Investigation of brainstom transmitter systems : pharmacological studies in the red nucleus of the cat.

Abstract

The red nucleus is a part of the so-called 'extrapyramidal system' (Brodal, 1963) and to lesions of this nucleus have been attributed dyskinetic phenomena clinically observed in man (see Carpenter, 1961). Catecholamines, especially noradrenaline, have been found in grey matter of the brainstem, while dopamine is strongly localized to the basal ganglia and structures related to them anatomically and in their control of motor function. The basal ganglia, comprised of the caudate nucleus, putamen, globus pallidus, internal capsule and claustrum are a part of the 'extrapyramidal system'and evidence of disordered dopamine metabolism in basal ganglia disease (Barbeau and Sourkes, 1961) implicates this compound in their function. The observation that dopamine is most prominent in the phylogenetically youngest structures (Bertler, 1961) would also seem to contradict the possibility of the presence of this amine being atavistic. The object of the experiments entailed in this thesis was to apply biogenic amines and some related compounds to red nucleus cells, microelectrophoretically, with a view to attempting to elucidate whether or not those amines which are found in this nucleus are concerned in synaptic function. Chapters One and Two constitute a review of relevant literature. Chapter One deals with the growth of the concept of the synapse and some recent observations on junctional morphology, as well as an outline of mechanisms subtending the phenomenon of synaptic transmission. A knowledge of the facts discussed in this chapter is essential before an attempt can be made to study the pharmacology of central synaptic transmission and it serves as a prolegomena for the rest of the treatise.