Dependence of long-term potentiation on the interval between A- and C-responses of the spinal dorsal horn neurons in rats.
We investigated whether tetanic stimulation (TS) of peripheral afferent nerves induced long-term potentiation (LTP) in the spinal dorsal horn of rats. Extracellular recordings from a wide dynamic range of neurons in the lumbosacral enlargement were performed using urethane-anaesthetized rats. High frequency electrical TS of sciatic nerves has revealed three groups of neurons based on their responses: LTP-induced, no-change and long-term depression-induced neurons. The firing pattern of LTP-induced neurons showed a short interval between A- and C-responses in comparison to the no-change neurons, which displayed longer intervals between A- and C-responses. During TS, coincident depolarization increased the probability of LTP induction. It can be suggested that coincident depolarization or increase in excitability of the postsynaptic dorsal horn neurons during TS may be necessary for successful induction of LTP through the dorsal horn.
Kim
Dong Kwan
DK
Department of Physiology and Biophysics, Seoul National University College of Medicine, 28 Yongon-Dong, Chongno-gu, Seoul 110-799, South Korea.
Jung
Sung Jun
SJ
Kim
Sang Jeong
SJ
Kwak
Jiyeon
J
Kim
Jun
J
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D004558:Electric Stimulation; D005260:Female; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D009412:Nerve Fibers / Q000502:physiology; D020671:Posterior Horn Cells / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000502:physiology; D013997:Time Factors
D011188:Potassium