Effects of Sex and Estrogen on Behavioral
Sensitization to Cocaine in Rats
by
Hu M, Becker JB.
Psychology Department, Neuroscience Program
and Reproductive Sciences Program,
University of Michigan, Ann Arbor, Michigan 48109.
J Neurosci 2003 Jan 15;23(2):693-699
ABSTRACTEstrogen rapidly enhances dopamine (DA) activity in the striatum and nucleus accumbens as well as behavioral responses to psychomotor stimulants in female rats but not males. This experiment was conducted to investigate the role of pulsatile estrogen treatment on and sex differences in the development and expression of sensitization of cocaine-induced rotational behavior in rats with unilateral striatal DA denervation. Four groups were tested: ovariectomized (OVX) females treated with 5 &mgr;g of estradiol benzoate (OVX+E), OVX females, castrated (CAST) males, and intact males. Animals received estrogen or vehicle 30 min before cocaine (0, 5, 10, or 20 mg/kg, i.p.) on 4 consecutive days, followed by 3 d without treatment for 3 weeks. At the conclusion of the experiment, animals were withdrawn from hormone and/or cocaine for 10 d, and all groups underwent a challenge test with 10 mg/kg cocaine. We report here that OVX+E females exhibit significantly greater sensitization of rotational behavior with a faster rate of sensitization than the three other groups. There is also a sex difference independent of gonadal hormones: OVX females exhibit a greater magnitude of sensitization of rotational behavior than do CAST males at 20 mg/kg cocaine. Furthermore, on the challenge test, OVX+E animals tested without estrogen treatment continue to exhibit greater rotational behavior than do all other groups. Thus, estrogen enhances sensitization to cocaine, there are sex differences in behavioral sensitization, and sensitization that develops under conditions with estrogen persists even when estrogen levels are low.Dopaminergic flies?
Dopaminergic agents
Cocaine immunization
The coke-craving brain
Cocaine and the lonely rat
Freebasing flies go hyperkinetic
01 02 03 04 05 06 07 08 09 10 11 12
13 14 15 16 17 18 19 20 21 22 23 24
Refs
HOME
HedWeb
cannabis-marijuana.com
Future Opioids
BLTC Research
Wirehead Hedonism
Paradise-Engineering
Utopian Pharmacology
The Hedonistic Imperative
When Is It Best to Take Crack Cocaine?
The Good Drug Guide
The Responsible Parent's Guide To
Healthy Mood Boosters For All The Family
