This effect has been labeled conditioned suppression or a conditioned emotional response.
A notable line of research that grew out of the conditioned suppression paradigm was that of Rescorla (e.
213-217) argued that emotions are special incidences of operant-respondent interactions and cited a number of studies from the conditioned suppression literature described above to illustrate how responding productive of food reinforcement is affected by the presentation of Pavlovian CSs.
Positive conditioned suppression: Conditioned suppression using positive reinforcers as the unconditioned stimuli.
Conditioned suppression and the effects of classical conditioning on operant behavior.
of immune responses has been shown since 1974, following a serendipitous discovery by a psychologist who was studying how quickly mice can learn to avoid drinking water which is flavored with something associated with nausea- in this case, nausea induced by the drug cyclophosphamide (an anti-cancer agent, which by coincidence is sometimes used to try to arrest progressive MS).
There has been continuing debate as to whether conditioned suppression (Estes & Skinner, 1941) or discriminated punishment (Geller & Seifter, 1960) are appropriate animal models for the assessment of clinical anxiolytics and related compounds.
We examined its utility in a recent series of experiments in which conditioned suppression (of lever pressing by rats) was modified by acute or chronic treatment with an anxiolytic (chlordiazepoxide) or an anticonvulsant that acts at the GABA/benzodiazepine receptor complex (valproate), or by one of these drugs in combination with a possible antagonist.
We sought to establish the similarity of action for a barbiturate to that of benzodiazepines for our conditioned suppression paradigm and to identify the pattern of interaction with putative antagonists.
In the first experiment, conditioned suppression was maintained on CS-US pairing sessions and sessions where injections of the saline vehicle were given throughout the drug phase (although one rat, L114, showed some temporary loss of conditioned suppression in the middle of the drug phase).
However, when pentobarbital was given with flumazenil, there was on most occasions an additional effect of flumazenil with less conditioned suppression being observed than under any other condition, On several such sessions, the CS rate was very similar to the pre-CS rate.
As in Experiment 1, all three rats showed sustained conditioned suppression on CS-US pairing sessions and vehicle sessions in the drug phase, and pronounced increases in CS rates occurred on pentobarbital days with some evidence of increases in pre-CS rates.