Strain differences in the response to the 5-HT1A receptor agonist, 8-OH-DPAT

• Published in: Pharmacology, biochemistry and behavior biochemistry and behavior, 2002-06, Vol.72 (3), p.533-542
• Main Authors: UPHOUSE, Lynda, MASWOOD, Sharmin, JACKSON, Astra, BROWN, Karen, PRULLAGE, Julia, MYERS, Tonya Brown, SHAHEEN, Farzana
• Format: Article
• Language: English
• Subjects: 8-Hydroxy-2-(di-n-propylamino)tetralin - pharmacology; Anatomical correlates of behavior; Animals; Behavioral psychophysiology; Biological and medical sciences; Dose-Response Relationship, Drug; Female; Fundamental and applied biological sciences. Psychology; Medical sciences; Neuropharmacology; Neurotransmitters. Neurotransmission. Receptors; Ovariectomy; Pharmacology. Drug treatments; Posture - physiology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rats; Rats, Inbred F344; Rats, Sprague-Dawley; Receptors, Serotonin - physiology; Receptors, Serotonin, 5-HT1; Serotonin Receptor Agonists - pharmacology; Serotoninergic system; Sexual Behavior, Animal - drug effects; Sexual Behavior, Animal - physiology; Species Specificity
• ISSN: 0091-3057; 1873-5177
• DOI: 10.1016/S0091-3057(02)00714-1

Fischer and Sprague-Dawley ovariectomized rats were hormonally primed with estradiol benzoate (EB) and progesterone, and the ability of the 5-HT(1A) receptor agonist, (+/-) 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), to inhibit lordosis behavior was examined. Both strains showed rapid inhibition of lordosis behavior following either intraperitoneal or subcutaneous treatment with 8-OH-DPAT. Similarly, in both strains, pretreatment with EB (1 week prior to estrogen and progesterone priming) attenuated the lordosis-inhibiting effects of 8-OH-DPAT. However, Sprague-Dawley females showed a greater decline in lordosis behavior with a lower dose of 8-OH-DPAT than did Fischer females. The strain difference was present in females that had been preprimed with EB as well as in females receiving a single estrogen and progesterone priming. Moreover, strain differences were present across different priming doses of EB. Sprague-Dawley females were also more likely to show flat body posture after injection with 8-OH-DPAT so that the greater sensitivity of this strain to the 5-HT(1A) receptor agonist was not restricted to the drug's effect on lordosis behavior. These findings lead to the suggestion that, relative to Fischer rats, Sprague-Dawley females are more responsive to the 5-HT(1A) receptor agonist. Possible explanations for this strain difference are discussed.