Production of Polydipsia in Normal Rats by an Intermittent Food Schedule

Abstract

Water drinking behavior of albino rats was studied as a function of two schedules of food reinforcement and one schedule of shock avoidance. Considerable water drinking occurred concurrently with the food reinforced response but none with the shock avoidance response. This difference might be attributed either to the use of food instead of shock or to the presence of timing behavior in conjunction with the food schedules but not the shock schedules. Problem Falk (1961) has reported that rats on a variable interval schedule of food reinforcement for bar pressing show a very high rate of drinking when a water bottle is placed in the test chamber. He has termed this phenomenon "psychogenic polydipsia" since the excessive intake of water is dependent on psychological factors, i.e. the schedule of food reinforcement for the bar-press response. It should be emphasized that the food reinforcement is not contingent on the water drinking response. Segal (1963) has demonstrated this phenomenon using the schedule of differential reinforcement of low rates. In the present experiment an attempt was made to replicate this phenomenon, not only with the above schedules of positive reinforcement, but also with a schedule of negative reinforcement. Method Six naive male albino rats were used. They were all food deprived and fed at the end of each daily 50 min. session. They were maintained at approximately 80% of normal body weight. A Grason-Stadler test chamber, shock generator and scrambler were used. Food reinforcements consisted of 45 mg Noyes pellets. The spout of the water bottle protruded through the right hand side of the intelligence panel into the test chamber. A Lehigh Valley Electronics drinkometer was used to record the drinking response. Two Ss were reinforced on a variable interval schedule with a mean of 64 sec.; two Ss were reinforced on a differential reinforcement of low rate schedule in which the required pause between responses was 8 sec.; and two Ss were reinforced on a non-cued avoidance schedule in which both the time between uninterrupted shocks and the time between an avoidance response and the next shock was 16 sec. The shock was .5 rna and lasted for .2 sec. Results The behavior of the food-reinforced animals was essentially the same as that previously reported by Falk (1961) and Segal (1963). The median numbers of drinking responses per session during the last three sessions of exposure to these schedules (sessions 16-18) were 4287 and 1279 for the animals on the variable interval schedule and 6586 and 5036 for the animals on the low rate schedule. Neither of the animals on the avoidance schedule emitted any drinking responses during these sessions. Discussion In non-cued avoidance experiments with rats, two different types of avoidance behavior are sometimes observed. In some instances, a sort of timing behavior develops in which the bar-press responses are so effectively spaced that most of the shocks are avoided and the average interresponse time is approximately the same as the amount of time the ...

Impulsivity Characterization in the Roman High- and Low-Avoidance Rat Strains: Behavioral and Neurochemical Differences

“…As a result of its characteristics of 'excessiveness' and 'persistence', SIP (Falk, 1961) has been suggested as a model of OCD (Platt et al, 2008;Woods et al, 1993). Moreover, the SIP model seems to be sensitive to detect susceptibilities in individuals to addictive behavior (Gilpin et al, 2008;Mittleman et al, 2003;Toscano et al, 2008) and bingeeating behavior (Moreno et al, 2009).…”

Schedule-induced water and saccharin polydipsia under haloperidol

“…Rats reinforced intermittently with dry food pellets drink excessively by consistently consuming water after reinforcement (Falk, 1961(Falk, , 1972. Such drinking is attenuated by atropine (Burks & Fisher, 1970), trihexyphenidyl (Keehn & Matsunaga, 1971), and haloperidol (Keehn, Coulson, & Klieb, 1976).…”

Comportamento adjunto: controvérsias e contribuições teóricas

“…Agredir em pombos ocorreu tipicamente após o alimento no estudo de Campagnoni, Lawler e Cohen (1986). No entanto, certos casos que pareceram exceções para Falk (o agredir em pombos não foi pós-alimento quando o esquema utilizado foi um FR 60 e FR 120, bem como a polidipsia ocorreu ao longo do intervalo com esquema de intervalo longo acima de 3 minutos), para Wetherington (1982) (Falk, 1961) e que ainda hoje se mantém como a mais importante. No entanto, é a característica mais controvertida quando se discute a adequação da linha de base e das medidas utilizadas para se definir o que é comportamento excessivo (Cohen & Looney, 1984Haydu & Silva, 1997Roper, 1981;Timberlake, 1982;Wetherington & Brownstein, 1982;Wetherington, 1982 (Burks, 1970;Flory, 1971;Wetherington, 1979); duração de beber por pelota (Wetherington, 1979) e porcentagem de ocorrência de beber por pelota (Allen & Kenshalo, 1976;Segai, Oden & Deadwyler, 1965;Wetherington, 1979).…”

“…(g) Não é Necessário um Esquema Contingente. Embora a polidipsia tenha sido observada primeiro durante o condicionamento da resposta operante de pressão à barra sob um esquema VI (Falk, 1961), posteriormente foi observada também com esquemas de liberação não contingente de alimento (Falk, 1966a;Schurtleff, Delamater & Riley, 1983). Outros comportamentos adjuntos, como agredir, lamber jatos de ar e "pica", foram observados sob esquemas não contingentes (FT) (citados por Falk, 1971).…”