systemic administration of 5-hydroxytryptophan or monoamine oxidase inhibition plus tryptophan administration abolishes the abnormal grooming behavior in each group of cats , and microinjections of 5-hydroxytryptophan or serotonin into the superior colliculi has the same effect , indicating that the change in a serotonergic system is a critical aspect of the abnormal behavior in cats with lesions and that a serotonergic system may also be involved in the genesis of the abnormal grooming behavior in thyroidectomized cats .
C0041249
tryptophan
C0000578
hydroxytryptophan