PERIPHERALLY SUPPRESSIVE EFFECTS OF KETAMINE ON SUBCUTANEOUS BEE VENOM-INDUCED PROLONGED,PERSISTENT FIRING OF SPINAL WIDE-DYNAMICRANGE NEURONS IN THE CAT
- VernacularTitle:周围注射氯氨酮对皮下注射蜜蜂毒引起的猫脊髓广动力阈神经元长时程持续性放电增强的抑制效应
- Author:
Huili LI
;
Jun CHEN
;
Ceng LUO
- Publication Type:Journal Article
- Keywords:
ketamine;
NMDA receptors;
subcutaneous bee venom injection;
wide-dynamic-range neuron. dorsal horn;
persistent nociception;
tissue injury;
cat
- From:
Chinese Journal of Neuroanatomy
2000;16(3):222-230
- CountryChina
- Language:Chinese
-
Abstract:
By using extracellular single unit recording technique, locally suppressive effects of a single dose of ketamine on sub-cutaneous (s. c. ) bee venom-induced increase in firing of wide dynamic-range (WDR) neurons in spinal dorsal horn were investi-gated on urcthane-chloralose anesthetized cats. Injection of bee venom s.c. into the cutaneous receptive field (RF) resulted in asingle phase of prolonged, persistently increased firing of WDR neurons over background activity for more than 1 h. Local pre-treatment with ketamine (100 mM, 0. 1 m l) into the center of RF where bee venom was injected produced a dramatic suppressionof the increased neuronal firing by 60% (3.10± 0.42 spikes/s, n= 5) when compared with saline pre-treated group (7.61 ± 0.17spikes/ s. n = 5 ). Moreover, local post-treatment with the same dose of ketamine also produced a profound suppression of the in-creased neuronal activity by 81% (1.51±0.06 spikes/s, n=5) when compared with the saline post-treated group (7.76±0.15spikes s, n=5). However, s.c. administration with the same dose of ketamine into a symmetrical region on the bee venom un-treated contralateral hindpaw produced no affection on the increased firing of the WDR neurons, suggesting that the suppressiveaction of local ketamine was not the result of systemic effects. The present result suggests that ketamine may exert its localantinociceptive effects mainly through the peripheral NMDA receptors in addition to its partially potential blocking effects onsodium and voltage-sensitive calcium channels.
