Changes in the paired-pulse ratio after long-term potentiation induced by 2- and 100-Hz tetanus in rat visual cortical slices.
The effects of 2- and 100-Hz tetanus on long-term potentiation (LTP) of field potentials recorded from layers II/III and induced in layer IV in rat visual cortical slices were examined. Paired-pulse stimulation was used to probe the different mechanisms of LTP induced by 2- and 100-Hz tetanus. The paired-pulse ratio (PPR) decreased after the LTP induced by 2-Hz tetanus, with the changes in PPR being correlated with LTP amplitude. However, in the LTP induced by 100-Hz tetanus, the changes in PPR were not correlated with LTP expression. These experiments suggest that an enhanced probability of presynaptic transmitter release underlies LTP induced by 2-Hz tetanus, but not LTP induced by 100-Hz tetanus.
Department of Physiology, School of Medicine, Xi'an Jiaotong University, Zhuque Dajie 205, Xi'an, Shaanxi 710061, PR China.
Bin
B
Pan
Dong-Wei
DW
Yang
Tai-Zhen
TZ
Han
Wen
W
Xie
D000818:Animals; D004558:Electric Stimulation / Q000379:methods*; D005071:Evoked Potentials / Q000502:physiology; D017774:Long-Term Potentiation / Q000502:physiology*; D008297:Male; D009924:Organ Culture Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D009435:Synaptic Transmission / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*