Effects of tissue preincubation and hypoxia on CA3 hippocampal neurons in the in vitro slice preparation.
Using the in vitro hippocampal slice preparation, we studied the electrophysiological properties of pyramidal cells in tissue that was 'preincubated' (2-6 h in a large, static volume of oxygenated bathing medium) before being placed in an interface chamber for study. Striking differences were found in 'preincubated' vs 'non-preincubated' CA3 cells. The preincubated cells had more negative resting potentials, higher input resistance, lower threshold for stimulus-evoked burst discharge and larger hyperpolarizing afterpotentials. Cells in the preincubated CA3 region were also more likely to show spontaneous synchronized burst discharge, but were relatively resistant to hypoxia-induced spreading depression. CA1 cells were less dramatically affected by preincubation, showing little difference from their non-preincubated counterparts. Possible mechanisms involved in the CA3 preincubation effect, including glial buffering alterations and changes in Na+, K+-ATPase activity, are discussed.
D000818:Animals; D002462:Cell Membrane / Q000502:physiology; D004553:Electric Conductivity; D005071:Evoked Potentials; D006624:Hippocampus / Q000503:physiopathology*; D002534:Hypoxia, Brain / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials; D009433:Neural Inhibition; D051381:Rats; D011919:Rats, Inbred Strains; D009435:Synaptic Transmission