SGER: Common Signals Modulating Waking and Movement.

University Of Arkansas Medical Sciences Campus, Little Rock AR

Investigators

Abstract

Although our movements seem smooth and continuous to us, they are not. They are generated by the brain in small steps. This pulsing signal from the brain is reflected in our muscles as what is known as physiological tremor; it occurs at about 10 pulses per second, and it occurs both during movement and rest. This pulsing signal is thought to save time and computational load in the brain, and serves to bring all parts of the motor system into step. The proposed studies will explore the possibility that a crucial part of the brain, the reticular activating system, which helps control sleep-wake cycles and arousal as well as posture and movement, generates this necessary background of activity, all at the same rate of about 10 pulses per second. Such a background of activity could participate in higher processes such as attention as well as lower motor processes such as changes in posture or locomotion. This widespread rhythm might be involved in such complex functions as fight-or-flight responses in which attention (perceiving a threat) and locomotion (fighting or escaping) are coordinated. In this project, higher brain regions involved in attention as well as lower brain regions controlling posture and movement will be studied, in order to determine if the reticular activating system talks to both higher and lower centers in the same fashion. This would explain how we can smoothly carry out complex fight-or-flight responses, and how we can change states, such as from sleeping to waking, and shift our motor system accordingly.