Interaction Between Tetanus Long-Term Potentiation and Hypoxia-Induced Potentiation in the Rat Hippocampus

M. Lyubkin 1 , D. M. Durand 1 , and M. A. Haxhiu 2 1 Departments of Biomedical Engineering and Neurosciences and 2 Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106 Lyubkin, M., D. M. Durand, and M. A. Haxhiu. Interaction between tetanus long-term potentiation and hypoxia-induced potentiation in the rat hippocampus. J. Neurophysiol. 78: 2475-2482, 1997. The interaction between tetanus-induced long-term potentiation (LTP) and hypoxia-induced potentiation was investigated by performing extracellular recordings in the CA1 region of rat hippocampus using a two-pathway design. Hippocampal slices were placed in an interface chamber containing artificial cerebrospinal fluid (ACSF) solution with high magnesium concentration. Hypoxia was induced by replacing the 5% CO 2 -95% O 2 gas mixture with 5% CO 2 -95% N 2 for 2 min. Tetanus-LTP was induced with 1-s, 100-Hz current pulses. Significant hypoxia-induced potentiation of the slope of the dendritic excitatory postsynaptic potential (EPSP) was found in ACSF containing 2 mM of magnesium 2, 27 ± 10% (mean ± SE; n = 16; P