Duration (in minutes) of total sleep time (TST), stage
I, II, III, IV and paradoxical sleep (SP) for standard nightly recording
time of 720 min.
A: During the control period (March 1970). B: During the administration of placebos (May 1970). C: During the administration of L-tryptophan (12 g per diem) (May
1970). D,E: During the administration of small dose of DL-5-HTP (less
than 2 g per diem) (April and May 1970).