Levodopa increases memory encoding and dopamine release in the striatum in the elderly

Neurobiol Aging. 2008 Feb;29(2):267-79. doi: 10.1016/j.neurobiolaging.2006.10.009. Epub 2006 Nov 13.

Abstract

Normal aging is associated with a decrease in dopaminergic function and a reduced ability to form new motor memories with training. This study examined the link between both phenomena. We hypothesized that levodopa would (a) ameliorate aging-dependent deficits in motor memory formation, and (b) increase dopamine availability at the dopamine type 2-like (D2) receptor during training in task-relevant brain structures. The effects of training plus levodopa (100mg, plus 25mg carbidopa) on motor memory formation and striatal dopamine availability were measured with [(11)C]raclopride (RAC) positron emission tomography (PET). We found that levodopa did not alter RAC-binding potential at rest but it enhanced training effects on motor memory formation as well as dopamine release in the dorsal caudate nucleus. Motor memory formation during training correlated with the increase of dopamine release in the caudate nucleus. These results demonstrate that levodopa may ameliorate dopamine deficiencies in the elderly by replenishing dopaminergic presynaptic stores, actively engaged in phasic dopamine release during motor training.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Attention / drug effects
  • Biomechanical Phenomena
  • Blood Pressure / drug effects
  • Corpus Striatum / diagnostic imaging
  • Corpus Striatum / drug effects*
  • Corpus Striatum / metabolism*
  • Cross-Over Studies
  • Dopamine / metabolism*
  • Dopamine Agents / pharmacology*
  • Dopamine Antagonists / metabolism
  • Double-Blind Method
  • Female
  • Heart Rate / drug effects
  • Humans
  • Levodopa / pharmacology*
  • Male
  • Memory / drug effects*
  • Motor Skills / drug effects
  • Positron-Emission Tomography / methods
  • Raclopride / metabolism
  • Teaching

Substances

  • Dopamine Agents
  • Dopamine Antagonists
  • Raclopride
  • Levodopa
  • Dopamine