Despite the importance of somatodendritic dopamine (DA) release in the Substantia Nigra pars compacta (SNc), its mechanism remains poorly understood. Using a novel approach combining fast-scan controlled-adsorption voltammetry (FSCAV) and single-unit electrophysiology, we have investigated the mechanism of somatodendritic release by directly correlating basal (non-stimulated) extracellular DA concentration ([DA] ), with pharmacologically-induced changes of firing of nigral dopaminergic neurons in rat brain slices. FSCAV measurements indicated that basal [DA] in the SNc was 40.7 ± 2.0 nM (at 34 ± 0.5°C), which was enhanced by amphetamine, cocaine, and L-DOPA, and reduced by VMAT2 inhibitor, Ro4-1284. Complete inhibition of firing by TTX decreased basal [DA] , but this reduction was smaller than the effect of D receptor agonist, quinpirole. Despite similar effects on neuronal firing, the larger decrease in [DA] evoked by quinpirole was attributed to cell membrane hyperpolarization and greater reduction in cytosolic free Ca ([Ca ] ). Decreasing extracellular Ca also reduced basal [DA] , despite increasing firing frequency. Furthermore, inhibiting L-type Ca channels decreased basal [DA] , although specific Ca 1.3 channel inhibition did not affect firing rate. Inhibition of sarcoplasmic/endoplasmic reticulum Ca -ATPase (SERCA) also decreased [DA] , demonstrating the importance of intracellular Ca stores for somatodendritic release. Finally, in vivo FSCAV measurements showed that basal [DA] in the SNc was 79.8 ± 10.9 nM in urethane-anesthetized rats, which was enhanced by amphetamine. Overall, our findings indicate that although tonic somatodendritic DA release is largely independent of action potentials, basal [DA] is strongly regulated by voltage-dependent Ca influx and release of intracellular Ca . OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1111/jnc.14587 | DOI Listing |
Breast Cancer Res Treat
January 2025
Department of Breast Surgery, Fujian Medical University Union Hospital, Fuzhou, 350001, Fujian , China.
Purpose: Age stratification influences the clinicopathological features and survival outcomes of breast cancer. We aimed to understand the effect of age on gene variants in young Chinese women with breast cancer compared with those from The Cancer Genome Atlas (TCGA).
Methods: Enrolled patients ≤ 40 years old (N = 370) underwent germline or somatic genetic testing using a 32-gene hereditary cancer panel at Fujian Union Hospital.
Sci Rep
January 2025
Division of Cardiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
Myocyte disarray and fibrosis are underlying pathologies of hypertrophic cardiomyopathy (HCM) caused by genetic mutations. However, the extent of their contributions has not been extensively evaluated. In this study, we investigated the effects of genetic mutations on myofiber function and fibrosis patterns in HCM.
View Article and Find Full Text PDFJ Anim Sci Biotechnol
January 2025
College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Background: The diverse types and processing methods of grains intricately influence the sites and digestibility of starch digestion, thereby impacting energy utilization. This study aimed to explore the impact of grain variety and processing methods on the net energy (NE) in dairy goats, analyzing these effects at the level of nutrient digestion and metabolism.
Methods: Eighteen castrated Guanzhong dairy goats (44.
Cells Dev
January 2025
Tunicate Laboratory, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa, Japan.
Butterfly wing eyespots are developmentally determined at the early pupal stage, when prospective eyespot focal cells underneath the pupal cuticle focal spot function as eyespot organizers in the pupal wing tissue. Here, we performed light microscopy and transmission electron microscopy (TEM) to describe cellular structures of pupal wing tissue with an eyespot organizer immediately after pupation using the Blue Pansy butterfly Junonia orithya. The pupal forewing dorsal epidermis was a pseudostratified monolayer of vertically elongated epidermal cells.
View Article and Find Full Text PDFNeuroscience
January 2025
Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, MEC, Av. Italia 3318, Montevideo, CP 11600, Uruguay; Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Iguá, Montevideo, 4225, CP 11400, Uruguay. Electronic address:
Local protein synthesis (LPS) in axons is now recognized as a physiological process, participating both in the maintenance of axonal function and diverse plastic phenomena. In the last decades of the 20th century, the existence and function of axonal LPS were topics of significant debate. Very early, axonal LPS was thought not to occur at all and was later accepted to play roles only during development or in response to specific conditions.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!