Differential response gradients to a Pavlovian safety signal following active avoidance training in young and adult rats

Abstract

Following 300 training trials in two-way shuttle avoidance signaled by a tone (CS+), two groups each of weanling and adult rats were given Pavlovian discrimination training in which the CS+ was followed by inescapable shock, and a more intense tone (C8-) signaled no shock. An additional group at each age level received both tones paired randomly with shock or no shock. Subsequent generalization tests along the frequency dimension indicated that both pups and adults tested at the CS+ intensity showed similar gradients of frequency control. Gradients for the adults tested at the C8-intensity tended to be inverted, with least responding at C8-, a result not found in the young subjects. The results were considered in light of Pavlovian extradimensional influences on the control of avoidance behavior.

Nicotine as a signal for the presence or absence of sucrose reward: a Pavlovian drug appetitive conditioning preparation in rats

“…From a conditioning perspective, this result is important because it demonstrates that changes in the salience of the training CS result in alterations in the CR. Similar results have been reported in a wide range of Pavlovian conditioning preparations (Rohrbaugh et al 1971;Scavio and Gormezano 1974;Brennan 1975;Czaplicki et al 1976). The ability to generate an orderly dose-effect function suggests that this preparation might be utilized to study the neuropharmacological processes mediatingthe ability of a drug to serve as a CS in much the same fashion that drug discrimination is used to study processes mediating a drug's ability to serve as a S D .…”

Salicylate-induced changes in auditory thresholds of adolescent and adult rats

“…This context effect, explained in terms of the relationship between training stimuli and generalization gradient decrements, has been reported in the classic literature on stimulus generalization (e.g., Hanson, 1959;Switalski, Lyons, & Thomas, 1966) and in a more recent study of salicylate-induced effects on generalization of suppression responses using novel stimuli . The similar influence of generalization decrement across age levels in this study is consistent with expectations based upon older studies of auditory generalization along the frequency dimension of an aversively trained CS, as well as dynamism effects obtained at both age levels when CS auditory intensity was varied (Brennan, 1975;Brennan & Riccio, 1972a, 197213).…”

Prefrontal lesion effects on suppression of open-field activity in young and adult rats

“…Age-related deficiencies in acquisition of active avoidance emerge with a stringent criterion (Egger & Livesey, 1972), and differential extinction of active avoidance has been shown with response-produced punishment (Riccio & Marrazo, 1972), after conditioned stimulus (CS) habituation (Wilson, Phinney & Brennan, 1974) or with a complexity of CS cues (Brennan & Barone, 1976). While comparable gradients of stimulus control of active avoidance in young and adult rats have been reported (Brennan & Riccio, 1972), Brennan (1975) found age differences in the generalization of a response-inhibiting, Pavlovian safety signal. Aversive effects on general activity in young and adult rats are relatively unexplored.…”