title: Peripheral withdrawal recruits distinct central nuclei in morphine-dependent rats.
abstract: This study examined if brain pathways in morphine-dependent rats are activated by opioid withdrawal precipitated outside the central nervous system. Withdrawal precipitated with a peripherally acting quaternary opioid antagonist (naloxone methiodide) increased Fos expression but caused a more restricted pattern of neuronal activation than systemic withdrawal (precipitated with naloxone which enters the brain). There was no effect on locus coeruleus and significantly smaller increases in Fos neurons were produced in most other areas. However in the ventrolateral medulla (A1/C1 catecholamine neurons), nucleus of the solitary tract (A2/C2 catecholamine neurons), lateral parabrachial nucleus, supramamillary nucleus, bed nucleus of the stria terminalis, accumbens core and medial prefrontal cortex no differences in the withdrawal treatments were detected. We have shown that peripheral opioid withdrawal can affect central nervous system pathways.
authors.affiliation: Department of Physiology and Pharmacology, The University of Queensland, Qld 4072, Brisbane, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Hamlin
authors.forename: K M
authors.initials: KM
authors.lastname: Buller
authors.forename: T A
authors.initials: TA
authors.lastname: Day
authors.forename: P B
authors.initials: PB
authors.lastname: Osborne
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D016762:Genes, fos / Q000502:physiology; D008297:Male; D009020:Morphine / Q000009:adverse effects; D009270:Naloxone / Q000037:antagonists & inhibitors / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009294:Narcotics / Q000009:adverse effects; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D017933:Peripheral Nervous System / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D013375:Substance Withdrawal Syndrome / Q000378:metabolism* / Q000473:pathology
chemical_list: D009292:Narcotic Antagonists; D009294:Narcotics; D009270:Naloxone; D009020:Morphine