Cycloheximide and acetoxycycloheximide: inhibition of tyrosine hydroxylase activity and amnestic effects.

Mice and rats trained after treatment with cycloheximide or acetoxycycloheximide in a conditioned avoidance response develop an amnesia of their training experience. This amnesia has been attributed to the profound inhibition of protein synthesis caused by the two antibiotics. Evidence is presented that additionally the antibiotics inhibit the activity of tyrosine hydroxylase, a finding that suggests that their amnestic effect may be due in part to reduction of the functional pool of norepinephrine.