Alpha and Gamma Interferons' Effects on Cortical and Hippocampal Neurons: Microiontophoretic Application and Single Cell Recording

Abstract

Responses of 96 extracellular spontaneous active cortical and hippocampal neurons to microiontophoretically applied four types of α interferons (α-IFNs), one type of γ interferon (γ-IFN) as well as three fractions of γ-IFNs were examined. All four types of α-IFN ejections increased the discharge of the majority of neuron tested. Significant differences of the number of cells excited and the intensity of the excitation among the 4 types of α-IFN were observed. The most significant effects were induced by Cantell's human leukocyte α-IFN followed by the Hoffman-LaRoche recombinant α-IFN which exhibited a dose dependent effect (i.e., each higher dose of IFN affected more neurons and intensified the excitation) on the hippocampal and cortical cells respectively. Neither the IFN carrier (albumin), nor the γ-IFNs and its fractions, as well as current ejection, altered the extracellular spontaneous active of these 96 cortical and hippocampal neurons respectively. These observations show that the immunomodulator α-IFNs, but not γIFNs, exerts excitatory effects on neuronal activity recorded from these two brain structures and support the view that the brain is capable of communicating with the immune system.