These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: The effects of gonadal steroids on brain stimulation reward in female rats.
    Author: Bless EP, McGinnis KA, Mitchell AL, Hartwell A, Mitchell JB.
    Journal: Behav Brain Res; 1997 Jan; 82(2):235-44. PubMed ID: 9030405.
    Abstract:
    The present study examined possible estrogen and/or progesterone effects on the mesolimbic dopamine (DA) system using brain stimulation reward (BSR). It is well known that BSR with electrical stimulation of the medial forebrain bundle (MFB) depends on the functioning of the mesolimbic DA system. If estrogen affects this system in a manner similar to its effects on the nigrostriatal DA system, reward measures would be expected to vary across the estrous cycle. Cycling female rats were trained to bar press for electrical stimulation to the MFB. Animals were tested at each stage of the estrous cycle, after ovariectomy and 4, 24, 48, 72 and 96 h after hormone replacement with estradiol (10 micrograms, s.c.), estradiol and progesterone (0.5 mg, s.c.), or oil (s.c.). The rewarding value of the stimulation and the maximum rate of bar pressing increased during estrus, but not during proestrus or metestrus, as compared with diestrus. Hormone replacement had differing effects on reward and motor performance. Motor performance increased 4 and 24 h after estrogen alone and 24 h after estrogen with the addition of progesterone 4 h before testing. The rewarding value of the stimulation increased only 24 h after estrogen together with an injection of progesterone 4 h before testing. These results indicate that gonadal steroids affect the functioning of the mesolimbic DA system.
    [Abstract] [Full Text] [Related] [New Search]