Rat tail flick reflex: Magnitude measurement of stimulus-response function, suppression by morphine and habituation

Earl Carstens, C. Wilson

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

1. To quantitatively investigate a nocifensive behavioral response, we developed a method to measure the magnitude of the rat's tail flick reflex and its modulation. A radial array of force transducers measured forces of tail flicks (in rostral, horizontal, and vertical planes) elicited by graded noxious radiant thermal stimulation of the conscious rat's tail, from which the overall movement vector was calculated. 2. The rostrally directed component of tail flicks was always larger than dorsal or horizontal components; the latter was usually in a preferred (left or right) direction regardless of which side of the tail was heated. Tail flick force vectors increased from 40 to 46-52°C and then leveled off. Stimulus-response functions were reproducible within and across rats and were fitted by second- order polynomial functions, whose correlation coefficients were similar when the left or right side of the tail was stimulated in separate sessions (r2 = 0.408 and 0.451, respectively). The inverse latency of tail flicks also increased with temperature in a manner fitted by a second-order polynomial (r2 = 0.707, 0.553 for left and right side, respectively). 3. Systemic administration of morphine (1 or 2 mg/kg ip) usually suppressed tail flicks in an all-or-none manner; i.e., flicks at all stimulus temperatures were either totally abolished (n = 7) or unaffected (n = 5) after morphine. In three rats, 1 mg/kg morphine suppressed tail flick magnitude subtotally, reducing the slope of the linear portion of the stimulus-response function. Morphine effects were reversed by the opiate antagonist naloxone. 4. Tail flick magnitude decreased over repeated trials of 44°C heat stimuli delivered to one tail site, recovered after a 15-min rest period, and decremented more quickly with subsequent stimulus repetition. The decrement was less at long (2 or 4 min) than at short (1 min) interstimulus intervals, and high (50°C) than at low (44°C) stimulus intensities. The reflex decrement transferred to a nearby stimulus site in some rats, and was 'dishabituated' after a noxious tail pinch. These observations are consistent with habituation of the tail flick reflex. 5. This method, therefore, provides a quantitative and reproducible measure of tail flick reflex magnitude that is sensitive to morphine. The underlying neural circuitry of the tail flick reflex is discussed in relation to limb withdrawal reflexes.

Original languageEnglish (US)
Pages (from-to)630-639
Number of pages10
JournalJournal of Neurophysiology
Volume70
Issue number2
StatePublished - 1993

Fingerprint

Morphine
Reflex
Tail
Opiate Alkaloids
Hot Temperature
Temperature
Naloxone
Transducers
Extremities

ASJC Scopus subject areas

  • Physiology
  • Neuroscience(all)

Cite this

Rat tail flick reflex : Magnitude measurement of stimulus-response function, suppression by morphine and habituation. / Carstens, Earl; Wilson, C.

In: Journal of Neurophysiology, Vol. 70, No. 2, 1993, p. 630-639.

Research output: Contribution to journalArticle

@article{2e1850d579964d09bcf92c02e42a3728,
title = "Rat tail flick reflex: Magnitude measurement of stimulus-response function, suppression by morphine and habituation",
abstract = "1. To quantitatively investigate a nocifensive behavioral response, we developed a method to measure the magnitude of the rat's tail flick reflex and its modulation. A radial array of force transducers measured forces of tail flicks (in rostral, horizontal, and vertical planes) elicited by graded noxious radiant thermal stimulation of the conscious rat's tail, from which the overall movement vector was calculated. 2. The rostrally directed component of tail flicks was always larger than dorsal or horizontal components; the latter was usually in a preferred (left or right) direction regardless of which side of the tail was heated. Tail flick force vectors increased from 40 to 46-52°C and then leveled off. Stimulus-response functions were reproducible within and across rats and were fitted by second- order polynomial functions, whose correlation coefficients were similar when the left or right side of the tail was stimulated in separate sessions (r2 = 0.408 and 0.451, respectively). The inverse latency of tail flicks also increased with temperature in a manner fitted by a second-order polynomial (r2 = 0.707, 0.553 for left and right side, respectively). 3. Systemic administration of morphine (1 or 2 mg/kg ip) usually suppressed tail flicks in an all-or-none manner; i.e., flicks at all stimulus temperatures were either totally abolished (n = 7) or unaffected (n = 5) after morphine. In three rats, 1 mg/kg morphine suppressed tail flick magnitude subtotally, reducing the slope of the linear portion of the stimulus-response function. Morphine effects were reversed by the opiate antagonist naloxone. 4. Tail flick magnitude decreased over repeated trials of 44°C heat stimuli delivered to one tail site, recovered after a 15-min rest period, and decremented more quickly with subsequent stimulus repetition. The decrement was less at long (2 or 4 min) than at short (1 min) interstimulus intervals, and high (50°C) than at low (44°C) stimulus intensities. The reflex decrement transferred to a nearby stimulus site in some rats, and was 'dishabituated' after a noxious tail pinch. These observations are consistent with habituation of the tail flick reflex. 5. This method, therefore, provides a quantitative and reproducible measure of tail flick reflex magnitude that is sensitive to morphine. The underlying neural circuitry of the tail flick reflex is discussed in relation to limb withdrawal reflexes.",
author = "Earl Carstens and C. Wilson",
year = "1993",
language = "English (US)",
volume = "70",
pages = "630--639",
journal = "Journal of Neurophysiology",
issn = "0022-3077",
publisher = "American Physiological Society",
number = "2",

}

TY - JOUR

T1 - Rat tail flick reflex

T2 - Magnitude measurement of stimulus-response function, suppression by morphine and habituation

AU - Carstens, Earl

AU - Wilson, C.

PY - 1993

Y1 - 1993

N2 - 1. To quantitatively investigate a nocifensive behavioral response, we developed a method to measure the magnitude of the rat's tail flick reflex and its modulation. A radial array of force transducers measured forces of tail flicks (in rostral, horizontal, and vertical planes) elicited by graded noxious radiant thermal stimulation of the conscious rat's tail, from which the overall movement vector was calculated. 2. The rostrally directed component of tail flicks was always larger than dorsal or horizontal components; the latter was usually in a preferred (left or right) direction regardless of which side of the tail was heated. Tail flick force vectors increased from 40 to 46-52°C and then leveled off. Stimulus-response functions were reproducible within and across rats and were fitted by second- order polynomial functions, whose correlation coefficients were similar when the left or right side of the tail was stimulated in separate sessions (r2 = 0.408 and 0.451, respectively). The inverse latency of tail flicks also increased with temperature in a manner fitted by a second-order polynomial (r2 = 0.707, 0.553 for left and right side, respectively). 3. Systemic administration of morphine (1 or 2 mg/kg ip) usually suppressed tail flicks in an all-or-none manner; i.e., flicks at all stimulus temperatures were either totally abolished (n = 7) or unaffected (n = 5) after morphine. In three rats, 1 mg/kg morphine suppressed tail flick magnitude subtotally, reducing the slope of the linear portion of the stimulus-response function. Morphine effects were reversed by the opiate antagonist naloxone. 4. Tail flick magnitude decreased over repeated trials of 44°C heat stimuli delivered to one tail site, recovered after a 15-min rest period, and decremented more quickly with subsequent stimulus repetition. The decrement was less at long (2 or 4 min) than at short (1 min) interstimulus intervals, and high (50°C) than at low (44°C) stimulus intensities. The reflex decrement transferred to a nearby stimulus site in some rats, and was 'dishabituated' after a noxious tail pinch. These observations are consistent with habituation of the tail flick reflex. 5. This method, therefore, provides a quantitative and reproducible measure of tail flick reflex magnitude that is sensitive to morphine. The underlying neural circuitry of the tail flick reflex is discussed in relation to limb withdrawal reflexes.

AB - 1. To quantitatively investigate a nocifensive behavioral response, we developed a method to measure the magnitude of the rat's tail flick reflex and its modulation. A radial array of force transducers measured forces of tail flicks (in rostral, horizontal, and vertical planes) elicited by graded noxious radiant thermal stimulation of the conscious rat's tail, from which the overall movement vector was calculated. 2. The rostrally directed component of tail flicks was always larger than dorsal or horizontal components; the latter was usually in a preferred (left or right) direction regardless of which side of the tail was heated. Tail flick force vectors increased from 40 to 46-52°C and then leveled off. Stimulus-response functions were reproducible within and across rats and were fitted by second- order polynomial functions, whose correlation coefficients were similar when the left or right side of the tail was stimulated in separate sessions (r2 = 0.408 and 0.451, respectively). The inverse latency of tail flicks also increased with temperature in a manner fitted by a second-order polynomial (r2 = 0.707, 0.553 for left and right side, respectively). 3. Systemic administration of morphine (1 or 2 mg/kg ip) usually suppressed tail flicks in an all-or-none manner; i.e., flicks at all stimulus temperatures were either totally abolished (n = 7) or unaffected (n = 5) after morphine. In three rats, 1 mg/kg morphine suppressed tail flick magnitude subtotally, reducing the slope of the linear portion of the stimulus-response function. Morphine effects were reversed by the opiate antagonist naloxone. 4. Tail flick magnitude decreased over repeated trials of 44°C heat stimuli delivered to one tail site, recovered after a 15-min rest period, and decremented more quickly with subsequent stimulus repetition. The decrement was less at long (2 or 4 min) than at short (1 min) interstimulus intervals, and high (50°C) than at low (44°C) stimulus intensities. The reflex decrement transferred to a nearby stimulus site in some rats, and was 'dishabituated' after a noxious tail pinch. These observations are consistent with habituation of the tail flick reflex. 5. This method, therefore, provides a quantitative and reproducible measure of tail flick reflex magnitude that is sensitive to morphine. The underlying neural circuitry of the tail flick reflex is discussed in relation to limb withdrawal reflexes.

UR - http://www.scopus.com/inward/record.url?scp=0027257301&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027257301&partnerID=8YFLogxK

M3 - Article

C2 - 8410163

AN - SCOPUS:0027257301

VL - 70

SP - 630

EP - 639

JO - Journal of Neurophysiology

JF - Journal of Neurophysiology

SN - 0022-3077

IS - 2

ER -