title: Morphine causes a delayed increase in glutamate receptor functioning in the nucleus accumbens core.
abstract: Enhanced excitatory neurotransmission in the mesocorticolimbic system may contribute to the persistence of addiction behaviour. Here, we demonstrated that glutamate-, N-methyl-D-aspartate (NMDA)- and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-induced [3H]-gamma-aminobutyric acid (GABA) release from superfused rat nucleus accumbens core slices is profoundly enhanced 3 weeks, but not 3 days, after a single s.c. morphine injection. This delayed increase in glutamate receptor functioning is associated with enhanced gene transcript levels of ionotropic NMDA and AMPA/kainate receptor subunits. These data reveal that morphine may progressively enhance glutamate neurotransmission within the nucleus accumbens core subsequent to drug exposure.
authors.affiliation: Research Institute Neurosciences Vrije Universiteit, Drug Abuse Program, Department of Medical Pharmacology, Free University Medical Center, VUmc, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands.
authors.forename: Edwin H
authors.initials: EH
authors.lastname: Jacobs
authors.forename: George
authors.initials: G
authors.lastname: Wardeh
authors.forename: August B
authors.initials: AB
authors.lastname: Smit
authors.forename: Anton N M
authors.initials: AN
authors.lastname: Schoffelmeer
mesh_terms: D000818:Animals; D018698:Glutamic Acid / Q000494:pharmacology; D007279:Injections, Subcutaneous; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D016202:N-Methylaspartate / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017470:Receptors, Glutamate / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects; D014316:Tritium; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D017470:Receptors, Glutamate; D014316:Tritium; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D016202:N-Methylaspartate; D009020:Morphine; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D011188:Potassium