Review The aging striatal dopamine function Olivier Darbin a, b, * a Department of Neurology, University South Alabama, 307 University Blvd., Mobile, AL 36688, USA b Division of System Neurophysiology, National Institute for Physiological Sciences, Okazaki, Japan article info Article history: Received 27 August 2011 Received in revised form 23 November 2011 Accepted 27 November 2011 Keywords: Elderly Catecholamine Nigro-striatal pathway Motor activity Dopamine depletion abstract Movement disorders are prevalent in the elderly and may have both central and peripheral origins. Age- related parkinsonism often results in movement disorders identical to some of the cardinal symptoms of typical Parkinson’s disease (TPD). Nevertheless, there may be limited similarity in the underlying dysfunction of the sensory-motor circuitry since these two conditions exhibit different changes in the nigro-striatal pathway. In this short review, we highlight some of the key distinctions between aging and TPD regarding striatal dopaminergic activity and discuss them in the context of therapeutic strategies to alleviate motor decline in the elderly. Ó 2011 Elsevier Ltd. All rights reserved. Contents 1. Introduction ....................................................................................................................... 00 2. Aging and striatal dopaminergic neurotransmission .................................................................................... 00 2.1. Striatal dopamine metabolism ................................................................................................. 00 2.2. Striatal dopamine receptors ................................................................................................... 00 2.3. Age-related response to dopaminergic treatments ................................................................................ 00 2.4. Aged-related striatal dopamine alterations: what are the possible consequences on basal ganglia circuitry activity? ..................... 00 2.5. Striatal dopaminergic system, aging and Parkinson’s disease ...................................................................... 00 3. Conclusion ........................................................................................................................ 00 Acknowledgment ............................................................................................................... 00 References ..................................................................................................................... 00 1. Introduction Motor signs of parkinsonism increase with aging and affect more than 50% of people over the age of 85 years [1]. They are predictive of lifespan [1e3], contribute to the perception of dete- rioration in quality of life [4] and have an economical impact. In the elderly, motor symptoms with the highest prevalence include: bradykinesia (37%), gait disturbance (51%) and rigidity (43%) but resting tremor, a cardinal symptom of typical Parkinson’s disease (TPD), has a low prevalence (5%) in the elderly [1]. In contrast to TPD, dopaminergic replacement strategies are ineffective at relieving the burden associated with age-related parkinsonism. Though this lack of benefit may indicate complex and diffuse alterations along the motor efferent pathway [5], it may also be due to the fact that TPD and age-related parkinsonism exhibit different neuropathological hallmarks in the central motor circuitry. Understanding the specificities of age-related parkinsonism, in comparison to TPD, is an important step for efficient cross discipline research between these two conditions. Ultimately, the identifica- tion of reversible central dysfunctions in the aging central motor circuitry could facilitate our ability to develop new therapeutic strategies to reduce the severity of or delay the onset of parkin- sonism related to aging. * Corresponding author. Department of Neurology, University of South Alabama College of Medicine, 3401 Medical Park Dr., Bldg 3, Suite 205, Mobile, AL 36608, USA. Tel.: þ1 770 329 8773; fax: þ1 251 660 5924. E-mail address: odarbin@usouthal.edu. Contents lists available at SciVerse ScienceDirect Parkinsonism and Related Disorders journal homepage: www.elsevier.com/locate/parkreldis 1353-8020/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.parkreldis.2011.11.025 Parkinsonism and Related Disorders xxx (2012) 1e7 Please cite this article in press as: Darbin O, The aging striatal dopamine function, Parkinsonism and Related Disorders (2012), doi:10.1016/ j.parkreldis.2011.11.025