Abstract
Hind limb scratching is used increasingly as an itch model in rodents. Scratching is usually quantified as the number of scratching bouts over a 60 min period. Since the antipruritic effect of scratching should depend on the total time of skin contact, then the duration of scratching bouts and within-bout scratching frequency may also be important factors. Therefore, we measured these parameters during episodes of scratching directed toward the site (nape of neck) of intradermal injection of serotonin in Sprague-Dawley rats. Serotonin elicited significantly more scratching bouts than saline. There was a biphasic pattern of scratching over time, with peaks at 10-20 and 40-50 min. Although cumulative bout duration (2-min intervals) had a similar biphasic distribution, the mean individual bout duration (2.1 s) did not change significantly over time. Within-bout scratching frequency remained constant over time at 8 Hz. The number of scratching bouts was suppressed in a dose dependent manner by naltrexone (3 and 5 mg/kg), while the individual bout duration and the within-bout frequency were not significantly different compared with serotonin-evoked scratching without naltrexone. These results validate the total number of scratching bouts as an indicator of the magnitude of itch-related scratching.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 137-143 |
| Number of pages | 7 |
| Journal | Journal of Neuroscience Methods |
| Volume | 126 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jun 30 2003 |
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Keywords
- Itch
- Naltrexone
- Rat
- Scratch reflex
- Scratching
- Serotonin
ASJC Scopus subject areas
- Neuroscience(all)
Cite this
Quantitative assessment of directed hind limb scratching behavior as a rodent itch model. / Nojima, Hiroshi; Carstens, Earl.
In: Journal of Neuroscience Methods, Vol. 126, No. 2, 30.06.2003, p. 137-143.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Quantitative assessment of directed hind limb scratching behavior as a rodent itch model
AU - Nojima, Hiroshi
AU - Carstens, Earl
PY - 2003/6/30
Y1 - 2003/6/30
N2 - Hind limb scratching is used increasingly as an itch model in rodents. Scratching is usually quantified as the number of scratching bouts over a 60 min period. Since the antipruritic effect of scratching should depend on the total time of skin contact, then the duration of scratching bouts and within-bout scratching frequency may also be important factors. Therefore, we measured these parameters during episodes of scratching directed toward the site (nape of neck) of intradermal injection of serotonin in Sprague-Dawley rats. Serotonin elicited significantly more scratching bouts than saline. There was a biphasic pattern of scratching over time, with peaks at 10-20 and 40-50 min. Although cumulative bout duration (2-min intervals) had a similar biphasic distribution, the mean individual bout duration (2.1 s) did not change significantly over time. Within-bout scratching frequency remained constant over time at 8 Hz. The number of scratching bouts was suppressed in a dose dependent manner by naltrexone (3 and 5 mg/kg), while the individual bout duration and the within-bout frequency were not significantly different compared with serotonin-evoked scratching without naltrexone. These results validate the total number of scratching bouts as an indicator of the magnitude of itch-related scratching.
AB - Hind limb scratching is used increasingly as an itch model in rodents. Scratching is usually quantified as the number of scratching bouts over a 60 min period. Since the antipruritic effect of scratching should depend on the total time of skin contact, then the duration of scratching bouts and within-bout scratching frequency may also be important factors. Therefore, we measured these parameters during episodes of scratching directed toward the site (nape of neck) of intradermal injection of serotonin in Sprague-Dawley rats. Serotonin elicited significantly more scratching bouts than saline. There was a biphasic pattern of scratching over time, with peaks at 10-20 and 40-50 min. Although cumulative bout duration (2-min intervals) had a similar biphasic distribution, the mean individual bout duration (2.1 s) did not change significantly over time. Within-bout scratching frequency remained constant over time at 8 Hz. The number of scratching bouts was suppressed in a dose dependent manner by naltrexone (3 and 5 mg/kg), while the individual bout duration and the within-bout frequency were not significantly different compared with serotonin-evoked scratching without naltrexone. These results validate the total number of scratching bouts as an indicator of the magnitude of itch-related scratching.
KW - Itch
KW - Naltrexone
KW - Rat
KW - Scratch reflex
KW - Scratching
KW - Serotonin
UR - http://www.scopus.com/inward/record.url?scp=0038798016&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0038798016&partnerID=8YFLogxK
U2 - 10.1016/S0165-0270(03)00074-8
DO - 10.1016/S0165-0270(03)00074-8
M3 - Article
C2 - 12814838
AN - SCOPUS:0038798016
VL - 126
SP - 137
EP - 143
JO - Journal of Neuroscience Methods
JF - Journal of Neuroscience Methods
SN - 0165-0270
IS - 2
ER -