Perinatal morphine II: changes in cortical plasticity.
We have previously shown that perinatal exposure to morphine impairs reactive plasticity of serotonin (5-HT) neurons following selective neonatal lesion (Gorio et al., J Neurosci Res 34:462-471, 1993). This study shows that morphine inhibits also that the compensatory sprouting of intact axons after partial denervation. Neonatal 6-OHDA injection causes norepinephrine (NE) depletion in the frontal cortex, which triggers a compensatory increase of dopamine, serotonin (5-HT), and met-enkephalin content correlated by the increased density of tyrosine hydroxylase- and 5-HT-positive axons. In perinatal morphine-treated rats, no compensatory changes are observed after neonatal 6-OHDA depletion of NE in the frontal cortex.
Germani
E
E
Department of Medical Pharmacology, University of Milan, Italy.
Lesma
E
E
De Biasi
S
S
Di Giulio
A M
AM
Bertelli
A
A
Gorio
A
A
D000818:Animals; D005260:Female; D005625:Frontal Lobe / Q000187:drug effects* / Q000648:ultrastructure; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009020:Morphine / Q000494:pharmacology*; D009473:Neuronal Plasticity / Q000187:drug effects*; D009638:Norepinephrine / Q000378:metabolism; D016627:Oxidopamine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D009020:Morphine; D016627:Oxidopamine; D009638:Norepinephrine