title: Changes in galanin and GalR1 gene expression in discrete brain regions after transient occlusion of the middle cerebral artery in female rats.
abstract: Injury to neurons results in up-regulation of galanin in some central and peripheral systems, and it has been suggested that this neuropeptide may play a protective and trophic role, primarily mediated by galanin receptor 2 (GalR2). The objective of the present study was to investigate galanin, GalR1, GalR2 and GalR3 gene expression in the female rat brain 7 days after a 60-min unilateral occlusion of the middle cerebral artery followed by reperfusion. Quantitative real-time PCR was employed in punch-biopsies from the locus coeruleus, somatosensory cortex and dorsal hippocampal formation, including sham-operated rats as controls. Galanin gene expression showed a ∼2.5-fold increase and GalR1 a ∼1.5-fold increase in the locus coeruleus of the ischemic hemisphere compared to the control side. Furthermore, the GalR1 mRNA levels decreased by 35% in somatosensory cortex of the ischemic hemisphere. Immunohistochemical analysis indicated a depletion of galanin from cell bodies and dendrites in the locus coeruleus after middle cerebral artery occlusion. The present results suggest that a stroke-induced forebrain lesion up-regulates synthesis of galanin and GalR1 in the locus coeruleus, a noradrenergic cell group projecting to many forebrain areas, including cortex and the hippocampal formation. These results support the notion that galanin may play a role in the response of the central nervous system to injury.
authors.affiliation: Division of Clinical Chemistry, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, County Council of Östergötland, Linköping, Sweden.
authors.forename: Lovisa
authors.initials: L
authors.lastname: Holm
authors.forename: Susanne
authors.initials: S
authors.lastname: Hilke
authors.forename: Csaba
authors.initials: C
authors.lastname: Adori
authors.forename: Elvar
authors.initials: E
authors.lastname: Theodorsson
authors.forename: Tomas
authors.initials: T
authors.lastname: Hökfelt
authors.forename: Annette
authors.initials: A
authors.lastname: Theodorsson
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D005260:Female; D019004:Galanin / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D020244:Infarction, Middle Cerebral Artery / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D044091:Receptor, Galanin, Type 1 / Q000235:genetics* / Q000378:metabolism; D044092:Receptor, Galanin, Type 2 / Q000235:genetics / Q000378:metabolism; D044093:Receptor, Galanin, Type 3 / Q000235:genetics; D015427:Reperfusion Injury / Q000235:genetics / Q000473:pathology; D015854:Up-Regulation / Q000502:physiology
chemical_list: D044091:Receptor, Galanin, Type 1; D044092:Receptor, Galanin, Type 2; D044093:Receptor, Galanin, Type 3; D019004:Galanin