Publication de 4 numéros par an
ISSN Imprimer: 2155-014X
ISSN En ligne: 2155-0158
Changes in Synaptic Plasticity due to Blockage of N-type Ca2+ Channels in Cultured Hippocampal Neurons
RÉSUMÉ
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 (ω-CgTx). Evoked inhibitory postsynaptic currents (eIPSCs) were studied using patch-clamp technique in whole-cell configuration in postsynaptic neuron and local extracellular paired pulse stimulation of single presynaptic axon by rectangular pulse with 0.4 ms duration, the impulse interval in pair was 150 ms. ω-CgTx (200 nM; 1 μM) in a dose-dependent manner irreversibly reduced the amplitude of paired eIPSCs by 25−49% and decreased PPD by 11−22% as 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.