Fluoxetine may influence lordosis of rats through effects on midbrain 3 alpha,5 alpha-THP concentrations

Cheryl A. Frye, Sandra M. Petralia, Madeline E. Rhodes, Benjamin Stein
Annals of the New York Academy of Sciences · 2003 · vol. 1007(1) , pp. 37–41 · doi:10.1196/annals.1286.004 · PMID:14993038 · W2068921647
Lab / animal OA: closed CC0 ⤵ 2 in-corpus citations
View on OpenAlex View on PubMed View at publisher
⚙ AI-generated summary by qwen3.7-flash, 2026-09-02 ⓘ

This study demonstrates that fluoxetine modulates rodent lordosis behavior by altering midbrain 3alpha,5alpha-THP concentrations, with systemic administration decreasing and local ventral tegmental area infusion increasing these neurosteroid levels.

One-sentence paraphrase of the abstract; not a substitute for reading it. No clinical advice. How this works

Abstract

5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP) in the ventral tegmental area (VTA) mediates lordosis of rodents. If fluoxetine's effects on lordosis are mediated in part by midbrain 3alpha,5alpha-THP, then fluoxetine regimens that decrease and increase lordosis would be expected to respectively lower and elevate midbrain 3alpha,5-THP levels. Experiment 1: Ovariectomized (ovx) rats received estradiol benzoate (EB; 5 micro g, SC) at 0 and 24 h and fluoxetine (20 mg/kg, IP) or vehicle 30 min before sex testing and tissue collection. Other rats received fluoxetine (10 mg/kg, IP) or vehicle for 15 days followed by EB-priming and testing. Systemic acute or chronic fluoxetine significantly decreased lordosis and midbrain 3alpha,5alpha-THP levels compared to vehicle. Experiment 2: Ovx rats with unilateral cannula to the VTA were primed with EB (5 micro g; 0, 24 h) and/or progesterone (0 or 100 micro g; 44 h, SC). At 47.5 h, fluoxetine (3.6 mM) or vehicle was infused to the VTA. At 48 h, rats were tested. Administering fluoxetine to the VTA significantly increased lordosis and midbrain 3alpha,5alpha-THP levels compared to vehicle infusions. Experiment 3: Ovx EB-primed rats were tested prior to, and 30 min after, treatmemt with acute fluoxetine (20 mg/kg, IP). Rats were then infused with 3alpha,5alpha-THP (100 ng) or vehicle to the VTA and were retested. 3alpha,5alpha-THP, but not vehicle, to the VTA reversed acute fluoxetine's inhibitory effects on lordosis. Together, these data suggest fluoxetine may alter lordosis in part through actions of 3alpha-THP in the midbrain.

My notes (saved in your browser only)

MeSH descriptors

Desoxycorticosterone Desoxycorticosterone Fluoxetine Mesencephalon Mesencephalon Sexual Behavior, Animal Animals Desoxycorticosterone Female Fluoxetine Mesencephalon Ovariectomy Posture Posture Rats Rats, Long-Evans Sexual Behavior, Animal Sexual Behavior, Animal

Citation neighborhood (no data yet)

We don't have any in-corpus citations linked to this paper yet. The paper's references may be in our DB but unresolved to ``paper_id`` (resolution happens at ingest when the cited DOI matches a row we already have). Run the cross-source citation reconcile pass to retry.

References (19)

Source provenance

openalex
last seen: 2026-06-10T17:14:06.276822+00:00
pubmed
last seen: 2026-10-08T21:02:24.140261+00:00
unpaywall
last seen: 2026-10-21T06:41:41.500114+00:00
License: CC0 · commercial use OK