Progestins’ effects on sexual behaviour of female rats and hamsters involving D1 and GABAA receptors in the ventral tegmental area may be G-protein-dependent

摘要: Abstract In the ventral tegmental area (VTA), progestins have actions involving dopamine type 1-like receptors (D 1 ) and γ-aminobutyric acid (GABA) A /benzodiazepine receptor complexes (GBRs) for lordosis. Evidence suggests that D GBRs can G-protein-mediated effects. We investigated if, in VTA, inhibiting G-proteins prevents - and/or GBR-mediated increases progestin-facilitated Hamsters, with bilateral guide cannulae to received systemic E 2 (10 μg) at hour 0 progesterone (P, 250 μg) 45. At 48, hamsters were pre-tested lordosis infused G-protein inhibitor, guanosine 5′- O -(2-thiodiphosphate) (GDP-β-S, 50 μM/side), or 10% DMSO saline vehicle. Thirty minutes after initial infusions, re-tested then immediately agonist, SKF38393 (100 ng/side), GBR muscimol Hamsters post-tested 30 min later. For rats, priming was followed by pre-testing 44. After pre-testing, rats infusions of GDP-β-S vehicle, SKF38393, muscimol, vehicle neurosteroid, 5α-pregnan-3α-ol-20-one (3α,5α-THP, 100 200 ng/side), β-cyclodextrin Rats tested each infusion as well 10 60 min 3α,5α-THP infusions. Inhibiting G-proteins, reduced ability P intra-VTA facilitate -primed hamsters. Blocking prevented SKF38393-, muscimol- 3α,5α-THP-mediated rats. Thus, progestins’ VTA involve may also include recruitment G-proteins.