Electrical stimulation of the brain stem in freely moving rats: I. Effects on behavior

Electrical stimulation (100 pulses/sec, 0.1 msec pulses) was applied to 129 sites located throughout the midbrain, pons and rostral medulla in freely moving rats, and behavioral effects recorded. Stimulation elicited a variety of motor patterns including head movements, turning, circling, forward locomotion (walking and running), freezing, chewing and fictive eating. Some of the behaviors appeared forced and unnatural, while others resembled normal movement. Some stimulation-bound behaviors appeared to be partially under environmental control. It is suggested that some behaviors elicited by stimulation of the brain stem may be due to relatively direct descending connections, but others may involve ascending inputs to the cerebral cortex as well.