Post-Tetanic Potentiation in the Visual System of Cats

¹ From the National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland

Post-tetanic potentiation (PTP) has been demonstrated in the soma response of the geniculate and in the positive potentials of the cortex by stimulation of the cat's optic nerve and recording from the lateral geniculate and visual cortex. Within limits, an increase in duration and intensity of tetanus produces an increased amount of PTP which lasts for a longer time. Occasionally the tract response is potentiated. Various explanations are offered to account for this change and the results are discussed in relation to the probable site of action of PTP. In any case the type of PTP examined in these experiments using anesthetized animals appears to be a property of the subnormal phase with a concomitant increase in the subliminal fringe.