Immune-modulatory drugs alter Candida albicans-induced sleep patterns in rabbits.

To evaluate the influences of immune responsiveness on sleep alteration during infectious disease, sleep was monitored during Candida albicans infection in rabbits treated with immune-modulating drugs. Intravenous administration of C. albicans to normal rabbits initially increased and subsequently decreased both the amount of slow-wave sleep (SWS) and delta-wave amplitudes (DWA) during SWS. Cortisone treatment attenuated these effects. The immunosuppressive drug cyclosporine did not alter the initial enhancement of SWS, but did attenuate the C. albicans-induced reduction in SWS time and potentiate the reduction in DWA. In contrast, administration of incomplete Freund's adjuvant and prior immunization with killed C. albicans, which were expected to enhance immune responsiveness, did not markedly alter C. albicans-induced alterations in SWS. However, the immune stimulant levamisole potentiated the effects of C. albicans on SWS. These data indicate that pharmacologic treatments expected to alter immune responsiveness modulate microbially induced sleep, and are consistent with the hypothesis that facets of the immune response mediate sleep changes during infectious disease.