Neuroscience 2003 Abstract
| Presentation Number: | 422.18 |
|---|---|
| Abstract Title: | Progesterone suppresses the estradiol-induced enhancement of cocaine self-administration in female rats. |
| Authors: |
Jackson, L. R.*1
; Becker, J. B.1,2,3
1Dept. Psychol, Univ. Michigan, Ann Arbor, MI 2Reprod Sci. Prgm, Univ. Michigan, Ann Arbor, MI 3Neurosci. Prgm, Univ. Michigan, Ann Arbor, MI |
| Primary Theme and Topics |
Neurological and Psychiatric Conditions - Addiction and Drugs of Abuse -- Cocaine |
| Secondary Theme and Topics | Autonomic, Neuroendocrine and Other Homeostatic Systems<br />- Neuroendocrine<br />-- Steroids and plasticity |
| Session: |
422. Addiction and Drugs of Abuse: Cocaine V Poster |
| Presentation Time: | Monday, November 10, 2003 9:00 AM-10:00 AM |
| Location: | Morial Convention Center - Hall F-I, Board # UU16 |
| Keywords: | drug abuse, estrogen, sex differences |
Female rats acquire cocaine self-administration more rapidly than do males. There are also estrous cycle effects on cocaine self-administration, with females having greater cocaine self-administration during estrus relative to other days of the cycle. Previous work from this laboratory has demonstrated that acute estradiol administration in ovariectomized (OVX) females enhances the acquisition of cocaine self-administration and increases the amount of cocaine self-administered (Hu et al, SFN Abstr., 2002). These experiments were conducted to examine the activational effects of ovarian hormone administration on acquisition of cocaine self-administration in male and female rats.
Six groups of adult Sprague Dawley rats were tested: OVX females treated with oil vehicle (OVX), OVX females treated with 5 µg estradiol benzoate (EB, OVX+E), OVX females treated with EB and 125 µg progesterone (E+P), castrated males treated with oil vehicle (Cast), castrated males treated with EB (Cast+E) and sham-castrated males treated with oil vehicle (Sham). Animals were tested on an FR1 schedule of reinforcement 5 days per week for three weeks at 0.3 mg/kg/inf cocaine (week 1), 0.4 mg/kg/inf (week 2) and 0.5 mg/kg/inf (week 3).
OVX+E females acquired cocaine self-administration more quickly, at the lowest dose and attained more cocaine than any other group. Progesterone administration concurrent with EB suppressed this effect. There were no differences between OVX and E+P, and neither were there between Cast, Cast+E and Sham males. These results suggest that, at this dose, progesterone treatment inhibits estradiol-enhanced acquisition of cocaine self-administration. Further, the effects of exogenous estradiol administration to gonadectomized animals are sexually dimorphic in that they enhance acquisition in female but not male rats.
Six groups of adult Sprague Dawley rats were tested: OVX females treated with oil vehicle (OVX), OVX females treated with 5 µg estradiol benzoate (EB, OVX+E), OVX females treated with EB and 125 µg progesterone (E+P), castrated males treated with oil vehicle (Cast), castrated males treated with EB (Cast+E) and sham-castrated males treated with oil vehicle (Sham). Animals were tested on an FR1 schedule of reinforcement 5 days per week for three weeks at 0.3 mg/kg/inf cocaine (week 1), 0.4 mg/kg/inf (week 2) and 0.5 mg/kg/inf (week 3).
OVX+E females acquired cocaine self-administration more quickly, at the lowest dose and attained more cocaine than any other group. Progesterone administration concurrent with EB suppressed this effect. There were no differences between OVX and E+P, and neither were there between Cast, Cast+E and Sham males. These results suggest that, at this dose, progesterone treatment inhibits estradiol-enhanced acquisition of cocaine self-administration. Further, the effects of exogenous estradiol administration to gonadectomized animals are sexually dimorphic in that they enhance acquisition in female but not male rats.
Supported by NIDA grant DA12677 to JBB
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2003 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2003. Online.
Copyright © 2003-2026 Society for Neuroscience; all rights reserved. Permission to republish any abstract or part of any abstract in any form must be obtained in writing by SfN office prior to publication.
