Dissociable rate-dependent effects of oral methylphenidate on impulsivity and D2/3 receptor availability in the striatum.
J Neurosci
; 35(9): 3747-55, 2015 Mar 04.
Article
em En
| MEDLINE
| ID: mdl-25740505
ABSTRACT
We have previously shown that impulsivity in rats is linked to decreased dopamine D2/3 receptor availability in the ventral striatum. In the present study, we investigated, using longitudinal positron emission tomography (PET), the effects of orally administered methylphenidate (MPH), a first-line treatment for attention deficit hyperactivity disorder, on D2/3 receptor availability in the dorsal and ventral striatum and related these changes to impulsivity. Rats were screened for impulsive behavior on a five-choice serial reaction time task. After a baseline PET scan with the D2/3 ligand [(18)F]fallypride, rats received 6 mg/kg MPH, orally, twice each day for 28 d. Rats were then reassessed for impulsivity and underwent a second [(18)F]fallypride PET scan. Before MPH treatment, we found that D2/3 receptor availability was significantly decreased in the left but not the right ventral striatum of high-impulse (HI) rats compared with low-impulse (LI) rats. MPH treatment increased impulsivity in LI rats, and modulated impulsivity and D2/3 receptor availability in the dorsal and ventral striatum of HI rats through inverse relationships with baseline levels of impulsivity and D2/3 receptor availability, respectively. However, we found no relationship between the effects of MPH on impulsivity and D2/3 receptor availability in any of the striatal subregions investigated. These findings indicate that trait-like impulsivity is associated with decreased D2/3 receptor availability in the left ventral striatum, and that stimulant drugs modulate impulsivity and striatal D2/3 receptor availability through independent mechanisms.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptores de Dopamina D2
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Inibidores da Captação de Dopamina
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Corpo Estriado
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Receptores de Dopamina D3
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Estimulantes do Sistema Nervoso Central
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Comportamento Impulsivo
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Metilfenidato
Limite:
Animals
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article