Changes in the rat sleep-wake cycle produced by D,L-beta-(1-naphthyl)alanine, a tryptophan analog.

The effects of i.p. injections of D,L-beta-(1-naphthyl)alanine, a synthetic analog of tryptophan were tested on the rat sleep-waking cycle. Administration of 30, 60 and 120 mg/kg resulted in a significant increase in slow-wave sleep (SWS) and a decrease in paradoxical sleep (PS). These modifications were dose-dependent. These results were compared with those previously obtained with L-tryptophan and several analogs and discussed in relation with possible changes in central serotonergic activity.