Motor Asymmetries and Drug Effects: Behavioral Analyses of Receptor Activation

Few brain areas have received as much attention over the past quarter of a century as the basal ganglia, and to the clinician there is a singular reason for such an intense research focus. The basal ganglia are often sites of major pathology in neurological movement disorders and thus represent those brain regions known to function in the initiation and control of movement. The challenge here is for drug therapy to in part replace or boost the action of failing basal gangliar neurons and hopefully provide relief from some of the clinical symptoms. To the scientist, the basal ganglia represent a fascinating intricate system of interconnecting neuronal pathways, often with demonstrable specific neurotransmitter interactions, and that, by selective manipulation of one or more of these neuronal tracts, can be seen to dramatically modify motor behavior in laboratory animals. This type of experimentation is not, however, simply confined to the basal ganglia (herein adjudged to comprise the caudate nucleus, putamen, globus pallidus, substantia nigra, and subthalamic nucleus), and more recent investigations have demonstrated similar motor influences by manipulating neuronal function in those brain areas that serve as potential neural relays between the basal ganglia and the spinal cord.