Effects of coping behavior on gastric lesions in rats as a function of predictability of shock

Abstract

Rats received shock that was predicted by either a light signal alone, light-tone complex signal or no signal. In the light signal alone and light-tone complex signal conditions, experimental rats which could avoid and/or escape shock developed less gastric ulceration than did yoked "helpless" rats which had exactly the s ame shock but had no control over shock. In the nonsignal condition, however, the experimental rats did not differ from the matched yoked rats. Ulceration of non-shock control rats was negligible as compared to experimental and yoked rats in each of the three warning conditions. Presence or absence of a safety signal has an effect on ulcerogenesis. The light signal alone condition was effective in reducing ulceration for" helpltss" rats as well as rats which could control shock. Thus, the effectiveness of a coping behavior depends on the reliable prediction of shock in a stressful situation.

Effects of unpredictability versus loss of predictability of shock on gastric lesions in rats

“…Despite the difficulty in making clear-cut interpretations regarding the etiological mechanisms (Badia, Harsh, & Abbot, 1979;Davis & Levine, 1982;Imada & Nageishi, 1982;Scheuer & Greenberg, 1982;Tsuda, Tanaka, Hirai, & Pare, 1983), it is reasonable to suggest, on the basis of the safety-signal hypothesis (Seligman & Binik, 1977), that both unpredictability and loss of predictability of shock have many deleterious consequences on the ulcerogenesis process because animals that have no safety signal (Le., no tone that indicates time out from shock) are the most stressed and consequently will continue to be subjected chronically to fear.…”

Effects of predictability on the welfare of captive animals

“…In other words, loss of predictability would be more detrimental to welfare than lack of predictability (unpredictability). This hypothesis is largely due to extrapolation of findings from studies indicating that loss of control over an aversive outcome, in animals that have previously been able to control it, is more stressful than never having had control (Hanson et al, 1976;Seligman, 1975;Tsuda et al, 1983;Weiss, 1971b). However, there was no difference in the amount and severity of gastric lesions shown by rats exposed to a loss of predictability of shock, compared to those that were continuously exposed to unpredictable shock (Tsuda et al, 1984).…”

Differential changes in noradrenaline turnover in specific regions of rat brain produced by controllable and uncontrollable shocks.

“…Recently, investigators have emphasized the importance of psychological factors such as controllability of stressors in the manifestation of stress-related behavioral and/or physiological disturbances (see Maier & Seligman, 1976; Weiss, 1977). It is now well documented that uncontrollable shock induces more gastric lesions (Tsuda, Tanaka, Hirai, & Paré, 1983; Tsuda, Tanaka, Nishikawa, & Hirai, 1983; Weiss, 1971) and also disrupts active responding at a later time (i.e., “learned helplessness”) than does controllable shock (Brown, Rosellini Samuels, & Riley, 1982; Seligman, 1975; Sherman, Sacquitne, & Petty, 1982). In the literature on stress-induced changes in NA function, there are several studies that dealt with the effects of shock controllability on disturbances of NA function in the brain.…”