Effects of Quinpirole on Operant Conditioning: Perseveration of Be havioral Components

Abstract Quinpirole (QNP) is reported to elicit repetitive spontaneous behaviors as well as reduce extinction of operant responses. To determine whether these effects represent perseveration of learned behaviors, behavioral components were examined during the acquisition and extinction of operant responses. Rats, receiving either 0, 0.08, or 0.60 mg/kg QNP were trained to nose poke to receive water. The lower dose interfered with acquisition, but once learned, behavioral characteristics were normal. The higher dose produced excessive time in the drinking well when water was delivered. When water was withheld, the control and 0.08 mg/kg dose groups altered their behavior by initially increasing nose poke duration, followed by a progressive extinction of the operant response. The higher dose group, however, did not modify the characteristics of their behaviors, but continued to perform the behavioral sequence in the absence of reward. These effects are not ascribable to generalized locomotor activation in that response rates during reinforced responses, as well as at the beginning of the extinction phase, did not differ significantly across treatment groups. These results indicate that perseveration effects of QNP are not accountable by general behavioral arousal, nor are specific to extinction. Instead, these effects appear to reflect reduced adaptability of learned behavioral patterns to changes in reinforcement contingencies

Discriminating Global Orientation of Two Element Sets

Perceived global organization of visual patterns is based upon the aggregate contribution of constituent components. Patterns constructed from multiple sources cooperate or compete for global organization. An investigation was made here of interactions between two interspersed element sets on global orientation. It was hypothesized that each set would operate as an integrated unit, and contribute independently to global orientation. Participants viewed a 10 x 10 array of Gabor patches, and indicated the predominant orientation of the array. In Experiment 1 all elements were rotated. Rotation up to 23° had little effect, whereas greater rotation produced a progressive shift on global orientation. In Experiment 2 a proportion of elements remained aligned while remaining elements were rotated. Embedding a proportion of aligned elements stabilized global orientation, which was dependent upon the proportion of aligned elements. Specifically, with 20% alignment, global orientation was similar to rotating all elements, whereas 80% alignment strongly biased perception towards aligned elements. The stabilizing effect varied with rotation of the second element set. Across levels of rotation, alignment effects rose to a peak then declined as element sets became orthogonal. In Experiment 3, each element set was rotated independently. Independent rotation of both sets altered global orientation, compressing the psychometric function for the single-element condition. Together, for interspersed element sets with explicit orientations, each set does not contribute independently to global orientation. Instead, element sets interact, where the contribution of one set, presented at a fixed rotation and fixed proportion, varies with the change to the second set

Chemical kinetics and photochemical data for use in stratospheric modeling. Evaluation number 6

Evaluated sets of rate constants and photochemical cross sections are presented. The primary application of the data is in the modeling of stratospheric processes, with particular emphasis on the ozone layer and its possible perturbation by anthropogenic and natural phenomena

Chemical kinetics and photochemical data for use in stratospheric modeling evaluation Number 8

This is the eighth in a series of evaluated sets of rate constants and photochemical cross sections compiled by the NASA Panel for Data Evaluation. The primary application of the data is in the modeling of stratospheric processes, with particular emphasis on the ozone layer and its possible perturbation by anthropogenic and natural phenomena. Copies of this evaluation are available from the Jet Propulsion Laboratory, Documentation Section, 111-116B, California Institute of Technology, Pasadena, California, 91109

Chemical kinetics and photochemical data for use in stratospheric modeling

Rate constants and photochemical cross sections are presented. The primary application of the data is for modeling of the stratospheric processes, with particular emphasis on the ozone layer and its possible perturbation by anthropogenic and natural phenomena

Chemical kinetic and photochemical data for use in stratospheric modelling

An evaluated set of rate constants and photochemical cross sections were compiled for use in modelling stratospheric processes. The data are primarily relevant to the ozone layer, and its possible perturbation by anthropogenic activities. The evaluation is current to, approximately, January, 1979

Chemical kinetics and photochemical data for use in stratospheric modeling

As part of a series of evaluated sets, rate constants and photochemical cross sections compiled by the NASA Panel for Data Evaluation are provided. The primary application of the data is in the modeling of stratospheric processes, with particular emphasis on the ozone layer and its possible perturbation by anthropogenic and natural phenomena. Copies of this evaluation are available from the Jet Propulsion Laboratory

Ozone-depleting substances (ODSs) and related chemicals

The amended and adjusted Montreal Protocol continues to be successful at reducing emissions and atmospheric abundances of most controlled ozone-depleting substances (ODSs).Global Ozone Research and Monitoring Projec