Induction of LTP in rat primary visual cortex: tetanus parameters.
Long-term potentiation (LTP), intensively studied in the hippocampus as a possible mnemonic device, has begun to be studied in the neocortex. In this study the effects of varying tetanic stimulus parameters on LTP of field potentials recorded from layer II/III induced by white matter stimulation in the in vitro rat visual cortical slice were examined. Low intensity tetanus was more effective in producing LTP than high-intensity tetanus, although single pulses of very high intensity reliably resulted in LTP. LTP consistently occurred following 2 Hz-60 min, or 100 Hz-10 min tetanus; whereas, 10 min of 7 and 25 Hz tetanus usually resulted in long-lasting depression. Although no obvious rule related tetanus frequency and duration to the incidence of LTP, an inverted-U relationship was found between tetanus frequency and LTP magnitude.
Berry
R L
RL
Neurobiology Department, Northeastern Ohio Universities College of Medicine, Rootstown 44272.
Teyler
T J
TJ
Han
T Z
TZ
D000818:Animals; D004558:Electric Stimulation; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D011930:Reaction Time / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*