The calcium dependency and tetrodotoxin sensitivity of extracellular dopamine levels were assessed by microdialysis in the neostriatum of 5-day-old rat pups and were compared with those obtained in adult rats. The removal of calcium from the dialysate reduced spontaneous levels of extracellular dopamine to 20% of normal in the 5-day-old pups and to 10% of normal in the adults. Calcium-free dialysate also decreased potassium-evoked dopamine release to approximately 20% of baseline in both ages. Furthermore, the addition of tetrodotoxin to the dialysate decreased spontaneous levels of extracellular dopamine to 10% of baseline in both ages. The effects of calcium removal and the addition of tetrodotoxin on extracellular levels of the dopamine metabolite 3,4-dihydroxyphenylacetic acid were less pronounced. The results of this study demonstrate that extracellular levels of dopamine sampled by microdialysis in rats as young as 5 days of age are both calcium dependent and tetrodotoxin sensitive; thus, they are derived from neuronal activity and not from injury caused by acute implantation of the probe. Other age-related differences support the hypothesis that dopamine release and turnover is greater in immature rats and may represent a form of compensation for incomplete dopamine nerve terminal ingrowth.
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http://dx.doi.org/10.1046/j.1471-4159.1994.62051741.x | DOI Listing |
Toxicol Sci
March 2025
Cerevel Therapeutics, LLC, Cambridge, MA.
Dopamine agonists (DAs) are approved for the treatment of hypodopaminergic pathologies, including Parkinson's disease, restless legs syndrome, and periodic limb movement disorder. During drug development, drugs acting on dopaminergic receptors are often associated with a rat-specific endocrine tumor response, including changes in fertility, which are ascribed to DA-induced suppression of pituitary prolactin release. Although these effects are not observed in or relevant to humans, given species differences in the effects of prolactin on reproductive organs, modeling DA-mediated changes in prolactin and the reproductive system remains important for preclinical drug development.
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March 2025
Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland.
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View Article and Find Full Text PDFColloids Surf B Biointerfaces
March 2025
State Key Laboratory of Swine and Poultry Breeding Industry, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China. Electronic address:
Treating bacterium-infected diabetic wounds remains a major medical challenge. Antimicrobial activity, remodeling of oxidative stress-heavy and angiogenesis-impaired microenvironments are critical factors for effective wound healing. Hydrogels can function as drug delivery systems that encompass all these capabilities to enhance wound healing.
View Article and Find Full Text PDFBehav Brain Funct
March 2025
Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan.
Background: Major depressive disorder is a significant global cause of disability, particularly among adolescents. The dopamine system and nearby neuroinflammation, crucial for regulating mood and processing rewards, are central to the frontostriatal circuit, which is linked to depression. This study aimed to investigate the effect of post-weaning isolation (PWI) on depression in adolescent mice, with a focus on exploring the involvement of microglia and dopamine D1 receptor (D1R) in the frontostriatal circuit due to their known links with mood disorders.
View Article and Find Full Text PDFEur J Nutr
March 2025
Department of Biomedical and Pharmaceutical Sciences, Graduate School, Kyung Hee University, Seoul, 02447, Republic of Korea.
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