Endogenous opioid facilitation of maternal memory in rats.
In rats, contact with pups at parturition establishes a form of maternal memory that enables female rats to respond rapidly to pups in the future. Treatment of pregnant female rats with the long-lasting micro opioid receptor antagonist, beta-funaltrexamine (beta-FNA), prior to parturition interfered with the establishment of maternal memory. Similar treatment 3 hr postpartum resulted in disrupted retention of maternal memory that appeared nonspecific, with both drug- and vehicle-treated rats displaying a deficit. However, infusion of the opioid antagonist 24 hr postpartum had no effect on the retention of maternal memory tested 7 days later. These findings indicate that the establishment of maternal memory is mediated by endogenous opioid activity around the time of parturition.
Byrnes
E M
EM
Department of Biomedical Sciences, Tufts University School of Veterinary Medicine, North Grafton, Massachusetts 01536, USA. elizabeth.byrnes@tufts.edu
Bridges
R S
RS
D000818:Animals; D001921:Brain / Q000502:physiology; D005260:Female; D007743:Labor, Obstetric / Q000502:physiology; D008425:Maternal Behavior / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology*; D018847:Opioid Peptides / Q000502:physiology*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012153:Retention, Psychology / Q000502:physiology
D018847:Opioid Peptides