Compounds of the formula
##STR1##
are useful for treating the cognitive deficits due to aging, stroke, head
trauma, Alzheimer's disease or other neurodegenerative diseases, or
schizophrenia and are also useful for the treatment of disorders such as
anxiety, aggression and stress, and for the control of various
physiological phenomena, such eating disorders, disorders of
thermoregulation, and sleep and sexual dysfunction.
