[Effects of interleukin-1 and interleukin-2 on electrophysiological characteristics of rat hippocampal neurons in culture].

The effects of recombinant human interleukin-1 beta (rhIL-1 beta) and interleukin-2 (rhIL-2) on the cultured rat hippocampal neurons were investigated with intracellular recording and extracellular micropressure ejection techniques. Experimental results showed that all of the neurons tested with rhIL-1 beta (100 U/ml) exhibited a 4.20 +/- 1.86 mV membrane hyperpolarization. 50% of the neurons treated with rhIL-2 (100 U/ml) showed a depolarization of 11.12 +/- 3.71 mV accompanied by bursting activity, while in a still higher concentration (1,000 U/ml) a 3.25 +/- 0.63 mV hyperpolarization was observed. All the above effects of rhIL-1 beta and rhIL-2 on the hippocampal neurons were completely reversible. The membrane resistance of the neurons was not significantly affected by these cytokines. These results suggest that the effects of cytokines IL-1 and IL-2 on the excitability of hippocampal neurons may be a way by which the immune system exerts a regulatory action on hippocampal function.