Workshop 6 Description:

Workshop 6: Sensory Motor System

In this workshop we will focus on modeling the basal ganglia in both birds and mammals. In mammals the basal ganglia are a group of forebrain nuclei that play an important, perhaps even central, role in the control of movement. They also appear to be involved in cognition, motivation and emotion. Dysfunction of the basal ganglia is associated with movement disorders such as Parkinson's disease and Huntington's chorea. Structures within the basal ganglia have in fact been the target of therapeutic surgical procedures including pallidotomy, lesioning of the subthalamic nuclei and deep brain stimulation.

Recent work has shown just how similar the organization and function of the basal ganglia is in both birds and mammals. Even better, experiments on the song system have provided a window into mammalian basal ganglion function. When a bird is deafened, its song deteriorates. When deafening is paired with lesion of the basal ganglia, however, this deterioration does not take place. This appears to be because the lesion has removed an instructive signal that is produced by the basal ganglia. These results are important for both studies of birdsong and for studies of motor learning, and they need to be discussed by both theoreticians and experimentalists who work on birds and mammals.

There is a rich array of data on basal ganglia physiology and connections in both groups. In mammals, numerous experiments have demonstrated that neurons with the basal ganglia display a variety of dynamic behavior; moreover patterns of neuronal activity, both spatial and temporal, differ between normal and pathological states. Neither the origins of these neural firing patterns nor the neuronal mechanisms that underlie the patterns are understood. Some mathematical models have been introduced recently to describe the various aspects of the basal ganglia, however these have been almost exclusively based on the average firing rates of the neurons, while ignoring their temporal dynamics. As experiments continue to demonstrate the importance of temporal dynamics, the need for more realistic, biophysically based models is becoming increasingly clear. The primary goal of this workshop is stimulate the development of models realistic enough to test hypotheses on the role of neuronal activity within the basal ganglia in both normal and pathological states.

The mathematical areas which are expected to be strongly involved in this workshop are partial and integral differential equations, dynamical systems and probability.