Hemiparkinsonian rats rotate toward the side with the weaker dopaminergic neurotransmission

Hemiparkinsonian rats rotate toward the side with the weaker dopaminergic neurotransmission

Autor Da Cunha, Claudio Google Scholar
Wietzikoski, Evellyn Claudia Google Scholar
Ferro, Marcelo Machado Google Scholar
Martinez, Glaucia Regina Google Scholar
Barbato Frazao Vital, Maria Aparecida Google Scholar
Hipolide, Debora Autor UNIFESP Google Scholar
Tufik, Sergio Autor UNIFESP Google Scholar
Canteras, Newton Sabino Google Scholar
Instituição Universidade Federal do Paraná (UFPR)
Universidade Federal de São Paulo (UNIFESP)
Universidade de São Paulo (USP)
Resumo Rats with unilateral lesion of the substantia nigra pars compacta (SNpc) have been used as a model of Parkinson's disease. Depending on the lesion protocol and on the drug challenge, these rats rotate in opposite directions. the aim of the present study was to propose a model to explain how critical factors determine the direction of these turns. Unilateral lesion of the SNpc was induced with 6-hydroxydopamine (6-OHDA) or 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Separate analysis showed that neither the type of neurotoxin nor the site of lesion along the nigrostriatal. pathway was able to predict the direction of the turns these rats made after they were challenged with apomorphine. However, the combination of these two factors determined the magnitude of the lesion estimated by tyrosine-hydroxylase immunohistochemistry and HPLC-ED measurement of striatal dopamine. Very small lesions did Dot cause turns, medium-size lesions caused ipsiversive turns, and large lesions caused contraversive turns. Large-size SNpc lesions resulted in an increased binding of [H-3] raclopride to D2 receptors, while medium-size lesions reduced the binding of [H-3]SCH-23390 D1 receptors in the ipsilateral striatum. These results are coherent with the model proposing that after challenged with a dopamine receptor agonist, unilaterally SNpc-lesioned rats rotate toward the side with the weaker activation of dopamine receptors. This activation is weaker on the lesioned side in animals with small SNpc lesions due to the loss of dopamine, but stronger in animals with large lesions due to dopamine receptor supersensitivity. (C) 2008 Elsevier B.V. All rights reserved.
Assunto substantia nigra pars compacta
turning behaviour
dopamine
basal ganglia
dopamine receptor
Parkinson's disease
MPTP
6-hydroxydopamine
Idioma Inglês
Data 2008-06-03
Publicado em Behavioural Brain Research. Amsterdam: Elsevier B.V., v. 189, n. 2, p. 364-372, 2008.
ISSN 0166-4328 (Sherpa/Romeo, fator de impacto)
Editor Elsevier B.V.
Extensão 364-372
Fonte http://dx.doi.org/10.1016/j.bbr.2008.01.012
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:000255604300016
URI http://repositorio.unifesp.br/handle/11600/30726

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