title: Ether-à-go-go 1 (Eag1) potassium channel expression in dopaminergic neurons of basal ganglia is modulated by 6-hydroxydopamine lesion.
abstract: The ether à go-go (Eag) gene encodes the voltage-gated potassium (K(+)) ion channel Kv10.1, whose function still remains unknown. As dopamine may directly affect K(+) channels, we evaluated whether a nigrostriatal dopaminergic lesion induced by the neurotoxin 6-hydroxydopamine (6-OHDA) would alter Eag1-K(+) channel expression in the rat basal ganglia and related brain regions. Male Wistar rats received a microinjection of either saline or 6-OHDA (unilaterally) into the medial forebrain bundle. The extent of the dopaminergic lesion induced by 6-OHDA was evaluated by apomorphine-induced rotational behavior and by tyrosine hydroxylase (TH) immunoreactivity. The 6-OHDA microinjection caused a partial or complete lesion of dopaminergic cells, as well as a reduction of Eag1+ cells in a manner proportional to the extent of the lesion. In addition, we observed a decrease in TH immunoreactivity in the ipsilateral striatum. In conclusion, the expression of the Eag1-K(+)-channel throughout the nigrostriatal pathway in the rat brain, its co-localization with dopaminergic cells and its reduction mirroring the extent of the lesion highlight a physiological circuitry where the functional role of this channel can be investigated. The Eag1-K(+) channel expression in dopaminergic cells suggests that these channels are part of the diversified group of ion channels that generate and maintain the electrophysiological activity pattern of dopaminergic midbrain neurons.
authors: Department of Physiology, School of Medicine, Campus USP, Ribeirão Preto, SP, Brazil.
authors: N R
authors: NR
authors: Ferreira
authors: M
authors: M
authors: Mitkovski
authors: W
authors: W
authors: Stühmer
authors: L A
authors: LA
authors: Pardo
authors: E A
authors: EA
authors: Del Bel
mesh_terms: D000818:Animals; D001479:Basal Ganglia / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D059290:Dopaminergic Neurons / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D051638:Ether-A-Go-Go Potassium Channels / Q000378:metabolism*; D005917:Globus Pallidus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D008297:Male; D009410:Nerve Degeneration / Q000139:chemically induced / Q000378:metabolism*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D016627:Oxidopamine / Q000633:toxicity*; D020734:Parkinsonian Disorders / Q000139:chemically induced / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013378:Substantia Nigra / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D013565:Sympatholytics / Q000633:toxicity; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D051638:Ether-A-Go-Go Potassium Channels; C496886:Kcnh1 protein, rat; D013565:Sympatholytics; D016627:Oxidopamine; D014446:Tyrosine 3-Monooxygenase