title: Pharmacological evidence for an abstinence-induced switch in 5-HT1B receptor modulation of cocaine self-administration and cocaine-seeking behavior.
abstract: Studies examining serotonin-1B (5-HT1B) receptor manipulations on cocaine self-administration and cocaine-seeking behavior initially seemed discrepant. However, we recently suggested based on viral-mediated 5-HT1B-receptor gene transfer that the discrepancies are likely due to differences in the length of abstinence from cocaine prior to testing. To further validate our findings pharmacologically, we examined the effects of the selective 5-HT1B receptor agonist CP 94,253 (5.6 mg/kg, s.c.) on cocaine self-administration during maintenance and after a period of protracted abstinence with or without daily extinction training. We also examined agonist effects on cocaine-seeking behavior at different time points during abstinence. During maintenance, CP 94,253 shifted the cocaine self-administration dose-effect function on an FR5 schedule of reinforcement to the left, whereas following 21 days of abstinence CP 94,253 downshifted the function and also decreased responding on a progressive ratio schedule of reinforcement regardless of extinction history. CP 94,253 also attenuated cue-elicited and cocaine-primed drug-seeking behavior following 5 days, but not 1 day, of forced abstinence. The attenuating effects of CP 94,253 on the descending limb of the cocaine dose-effect function were blocked by the selective 5-HT1B receptor antagonist SB 224289 (5 mg/kg, i.p.) at both time points, indicating 5-HT1B receptor mediation. The results support a switch in 5-HT1B receptor modulation of cocaine reinforcement from facilitatory during self-administration maintenance to inhibitory during protracted abstinence. These findings suggest that the 5-HT1B receptor may be a novel target for developing medication for treating cocaine dependence.
authors.affiliation: School of Life Sciences, Arizona State University , Box 874501, Tempe, Arizona 85287, United States.
authors.forename: Nathan S
authors.initials: NS
authors.lastname: Pentkowski
authors.forename: Bryan G
authors.initials: BG
authors.lastname: Harder
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Brunwasser
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Bastle
authors.forename: Natalie A
authors.initials: NA
authors.lastname: Peartree
authors.forename: Krishna
authors.initials: K
authors.lastname: Yanamandra
authors.forename: Matt D
authors.initials: MD
authors.lastname: Adams
authors.forename: Taleen
authors.initials: T
authors.lastname: Der-Ghazarian
authors.forename: Janet L
authors.initials: JL
authors.lastname: Neisewander
mesh_terms: D000818:Animals; D003042:Cocaine / Q000008:administration & dosage / Q000494:pharmacology; D019970:Cocaine-Related Disorders / Q000188:drug therapy / Q000378:metabolism*; D003216:Conditioning, Operant / Q000187:drug effects / Q000502:physiology; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D058999:Drug-Seeking Behavior / Q000187:drug effects / Q000502:physiology*; D005108:Extinction, Psychological / Q000187:drug effects / Q000502:physiology; D008297:Male; D010881:Piperidones / Q000494:pharmacology; D011725:Pyridines / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044302:Receptor, Serotonin, 5-HT1B / Q000378:metabolism*; D012055:Reinforcement Schedule; D012646:Self Administration; D058825:Serotonin 5-HT1 Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology; D058829:Serotonin 5-HT1 Receptor Antagonists / Q000494:pharmacology; D013141:Spiro Compounds / Q000494:pharmacology; D013375:Substance Withdrawal Syndrome / Q000188:drug therapy / Q000378:metabolism*; D013997:Time Factors
chemical_list: C097067:CP 94253; D018765:Dopamine Uptake Inhibitors; D010881:Piperidones; D011725:Pyridines; D044302:Receptor, Serotonin, 5-HT1B; C108518:SB 22489G; D058825:Serotonin 5-HT1 Receptor Agonists; D058829:Serotonin 5-HT1 Receptor Antagonists; D013141:Spiro Compounds; D003042:Cocaine