ULTRAWEAK BIOCHEMILUMINESCENCE DETECTED FROM RAT HIPPOCAMPAL SLICES

FROM any kind of living organisms, very weak spontaneous light emissio n without excitation light (ultraweak biochemiluminescence) is observe d. We succeeded to detect ultraweak biochemiluminescence from rat hipp ocampal slice preparation at the order of 10(-19) W/mm(2) by a single- photon detector using a silicon avalanche photodiode. It was shown tha t depolarization induced by the high concentration of potassium caused an increase in the intensity of biochemiluminescence from the rat hip pocampal slice, and that suppression of neural activity by tetrodotoxi n elicited a decrease of its luminescence. These findings suggest that correlation between the intensity of ultraweak biochemiluminescence a nd neural metabolic activity.