title: Alteration of striatal dopaminergic function induced by glioma development: a microdialysis and immunohistological study in the rat striatum.
abstract: Tumoral growth effects on brain circuitry and neurochemical activities remain poorly documented. This study evaluates C6 graft effects on striatal dopaminergic afferent projections at both anatomical and functional levels. Immunohistochemistry was performed to investigate changes in neurofilament (NF), tyrosine hydroxylase (TH) and dopamine transporter (DAT) expression. Dopaminergic turnover was assessed using multiprobe microdialysis in freely-moving rat. In C6 graft striatum, dopamine (DA) catabolites were reduced in glioblastoma (DOPAC: -61%, HVA: -62%). In contrast, the DA level remained unchanged. Staining for NF, TH and DAT was drastically decreased inside the tumor. Our histological data report that striatal tumoral growth is associated with a decrease in the density of dopaminergic endings which can explain, at least in part, the decrease in DA turnover. The decrease in DAT transporter expression and the lack of change in DA level may result from an increase in DA diffusion from the peripheral areas of the tumor. In conclusion, glioblastoma growth has major consequences on the local neuronal circuitry and its neurochemistry. Changes in inter-connections and neurotransmitter turnover may result in abnormal neuronal firing activity and participate in clinical disorders associated with glioblastoma diagnosis.
authors.affiliation: Service de Neurochirurgie, CHU Pasteur, 30 Avenue de la Voie Romaine, UNSA, 06002 Nice Cedex 01, France. lonjon.m@chu-nice.fr
authors.forename: M
authors.initials: M
authors.lastname: Lonjon
authors.forename: M H
authors.initials: MH
authors.lastname: Quentien
authors.forename: J J
authors.initials: JJ
authors.lastname: Risso
authors.forename: J F
authors.initials: JF
authors.lastname: Michiels
authors.forename: E
authors.initials: E
authors.lastname: Carre
authors.forename: J C
authors.initials: JC
authors.lastname: Rostain
authors.forename: O
authors.initials: O
authors.lastname: Darbin
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000344:Afferent Pathways / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D000818:Animals; D001932:Brain Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D015536:Down-Regulation / Q000502:physiology; D045604:Extracellular Fluid / Q000378:metabolism; D005910:Glioma / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D006719:Homovanillic Acid / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000378:metabolism; D017551:Microdialysis; D009368:Neoplasm Transplantation; D017072:Neostriatum / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D009419:Nerve Tissue Proteins; D016900:Neurofilament Proteins / Q000378:metabolism; D009473:Neuronal Plasticity / Q000502:physiology*; D017729:Presynaptic Terminals / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014407:Tumor Cells, Cultured; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D016900:Neurofilament Proteins; C493216:Slc6a3 protein, rat; D015102:3,4-Dihydroxyphenylacetic Acid; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine; D006719:Homovanillic Acid