Continuous reversal using internal or external cues: A novel test measuring set shifting in Parkinsonian rats

Thibaut SESIA, Rob HAMELEERS, Rinske VLAMINGS, Eva WOLBERT, Süleyman KAPLAN, Arjan BLOKLAND, Yasin TEMEL
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Abstract


Parkinson’s disease (PD) is a predominant movement disorder, but profound cognitive deficits (e.g. bradyphrenia, memory, and set shifting) also occur. To model the deficits in set shifting using internal and external cues in rats we developed a continuous reversal task in which the active lever, left or right lever, alternated after a variable number of lever presses. In one task the active lever was signaled by a light (external cue condition, EC) whereas in the other task the active lever was not signaled (internal cue condition, IC). In this study we evaluated the effects of a partial bilateral striatal 6-OHDA lesion as model for PD on the performance in both tasks. Following behavioral testing the lesions were verified using tyrosine hydroxylase (TH) immunohistochemistry. The 6-OHDA lesioned animals were specifically impaired in the IC condition and not in the EC task. In other words, the lesioned animals kept pressing a lever longer although it was not longer active. The present response switching task is sensitive to 6-OHDA lesions and may mimic set-shifting deficits in PD.

J. Exp. Clin. Med., 2012; 29:183-186

Keywords


Set-shifting; continuous reversal; 6-OHDA lesion; Parkinson’s disease

Full Text:

183


DOI: http://dx.doi.org/10.5835/jecm.omu.29.03.005