Coherence of neuronal firing of the entopeduncular nucleus with motor cortex oscillatory activity in the 6-OHDA rat model of Parkinson's disease with levodopa-induced dyskinesias.
Exp Brain Res
; 234(4): 1105-18, 2016 Apr.
Article
em En
| MEDLINE
| ID: mdl-26724931
ABSTRACT
The pathophysiological mechanisms leading to dyskinesias in Parkinson's disease (PD) after long-term treatment with levodopa remain unclear. This study investigates the neuronal firing characteristics of the entopeduncular nucleus (EPN), the rat equivalent of the human globus pallidus internus and output nucleus of the basal ganglia, and its coherence with the motor cortex (MCx) field potentials in the unilateral 6-OHDA rat model of PD with and without levodopa-induced dyskinesias (LID). 6-hydroxydopamine-lesioned hemiparkinsonian (HP) rats, 6-OHDA-lesioned HP rats with LID (HP-LID) rats, and naïve controls were used for recording of single-unit activity under urethane (1.4 g/kg, i.p) anesthesia in the EPN "on" and "off" levodopa. Over the MCx, the electrocorticogram output was recorded. Analysis of single-unit activity in the EPN showed enhanced firing rates, burst activity, and irregularity compared to naïve controls, which did not differ between drug-naïve HP and HP-LID rats. Analysis of EPN spike coherence and phase-locked ratio with MCx field potentials showed a shift of low (12-19 Hz) and high (19-30 Hz) beta oscillatory activity between HP and HP-LID groups. EPN theta phase-locked ratio was only enhanced in HP-LID compared to HP rats. Overall, levodopa injection had no stronger effect in HP-LID rats than in HP rats. Altered coherence and changes in the phase lock ratio of spike and local field potentials in the beta range may play a role for the development of LID.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Levodopa
/
Oxidopamina
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Núcleo Entopeduncular
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Transtornos Parkinsonianos
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Discinesia Induzida por Medicamentos
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Córtex Motor
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Exp Brain Res
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Alemanha