SLEEP PATTERNS ARE DISTURBED IN CATS INFECTED WITH FELINE IMMUNODEFICIENCY VIRUS

Human immunodeficiency virus (HIV)-related sleep disturbances have bee n reported early in AIDS. Likewise, the feline immunodeficiency virus (FIV), a natural lentivirus pathogen of cats, produces a similar immun odeficiency syndrome with neurological sequelae. To identify the neuro physiological substrate of FIV infection in brain, patho gen-free cats were infected with the Maryland strain of FIV. Eight weeks after inoc ulation, all FIV-infected cats seroconverted and virus was detected in the cerebrospinal fluid and in the mononuclear cells of peripheral bl ood. Ten to 12 months after the FIV inoculation, inoculated and contro l cats were surgically implanted with electrodes to record the sleep/w ake cycle. These sleep recordings were obtained under conditions contr olling for environmental variables and instrumental adaptation. FIV in fected cats spent 50% more time awake than the sham-inoculated control s and exhibited many more sleep/waking stage shifts-i.e., 40% more tha n controls. In addition, FIV-infected cats showed approximate to 30% o f rapid eye movement (REM) sleep reduction compared to controls. The l atency to sleep and REM sleep onset was also significantly delayed in FIV-infected cats. In addition, a remarkable increase in cortically re corded spindle activity (8-13 Hz) was observed during slow-wave sleep in some infected subjects, similar to changes described in HIV-infecte d humans. Moreover, infected cats exhibited no overt signs of systemic morbidity, such as hyperpyrexia or body weight loss. These results in dicate that FIV-infected cats exhibit sleep abnormalities similar to t he sleep disturbances previously described in AIDS patients and furthe r support the feline preparation as a valuable animal model of HN infe ction of the central nervous system.