Effects of low-level septal stimulation on escape: Significance for limbic-midbrain interactions in pain.

Abstract

Continuous low-level septal stimulation invariably had a significant facilitative effect on escape from footshock. However, the effect of septal stimulation on escape from aversive dorsal midbrain stimulation was either facilitative or the reverse depending on the rat's predominating reaction to stimulation of the same septal site with currents high enough to produce either an approach ("positive") reaction, or an escape ("negative") reaction. While continuous low-level negative septal stimulation speeded centrally elicited escape, continuous low-level positive septal stimulation slowed escape. These (and heart-rate) findings are discussed in relation to the pain theory of Melzack and co-workers.

Inhibitory interactions between appetitive and aversive stimuli.

“…Finally, a number of studies have found that presenting positive ICS can actually enhance aversively motivated behavior. Gardner and Malmo (1969) observed that presenting positive ICS in the same compartment as footshock actually decreased escape latencies, even though comparable stimulation interfered with escape when ICS to a midbrain tegmentum site was used as the aversive stimulus. Positive ICS can also facilitate avoidance behavior if it is administered coincident with (L. Stein, 1965) or just prior to the onset of (Carder, 1970) the warning signal in a two-way active avoidance task, or alternatively, during performance controlled by a free operant avoidance schedule (Carder, 1970;Margules & Stein, 1968).…”

Conditioned suppression of medial forebrain bundle and septal intracranial self-stimulation in the rat: Evidence for a fear-relief mechanism of the septum.

“…Whether the septal region is analgesic is problematic, and the literature is somewhat ambiguous. Thus Gardner and Malmo (1969) reported hyperalgesia to septal stimulation; Breglio, Anderson, and Merrill (1970) reported analgesia; and Mayer and Liebeskind (1974) reported mixed results. Obviously, if analgesia is produced by stimulation of the septum but not by stimulation of the MFB, this might result in the reduced effectiveness of footshock as a US.…”

Septum and behavior: A review.

“…No particular anatomical region within the septum has been associated with facilitated learning of the two-way avoidance problem (Donovick, 1968). Unilateral lesions (Green & Schwartzbaum, 1968;Hamilton, 1970;Hamilton et al, 1970;Kenyon & Krieckhaus, 196Sa), unilateral stimulation (Gardner & Malmo, 1969;Goldstein, 1966a), and small lesions (Kenyon & Krieckhaus,196Sa) produce effects at least as large as those found after bilateral lesions.…”