AMPA and NMDA receptor-dependent spinal LTP after nociceptive tetanic stimulation.
LTP is often studied as a model of synaptic plasticity. Plasticity in pain control systems may involve mechanisms similar to those involved in learning. We recently reported LTP of both the A beta and C-fibre evoked responses of single dorsal horn neurons after a tetanic stimulation of the sciatic nerve, lasting for at least 6 h. In the present paper we show that identical stimulation induced LTP only of the C-fibre evoked response after blockade of muscular contractions during the tetanus. The C-fibre evoked response increased significantly less after pretreatment with either the AMPA antagonist NBQX or the NMDA antagonist D-AP5 (mean increase 33%) than in untreated animals (105%, p < 0.001), indicating that both AMPA and NMDA receptor stimulation are involved in the induction of LTP.
Svendsen
F
F
Department of Physiology, University of Bergen, Norway.
Tjølsen
A
A
Hole
K
K
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D017774:Long-Term Potentiation / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D010146:Pain / Q000503:physiopathology*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000187:drug effects / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000502:physiology*; D013116:Spinal Cord / Q000502:physiology*
D018691:Excitatory Amino Acid Antagonists; D011810:Quinoxalines; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D015763:2-Amino-5-phosphonovalerate