Effects of chloramphenicol on brain energy metabolism using 31P spectroscopy: influences on sleep-wake states in rat

Effects of chloramphenicol (antibiotic inhibiting complex-1 of respiratory chain) and thioamphenicol (TAP, a structural analog of CAP inactive on complex-1) were examined on cerebral energy metabolites and sleep-wake cycle architecture in rat. In the first group, animals were chronically equipped with a cranial surface resonator and ³¹P spectroscopic measurements were performed using a 2 T magnetic resonance spectrometer (operating frequency 34.46 MHz). CAP administration (400 mg/kg, tail vein, light period) induced deficits in phosphocreatine (−30%, p  < 0.01) and ATP (−40%, p  < 0.01), whereas TAP (400 mg/kg) had no effect. In the second group, animals were chronically implanted with polygraphic electrodes for EEG and electromyogram recordings. CAP administered intraperitoneally at light-onset reduced rapid-eye movement (REM) sleep (−60% in the first 6 h of light period, p  < 0.01), increased waking state (+65% in the first 6 h of light period, p  < 0.01), and slightly affected slow-wave sleep (SWS). During waking state, θ and σ power bands of the EEG were, respectively, increased and decreased ( p  < 0.05). During SWS, delta power band was reinforced ( p  < 0.05), while θ, α, and σ bands were decreased ( p  < 0.05). No changes occurred during REM sleep. TAP had no effect on sleep-wake states and spectral components of the EEG. Overall, these data indicate that REM sleep occurrence is linked to an aerobic production of ATP.