Objective The present study aimed to investigate the electrophysiological properties of wide dynamic range （WDR） neurons in spinal dorsal horn of rats with neuropathic pain induced by lumber 5 （L5） spinal nerve li...Objective The present study aimed to investigate the electrophysiological properties of wide dynamic range （WDR） neurons in spinal dorsal horn of rats with neuropathic pain induced by lumber 5 （L5） spinal nerve ligation （SNL） in a large size of samples.Methods Adult Sprague-Dawley rats were divided into normal and SNL groups.Electrophysiological technique was used to record the characteristics of WDR neurons in the spinal dorsal horn.Results Compared with the WDR neurons in normal rats,the WDR neurons in SNL rats showed an increase in excitability,manifested by an enlargement of the receptive field size,an increase in the proportion of neurons that exhibited spontaneous activities,decreases in the Cresponse threshold and latency,and an increase in the C-response duration.In addition,the numbers of A-and C-fiberevoked discharges were smaller in SNL rats than in normal rats.Conclusion The excitability of spinal WDR neurons increased in rats with neuropathic pain induced by L5 SNL.The increase in excitability of WDR neurons may contribute to the development of neuropathic pain.展开更多
In order to determine how nociceptive input conveyed by the C-fibers terminating in superficial lam-inae of the spinal cord reaches the wide dynamic range (WDR) cells in deeper dorsal horn, which functions as ascend-i...In order to determine how nociceptive input conveyed by the C-fibers terminating in superficial lam-inae of the spinal cord reaches the wide dynamic range (WDR) cells in deeper dorsal horn, which functions as ascend-ing projection pathway, the morphological features of some WDR cells in the deeper dorsal horn of the cat lumbar spinal cord were studied by intracellular injection of horseradish peroxidase and physiological characterization. One of the fully stained neurons with somata in lamina V and dendrites that entered lamina Ⅱ were examined by electron mi-croscopy. Immunogold staining of ultrathin sections through the labeled proximal dendrites in lamina Ⅱ revealed that these dendrites received numerous synapses from substance P and glutamate immunoreactive (IR) axons, which were considered originating from C-fibers. In addition, many GABA-IR terminals were found presynaptic to the labeled dendrites. The results, therefore, suggest that the information carried by primary afferent can be sent from the super-ficial dorsal horn to the deeper laminae through monosynaptic contacts between C-fiber terminals and the long dorsal dendrites of some WDR cells in the deeper laminae, and that GABAergic system is involved in postsynaptic control to modulate the transmission of nociceptive sensory information.展开更多
Objective To analyse the antinociceptive effect of red nucleus (RN) and its role in the antinociceptive effect of muscle spindle afferents. Methods The single units of RN or wide dynamic range (WDR) neuron in the sp...Objective To analyse the antinociceptive effect of red nucleus (RN) and its role in the antinociceptive effect of muscle spindle afferents. Methods The single units of RN or wide dynamic range (WDR) neuron in the spinal cord dorsal horn were extracelluarly recorded. The effects of RN stimulation on nociceptive responses (C fibers evoked responses, C responses) of WDR neurons were observed. The influence of muscle spindle afferents elicited by intravenous administration of succinylcholine (Sch) on the spontaneous discharge of RN neurons and on C responses of WDR neurons were observed. The effect of muscle spindle afferents on C responses of WDR neurons after unilateral lesions of RN was also observed. Results Electrical stimulation of the RN produced a significantly inhibitory effect on the nociceptive responses of WDR neurons. RN neurons were excited by muscle spindle afferents. Muscle spindle afferents significantly inhibited C response of WDR neurons and this inhibitory effect was reduced by lesions of RN. Conclusion RN neurons have a significant antinociceptive effect and might be involved in the antinociceptive effects elicited by muscle spindle afferents.展开更多
基金supported by the Youth Project of National Natural Science Foundation of China(No.31200836)the Natural Science Foundation for Colleges and Universities in Jiangsu Province+3 种基金China(No.12KJD320005)Zhen Xing Project/the Special Talent Fund of Dean of Xuzhou Medical CollegeJiangsu ProvinceChina(No.2012KJZ15)
基金supported by the grants from National Natural Science Foundation of China(No. 30600173,81070893)the Key Project of China Ministry of Education(No. 109003)+1 种基金the National Basic Research Development Program(973 Program) of China (No.2007CB512501)Beijing Municipal Commission of Education "Special Grants for Outstanding Ph.D Program Tutors"
文摘Objective The present study aimed to investigate the electrophysiological properties of wide dynamic range （WDR） neurons in spinal dorsal horn of rats with neuropathic pain induced by lumber 5 （L5） spinal nerve ligation （SNL） in a large size of samples.Methods Adult Sprague-Dawley rats were divided into normal and SNL groups.Electrophysiological technique was used to record the characteristics of WDR neurons in the spinal dorsal horn.Results Compared with the WDR neurons in normal rats,the WDR neurons in SNL rats showed an increase in excitability,manifested by an enlargement of the receptive field size,an increase in the proportion of neurons that exhibited spontaneous activities,decreases in the Cresponse threshold and latency,and an increase in the C-response duration.In addition,the numbers of A-and C-fiberevoked discharges were smaller in SNL rats than in normal rats.Conclusion The excitability of spinal WDR neurons increased in rats with neuropathic pain induced by L5 SNL.The increase in excitability of WDR neurons may contribute to the development of neuropathic pain.
基金Project supported by the State Science and Technology Commission and the National Natural Science Foundation of China.
文摘In order to determine how nociceptive input conveyed by the C-fibers terminating in superficial lam-inae of the spinal cord reaches the wide dynamic range (WDR) cells in deeper dorsal horn, which functions as ascend-ing projection pathway, the morphological features of some WDR cells in the deeper dorsal horn of the cat lumbar spinal cord were studied by intracellular injection of horseradish peroxidase and physiological characterization. One of the fully stained neurons with somata in lamina V and dendrites that entered lamina Ⅱ were examined by electron mi-croscopy. Immunogold staining of ultrathin sections through the labeled proximal dendrites in lamina Ⅱ revealed that these dendrites received numerous synapses from substance P and glutamate immunoreactive (IR) axons, which were considered originating from C-fibers. In addition, many GABA-IR terminals were found presynaptic to the labeled dendrites. The results, therefore, suggest that the information carried by primary afferent can be sent from the super-ficial dorsal horn to the deeper laminae through monosynaptic contacts between C-fiber terminals and the long dorsal dendrites of some WDR cells in the deeper laminae, and that GABAergic system is involved in postsynaptic control to modulate the transmission of nociceptive sensory information.
基金This work was supported by the National Brain Science Basic Research Program (No.G1999054000) and National Natural Science Foundation of China (No. 30100052, 30200077, 30325023).
基金ThisresearchwassupportedbytheNationalNaturalScienceFoundationofChina (No .3 90 70 3 3 4)
文摘Objective To analyse the antinociceptive effect of red nucleus (RN) and its role in the antinociceptive effect of muscle spindle afferents. Methods The single units of RN or wide dynamic range (WDR) neuron in the spinal cord dorsal horn were extracelluarly recorded. The effects of RN stimulation on nociceptive responses (C fibers evoked responses, C responses) of WDR neurons were observed. The influence of muscle spindle afferents elicited by intravenous administration of succinylcholine (Sch) on the spontaneous discharge of RN neurons and on C responses of WDR neurons were observed. The effect of muscle spindle afferents on C responses of WDR neurons after unilateral lesions of RN was also observed. Results Electrical stimulation of the RN produced a significantly inhibitory effect on the nociceptive responses of WDR neurons. RN neurons were excited by muscle spindle afferents. Muscle spindle afferents significantly inhibited C response of WDR neurons and this inhibitory effect was reduced by lesions of RN. Conclusion RN neurons have a significant antinociceptive effect and might be involved in the antinociceptive effects elicited by muscle spindle afferents.
