Biomedical subjects

C L Wetherington

Publications and source records attributed to C L Wetherington.

7 recordsLinked to original sources

PubMed1991

The effects of food schedule adaptation on the ability of naloxone to suppress the acquisition of schedule-induced polydipsia.

Naloxone suppressed the acquisition of schedule-induced polydipsia (SIP) in rats given no previous exposure to the feeding schedule. Adaptation to the feeding schedule prior to SIP acquisition attenuated this suppression. Specifically, water consumption, bout probability, licks/bout and maximum lick rates during the interpellet interval (IPI) were significantly increased by adaptation. Although adaptation attenuated the suppressive effects of naloxone on SIP, this attenuation was not complete. Adapted, naloxone-treated subjects displayed both decreased water consumption and bout probability as compared to distilled water-treated controls. Unlike the effects of adaptation on naloxone's suppression of SIP, adaptation completely eliminated naloxone's suppression of feeding. That adapted subjects ate at control levels while still displaying a lower level of SIP suggests that the suppressive effect of naloxone on the acquisition of SIP is not an indirect effect of naloxone on feeding, but rather a direct effect of naloxone on developing SIP. Given that naloxone has a general suppressive effect on drinking (including SIP), what remains to be determined is why naloxone has no effect on established SIP. Possible explanations for this are discussed.

Adaptation, Psychological↗

PubMed1987

The differential effects of naloxone hydrochloride on the acquisition and maintenance of schedule-induced polydipsia.

Rats injected with the opiate antagonist, naloxone hydrochloride (10 mg/kg), 15 min prior to sessions in which they were given free food on a fixed time 75-sec schedule, displayed retarded acquisition of schedule-induced polydipsia relative to vehicle-injected subjects. Rats injected with naloxone after schedule-induced polydipsia had been acquired were unaffected, i.e., they continued to drink at control levels. Given that schedule-induced polydipsia has been considered non-opioid in nature, because of previous reports of its insensitivity to naloxone, the present report of differential effects of naloxone on the acquisition and maintenance of schedule-induced polydipsia suggests that some modification of this conclusion is necessary. Possible alternative mechanisms for these differential effects are discussed.

Animals↗

PubMed1986

Diminution of schedule-induced polydipsia after a long rest period.

Schedule-induced polydipsia was established in four food-deprived rats given daily hourly sessions in which a food pellet was presented once each min. Sessions were then discontinued for approximately six months. After this rest period, the daily sessions were resumed. Relative to the water intake during the last five sessions prior to the rest period, water intake during the first five sessions after the rest period exhibited a 55.5%, 10.3%, 32.0% and 29.6% decrement for the four rats, respectively. These results are discussed in terms of a sensitization view of schedule-induced polydipsia.

Animals↗

PubMed1985

A software package for the microcomputer control and analysis of research on schedule-induced polydipsia.

This manuscript describes a software package called POLY which offers a range of routines designed to allow the user to set up, run and analyze data for research on schedule-induced polydipsia. The three major routines described are SETUP, RUN and ANALYSIS. The routines are flexible and give the user efficient control over the parameters of the research and the collection and analysis of the data. Although designed for research on schedule-induced polydipsia, the software can be used for other research purposes, requiring only changes in the support hardware.

Animals↗

PubMed1983

Schedule-induced polydipsia and size of water dipper.

Schedule-induced polydipsia as a function of six water dipper sizes was examined in four food-deprived rats under Fixed Time 1- and 2-minute schedules. Increasing dipper size increased session water intake but did not affect the number of intervals containing at least one barpress (i.e., number of bouts), nor the number of barpresses per bout, nor the temporal distribution of barpressing within the interfood interval. Previous research showing polydipsic intake to be impervious to other types of restrictions on water availability have suggested the notion of a volume constancy mechanism. The present research raises questions about the operation of the volume constancy mechanism, questions about how to conceptualize the dipper size manipulation, and questions about variables which affect the temporal locus of drinking.

Animals↗

PubMed1982

Is adjunctive behavior a third class of behavior?

Research during the past 20 years has revealed that intermittent food presentation to a variety of organisms results in an inordinately excessive consumption of water as well as other behaviors including attack, pica, escape, and alcohol consumption. Such behavior has not been thought to be either respondent or operant behavior, but instead has been regarded as a new behavioral category termed "adjunctive behavior." This paper reexamines the rejection of adjunctive behavior as either operant or respondent behavior and concludes that the rejection was premature. This paper also reexamines the argument that there is a unique class of adjunctive behavior and concludes that there is not. It is recommended that given the growing difficulties in maintaining an operant-respondent dichotomy, rather than admitting adjunctive behavior into either of these categories, research efforts should de-emphasize preconceived and outdated notions about categories of behavior and how such behaviors should behave and instead focus on mapping functional relationships between behavior and various procedures for presenting non-contingent stimuli.

Animals↗

PubMed1979

Schedule-induced drinking: rate of food delivery and Herrnstein's equation.

Schedule-induced drinking was measured in four rats exposed to fixed-time schedules of food ranging from 30 to 480 seconds. Herrnstein's (1970, 1974) equation relating rate of a single response as a hyperbolic function of reinforcement rate provided a good fit to three measures of drinking: lick rate, ingestion rate, and relative time spent drinking. The functions relating the three measures of drinking to reinforcement rate were of similar form. Herrnstein's equation also provided a good description of some already published data on schedule-induced drinking. The fit both to the present data and to the already published data was improved somewhat by computing the measures by subtracting from the time base a latency constant representing the minimal time required to consume the food pellet and travel to the water source. The data from this study provide two correspondences between operant behavior and schedule-induced behavior: (a) conformity to Herrnstein's equation and (b) equivalence of rate and relative time measures.

Animals↗