Abstract
Diffuse noxious inhibitory control (DNIC) occurs when the response to a noxious stimulus is inhibited by a second, spatially remote noxious stimulus. The minimum alveolar anesthetic concentration (MAC) to suppress movement is not altered by a second remote noxious stimulus. We hypothesized that DNIC would be depressed in the peri-MAC range. Rats were anesthetized with isoflurane, and MAC was measured. We recorded dorsal horn neuronal responses to noxious thermal stimulation of the hindpaw, with or without concomitant supramaximal noxious mechanical stimulation of the tail or contralateral hindpaw. At 0.8 MAC, the tail clamp decreased neuronal responses 70% compared with control heat-evoked responses (from 1032 ± 178 impulses per minute to 301 ± 135 impulses per minute; P < 0.05). The tail clamp had no significant effect on neuronal responses at 1.2 MAC (from 879 ± 139 impulses per minute to 825 ± 191 impulses per minute; P > 0.05). Similarly, 1.2 MAC isoflurane significantly depressed DNIC elicited by hindpaw clamping. In another group, the cervical spinal cord was reversibly blocked by cooling to determine whether the inhibition was mediated supraspinally. With spinal cord cooling, the counterstimulus-evoked inhibition was not observed at 0.8 MAC. These results suggest that DNIC involves supraspinal structures and is present at subMAC isoflurane concentrations but is depressed at more than 1 MAC.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 111-116 |
| Number of pages | 6 |
| Journal | Anesthesia and Analgesia |
| Volume | 97 |
| Issue number | 1 |
| State | Published - Jul 1 2003 |
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ASJC Scopus subject areas
- Anesthesiology and Pain Medicine
Cite this
Isoflurane depresses diffuse noxious inhibitory controls in rats between 0.8 and 1.2 Minimum alveolar anesthetic concentration. / Jinks, Steven L.; Antognini, Joseph F.; Carstens, Earl.
In: Anesthesia and Analgesia, Vol. 97, No. 1, 01.07.2003, p. 111-116.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Isoflurane depresses diffuse noxious inhibitory controls in rats between 0.8 and 1.2 Minimum alveolar anesthetic concentration
AU - Jinks, Steven L.
AU - Antognini, Joseph F.
AU - Carstens, Earl
PY - 2003/7/1
Y1 - 2003/7/1
N2 - Diffuse noxious inhibitory control (DNIC) occurs when the response to a noxious stimulus is inhibited by a second, spatially remote noxious stimulus. The minimum alveolar anesthetic concentration (MAC) to suppress movement is not altered by a second remote noxious stimulus. We hypothesized that DNIC would be depressed in the peri-MAC range. Rats were anesthetized with isoflurane, and MAC was measured. We recorded dorsal horn neuronal responses to noxious thermal stimulation of the hindpaw, with or without concomitant supramaximal noxious mechanical stimulation of the tail or contralateral hindpaw. At 0.8 MAC, the tail clamp decreased neuronal responses 70% compared with control heat-evoked responses (from 1032 ± 178 impulses per minute to 301 ± 135 impulses per minute; P < 0.05). The tail clamp had no significant effect on neuronal responses at 1.2 MAC (from 879 ± 139 impulses per minute to 825 ± 191 impulses per minute; P > 0.05). Similarly, 1.2 MAC isoflurane significantly depressed DNIC elicited by hindpaw clamping. In another group, the cervical spinal cord was reversibly blocked by cooling to determine whether the inhibition was mediated supraspinally. With spinal cord cooling, the counterstimulus-evoked inhibition was not observed at 0.8 MAC. These results suggest that DNIC involves supraspinal structures and is present at subMAC isoflurane concentrations but is depressed at more than 1 MAC.
AB - Diffuse noxious inhibitory control (DNIC) occurs when the response to a noxious stimulus is inhibited by a second, spatially remote noxious stimulus. The minimum alveolar anesthetic concentration (MAC) to suppress movement is not altered by a second remote noxious stimulus. We hypothesized that DNIC would be depressed in the peri-MAC range. Rats were anesthetized with isoflurane, and MAC was measured. We recorded dorsal horn neuronal responses to noxious thermal stimulation of the hindpaw, with or without concomitant supramaximal noxious mechanical stimulation of the tail or contralateral hindpaw. At 0.8 MAC, the tail clamp decreased neuronal responses 70% compared with control heat-evoked responses (from 1032 ± 178 impulses per minute to 301 ± 135 impulses per minute; P < 0.05). The tail clamp had no significant effect on neuronal responses at 1.2 MAC (from 879 ± 139 impulses per minute to 825 ± 191 impulses per minute; P > 0.05). Similarly, 1.2 MAC isoflurane significantly depressed DNIC elicited by hindpaw clamping. In another group, the cervical spinal cord was reversibly blocked by cooling to determine whether the inhibition was mediated supraspinally. With spinal cord cooling, the counterstimulus-evoked inhibition was not observed at 0.8 MAC. These results suggest that DNIC involves supraspinal structures and is present at subMAC isoflurane concentrations but is depressed at more than 1 MAC.
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UR - http://www.scopus.com/inward/citedby.url?scp=0038311848&partnerID=8YFLogxK
M3 - Article
C2 - 12818952
AN - SCOPUS:0038311848
VL - 97
SP - 111
EP - 116
JO - Anesthesia and Analgesia
JF - Anesthesia and Analgesia
SN - 0003-2999
IS - 1
ER -