Anticipatory Sustained and Action Potentials in Rats
Final rept. 16 Jun 1986-15 Jun 1989
CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF PSYCHIATRY
Pagination or Media Count:
In the rat, slow or sustained electrical potentials of cerebral cortex nonrhythmic potentials enduring longer than a half second accompany responses to reinforcements of the rewarding type milk or electrical stimulation of the medial forebrain bundle. The cortex acquires sustained potential gradients of negative polarity as subjects learn to anticipate rewards. Called anticipatory potential gradients or APGs, they develop as a function of fixed time intervals between rewards temporal conditioning or in relation to cues of upcoming reward simple conditioning. The slopes of the gradients decrease when the rats are trained to long 30 second anticipatory intervals and increase when trained to shorter 10 second intervals. If we present the rewards at irregular intervals during a session the APGs disappear entirely. The rats require certainty in the timing in order to preserve their cerebral cortical APGs. Restoration of the APGs to pretrial baselines takes the form of a relative positive shift subsidence of the negative shift following the rewards. Keywords DD1473 only Slow potentials Sustained potentials SP APG Temporal conditioning Simple conditioning Rats Cerebral cortex Electrical reward Self stimulation Anticipatory potential gradients Mass unit potentials Paradoxical decrement.
- Anatomy and Physiology