argipressin--des-glynh2(9)- and Memory-Disorders

This review critically evaluates the animal and human research concerning vasopressin's putative mnemonic role. Weaknesses in the interpretations of the early animal experiments as well as the implications of the later inconsistent findings are discussed. It is concluded that both the initial enthusiasm and the subsequent skepticism concerning this hypothesized role were premature. This conclusion applies equally to the human research. A review of these studies reveals that almost all of the negative reports involved cognitively-impaired individuals. The relatively few studies that have been conducted concerning vasopressin's effects in unimpaired human subjects are consistent with the hypothesis that vasopressin does affect cognition, though both the mechanism of action and the specific cognitive processes which are altered have yet to be elucidated.

Topics: Animals; Arginine Vasopressin; Arousal; Avoidance Learning; Blood-Brain Barrier; Deamino Arginine Vasopressin; Extinction, Psychological; Haplorhini; Humans; Lypressin; Memory; Memory Disorders; Mice; Rats; Rats, Brattleboro; Vasopressins

In a double-blind cross-over trial the memory effect of the neuropeptide desglycinamide arginine vasopressin (DGAVP) was selected because of its well-documented facilitatory effects on memory components in rodents. Patients with stabilized or progressive amnesic disorders (Korsakoff disease, early stages of Alzheimer dementia, head injuries and other central nervous system diseases) did not respond to the drug. Factors possibly explaining the discrepancy with animal research are discussed.

Topics: Adult; Aged; Amnesia; Arginine Vasopressin; Clinical Trials as Topic; Cognition; Double-Blind Method; Female; Humans; Intelligence Tests; Learning; Male; Memory; Memory Disorders; Middle Aged; Oxytocin; Random Allocation; Vasopressins

Repeated social defeat followed by individual housing caused a long-term impairment of social memory in male rats. Social memory, as assessed in the social discrimination test using an intertrial interval of 3 min, was impaired for at least 8 weeks after the social defeat experience. Since social memory of male rodents depends on proper functioning of the sexually dimorphic vasopressin system, it was investigated whether a centrally active vasopressin fragment could restore the impaired social memory. Subcutaneous administration of 6 microg/kg of the vasopressin fragment desglycinamide-vasopressin (VP1-8) 40 days after social defeat slightly improved social memory in both control and socially defeated rats. It is concluded that social defeat followed by individual housing caused a long-term impairment of social memory, which was not restored by treatment with VP1-8.

Topics: Animals; Arginine Vasopressin; Chronic Disease; Dominance-Subordination; Injections, Subcutaneous; Interpersonal Relations; Male; Memory; Memory Disorders; Rats; Rats, Wistar; Reference Values; Social Isolation; Time Factors