Schedule‐Induced Polydipsia: A Rat Model of Obsessive‐Compulsive Disorder

Abstract

Obsessive-compulsive disorder (OCD) is difficult to model in animals due to the involvement of both mental (obsessions) and physical (compulsions) symptoms. Due to limitations of using animals to evaluate obsessions, OCD models are limited to evaluation of the compulsive and repetitive behaviors of animals. Of these, models of adjunctive behaviors offer the most value in regard to predicting efficacy of anti-OCD drugs in the clinic. Adjunctive behaviors are those that are maintained indirectly by the variables that control another behavior, rather than directly by their own typical controlling variables. Schedule-induced polydipsia (SIP) is an adjunctive model in which rats exhibit exaggerated drinking behavior (polydipsia) when presented with food pellets under a fixed-time schedule. The polydipsic response is an excessive manifestation of a normal behavior (drinking), providing face validity to the model. Furthermore, clinically effective drugs for the treatment of OCD decrease SIP. This protocol describes a rat SIP model of OCD and provides preclinical data for drugs that decrease polydipsia and are clinically effective in the treatment of OCD.

Inhibition of hippocampal plasticity in rats performing contrafreeloading for water under repeated administrations of pramipexole

“…Taken together, these results suggest that CFL induced by dopaminergic drugs models some key hallmarks of the obsessive-compulsive disorder (OCD) in that the contingent response is excessive, time consuming, and disconnected to the outcome it is performed for. Our findings are in line with the notion that dopaminergic stimulation enhances compulsive drinking during schedule-induced polydipsia (SIP), a reliable model of OCD whereby rats drink in excess of need following intermittent food presentation (Platt et al 2008;Moreno and Flores 2012;Hawken and Beninger 2014).…”

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

“…The polydipsia characterized in SIP seems to feature both motor and cognitive aspects of psychological obsession through an excessive manifestation of a normal behavior (i.e., drinking), thus demonstrating good face validity in modeling OCD (Platt et al 2008). In fact, SIP has long been used in the development of novel pharmaceutical agents to treat OCD (Woods-Kettelberger et al 1997).…”

“…Throughout SIP, responses preceding the next reward can be shaped via a series of scheduled activities and can include three striking behavioral phases, termed adjunctive, facultative, and terminal behaviors, which in rats correspond to licking the water supply, locomotion, and poking the magazine that dispenses pellets, respectively. Recently, SIP has been recognized as having good face validity for chronic stress-induced compulsive behavior; therefore, it may be used as a rat model of obsessive-compulsive disorder (OCD) (Platt et al 2008;Woods-Kettelberger et al 1997).…”

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).…”

“…We also examined possible between-strain differences on schedule-induced polydipsia (SIP) task that has been suggested as a model of OCD (Platt et al, 2008;Rosenzweig-Lipson et al, 2007;Woods et al, 1993;Woods-Kettelberger et al, 1996). As impulsive behaviors have been related to monoaminergic dysfuctions (Winstanley et al, 2006), we assessed basal neurochemical function in the striatum and nucleus accumbens of RHA-I and RLA-I rats.…”