A Theory of the Striatum: (Studies in the Neurosciences S.)

The striatum has been implicated in a number of neutological and psychiatric diseases. It has received considerable attention from pharmacologists, neuroanatomists, neuropathologists, and electrophysiologists. However, until now no comprehensive theory of the striatum has emerged. This book is a serious attempt at such a theory. The first part is concerned with an analysis of evidence from anatomical, behavioural, clinical and pharmacological studies of the stratum. After a brief introduction to the methods of theoretical neuroscience, the experimental evidence on the role of the striatum in behaviour and learning is reviewed by an analysis of the evidence on the internal connectivity of the striatum, and the input and output organization. This first part ends with a review of synaptic modification as the basis of learning. The second part is devoted to formalising the model developed in the previous chapters. Computer simulation is used to study the short-term dynamic behaviour of the model, and the long-term structural evolution during learning. Finally the ideas developed through literature review and computer simulation are applies to the question of the contribution of the striatum to the operation of cell assembles in the cerebral cortex..

Table of Contents:
Introduction. Statement of the problem. The need for a theory. The potential of a modelling approach. Why model the striatum? Executive functions of the striatum. Brain models and psychological theory. Overall organization of the arguments. The Functions of the Striatum. Introduction. Older ideas about striatal function. The striatum in the preparation for a preprogrammed action. Striatal involvement in selection and exclusion. The striatum in learning- from knowledge of results. Summary. The Striatal Skeleton. Introduction. The striatum as a field of inhibitory domains. The corticostriatal afferents. Striatal output. Output from the basal -ganglia to the cortex. An estimate of the size of an inhibitory, domain. Implications of domains for information processing,. Conclusions. Learning: Basis in Synaptic Modification. Introduction. Two types of learning and synaptic modification. Biophysical mechanisms in LTP induction. Learning and synaptic modification in the striatal. Summary. Formalization of the Model. Introduction. Definition of the striatal model. Choice of parameter ,values. Simulation techniques. Simulations. Introduction. Striatal neurodynamics: short-term activity patterns. Learning- in the striatal model: structural evolution. Summary. Discussion. Inhibition in the striatum. Reinforcement learning in neural nets. The striatum and reward-mediated learning,: limitations. A theory of the -striatum. Summary. Bibliography. Index. 37 illus.