Effects of systemic administration of mirtazapine on respiratory muscle activity in sleeping rats.

ABSTRACT

Mirtazapine (MIRT) is an antidepressant with mixed noradrenergic and serotonergic effects in central nervous system. The present study was undertaken to assess whether MIRT can stimulate genioglossus muscle (GG) activity in the conscious, behaving rat. Nine male rats were chronically instrumented with GG and neck muscle EMG electrodes. EEG electrodes were implanted to acquire sleep stage. Results demonstrated a dose-dependent effect of MIRT on GG activity during sleep, although no changes reached statistical significance. Low dose MIRT (0.1 mg/kg) showed a slight increase in GG phasic activity. In contrast, higher doses of MIRT (0.5-1.0 mg/kg) tended to decrease GG activity relative to vehicle, in addition to decreasing total sleep time.