striatum of nine chronic heroin users and 14 control subjects. Striatal levels of the vesicular monoamine transporter were normal, suggesting that the density of dopamine nerve terminals is not reduced in heroin users. In nucleus accumbens, levels of tyrosine hydroxylase protein (-25%) and those of the dopamine metabolite homovanillic acid (-33%) were reduced significantly together with a trend for decreased dopamine (-32%) concentration. These changes could reflect either a compensatory downregulation of dopamine biosynthesis in response to prolonged dopaminergic stimulation caused by heroin, or reduced axoplasmic transport of tyrosine hydroxylase. Striatal levels of serotonin were either normal or elevated whereas concentrations of the serotonin metabolite 5-hydroxyindoleacetic acid were decreased by 27-38%. Our data suggest that chronic heroin exposure might produce a modest reduction in dopaminergic and serotonergic activity that could affect motivational state and impulse control, respectively.
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http://dx.doi.org/10.1016/S0893-133X(00)00209-8 | DOI Listing |
Pharmacol Res
March 2025
Biological Psychiatry Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Via Pilastroni 4, 25125 Brescia, Italy; Department of Pharmacological and Biomolecular Sciences, University of Milan, Via Balzaretti 9, 20133 Milan, Italy. Electronic address:
Schizophrenia is a severe and debilitating psychiatric disorder that profoundly impacts cognitive, emotional, and social functioning. Despite its devastating personal and societal toll, current treatments often provide only partial relief, underscoring the urgent need for innovative therapeutic strategies. This review explores emerging approaches that target the complex neurobiological underpinnings of schizophrenia, moving beyond traditional dopamine-centric models.
View Article and Find Full Text PDFAdv Sci (Weinh)
March 2025
Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.
The surge of new psychoactive substances (NPS) poses significant public health challenges due to their unregulated status and diverse effects. However, existing in vivo models for evaluating their activities are limited. To address this gap, this study utilizes the model organism Caenorhabditis elegans (C.
View Article and Find Full Text PDFSci Rep
March 2025
Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, 575018, India.
Tinospora cordifolia has been used for thousands of years to treat various health conditions, including neurodegenerative diseases. The study aimed to elucidate the mechanism of action and protein targets of T. cordifolia in the context of Alzheimer's disease through untargeted metabolomics and network pharmacology.
View Article and Find Full Text PDFNeurotoxicology
March 2025
Department of Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL, USA. Electronic address:
Chronic exposure to elevated levels of manganese (Mn) induces manganism, a neurological disorder, exhibiting symptoms resembling Parkinson's disease (PD). Mn is well known to dysregulate dopaminergic (DAergic) function, and the repressor element-1 silencing transcription factor (REST) induces protection against Mn-induced toxicity and several neurodegenerative diseases, including PD and Alzheimer's disease. In the present study, we investigated if DAergic REST plays a role in Mn-induced neurotoxicity by assessing behavioral deficits and alteration of neurotransmitter levels using high-performance liquid chromatography with electrochemical detector (HPLC-ECD), and microdialysis between DAergic-specific REST-deleted (REST cKO) mice and REST loxP mice as a wild-type (WT) control.
View Article and Find Full Text PDFBrain
March 2025
Univ Lyon, Lyon Neuroscience Research Center (CRNL), CNRS UMR 5292, INSERM U1028, F- 69675 Bron, France.
Impulse control disorders (ICDs) are frequent and particularly distressing neuropsychiatric symptoms in patients with Parkinson's disease (PD) which are related to impaired behavioural inhibition. Multiple PET imaging studies indicate that striatal dopaminergic abnormalities contribute to hyperdopaminergic functioning in PD patients with ICD (PDICD+) and to the dysregulation of the limbic fronto-striatal networks which are critical for reward-related decision impulsivity. However, the serotonergic system is central to response inhibition and plays a critical role in neuropsychiatric symptoms in PD, but its role remains undetermined in PDICD.
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