Shock-induced hyperalgesia:: Evidence forebrain systems play an essential role

Exposure to a few moderately intense (1-mA) tailshocks has opposite effects on two measures of pain reactivity in rats. Tail-withdrawal to radiant heat is inhibited (antinociception) while vocalization thresholds are lowered (hyperalgesia) to both heat and shock (King et al., 1996). Prior work indic...

Full description

Saved in:
Bibliographic Details
Published in:Behavioural brain research 1999-04, Vol.100 (1), p.33-42
Main Authors: King, Tamara E., Crown, Eric D., Sieve, Amy N., Joynes, Robin L., Grau, James W., Meagher, Mary W.
Format: Article
Language:English
Subjects:
Anatomical correlates of behavior
Anesthesia
Animals
Antinociception
Arousal - physiology
Behavioral psychophysiology
Biological and medical sciences
Brain Mapping
Decerebration
Electroshock
Fear
Fear - physiology
Freezing
Frontal cortex
Frontal Lobe - physiology
Fundamental and applied biological sciences. Psychology
Hyperalgesia
Male
Nociceptors - physiology
Pain
Pain Threshold - physiology
Prosencephalon - physiology
Psychology. Psychoanalysis. Psychiatry
Psychology. Psychophysiology
Rats
Rats, Sprague-Dawley
Shock
Tail - innervation
Thermosensing - physiology
Vocalization
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Exposure to a few moderately intense (1-mA) tailshocks has opposite effects on two measures of pain reactivity in rats. Tail-withdrawal to radiant heat is inhibited (antinociception) while vocalization thresholds are lowered (hyperalgesia) to both heat and shock (King et al., 1996). Prior work indicates that this hyperalgesia represents an unconditioned response and that it enhances the acquisition of both conditioned freezing and an avoidance response to thermal pain. The present experiments begin to explore the neural mechanisms that underlie hyperalgesia. Experiments 1 and 2 demonstrated that hyperalgesia is eliminated by both decerebration and pentobarbital anesthesia. Lesions limited to the frontal pole had a similar effect (Experiment 3). Experiment 4 showed that lesioning the frontal pole also disrupted the acquisition of conditioned fear.
ISSN:0166-4328
1872-7549
DOI:10.1016/S0166-4328(98)00110-7