Male rat sexual behavior compared after 6-OHDA and electrolytic lesions in the dorsal NA bundle region of the midbrain.
Forebrain catecholamine depletion and midbrain histological damage in adult male rats were investigated as a function of 6-hydroxydopamine dosage in the range 4 microgram in 2 microliter to 8 micrograms in 4 microliter, stereotaxically injected at 0.43 microliter/min bilaterally in the region of the ascending dorsal noradrenaline bundle of the locus coeruleus, without and with a 30-60 min earlier 25 mg/kg intraperitoneal dose of desmethylimipramine (DMI). Sexual behavior of the male rat was compared for treatment with 4 microgram in 2 microliter 6-OHDA, without and with 25 mg/kg protective dose of DMI, and alternatively for 1 mA 30 sec bilateral electrolytic lesions at the same location. For the behaviorally tested rats receiving 6-OHDA treatment, cortical noradrenaline was depleted to 17% and to 81% of control, without and with DMI, respectively. Hypothalamic NA was depleted to 60% and 102% (no depletion), respectively. Caudate dopamine depletion did not reach significance at P = 0.05. For rats with electrolytic lesions cortical NA was depleted to 46% of control and caudate dopamine was not depleted. For the electrolytically lesioned rats, the first 3 post-ejaculatory intervals decreased by an average of 24%, while the 1 h ejaculatory frequency increased by 17%, which confirms a prior finding. However, no measured sexual behavioral effects were observed with 6-OHDA. Thus, interrupting the dorsal noradrenaline bundle has not been shown to have any effect on sexual behavior in the male rat.
D000818:Animals; D003891:Desipramine / Q000494:pharmacology; D006892:Hydroxydopamines / Q000494:pharmacology; D008125:Locus Coeruleus / Q000502:physiology; D008297:Male; D008636:Mesencephalon / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000502:physiology*; D051381:Rats; D012726:Sexual Behavior, Animal / Q000502:physiology*
D006892:Hydroxydopamines; D003891:Desipramine; D009638:Norepinephrine