In the paraventricular nucleus of the hypothalamus (PVN), experimental stress paradigms that suppress gamma-aminobutyric acid (GABA) inputs to parvocellular neuroendocrine cells (PNCs) also increase the expression of brain-derived neurotrophic factor (BDNF). In the adult CNS, BDNF regulates the efficacy of GABAergic transmission, but its contributions to functional changes at inhibitory synapses in the PVN have not been investigated. Analysis of quantal transmission revealed a decrease in the frequency of miniature inhibitory postsynaptic currents (mIPSCs) in response to BDNF with no accompanying changes in their amplitude. These effects were completely blocked by prior inclusion of the TrKB receptor antagonist K252a in the patch pipette. Inclusion of a dynamin inhibitory peptide in the patch pipette also blocked the effects of BDNF, consistent with an all-or-none removal of clusters of postsynaptic GABAA receptors. Finally, to confirm a decrease in the availability of postsynaptic GABAA receptors, we tested the effects of BDNF on focal application of the GABAA agonist muscimol. Postsynaptic responses to muscimol were reduced after BDNF. Collectively, these data indicate that BDNF remodels functional synaptic contacts putatively by reducing the surface expression of postsynaptic GABAA receptors.
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http://dx.doi.org/10.1152/jn.01135.2005 | DOI Listing |
Pharmaceuticals (Basel)
November 2024
Division of Physiology, Department of Pharmacology, Physiology, and Microbiology, Karl Landsteiner University of Health Sciences, 3500 Krems, Austria.
Background: αδ proteins regulate membrane trafficking and biophysical properties of voltage-gated calcium channels. Moreover, they modulate axonal wiring, synapse formation, and trans-synaptic signaling. Several rare missense variants in CACNA2D1 (coding for αδ-1) and CACNA2D3 (coding for αδ-3) genes were identified in patients with autism spectrum disorder (ASD).
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
September 2024
Engineering Research Center, Ministry of Education, Hubei University of Chinese Medicine Wuhan 430065, China Hubei Shizhen Labortary Wuhan 430065, China.
Commun Biol
December 2024
Department of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
GABAergic synapses critically modulate neuronal excitability, and plastic changes in inhibitory synaptic strength require reversible interactions between GABA receptors (GABARs) and their postsynaptic anchor gephyrin. Inhibitory long-term potentiation (LTP) depends on the postsynaptic recruitment of gephyrin and GABARs, whereas the neurotransmitter GABA can induce synaptic removal of GABARs. However, the mechanisms and players underlying plastic adaptation of synaptic strength are incompletely understood.
View Article and Find Full Text PDFJ Neurophysiol
December 2024
Department of Physiology & Pharmacology, University of Georgia, Athens, Georgia, United States.
Although the actions of dopamine throughout the brain are clearly linked to motivation and cognition, the specific role(s) of dopamine in the CA1 subfield of the ventral hippocampus (vH) is unresolved. Prior preclinical studies suggest that dopamine D receptors (DRs) expressed on CA1 pyramidal cells exhibit a unique capacity to modulate mechanisms of long-term synaptic plasticity, but less is known about how interneuronal inputs modulate these cells. We hypothesized that inputs from μ-opioid receptor (MOR)-expressing inhibitory interneurons selectively modulate the activity of postsynaptic DRs expressed on CA1 principal cells to shape neurotransmission in the rat vH.
View Article and Find Full Text PDFEur J Neurosci
December 2024
Department of Applied Science and Neuroscience, William & Mary, Williamsburg, Virginia, USA.
Breathing behaviour is subject to emotional regulation, but the underlying mechanisms remain unclear. Here, we demonstrate a direct relationship between the central amygdala, a major output hub of the limbic system associated with emotional brain function, and the brainstem pre-Bötzinger complex, which generates the fundamental rhythm and pattern for breathing. The connection between these two sites is monosynaptic and inhibitory, involving GABAergic central amygdala neurons whose axonal projections act predominantly via ionotropic GABA receptors to produce inhibitory postsynaptic currents in pre-Bötzinger neurons.
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