Thalamic Networks for Relay and Modulation is the third in a series that springs from an idea of Giorgio Macchi who wished to establish periodical updates on thalamic research by bringing to Italy investigators who would engage in an international sharing of ideas and experiences. It reflects the renewed interest in the modulation of thalamic relay activity by intrinsic and extrinsic sources, while continuing to underscore the essential role of the thalamus as the gatekeeper of the cerebral cortex and of the pathways to perception. The papers that form the substance of this book were presented at a Symposium held at the Catholic University, Rome, Italy, in September 1992, as a Satellite to the 15th Annual Meeting of the European Neuroscience Association. The volume is organized into four parts. Part I is basically concerned with developmental and evolutionary approaches. Part II highlights relay functions of visual, motor, and somatosensory relay nuclei and relay functions of the intralaminar nuclei. Part III deals primarily with the pharmacology of thalamic neurons. Part IV emphasizes the mechanisms that underlie the functional assembly of thalamic cells into collectively acting ensembles, largely revealed in rhythmic oscillations, and on the behavioral manifestations that accompany them.