Response suppression and facilitation by aversive stimuli following septal lesions in rats: A review and model

Abstract

Evidence concerning the effects of septal damage on the performance of rats in tasks involving shock and frustrative nonreward is reviewed. It is argued that the behavior of rats with septal lesions cannot be understood in terms of either a change in the functional intensity of aversive stimuli or the ability to register contingencies between such stimuli and responding. Rather, the lesion appears to decrease the suppressive property of aversive stimuli while augmenting their facilitative or drive-enhancing property. On the basis of the evidence, a model of the processing of aversive stimuli is proposed. The model assumes that aversive stimuli are processed by two relatively independent systems: a response suppression system associated with septal functioning and a response facilitation system associated with amygdala functioning. While the facilitation mechanism is activated by stimuli of both positive and negative affective value, the suppression system is sensitive to only aversive events. Further, it is suggested that an additional septal mechanism, sensitive to both positive and negative stimuli exerts inhibitory control over the facilitation system. '

Effects of lateral and medial septal lesions on response suppression maintained by response-contingent and response-independent shock

“…This hypothesis is supported by considerable behavioral (Gray, 1975) and psychopharmacological data. It is also supported by the results of experiments in which large septal (Dickinson, 1974;Lubar & Numan, 1973) or hippocampal lesions (Altman, Brunner, & Bayer, 1973) have been studied. Thus, when large, unselective lesions have been used, they have been shown to disinhibit the response suppression produced either by nonreward or by shock.…”

Symmetrical effects of amphetamine and alpha-flupenthixol on conditioned punishment and conditioned reinforcement: contrasts with midazolam

“…This pattern of results is anticipated by early work examining the effect of septal lesions on punished responding which suggested that aversive stimuli, in addition to punishing effects, also serve to increase the general motivation or behavioural activation of the animals, i.e. they have both aversive and invigorating properties (Dickinson 1974(Dickinson , 1975. The preference for the CP lever under midazolam is therefore the result of the loss of the aversive impact of the CS+, without loss of its invigorating properties.…”

Emotionality in male and female rodents: A reply to Archer

“…I have summarized some relevant findings in Table 2. These concern Broadhurst's (1960,1975) selective breeding programme (MNR relative to MR rats are similar to females relative to males: Gray, 1971 b); the effects of anti-anxiety drugs (drugged relative to undrugged animals are similar to females relative to males: Gray, 1977); and the effects of septal lesions (lesioned relative to intact animals are similar to females relative to males : Lubar & Numan, 1973;Dickinson, 1974). Table 2 summarizes a great deal of information.…”