[Current concepts of the neuromorphology and neurochemistry of the striatal cholinergic system and its role in regulating movement]

Abstract

The recent neuromorphological and neurochemical data are reviewed concerning the organization of the striatal cholinergic system. A conclusion is made that the nigrostriatal dopamine and intrastriatal acetylcholine have the opposite effects on the main efferent outputs of striatum, including the expression of peptides which determines their involvement. The crucial role was proposed of the striatal cholinergic system in switching on and regulation of the so called indirect efferent pathway which controls the main striatal targets: the medial part of globus pallidus and reticular part of substantia nigra. On the basis of experimental and clinical data, we have suggested an important role of the activation of the striatal cholinergic system in the muscle tone control and the control of the main component of postural adjustment (unloading the working limb), in the inhibition of phasic components of a movement, and in the inhibition of unwanted movements during a behavioural task realization. The conclusion was experimentally supported about the possibility of changes in the motor behaviour, using the adequate pharmacological influence on the striatal cholinergic system. At the same time, the long-term fixed imbalance in the function of striatal efferent systems leads to a pathology of motor activity. The increase in the striatal cholinergic activity and/or decrease in the nigrostriatal dopaminergic effects may be the cause of Parkinson's disease.