The Thalamus A New Proposal

Rarely in neuroscience does an idea come along that illuminates an entire field of work and promises to shape its future—this may have just happened for the thalamus and the way we view its relationship with the cerebral cortex. The mammalian thalamus is a paired structure comprising a relatively small group of neuronal nuclei that sits in roughly the center of the brain, on either side of the third ventricle. Virtually all sensory information coming from the periphery must first pass through the thalamus before reaching the cerebral cortex. Despite its key location, or perhaps because of it, the thalamus has traditionally been viewed as a simple relay that passes on messages to the cortex largely as they come in and that does little in the way of information processing or integration. This view of the thalamus as merely a relay has recently been called into question, and evidence is beginning to accumulate that, while the thalamus un-background to their reasoning and to synthesize their doubtedly relays inputs to cortex, it may actually play suggestions as to what the role of the thalamus might be. a much more dynamic role in the processing and trans-The book can be divided into two parts. The first mission of information. In " Exploring the Thalamus, " S. presents many of the known structural and functional Murray Sherman and Ranier W. Guillery, two neuroscien-features of the thalamus. This moves from a somewhat tists who have devoted their careers to studying the traditional overview of the thalamus in chapter I, to a thalamus, tackle the problem of trying to make sense more detailed look at the different classes of neuron of what is known (and not known) about the thalamus that make up the thalamus in chapter II. Chapter III and to move toward an understanding of what role(s) looks at the types of afferent that provide input to the the thalamus plays. They succeed admirably and, in thalamus. Differences in the structure of afferents are the process, make a novel proposal for a role for the clearly demonstrated at both the light and electron mi-thalamus in cortical function that might do no less than croscopic level. In chapter IV, the intrinsic electrophysio-transform the field. logical properties of thalamic neurons are discussed. The title is apt, conveying well the thrust of the book. This chapter starts with an overview of cable theory and As mentioned …