title: Pharmacological modulation of lateral habenular dopamine D2 receptors alters the anxiogenic response to cocaine in a runway model of drug self-administration.
abstract: Cocaine has long been known to produce an initial "high" followed by an aversive/anxiogenic "crash". While much is known about the neurobiology of cocaine's positive/rewarding effects, the mechanisms that give rise to the drug's negative/anxiogenic actions remain unclear. Recent research has implicated the lateral habenula (LHb) in the encoding of aversive events including the anxiogenic response to cocaine. Of particular interest in this regard are the reciprocal connections between the LHb and the ventral tegmental area (VTA). VTA-DA neurons innervate different subsets of LHb cells that in turn feedback upon and modulate VTA neuronal activity. Here we examined the impact of D2 receptor activation and inhibition on the anxiogenic response to cocaine using a runway model of self-administration that is sensitive to the dual and opposing effects of the drug. Male rats ran a straight alley for IV cocaine (1.0mg/kg) following bilateral intra-LHb infusions of the D2 receptor antagonist, cis-flupenthixol (0, 7.5 or 15μg/side) or the D2 agonist, sumanirole (0, 5 or 10μg/side). Vehicle-pretreated controls developed approach-avoidance conflict behaviors about goal-box entry reflective of the dual positive and negative effects of cocaine. These behaviors were significantly diminished during LHb-D2 receptor antagonism and increased by the LHb D2 receptor agonist. These results demonstrate that activity at the D2 receptor in the lateral habenula serves to modulate the anxiogenic response to cocaine.
authors.affiliation: Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, California 93106-9660, United States.
authors.forename: Kerisa
authors.initials: K
authors.lastname: Shelton
authors.affiliation: Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, California 93106-9660, United States.
authors.forename: Kelsie
authors.initials: K
authors.lastname: Bogyo
authors.affiliation: Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, California 93106-9660, United States.
authors.forename: Tinisha
authors.initials: T
authors.lastname: Schick
authors.affiliation: Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, California 93106-9660, United States. Electronic address: ettenberg@psych.ucsb.edu.
authors.forename: Aaron
authors.initials: A
authors.lastname: Ettenberg
mesh_terms: D000818:Animals; D001007:Anxiety / Q000139:chemically induced* / Q000188:drug therapy / Q000378:metabolism; D001562:Benzimidazoles / Q000494:pharmacology; D002408:Catheters, Indwelling; D003042:Cocaine / Q000008:administration & dosage*; D019970:Cocaine-Related Disorders / Q000188:drug therapy / Q000378:metabolism / Q000523:psychology*; D003220:Conflict, Psychological; D004195:Disease Models, Animal; D018491:Dopamine Agonists / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage*; D005475:Flupenthixol / Q000494:pharmacology; D019262:Habenula / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000819:agonists / Q000378:metabolism*; D012646:Self Administration
chemical_list: D001562:Benzimidazoles; C000607792:DRD2 protein, rat; D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D018765:Dopamine Uptake Inhibitors; D017448:Receptors, Dopamine D2; C108539:U 95666E; D005475:Flupenthixol; D003042:Cocaine
keywords: anxiety; cis-flupenthixol; cocaine; lateral habenula; runway self-administration; sumanirole