NEUROPHARMACOLOGY AND NEUROTOXICOLOGYProlonged 5-HT1A/5-HT2A receptor cross-talk is absent prior to adulthood in ratsPetrunich, Maureen L.a b; Garcia, Franciscac; Carrasco, Gonzalo A.a b c; Battaglia, Georgea b cAuthor Information aNeuroscience Graduate Program bNeuroscience Institute cDepartment of Pharmacology, Loyola University Chicago, Maywood, Illinois, USA Correspondence to George Battaglia, PhD, Department of Pharmacology, Loyola University Chicago, 2160 South First Avenue, Maywood, IL 60153, USA Tel: +1 708 216 5680; fax: +1 708 216 6596; e-mail: firstname.lastname@example.org Present address of Gonzalo A. Carrasco is Department of Pharmacology and Toxicology, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS 66045, USA. Received 12 June 2008; accepted 1 July 2008 NeuroReport: October 8th, 2008 - Volume 19 - Issue 15 - p 1457-1461 doi: 10.1097/WNR.0b013e32830edd6d Buy SDC Metrics Abstract In adult rats, serotonin 1A (5-HT1A) receptor activation produces heterologous desensitization of serotonin 2A (5-HT2A) neuroendocrine function at 1 h that persists up to 72 h. This study determined whether prolonged 5-HT1A/5-HT2A cross-talk exists before sexual maturation. Adolescent male rats (postnatal day 39) received an injection with saline or (+)-8-hydroxy-2-(di-n-propylamino)tetralin hydrobromide [(+)8-OH-DPAT] 24 h before receiving a challenge injection of saline, (+)-8-hydroxy-2-(di-n-propylamino)tetralin hydrobromide, or (−)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane HCl [(−)DOI] o assess changes in basal, 5-HT1A, and 5-HT2A receptor-mediated hormone responses. Although homologous desensitization of 5-HT1A neuroendocrine responses was present at 24 h, heterologous desensitization of 5-HT2A neuroendocrine responses was not. These data suggest that 5-HT1A heterologous desensitization of 5-HT2A receptor function does not develop until adulthood, is more transient, or follows a different time course before maturation. © 2008 Lippincott Williams & Wilkins, Inc.