DRL Interresponse‐time Distributions: Quantification by Peak Deviation Analysis

Abstract

Peak deviation analysis is a quantitative technique for characterizing interresponse-time distributions that result from training on differential-reinforcement-of-low-rate schedules of reinforcement. It compares each rat's obtained interresponse-time distribution to the corresponding negative exponential distribution that would have occurred if the rat had emitted the same number of responses randomly in time, at the same rate. The comparison of the obtained distributions with corresponding negative exponential distributions provides the basis for computing three standardized metrics (burst ratio, peak location, and peak area) that quantitatively characterize the profile of the obtained interresponse-time distributions. In Experiment 1 peak deviation analysis quantitatively described the difference between the interresponse-time distributions of rats trained on variable-interval 300-s and differential-reinforcement-of-low-rate 72-s schedules of reinforcement. In Experiment 2 peak deviation analysis differentiated between the effects of the psychomotor stimulant d-amphetamine, the anxiolytic compound chlordiazepoxide, and the antidepressant desipramine. The results suggest that peak deviation analysis of interresponse-time distributions may provide a useful behavioral assay system for characterizing the effects of drugs.

Fractionating Impulsivity: Contrasting Effects of Central 5-HT Depletion on Different Measures of Impulsive Behavior

“…The most successful example of the former category are delaydiscounting paradigms in which impulsive choice is defined as the selection of a small but immediate reward over a larger but delayed one (Evenden and Ryan, 1996;Mazur, 1987;Richards et al, 1999;Wogar et al, 1993). In the latter category, it has also proved possible to assess the ability of an animal to withhold from making a response, for example in differential reinforcement of low-rate schedules (DRL) (eg Fletcher, 1995;Richards et al, 1993), and in 'go/no-go' tasks (eg Harrison et al, 1999).…”

Prenatal choline supplementation alters the timing, emotion, and memory performance (TEMP) of adult male and female rats as indexed by differential reinforcement of low-rate schedule behavior

“…Responses emitted before the criterion time are not reinforced, but instead reset the experimental clock, forcing the subject to withhold responding again until the criterion time has passed. Hence, this schedule can access both the self-paced timing ability of subjects, as well as their capacity to inhibit impulsive responding following errors (e.g., Richards et al 1993;Evenden 1999;Ripley et al 2001). We utilized a series of DRL schedule values in order to study emotional behavior as indexed by premature burst responding, as well as memory endurance indexed by the resistance to change during the transition from one criterion time to another.…”

Antidepressant-Like Effects of the Corticotropin-Releasing Factor 1 Receptor Antagonist, SSR125543, and the Vasopressin 1b Receptor Antagonist, SSR149415, in a DRL-72 s Schedule in the Rat

“…It is possible that the effects of SSR149415 and SSR125543 on DRL-72 s performance result from an interaction with monoaminergic systems, such as the serotonergic (5-HT) and norepinephrine (NE) neurotransmissions (Carrasco and Van de Kar, 2003;Lowry et al, 2000;Day et al, 2004;Price et al, 1998). It has been demonstrated that the activity of classical antidepressants in DRL-72 s schedules relies on their ability to modulate 5-HT and NE neurotransmission (Britton and Koob, 1989;Richards and Seiden, 1991;Richards et al, 1993;Balcells-Olivero et al, 1998;Dekeyne et al, 2002). Experiments with the CRF1 receptor antagonist CP154,526 have shown that this compound did not alter basal levels of cortical 5-HT, NE, and dopamine, in freely moving rats (Millan et al, 2001).…”

“…The following parameters were automatically recorded by the Med-PC software: the total number of lever-presses emitted during the session, the number of food pellets obtained (ie the number of reinforced responses), and the inter-response time (IRT, the time elapsed between two lever-presses; Richards et al, 1993). IRTs were subsequently split into nine bins (IRT bin (0-12 s), IRT bin (13-24 s),y, IRT bin (85-96 s), and IRT bin (496 s)).…”

“…From these raw data, the percentage of lever-presses emitted in each of the nine 12 s bins and the percentage of lever-presses reinforced were calculated using a Macro procedure with the Excel s software (percentages were calculated as a function of the total number of lever-presses emitted during the session). The percentages of lever-presses during two IRT bins in particular were analyzed: (1) the IRT bin (0-12 s), corresponding to the 'burst responses' and shown to be sensitive to benzodiazepine-like compounds (Richards et al, 1993); (2) the IRT bin (49-96 s), as it has been shown to be particularly sensitive to antidepressant drugs (Cohen et al, 1997).…”