D-fenfluramine activates rat oxytocinergic and vasopressinergic neurons through different mechanisms.
Activation of serotonin neurotransmission produces increase of plasma oxytocin, prolactin, vasopressin and ACTH levels. Using dual-immunocytochemistry, the number of oxytocinergic neurons in the hypothalamic magnocellular nuclei co-storing Fos after administration of D-fenfluramine was found to be 15-fold higher compared to vehicle, comprising about 30% of the total number of these neurons. Vasopressinergic neurons were virtually not affected. These results show that serotonergic neurotransmission induces Fos transcription in oxytocinergic neurons that may lead to a release of oxytocin to the general circulation, whereas vasopressinergic neurons are activated through another mechanism.
Mikkelsen
J D
JD
Department of Neurobiology, H. Lundbeck A/S, Copenhagen-Valby, Denmark. jdm@zp.dk
Jensen
J B
JB
Engelbrecht
T
T
Mørk
A
A
D000818:Animals; D005277:Fenfluramine / Q000494:pharmacology*; D016762:Genes, fos / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D010121:Oxytocin / Q000187:drug effects* / Q000378:metabolism; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018490:Serotonin Agents / Q000494:pharmacology*; D014667:Vasopressins / Q000187:drug effects* / Q000378:metabolism
D018490:Serotonin Agents; D014667:Vasopressins; D005277:Fenfluramine; D010121:Oxytocin