Short-term memory: the role of the midbrain reticular formation

Low-intensity electrical stimulation of the midbrain reticular formation (MRF) in rats disrupted retention in a discrete-trail delayed alternation task independent of temporal locus of application of the stimulation. The stimulation did not appear to disrupt a motor set, have rewarding or aversive consequences, alter arousal level significantly, or affect encoding or retrieval processes. It is suggested that MRF stimulation might alter delayed alternation performance via neural and behavioral mechanisms associated with the maintenance of activated memory traces over short periods of time.