scholarly journals BDNF Induces Calcium Elevations Associated With IBDNF, a Nonselective Cationic Current Mediated by TRPC Channels

2007 ◽  
Vol 98 (4) ◽  
pp. 2476-2482 ◽  
Author(s):  
Michelle D. Amaral ◽  
Lucas Pozzo-Miller
Keyword(s):  
Hippocampal Neurons ◽  
Transient Receptor Potential ◽  
Pyramidal Neurons ◽  
Receptor Potential ◽  
Trpc Channels ◽  
Hippocampal Pyramidal Neurons ◽  
Cationic Current ◽  
Intracellular Ca ◽  
Transient Receptor ◽  
Nonselective Cationic Current

Brain-derived neurotrophic factor (BDNF) has potent actions on hippocampal neurons, but the mechanisms that initiate its effects are poorly understood. We report here that localized BDNF application to apical dendrites of CA1 pyramidal neurons evoked transient elevations in intracellular Ca2+ concentration, which are independent of membrane depolarization and activation of N-methyl-d-aspartate receptors (NMDAR). These Ca2+ signals were always associated with IBDNF, a slow and sustained nonselective cationic current mediated by transient receptor potential canonical (TRPC3) channels. BDNF-induced Ca2+ elevations required functional Trk and inositol-tris-phosphate (IP3) receptors, full intracellular Ca2+ stores as well as extracellular Ca2+, suggesting the involvement of TRPC channels. Indeed, the TRPC channel inhibitor SKF-96365 prevented BDNF-induced Ca2+ elevations and the associated IBDNF. Thus TRPC channels emerge as novel mediators of BDNF-induced intracellular Ca2+ elevations associated with sustained cationic membrane currents in hippocampal pyramidal neurons.

scholarly journals Transient Receptor Potential Vanilloid 4 Activation-Induced Increase in Glycine-Activated Current in Mouse Hippocampal Pyramidal Neurons

2018 ◽  
Vol 45 (3) ◽  
pp. 1084-1096 ◽  
Author(s):  
Mengwen Qi ◽  
Chunfeng Wu ◽  
Zhouqing Wang ◽  
Li Zhou ◽  
Chen Men ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Transient Receptor Potential ◽  
Pyramidal Neurons ◽  
Receptor Potential ◽  
Chloride Ion ◽  
Transient Receptor Potential Vanilloid ◽  
Patch Clamp Recording ◽  
Hippocampal Pyramidal Neurons ◽  
Protein Levels ◽  
Transient Receptor

Background/Aims: Glycine plays an important role in regulating hippocampal inhibitory/ excitatory neurotransmission through activating glycine receptors (GlyRs) and acting as a co-agonist of N-methyl-d-aspartate-type glutamate receptors. Activation of transient receptor potential vanilloid 4 (TRPV4) is reported to inhibit hippocampal A-type γ-aminobutyric acid receptor, a ligand-gated chloride ion channel. GlyRs are also ligand-gated chloride ion channels and this paper aimed to explore whether activation of TRPV4 could modulate GlyRs. Methods: Whole-cell patch clamp recording was employed to record glycine-activated current (IGly) and Western blot was conducted to assess GlyRs subunits protein expression. Results: Application of TRPV4 agonist (GSK1016790A or 5,6-EET) increased IGly in mouse hippocampal CA1 pyramidal neurons. This action was blocked by specific antagonists of TRPV4 (RN-1734 or HC-067047) and GlyR (strychnine), indicating that activation of TRPV4 increases strychnine-sensitive GlyR function in mouse hippocampal pyramidal neurons. GSK1016790A-induced increase in IGly was significantly attenuated by protein kinase C (PKC) (BIM II or D-sphingosine) or calcium/calmodulin-dependent protein kinase II (CaMKII) (KN-62 or KN-93) antagonists but was unaffected by protein kinase A or protein tyrosine kinase antagonists. Finally, hippocampal protein levels of GlyR α1 α2, α3 and β subunits were not changed by treatment with GSK1016790A for 30 min or 1 h, but GlyR α2, α3 and β subunits protein levels increased in mice that were intracerebroventricularly (icv.) injected with GSK1016790A for 5 d. Conclusion: Activation of TRPV4 increases GlyR function and expression, and PKC and CaMKII signaling pathways are involved in TRPV4 activation-induced increase in IGly. This study indicates that GlyRs may be effective targets for TRPV4-induced modulation of hippocampal inhibitory neurotransmission.

scholarly journals TRPC5-CaV3 complex mediates Leptin-induced excitability in hypothalamic neurons

2020 ◽  
Author(s):  
Paula P. Perissinotti ◽  
Elizabeth Martínez-Hernández ◽  
Erika S. Piedras-Rentería
Keyword(s):  
Transient Receptor Potential ◽  
Calcium Influx ◽  
Receptor Potential ◽  
Membrane Depolarization ◽  
Macromolecular Complex ◽  
Trpc Channels ◽  
Neuron Excitability ◽  
Intracellular Ca ◽  
Transient Receptor

ABSTRACTLeptin regulates hypothalamic POMC+ (pro-opiomelanocortin) neurons by inducing TRPC (Transient Receptor Potential Cation) channel-mediate membrane depolarization. Here we assessed the role of T-type channels on POMC neuron excitability and leptin-induced depolarization in vitro. We demonstrate T-type currents are indispensable for both processes, as treatment with NNC-55-0396 prevented the membrane depolarization and rheobase changes induced by leptin in cultured mouse POMC neurons. Furthermore, we demonstrate TRPC1/C5 channels and CaV3.1 and CaV3.2 channels co-exist in complex. The functional relevance of this complex was corroborated using intracellular Ca2+ chelators; intracellular BAPTA (but not EGTA) application was sufficient to preclude POMC neuron excitability by preventing leptin-induced calcium influx through TRPC channels and T-type channel function.We conclude T-type channels are integral in POMC neuron excitability. Leptin activation of TRPC channels existing in a macromolecular complex with T-type channels recruits the latter by locally-induced membrane depolarization, further depolarizing POMC neurons, triggering action potentials and excitability.

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