کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8838022 | 1612916 | 2017 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Effects of levodopa on stimulus-response learning versus response selection in healthy young adults
ترجمه فارسی عنوان
اثرات لوودوپا در یادگیری واکنش برانگیختگی و انتخاب پاسخ در بزرگسالان جوان سالم
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علم عصب شناسی
علوم اعصاب رفتاری
چکیده انگلیسی
Dopaminergic therapy has been shown to worsen some cognitive functions, particularly learning, in Parkinson's disease (PD). This has been attributed to dopamine overdose of brain regions that are relatively dopamine replete. Dopamine dosages are titrated to the severely depleted dorsal striatum (DS). According to this account, dopaminergic therapy should worsen cognitive functions in healthy young adults who have normal dopamine levels. As a critical test of the dopamine overdose hypothesis, we tested the effect of levodopa on learning stimulus-response associations and on performing stimulus-specific responses once these associations were learned. In a randomized, double-blind, placebo-controlled, between-subjects design, 40 healthy young adults completed a stimulus-response learning task on either levodopa or placebo. Half of the participants received 100Â mg of levodopa and 25Â mg of carbidopa whereas the other half received an equal volume of placebo. In Session 1, participants learned to associate abstract images with specific key-press responses through trial and error with outcome feedback. In Session 2, participants performed stimulus-specific selections to abstract images they had previously learned in Session 1. Participants treated with levodopa compared to those on placebo demonstrated unambiguously less efficient acquisition of stimulus-response associations. The groups did not differ in their ability to enact stimulus-specific selections once they were learned, however, even though these responses were not overlearned. This pattern of findings is entirely consistent with the effect of levodopa on cognition in PD. The deleterious effects of levodopa on learning seem independent of PD pathology. These results have important implications for understanding mechanisms of cognitive dysfunction in PD and caution about the potential for cognitive deficits in patients treated with levodopa for other indications.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Behavioural Brain Research - Volume 317, 15 January 2017, Pages 553-561
Journal: Behavioural Brain Research - Volume 317, 15 January 2017, Pages 553-561
نویسندگان
Andrew Vo, Ken N. Seergobin, Penny A. MacDonald,