Different effects of 2 and 100 Hz tetanus on the expression of long-lasting long-term potentiation in rat visual cortical slices.
Long-term potentiation (LTP) can be induced by various tetanic parameters in the mammalian visual cortex. However, little researches have been done on the relationship between the expression of the long-lasting LTP (late phase LTP or L-LTP) lasting more than 3 h and the tetanic parameters. In the present study, the effects of 2 Hz and 100 Hz tetanic parameters on L-LTP of the field potentials were recorded from the layer II/III of the rat visual cortical slices in response to stimulation of the layer IV. As a result, tetanic parameters that had more than 300 pulses reliably induced L-LTP in the postnatal day 15-21 rats. Obviously different L-LTP expressions were induced by 2 Hz and 100 Hz tetani. There was no difference in L-LTP expression induced by the parameters with the same frequency and different total pulses. These data suggest that L-LTPs induced by different frequency parameters may have different induction and maintenance mechanisms; L-LTPs induced by the parameters with the same frequency may have the same mechanisms.
Pan
Bin
B
Department of Physiology, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China.
Yang
Dong-Wei
DW
Han
Tai-Zhen
TZ
D000818:Animals; D004558:Electric Stimulation / Q000379:methods*; D017774:Long-Term Potentiation / Q000502:physiology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D009435:Synaptic Transmission / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*