title: Cocaine seeking and taking: role of hippocampal dopamine D1-like receptors.
abstract: Despite the well-documented involvement of dopamine D1-like receptor stimulation in cocaine-induced goal-directed behaviours, little is known about the specific contribution of D1-like receptor populations in the dorsal hippocampus (DH) to drug context-induced cocaine-seeking or drug-reinforced instrumental behaviours. To investigate this question, rats were trained to lever press for un-signalled cocaine infusions in a distinct context followed by extinction training in a different context. Cocaine-seeking behaviour (non-reinforced lever responding) was then assessed in the previously cocaine-paired and extinction contexts. SCH23390-induced D1-like receptor antagonism in the DH, but not the overlying trunk region of the somatosensory cortex, dose-dependently inhibited drug context-induced cocaine-seeking behaviour, without altering cocaine-reinforced instrumental responding, cocaine intake, food-reinforced instrumental responding, or general motor activity, relative to vehicle treatment. These findings suggest that D1-like receptor stimulation in the DH is critical for the incentive motivational effects and/or memory of cocaine-paired contextual stimuli that contribute to drug-seeking behaviour.
authors.affiliation: Department of Chemistry,North Carolina State University,Raleigh,USA.
authors.forename: Xiaohu
authors.initials: X
authors.lastname: Xie
authors.affiliation: Behavioural Genetics Laboratory, Department of Psychiatry,Harvard Medical School, McLean Hospital,Belmont,USA.
authors.forename: Audrey M
authors.initials: AM
authors.lastname: Wells
authors.affiliation: Department of Integrative Physiology and Neuroscience,Washington State University College of Veterinary Medicine,Pullman, WA,USA.
authors.forename: Rita A
authors.initials: RA
authors.lastname: Fuchs
mesh_terms: D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D003042:Cocaine / Q000008:administration & dosage*; D003216:Conditioning, Operant / Q000187:drug effects; D018492:Dopamine Antagonists / Q000494:pharmacology; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage*; D058999:Drug-Seeking Behavior / Q000187:drug effects*; D005108:Extinction, Psychological / Q000187:drug effects; D007839:Functional Laterality; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012054:Reinforcement, Psychology; D012646:Self Administration
chemical_list: D001552:Benzazepines; D018492:Dopamine Antagonists; D018765:Dopamine Uptake Inhibitors; D017447:Receptors, Dopamine D1; C534628:SCH 23390; D003042:Cocaine