Chemical sympathectomy and avoidance learning in the rat.

Abstract

Depletion of peripheral sympathetic noradrenaline, induced by ip injection of 6-hydroxydopamine, led to significant decrements in escape and avoidance responding when the required response was difficult, but not when it was relatively easy to acquire. The present results are similar to those obtained with adrenal-demedullated subjects. These findings clarify the role of the sympathetic nervous system in the motivation of behavior elicited by aversive stimulation. Implications for two-process theory and the "Kamin effect" or "learned helplessness" were discussed.x This research forms part of a dissertation presented to Macquarie University by E. L. Di Giusto in partial fulfillment of the requirements for the PhD degree. The authors wish to thank Astra Chemicals Pty Ltd. for their generous supply of 6-hydroxydopamine.2 Requests for reprints should be sent to M. G.

Heart rate and muscle tension correlates of conditioned suppression in humans.

“…Since conditioned suppression occurred on all four test trials, these results do not support the hypothesis (Zeiner et al, 1969) that autonomic respondents mediate suppression. The results of the present study are in agreement, however, with the view that autonomically mediated physiological responses resulting from classical aversive conditioning are not necessary for the mediation of somatic response change (Di Giusto & King, 1972;Rescorla & Solomon, 1967).…”

“…This hypothesis has its origins in early formulations of two-process theory which stated that responses mediated by the autonomic and particularly the sympathetic nervous system (e.g., heart rate) were components of the fear response (e.g., Mowrer, 1947). Since these early formulations, a considerable body of evidence has indicated that surgically or drug induced modifications of the sympathetic nervous system do not necessarily lead to changes in aversively conditioned responses such as passive avoidance , active avoidance (Di Giusto & King, 1972), and conditioned suppression (Pappas, Di Cara, & Miller, 1972). While aversively conditioned sympathetic responses may not be a component of the fear response they may still index fear, and this view has wide acceptance in both experimental (Germana, 1969) and clinical (Wolpe, 1966) circles.…”

Central catecholamine and peripheral noradrenaline depletion by 6-hydroxydopamine and active avoidance learning in rats.

“…To date, Pappas and Sobrian have found that following neonatal treatments with 6-OHDA, subsequent one-way avoidance learning was not affected, whereas Lord, King, and Pfister (1976, Experiment 6) have reported that after the same injection procedure, acquisition of two-way shuttle avoidance was seriously impaired. An interesting parallel exists between these effects of dual depletion and those of Di Giusto and King (1972) and Lord et al (1976, Experiment 4) for acute peripheral sympathectomy by the use of 6-OHDA. The functional significance in active aversive learning of such acute sympathectomy of the rat is reliable deleterious effects on acquisition of two-way shuttle avoidance, but not of one-way avoidance, provided the task is readily acquired, viz., by using simultaneous rather than trace conditioning.…”

“…Further empirical studies are required, however, before the significance of whole brain depletion on active avoidance can be assessed. In keeping with the dual depletion studies, Cooper, Breese, Grant, and Howard (1973) found that following chronic central depletion, frequency of avoidance was significantly reduced (latency was not reported) on a two-way task but that one-way active avoidance was also impaired (cf Di Giusto & King, 1972). The one-way procedure of Cooper et al (1972) is difficult to categorize, however, since no explicit conditioned stimulus (CS) was given other than raising the guillotine door leading to the safe compartment.…”

“…Acquisition of shuttle avoidance in the rat is adversely affected by the following 6-OHDA treatment effects: (a) chronic whole brain depletion in immature and adrenergically developed rats (Cooper et al, 1973;Smith et al, 1973), (b) acute peripheral depletion in adrenergically developed rats (Di Giusto & King, 1972;Lord et al, 1976, Experiment 4), and (c) chronic central and peripheral depletion in neonatally treated rats (Lord et al, 1976, Experiment 5).…”