Reticular Stimulation and Chlorpromazine: An Animal Model for Schizophrenic Overarousal

Abstract

It has been postulated that certain schizophrenic patients are in a state of continual central excitation and that improvement in these patients after treatment with chlorpromazine is a result of the action of the drug in reducing this excitation. A model was developed to test this postulated state of central excitation. Rats were electrically stimulated in the mesencephalic reticular formation while performing a simple attention task. Stimulation or treatment with chlorpromazine impaired the performance of the animals; however, the two treatments together resulted in performance indistinguishable from that seen after injections of saline alone.

Scopolamine attenuates the motor disruptions but not the attentional disturbances induced by haloperidol in a sustained attention task in the rat

“…These results support and extend the findings of previous reports which have demonstrated an increase in errors of omission following neuroleptic treatment in animals (Kornetsky and Bain 1965;Kornetsky and Eliasson 1969;Eliasson and Kornetsky 1972). Because an increase in errors of omission is believed to reflect a decrease in sustained attention capabilities in humans (Kornetsky 1972), the increase in omission errors observed here suggests that haloperidol may interfere with attentional processing in rats.…”

“…If scopolamine could be shown to attenuate a haloperidol-induced disruption in attentional performance, then the previously reported increases in errors of omission following neuroleptic treatment (Kornetsky and Bain 1965;Kornetsky and Eliasson 1969;Eliasson and Kornetsky 1972) may have been due to operant rate declines and may not have been due to a direct effect on attentional behavior. If, however, scopolamine normalized haloperidol-impaired motor functioning as reflected in normal response latencies, while leaving a haloperidol-induced attention disruption intact, then a possible role for sustained attention task procedures in animal models of neuroleptic drug response would be suggested.…”

The 5-choice serial reaction time task: behavioural pharmacology and functional neurochemistry

“…When I began this project in about 1977, a number of test procedures had been developed for assessing in animals different aspects of attention (sometimes called continuous performance), such as those introduced by Rosvold and Mirsky (Rosvold et al 1956;Mirsky and Rosvold 1960) and Kornetsky and Eliasson (1969). However, although some basic drug effects had been described using these procedures, neither of these groups had begun to address the possible roles of central neurotransmitter systems upon which such drugs most probably acted.…”

Psychophysiological and Neurophysiological Aspects of Schizophrenia

“…Since the brain stem reticular formation has long been known to be the central agent in brain activation, the above· conclusion implicates this system. One direct attempt at testing this hypothesis was made by Kornetsky & Eliasson (1969). They implanted electrodes in the mesencephalic reticular formation in rats, and observed the effects of: a) electric stimulation in this area; and b) treatment with chlorpromazine.…”