Central cholinergic blockade and two-way avoidance acquisition: The role of response disinhibition

Bidirectional avoidance by mice as a function of CS, US, and apparatus variables

“…Such conditions include punishment of intertrial crossings (Bignami, Amorico, FrontaIi, & Rosie, 1971;Schwartzbaum, Green, Beatty, & Thompson, 1967; for a similar effect of intertrial response prevention, see Moot, Nelson, & Bolles, 1974) and increases in shock intensity (Anisman & Waller, 1972;Archer, Ogren, & Johansson, 1984;Bauer, 1972;Bignamiet al, 1971;Cicala, Owen, & Hill, 1976;Henderson, 1970;Johnson & Church, 1965;Levine, 1966;McAllister, McAllister, & Douglass, 1971;Moyer & Korn, 1964;Schwartzbaum et al, 1967;Theios, Lynch, & Lowe, 1966). A similar assertion can tentatively be made with regard to the impairment of rat avoidance obtained by the use of a central partition with an opening of limited size at floor level (Bignami et al, 1971;Dalby & Shuttlesworth, 1978;Henderson, 1970; for preexposure conditions modifying this effect, see Alleva, De Acetis, Amorico, & Bignarni, 1983). In fact, the periods of shock experienced by animals moving in a random fashion in the initial stages of training, before they learn to reach the safe part of the box, are more extended in the presence of a partition than in its absence.…”

“…Brief intervals, which produce high initial shock densities, lead to slower acquisition than do longer intervals. Proposed explanations include response competition and reinforcement models (Archeret al, 1984;Bignami et al, 1971;Brush, 1962;Denny, Zerbolio, & Weisman, . 1969;Kurtz & Shafer, 1967;Levine & England, 1960;McAllister et al, 1971;Murphy & Miller, 1956).…”

“…Under the conditions used by these investigators, "light on" was also unable to exert excitatorycontrol. By contrast, a considerable amount of work, includingthat on "light-on/light-off' comparisons mentioned above, shows that "light on" can be an effective avoidance CS (see, e.g., Bignami et al, 1971;Cicala & Azorlosa, 1984; Giardini, Amorico, De Acetis, .…”

Handbook of Psychopharmacology

“…On the basis of these negative posttraining results, they rejected the hypothesis that physostigmine exerts its effects on memory. Instead, they proposed that the drug enhances inhibition of nonrewarded responses thereby reducing errors and improving performance (see also Bignami et al, 1971). This hypothesis has received independent support from a study by Leaton and Kreindler (1972), who showed that during operant brightness discrimination training, physostigmine-induced facilitation of learning is primarily achieved by reductions in the response rate associated with the non rewarded stimulus.…”

“…A gradual reduction of scopolamine dosage over nine sessions alleviated the precipitous loss of responding associated with sudden transfer to testing with saline (see discussion of "state dependency" in Section 8.2). A further complication is that the improvement of two-way avoidance learning by scopolamine can be eliminated by using massed training or long intertrial intervals (Bignami et at., 1971). Taken together, these factors give good grounds for suspecting that an effect on performance is a major, if not the primary effect of scopolamine in two-way avoidance experiments.…”