Some Effects of Exposure to a Heat Stressor upon the Rat’s Subsequent Reactions to that Stressor

J. D. Greeley, R. F. Westbrook

Research output: Contribution to journalArticleResearchpeer-review

Abstract

In six experiments, rats were placed on a heated plate on two occasions (test and retest), and the latencies with which they licked their paws were taken as an index of their sensitivity to nociceptive stimulation. Experiment 1 provided evidence that rats were selectively analgesic on retest depending upon the intensity of the heat experienced on the initial test. Experiment 2 showed that this analgesia was recruited rapidly and was long-lasting, as it was observed when retest was scheduled as early as 0.2 and as late as 48 h after the initial exposure to the hot-plate. Experiment 3 documented a role for conditioning processes, as this analgesia was removed by an extinction-like procedure conducted between test and retest. Experiments 4 and 5 provided evidence for a non-opioid mechanism of pain control, because the analgesia was not diminished by the opioid antagonist, naloxone, nor by a history of morphine injections. These experiments also revealed that the analgesia observed on retest was enhanced and reduced when rats were given naloxone and morphine, respectively, on the initial test. Finally, Experiment 6 showed that the analgesia on retest summated with that produced by morphine. The results were taken to mean that the hot-plate assay for analgesia can itself activate endogenous mechanisms of pain control, and some speculations were offered as to how this occurred.

LanguageEnglish
Pages241-265
Number of pages25
JournalQuarterly Journal of Experimental Psychology Section B: Comparative and Physiological Psychology
Volume42
Issue number3
DOIs
Publication statusPublished - 1 Aug 1990

Fingerprint

analgesia
Analgesia
Hot Temperature
heat
morphine
rats
Morphine
naloxone
experiment
Naloxone
pain
testing
narcotic antagonists
Pain
Narcotic Antagonists
analgesics
Analgesics
effect
exposure
conditioning

Cite this

@article{448080c8d4954e89a058da6178fec916,
title = "Some Effects of Exposure to a Heat Stressor upon the Rat’s Subsequent Reactions to that Stressor",
abstract = "In six experiments, rats were placed on a heated plate on two occasions (test and retest), and the latencies with which they licked their paws were taken as an index of their sensitivity to nociceptive stimulation. Experiment 1 provided evidence that rats were selectively analgesic on retest depending upon the intensity of the heat experienced on the initial test. Experiment 2 showed that this analgesia was recruited rapidly and was long-lasting, as it was observed when retest was scheduled as early as 0.2 and as late as 48 h after the initial exposure to the hot-plate. Experiment 3 documented a role for conditioning processes, as this analgesia was removed by an extinction-like procedure conducted between test and retest. Experiments 4 and 5 provided evidence for a non-opioid mechanism of pain control, because the analgesia was not diminished by the opioid antagonist, naloxone, nor by a history of morphine injections. These experiments also revealed that the analgesia observed on retest was enhanced and reduced when rats were given naloxone and morphine, respectively, on the initial test. Finally, Experiment 6 showed that the analgesia on retest summated with that produced by morphine. The results were taken to mean that the hot-plate assay for analgesia can itself activate endogenous mechanisms of pain control, and some speculations were offered as to how this occurred.",
author = "Greeley, {J. D.} and Westbrook, {R. F.}",
year = "1990",
month = "8",
day = "1",
doi = "10.1080/14640749008401883",
language = "English",
volume = "42",
pages = "241--265",
journal = "Quarterly Journal of Experimental Psychology Section B: Comparative and Physiological Psychology",
issn = "0272-4995",
publisher = "Psychology Press",
number = "3",

}

Some Effects of Exposure to a Heat Stressor upon the Rat’s Subsequent Reactions to that Stressor. / Greeley, J. D.; Westbrook, R. F.

In: Quarterly Journal of Experimental Psychology Section B: Comparative and Physiological Psychology, Vol. 42, No. 3, 01.08.1990, p. 241-265.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Some Effects of Exposure to a Heat Stressor upon the Rat’s Subsequent Reactions to that Stressor

AU - Greeley, J. D.

AU - Westbrook, R. F.

PY - 1990/8/1

Y1 - 1990/8/1

N2 - In six experiments, rats were placed on a heated plate on two occasions (test and retest), and the latencies with which they licked their paws were taken as an index of their sensitivity to nociceptive stimulation. Experiment 1 provided evidence that rats were selectively analgesic on retest depending upon the intensity of the heat experienced on the initial test. Experiment 2 showed that this analgesia was recruited rapidly and was long-lasting, as it was observed when retest was scheduled as early as 0.2 and as late as 48 h after the initial exposure to the hot-plate. Experiment 3 documented a role for conditioning processes, as this analgesia was removed by an extinction-like procedure conducted between test and retest. Experiments 4 and 5 provided evidence for a non-opioid mechanism of pain control, because the analgesia was not diminished by the opioid antagonist, naloxone, nor by a history of morphine injections. These experiments also revealed that the analgesia observed on retest was enhanced and reduced when rats were given naloxone and morphine, respectively, on the initial test. Finally, Experiment 6 showed that the analgesia on retest summated with that produced by morphine. The results were taken to mean that the hot-plate assay for analgesia can itself activate endogenous mechanisms of pain control, and some speculations were offered as to how this occurred.

AB - In six experiments, rats were placed on a heated plate on two occasions (test and retest), and the latencies with which they licked their paws were taken as an index of their sensitivity to nociceptive stimulation. Experiment 1 provided evidence that rats were selectively analgesic on retest depending upon the intensity of the heat experienced on the initial test. Experiment 2 showed that this analgesia was recruited rapidly and was long-lasting, as it was observed when retest was scheduled as early as 0.2 and as late as 48 h after the initial exposure to the hot-plate. Experiment 3 documented a role for conditioning processes, as this analgesia was removed by an extinction-like procedure conducted between test and retest. Experiments 4 and 5 provided evidence for a non-opioid mechanism of pain control, because the analgesia was not diminished by the opioid antagonist, naloxone, nor by a history of morphine injections. These experiments also revealed that the analgesia observed on retest was enhanced and reduced when rats were given naloxone and morphine, respectively, on the initial test. Finally, Experiment 6 showed that the analgesia on retest summated with that produced by morphine. The results were taken to mean that the hot-plate assay for analgesia can itself activate endogenous mechanisms of pain control, and some speculations were offered as to how this occurred.

UR - http://www.scopus.com/inward/record.url?scp=0025469123&partnerID=8YFLogxK

U2 - 10.1080/14640749008401883

DO - 10.1080/14640749008401883

M3 - Article

VL - 42

SP - 241

EP - 265

JO - Quarterly Journal of Experimental Psychology Section B: Comparative and Physiological Psychology

T2 - Quarterly Journal of Experimental Psychology Section B: Comparative and Physiological Psychology

JF - Quarterly Journal of Experimental Psychology Section B: Comparative and Physiological Psychology

SN - 0272-4995

IS - 3

ER -