Effect of neonatal beta-endorphin imprinting on sexual behavior and brain serotonin level in adult rats.
A single dose (3 microg) beta-endorphin was administered to newborn female and male rats (hormonal imprinting). In adult age (at 5 months) sexual behavior, steroid hormone binding capacity and brain serotonin content was studied. Females' sexual activity (lordosis quotient) significantly decreased and more animals protested against mounting (ratio of kicking and crying 21/24 vs. 8/24; p < 0.001). Males' sexual activity did not change, however more males were aggressive (4/10 vs. 1/10). Uterine estrogen receptor density significantly increased and affinity decreased. There was no change in the binding capacity of thymic glucocorticoid receptors. In the brain, five regions were studied for serotonin content. There was a gender difference in serotonin level and the intragroup differences were also high. In the endorphin treated males the serotonin level was significantly lower than in the controls. In the endorphin treated females the intragroup scattering has been significantly reduced. Nociceptin content of the cerebrospinal fluid was not changed. The experiments call attention to the possibility of adjustment of sexual and behavioral sphere by the individually different endorphin surge during labor.
Department of Genetics, Cell and Immunobiology, Semmelweis University, H-1445, POB 370, Budapest, Hungary. sagyor@dgci.sote.hu
G
G
Csaba
Barbara
B
Knippel
Cs
C
Karabélyos
Agnes
A
Inczefi-Gonda
Monika
M
Hantos
L
L
Tóthfalusi
Kornélia
K
Tekes
D000374:Aggression / Q000187:drug effects; D000818:Animals; D000831:Animals, Newborn / Q000523:psychology*; D001923:Brain Chemistry / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D003907:Dexamethasone / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D005260:Female; D007173:Imprinting, Psychological / Q000187:drug effects*; D007700:Kinetics; D008297:Male; D018847:Opioid Peptides / Q000134:cerebrospinal fluid; D051381:Rats; D017208:Rats, Wistar; D011960:Receptors, Estrogen / Q000378:metabolism; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism*; D012727:Sex Characteristics; D012726:Sexual Behavior, Animal / Q000187:drug effects*; D013950:Thymus Gland / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D014599:Uterus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D001615:beta-Endorphin / Q000494:pharmacology*; D000097629:Nociceptin
D003907:Dexamethasone; D004958:Estradiol; D018847:Opioid Peptides; D011960:Receptors, Estrogen; D011965:Receptors, Glucocorticoid; D012701:Serotonin; D001615:beta-Endorphin; D000097629:Nociceptin