Decreased firing of striatal neurons related to licking during acquisition and overtraining of a licking task.
J Neurosci
; 29(44): 13952-61, 2009 Nov 04.
Article
em En
| MEDLINE
| ID: mdl-19890005
Neurons that fire in relation to licking, in the ventral part of the dorsolateral striatum (DLS), were studied during acquisition and performance of a licking task in rats for 14 sessions (2 h/d). Task learning was indicated by fewer errors of omission of licking and improved movement efficiency (i.e., shorter lick duration) over sessions. Number of licks did not change over sessions. Overtraining did not result in habit formation, as indicated by similar reductions of licking responses following devaluation by satiety in both early and late sessions. Twenty-nine lick neurons recorded and tracked over sessions exhibited a significant linear decrease in average firing rate across all neurons over sessions, correlating with concurrent declines in lick duration. Individually, most neurons (86%) exhibited decreased firing rates, while a small proportion (14%) exhibited increased firing rates, during lick movements that were matched over sessions. Reward manipulations did not alter firing patterns over sessions. Aside from the absence of habit formation, striatal processing during unconditioned movements (i.e., licking) was characterized by high activity of movement-related neurons during early performance and decreased activity of the same neurons during overtraining, similar to our previous report of head movement neurons during acquired, skilled, instrumental head movements that ultimately became habitual (Tang et al., 2007). Decreased activity in DLS neurons may reflect a common neural mechanism underlying improvement in movement efficiency with overtraining. Nonetheless, the decreased striatal firing in relation to a movement that did not become habitual demonstrates that not all DLS changes reflect habit formation.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Desempenho Psicomotor
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Potenciais de Ação
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Corpo Estriado
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Aprendizagem
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Atividade Motora
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Neurônios
Limite:
Animals
Idioma:
En
Revista:
J Neurosci
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Estados Unidos