Impaired acquisition of skilled behavior in rotarod task by moderate depletion of striatal dopamine in a pre-symptomatic stage model of Parkinson's disease

• DOI: 10.1016/j.neures.2004.12.006
• Publication Date: 2005-01-11T12:29:51Z
• Authors: Taichi Ogura; Masanori Ogata; Hisanao Akita; Susumu Jitsuki; Lisa Akiba; Kazuko Noda; Sumio Hoka; Makoto Saji
• Keywords: Male; 0301 basic medicine; Behavior, Animal; Cell Survival; Dopamine; Microdialysis; Medial Forebrain Bundle; Cell Count; Parkinson Disease; Motor Activity; Immunohistochemistry; Corpus Striatum; Functional Laterality; Amphetamine; Disease Models, Animal; 03 medical and health sciences; Hindlimb Suspension; Motor Skills; Exploratory Behavior; Animals; Central Nervous System Stimulants; Oxidopamine

In view of recent findings that suggest that the nigrostriatal dopamine (DA) system plays a role in motor control and the acquisition of habits and skills, we hypothesized that the striatum-based function underlying the acquisition of skilled behaviors might be more vulnerable to dopamine depletion than the motor control. To test this hypothesis, we investigated whether impaired acquisition of skilled behaviors occurs in a pre-symptomatic stage model of Parkinson's disease (PD). By using the microdialysis method and the 6-OHDA-technique to destroy dopamine neurons, we confirmed that rats with unilateral partial lesions of the nigral dopamine cells by 6-OHDA are suitable for a pre-symptomatic stage model of Parkinson's disease. The rats in this model exhibited moderate disruption of striatal dopamine release function and relatively intact motor functions. In a rotarod test, the impaired acquisition of skilled behavior occurred in rats with bilateral partial lesions of the nigral dopamine cells by 6-OHDA. These rats displayed intact general motor functions, such as locomotor activity, adjusting steps, equilibrium function and muscle strength. Based on these results, we concluded that the striatum-based function underlying the acquisition of skilled behaviors or sensorimotor learning may be more vulnerable to dopamine depletion than the motor control.