title: Morphine withdrawal-induced abnormalities in the VTA: confocal laser scanning microscopy.
abstract: Morphine withdrawal is characterized by functional alterations at the level of the ventrotegmental area. We investigated the effects of chronic morphine administration and withdrawal on the morphological properties of immuno-labelled tyrosine hydroxylase-positive neurons of the rat ventrotegmental area with a confocal laser scanning microscope. Morphological evaluation revealed a reduction in the area and perimeter of tyrosine hydroxylase-positive somata in morphine-withdrawn rats. Conversely, the number of cells per field was found to have increased in the naloxone group. Collectively, the present results indicate that withdrawal from a chronic morphine treatment, and not chronic morphine per se, modifies cellular morphology of tyrosine hydroxylase-positive, presumably dopamine-containing, neurons of the rat VTA. This is consistent with the idea that withdrawal from morphine alters functioning of the mesolimbic dopamine system and provides a direct morphological correlate for the functional abnormalities typical of morphine withdrawal.
authors.affiliation: Department of Animal Biology and Ecology, University of Cagliari, Italy.
authors.forename: Saturnino
authors.initials: S
authors.lastname: Spiga
authors.forename: Giuliana P
authors.initials: GP
authors.lastname: Serra
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Puddu
authors.forename: Marzia
authors.initials: M
authors.lastname: Foddai
authors.forename: Marco
authors.initials: M
authors.lastname: Diana
mesh_terms: D000818:Animals; D002452:Cell Count; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D009020:Morphine / Q000009:adverse effects*; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009294:Narcotics / Q000009:adverse effects*; D009474:Neurons / Q000187:drug effects / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D013375:Substance Withdrawal Syndrome / Q000473:pathology*; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D017557:Ventral Tegmental Area / Q000166:cytology / Q000187:drug effects / Q000473:pathology*
chemical_list: D009292:Narcotic Antagonists; D009294:Narcotics; D009270:Naloxone; D009020:Morphine; D014446:Tyrosine 3-Monooxygenase