Pedunculo-pontine control of visually guided saccades.

The cholinergic pedunculopontine tegmental nucleus (PPTN) is one of the major ascending arousal systems in the brainstem, and it is linked to motor, limbic and sensory centers. Despite an abundance of anatomical and physiological data, however, the functional role of PPTN neurons in behavioral control is still unresolved. In this chapter, we hypothesize that the PPTN is implicated in the integrative control of movement, particularly the reinforcement of tasks performed during conscious behavior. We present a new model of the PPTN's involvement in the control of arousal, attention and reinforcement aspects of motor behavior, with a focus on the control of saccadic eye movements.