[The role of N-type high-voltage-activated calcium channels in plasticity regulation of inhibitory synaptic transmission in cultured hippocampal neurons].
Now it is clear that N-type Ca2+ channels contribute to synaptic transmission at many of CNS synapses. However, it is not known whether presynaptic N-type Ca2+ channels contribute to short-term synaptic plasticity (STP) mediated by GABA release at inhibitory synapses of cultured hippocampal neurons. We studied the sensitivity of GABAergic paired pulse depression (PPD) as a common form of STP to selective N-type high-voltage-activated Ca2+ channels blocker omega-conotoxin (omegaCgTx). Evoked inhibitory postsynaptic currents (eIPSCs) were studied using patch-clamp technique in whole-cell configuration in postsynaptic neuron and local exteracellular paired pulse stimulation of single presynaptic axon by rectangular pulse with 0.4 ms duration, the interpulse interval in pair was 150 ms. CgTx (200 nM; 1 microM) in a dose-dependent manner irreversibly reduced the amplitude of paired eIPSCs by 25-49% and decreased PPD by 11-22% compared with control. These results confirm that N-type Ca2+ channels are highly involved in inhibitory synaptic transmission and short-term synaptic plasticity in cultured hippocampal neurons.
Mizerna
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Fedulova
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Veselovs'kyĭ
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D000818:Animals; D000831:Animals, Newborn; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020864:Calcium Channels, N-Type / Q000378:metabolism / Q000502:physiology*; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D053444:Inhibitory Postsynaptic Potentials / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D017729:Presynaptic Terminals / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D005680:gamma-Aminobutyric Acid / Q000378:metabolism; D020960:omega-Conotoxins / Q000494:pharmacology
D002121:Calcium Channel Blockers; D020864:Calcium Channels, N-Type; D020960:omega-Conotoxins; D005680:gamma-Aminobutyric Acid