Earl X. Freed

Criteria for an animal model of alcoholism.

A correspondence between the various components of human alcoholism and their animal analogue has not yet been achieved; in some part, this failure resides with experimental attempts which obtain which obtain only surface equivalencies and which lack an underlying motivational structure. Seven criteria for an animal model are proposed including the oral ingestion of alcohol without food deprivation, substantial ingestion of alcohol with competing fluids available, drinking directed to the intoxicating effect of alcohol, the performance of work to obtain alcohol, the maintenance of intoxication over a long period and, finally, the production of physical dependence and, on withdrawal, the abstinence syndrome.

A Fortuitous Observation regarding “Psychogenic” Polydipsia:

Observations are reported of 5 rats, which had developed schedule-induced polydipsia and essentially stopped drinking, but not bar pressing, when they manipulated or chewed cellulose material from the excreta tray under the conditioning chamber. Polydipsia reappeared with removal of cellulose. This suggested that drinking was one of a number of inter-pellet behaviors depending upon available stimuli.

Differential tolerance to pentobarbital in rats bred for differences in alcohol sensitivity

Two lines of rats bred for differences in motor impairment following alcohol treatment were also found to be differentially affected by sodium pentobarbital in three experiments. The most affected (MA) animals, bred for sensitivity to alcohol, showed a decrement in stabilimeter activity at doses of 8 mg and 16 mg pentobarbital per kg body weight. The least affected (LA) animals, bred for insensitivity to alcohol, were affected only by the higher dose, at which the resulting imapairment was still less than that of the MA group. This finding was partially replicated in a second study designed to test the possibility of an activating effect of pentobarbital on LA animals at 8 mg/kg. In a final study, MA animals were more likely to lose their righting reflex than LA animals at a dose of 18 mg/kg, and ‘slept’ longer following this dose. These results indicate that the differential sensitivity shown by these animals is not specific to alcohol, but can be generalized to another depressant.

A RAT MODEL OF ALCOHOLISM

The behavior of rats manifesting psychogenic polydipsia is impressive-because it is predictable, excessive, and atypical and, when the fluid consumed is ethanol, because it is at first glance reminiscent of the compulsive drinking of the alcoholic. Polydipsic consumption of ethanol has been a useful tool in psychological research*Z2 where a methodology for self-administration of alcohol was needed in lieu of the more traumatic intraperitoneal injection. As initially reported by Falk,3 schedule-induced polydipsia occurs when food-deprived rats, trained to bar-press for a food pellet on a continuous reinforcement schedule, are introduced to a schedule of intermittent food rewards; later the bar press was found not to be essential. A pattern of alternation of pellet consumption and bursts of licking is displayed, with rats often drinking about half their body weight in water in a three-hour session. The same phenomenon, albeit with lower levels of fluid consumption (because of physiological limitations) occurs if an alcohol solution is substituted for water. It has not been uncommon to obtain alcohol levels ranging up to 0.30% in the blood when rats drink up to 6% of their weight in 5.6% w/v alcohol during a 60-minute experimental session. Such behavior, even if anthropomorphism is guarded against, lends itself to interpretation in terms of an animal model of alcohol addiction. However, a number of our recent studies, investigating the basis for the immoderate alcohol consumption, raise questions about the validity of this model for man’s alcoholism. Clinical and anecdotal evidence suggests that man primarily uses alcohol as a psychopharmacological agent. A suitable animal model of alcohol addiction, then, should incorporate this dynamic. However, if the basis of the rat’s excessive consumption of alcohol, for example in the polydipsic situation, is subject to major control by other than ethanol’s pharmacodynamic effects, then a true model is lacking and what has been achieved is but a mimicry of man’s abuse of alcohol. We have focused on the hypothesis that food-deprived rats utilize alcohol as a ready source of caloric replenishment, a proposition offered e a ~ I i e r . ~ * ~ Food deprivation, with concomitant body-weight loss and maintenance at about 80% of free-feeding weight, and intermittent delivery of food pellets appear to be the sine qua non for schedule-induced polydipsia;s if rats are food-satiated their polydipsic drinking of either alcohol or water c e a ~ e s . ~ When, however, the intermittent delivery of food pellets to the food-deprived rat is stopped, water consumption is rapidly extinguished but alcohol intake remains high.8 Finally, there is ready extinction of the polydipsic consumption of acetone,s which, gram for gram, has a similar pharmacologic action to ethanol but, unlike ethanol, is by virtue of its essential nonmetabolism devoid of calories. Data depicted in FIGURE 1 are interpreted as indicating that the equi-intoxicating, but non-caloric, acetone is treated during extinction as if it were water. In this same experiment, a group ’ This work was supported in part by National Institute of Health Grant NH-11612,

Inconstancy of drinking bursts during schedule-induced polydipsia

Cumulative records of 16 rats from three previous studies of schedule-induced polydipsia were divided into quarters, and the mean number of licks per pellet for each quarter was calculated. Analysis of variance revealed a significant “quarters” effect, interpreted as indicating that the number of licks per pellet decreased as the session progressed. This finding was discussed in terms of methodological considerations for research on the effects of “meal” size on schedule-induced polydipsia.

Schedule-induced polydipsia with nutritive and nonnutritive reinforcers

Eighteen Charles River (cd) male rats were conditioned to drink water polydipsically by the delivery of food pellets on FFI 45 sec, and then, varying percentages of sweetened nonnutritive pellets were substituted for the nutritive pellets. The mean volume of water ingested decreased with decreased nutritive content of the pellets, suggesting a relationship between schedule-induced polydipsia in the rat and the nutritive content of the reinforcer.

The independence of barpressing and schedule-induced drinking

In a study of schedule-induced polydipsia in rats, water was not made available within the operant chamber until magazine and barpress training and adaptation to the intermittent schedule were completed. A gradual development of schedule-induced drinking without corresponding changes in barpressing behavior was seen. In a second experiment, rats differing in the number of barpresses emitted on two temporally similar fixed-interval schedules did not differ significantly in volumes of water consumed during interpellet intervals. Both studies demonstrate the independence of barpressing and schedule-induced drinking.

Normative Data on a Self-Ad Ministered Projective Question for Children

Abstract An attempt was made to define “group reference points or base lines” in responses of 3,863 children, ages 8 to 17, to brief, self-administered projective questions about which animals they would and would not choose to be. It was felt that the efficacy of this device as a self-administered technique was demonstrated. Statistically significant age and sex differences were found as well as evidence of clustering of choices which was interpreted as a kind of conformity. Directions for future research were noted.

Effects of conflict upon schedule-induced consumption of water and alcohol

Schedule-induced polydipsic consumption of water and ethanol was conditioned in two groups of 6 Charles River rats which were then exposed to approach-avoidance (food-shock) conflict. Water intake was attenuated by conflict but ethanol consumption remained essentially unaltered. Alcohols pharmacodynamic effect was implicated as responsible for differences in fluid consumption by the two groups.

ETHNIC IDENTIFICATION OF HOSPITALIZED JEWISH PSYCHIATRIC PATIENTS: AN EXPLORATORY STUDY.

JEWISH ethnic identification has come under close scrutiny by social scientists who have commented on many of the problems inherent in this area. An oftmentioned aspect has been negative identification, Jewish anti-Semitism, or &dquo;identification with the aggressor&dquo;, a phrase attributed to Anna Freud(4). Bettelheim described the behaviour of some Jewish prisoners in World War II concentration camps who patterned their garb and behaviour after that of their Nazi guards(2). Lewin noted the &dquo;negative chauvinism&dquo; or &dquo;Jewish self-hatred&dquo; which was found in Jews whose chronic frustration was directed against themselves and fellow Jews~6>. He felt that this tension resulted from the conflicts which the Jew faced in