EFFECTS OF LACTATE AND PYRUVATE ON GLUCOSE DEPRIVATION IN RAT HIPPOCAMPAL SLICES

RAT hippocampal slices were used to evaluate the effects of glucose de privation and the ability of lactate or pyruvate to preserve histologi cal integrity and synaptic function. Dark cell changes were observed d uring 180 min incubations in glucose-free solutions. These changes wer e blocked by substituting 10 mM lactate or pyruvate for glucose during the incubation. Excitatory postsynaptic potentials disappeared during 60 min of glucose deprivation but were restored by subsequent introdu ction of glucose, lactate or pyruvate. Incubation of slices with iodoa cetate revealed a distinct pattern of damage that was blocked complete ly by pyruvate and partially by lactate. These results indicate that e xogenous pyruvate and lactate can serve as energy substrates in the hi ppocampus when glucose is unavailable or glycolytic metabolism is impa ired.