Individual differences in schedule-induced polydipsia and the role of gabaergic and dopaminergic systems

Abstract

These data provide novel evidence that individual differences in SIP are not predictive of behavioral reactivity in animal models of anxiety and suggest an important role for the dopaminergic system in such individual differences. These findings point to SIP as a useful animal model for investigating the neurobiological basis of vulnerability to several psychopathologies in which the dopaminergic system is involved.

Schedule-induced polydipsia as a model of compulsive behavior: neuropharmacological and neuroendocrine bases

“…Moreover, rats classified according to SIP acquisition as high drinkers (HD) and low drinkers (LD) manifest differences in pharmacological challenge with dopaminergic drugs. SIP was reduced in HD animals with 0.5 mg/kg of D-amphetamine and 10 mg/kg of cocaine, while in LD rats, SIP was reduced only at the higher dose of 2 mg/kg of Damphetamine (López-Grancha et al 2008). Thus, consistent with human data on inhibitory response control in the stop task previously mentioned (de Wit et al 2007), D-amphetamine effectively reduced the compulsive drinking in HD, perhaps by improving response inhibitory control over stopping an action.…”

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

“…Water bottles containing 100-ml fresh water were provided immediately before each session. The following measures were recorded for each rat: (a) total amount of water (ml) removed from the bottle, (b) total number of licks, and (c) and total number of nose-pokes (see López-Grancha et al, 2008, for more details).…”

“…A detailed description of the apparatus has been provided previously for SIP and delay-discounting task (Cardona et al, 2006;López-Grancha et al, 2008). The same chambers were also used in the 5-CSRT task, with an array of five contiguous square holes (2.5 cm), 2.2-cm deep and 2 cm above floor level at the back panel.…”

“…Curiously and relevant to this work, these disorders also share impulsivity as one of the main symptoms (American Psychiatric Association, 2000). In fact, the development of SIP has revealed marked individual differences among animals (Cardona et al, 2006;López-Grancha et al, 2008;Valenstein, 1984, 1985;Piazza et al, 1993), allowing their separation into high (HD) and low drinkers (LD) populations, according to whether their rates of drinking are above or below the median. Our findings show a high correspondence of RHA-I and HD and between RLA-I and LD.…”

Role of nitric oxide in amphetamine-induced sensitization of schedule-induced polydipsic rats

“…All drugs were prepared to produce a total injection volume of 1.0 ml/kg and were injected intraperitoneally (i.p.). The AMPH doses used in this study have been previously shown to disrupt SIP (Liu et al 2005;López-Grancha et al 2008). The L-NAME dose used to antagonize the AMPH-induced behaviors in rats varies across a wide range in different experimental paradigms (Afanas'ev et al 2000;Przegaliński and Filip 1997;Przewłocka et al 1996;Stewart et al 1994).…”