Tetraethylammonium-induced long-term potentiation in layer V horizontal connections of rat motor cortex.
The possibility for the induction of long-lasting synaptic plasticity by the potassium channel blocker tetraethylammonium (TEA) was investigated in adult rat motor cortex in vitro. Brief application of TEA (25 mM) resulted in a long-term potentiation (LTP(K)) of field potentials evoked in layer V intralaminar connections by 59+/-17%. This effect could be prevented by preincubation with nifedipine, a voltage-dependent calcium channel blocker (20 microM), but not by N-methyl-D-aspartate (NMDA) receptor antagonist 2-amino-5-phosphonovalerate (APV, 100 microM). LTP(K) induction resulted in a smaller relative potentiation of a response to the second pulse of a pair (60 ms interpulse interval). These results indicate a potential of layer V horizontal connections for a NMDA receptor-independent form of persistent synaptic enhancement.
Jagodzinski
P
P
Institute of Zoology, Jagiellonian University, Ingardena 6, 30-060, Krakow, Poland.
Hess
G
G
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D005071:Evoked Potentials; D005260:Female; D066298:In Vitro Techniques; D017774:Long-Term Potentiation; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009543:Nifedipine / Q000494:pharmacology; D026902:Potassium Channel Blockers; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D009435:Synaptic Transmission; D019789:Tetraethylammonium / Q000494:pharmacology*
D002121:Calcium Channel Blockers; D026902:Potassium Channel Blockers; D016194:Receptors, N-Methyl-D-Aspartate; D019789:Tetraethylammonium; D015763:2-Amino-5-phosphonovalerate; D009543:Nifedipine