AIM: To investigate and compare the effects of spinal D-(-)-2-amino-7-phosphonoheptanoic acid (AP-7) and 6-cyano-7-nitroquinoxaline-2,3-dione disodium (CNQX),two glutamate receptor antagonists, on the responses of dor...AIM: To investigate and compare the effects of spinal D-(-)-2-amino-7-phosphonoheptanoic acid (AP-7) and 6-cyano-7-nitroquinoxaline-2,3-dione disodium (CNQX),two glutamate receptor antagonists, on the responses of dorsal horn neurons to colorectal distension (CRD) in adult rats exposed to neonatal colon irritation (CI).METHODS: Hypersensitive SD rats were generated by CI during postnatal days 8, 10 and 12. Experiments on adult rats were performed using extracellular single-unit recording. The effects of spinal application of AP-7 (0.001,0.01, 0.1, 1 mmoL) were tested on the CRD-evoked neuronal responses in 16 controls and 17 CI rats. The effects of CNQX (0.2, 2, 5, 10 μmoL) were also tested on the CRD-evoked responses of 17 controls and 18 CI neurons.RESULTS: (1) The average responses of lumbosacral neurons to all intensities of CRD in CI rats were significantly higher than those in control rats; (2) In control rats, AP-7 (0.01 mmoL) had no significant effect on the neuronal response to all intensities of CRD (20,40, 60, 80 mmHg); while AP-7 (0.1 mmoL) inhibited the neuronal response to 80-mmHg CRD. By contrast, in CI rats, AP-7 (0.01-1 mmoL) attenuated the CRD-evoked neuronal responses to all distention pressures in a dosedependent manner; (3) In control rats, CNQX (2 μmoL)had no significantly effect on the neuronal response to all intensities of CRD; however, CNQX (5 μmoL) significantly attenuated the responses to CRD in the 40-80 mmHg range. By contrast, CNQX (2-10 μmoL)significantly decreased the neuronal responses in CI rats to non-noxious and noxious CRD in a dose-dependent manner.CONCLUSION: Our results suggest that spinal N-methyl-D-aspartate (NMDA) and non-NMDA receptors may contribute to the processing of central sensitivity in a neonatal CI rat model, but they may play different roles in it.展开更多
Deciphering the neuronal response to injury in the spinal cord is essential for exploring treatment strategies for spinal cord injury(SCI).However,this subject has been neglected in part because appropriate tools are ...Deciphering the neuronal response to injury in the spinal cord is essential for exploring treatment strategies for spinal cord injury(SCI).However,this subject has been neglected in part because appropriate tools are lacking.Emerging in vivo imaging and labeling methods offer great potential for observing dynamic neural processes in the central nervous system in conditions of health and disease.This review first discusses in vivo imaging of the mouse spinal cord with a focus on the latest imaging techniques,and then analyzes the dynamic biological response of spinal cord sensory and motor neurons to SCI.We then summarize and compare the techniques behind these studies and clarify the advantages of in vivo imaging compared with traditional neuroscience examinations.Finally,we identify the challenges and possible solutions for spinal cord neuron imaging.展开更多
The new double projecting neurons were found in the cat spinal dorsal horn by the double retrograde fluorescent tracing technique.Fast Blue(FB)was injected into unilateral dorsal column nucleus(DCN)of adult cats anest...The new double projecting neurons were found in the cat spinal dorsal horn by the double retrograde fluorescent tracing technique.Fast Blue(FB)was injected into unilateral dorsal column nucleus(DCN)of adult cats anesthetized with pentobarbital.Nuclear Yellow(NY)was injected ipsilaterally into the lateral cervical nucleus(LCN)8-9 days later.After an additional 18-30 hrs.展开更多
singe unit discharge recordings were made from 42 WDR neurons in spinal dorsal horn in the rat. These neurons could he driven by electrical stimull activiting innocuous and noxious afferent fibres in the ipsilateral p...singe unit discharge recordings were made from 42 WDR neurons in spinal dorsal horn in the rat. These neurons could he driven by electrical stimull activiting innocuous and noxious afferent fibres in the ipsilateral plantar nerve. Traditional manual acupuncture delivered at the local acupoints Zusanli, Chengshan, Kunlun and Yongquan induced a strong inhibition or the C-fiber response. in 19 of 42 neurons obtained but did not after the A-fibre response of the neurons. The inhibition of the fibre response outlasted the period of acupuncture for more than 30 min. Neither Anor C-fibre responses in the remaining 23 neurous could be affected by manual acupuncture. These results suggest that the acupuncture stimulation specifically influences nociceptive nociceptive transmission,maybe through a presynaptic action,Furthermore, the fact that the inhibitory effect outlasts the stimulation by more than 30 min indicates that either a neuromodulatory ,presumably peptidergic action is at hand or that a temporary synaptic modification occurs in the spinal dorsal horn.展开更多
Antidromic and orthodromic responses of the projection neurons in the dorsal horn ofthe spinal cord have been recorded by a glass microelectrode in anesthetized and paralyz-ed cats. Furthermore, the effect of cervical...Antidromic and orthodromic responses of the projection neurons in the dorsal horn ofthe spinal cord have been recorded by a glass microelectrode in anesthetized and paralyz-ed cats. Furthermore, the effect of cervical segment antidromic stimulation to orthodromicresponse of the projection neurons has been observed by way of conditioning-test stimulation. Among all the spinocervical tract neurons (SCT), the dorsal column postsynaptic neu-rons (DCPS) and the spinocervical tract-dorsal column postsynaptic neurons (SCT-DCPS),which were identified by cervical segment antidromic stimulation, 46% are low-thresholdmechanoreceptive (LTM) and 54% are wide-dynamic-range (WDR) neurons. Most LTMneurons can evoke the same response to both 10 times (10 T) and 50 times (50 T) the thresh-old stimulation on the peroneal nerve. Most WDR neurons to 50 T intensity stimulation arestronger than the 10 T stimulation. Under the antidromic-cervical segment conditioningstimulation, the amount of orthodromic-discharging in most WDR and few LTM neuronsreduced significantly. The result shows that both LTM and WDR projection neurons in the spinal cord canrespond to all peripheral Aβ fibers and part of the Aδ fibers; there are some inhibitionaldescending fibers which affect the projection neurons in the cervical segment dorsal col-umn and dorsolateral funiculi.展开更多
文摘AIM: To investigate and compare the effects of spinal D-(-)-2-amino-7-phosphonoheptanoic acid (AP-7) and 6-cyano-7-nitroquinoxaline-2,3-dione disodium (CNQX),two glutamate receptor antagonists, on the responses of dorsal horn neurons to colorectal distension (CRD) in adult rats exposed to neonatal colon irritation (CI).METHODS: Hypersensitive SD rats were generated by CI during postnatal days 8, 10 and 12. Experiments on adult rats were performed using extracellular single-unit recording. The effects of spinal application of AP-7 (0.001,0.01, 0.1, 1 mmoL) were tested on the CRD-evoked neuronal responses in 16 controls and 17 CI rats. The effects of CNQX (0.2, 2, 5, 10 μmoL) were also tested on the CRD-evoked responses of 17 controls and 18 CI neurons.RESULTS: (1) The average responses of lumbosacral neurons to all intensities of CRD in CI rats were significantly higher than those in control rats; (2) In control rats, AP-7 (0.01 mmoL) had no significant effect on the neuronal response to all intensities of CRD (20,40, 60, 80 mmHg); while AP-7 (0.1 mmoL) inhibited the neuronal response to 80-mmHg CRD. By contrast, in CI rats, AP-7 (0.01-1 mmoL) attenuated the CRD-evoked neuronal responses to all distention pressures in a dosedependent manner; (3) In control rats, CNQX (2 μmoL)had no significantly effect on the neuronal response to all intensities of CRD; however, CNQX (5 μmoL) significantly attenuated the responses to CRD in the 40-80 mmHg range. By contrast, CNQX (2-10 μmoL)significantly decreased the neuronal responses in CI rats to non-noxious and noxious CRD in a dose-dependent manner.CONCLUSION: Our results suggest that spinal N-methyl-D-aspartate (NMDA) and non-NMDA receptors may contribute to the processing of central sensitivity in a neonatal CI rat model, but they may play different roles in it.
基金supported by the National Natural Science Foundation of China,No.82272478(to PT)。
文摘Deciphering the neuronal response to injury in the spinal cord is essential for exploring treatment strategies for spinal cord injury(SCI).However,this subject has been neglected in part because appropriate tools are lacking.Emerging in vivo imaging and labeling methods offer great potential for observing dynamic neural processes in the central nervous system in conditions of health and disease.This review first discusses in vivo imaging of the mouse spinal cord with a focus on the latest imaging techniques,and then analyzes the dynamic biological response of spinal cord sensory and motor neurons to SCI.We then summarize and compare the techniques behind these studies and clarify the advantages of in vivo imaging compared with traditional neuroscience examinations.Finally,we identify the challenges and possible solutions for spinal cord neuron imaging.
文摘The new double projecting neurons were found in the cat spinal dorsal horn by the double retrograde fluorescent tracing technique.Fast Blue(FB)was injected into unilateral dorsal column nucleus(DCN)of adult cats anesthetized with pentobarbital.Nuclear Yellow(NY)was injected ipsilaterally into the lateral cervical nucleus(LCN)8-9 days later.After an additional 18-30 hrs.
文摘singe unit discharge recordings were made from 42 WDR neurons in spinal dorsal horn in the rat. These neurons could he driven by electrical stimull activiting innocuous and noxious afferent fibres in the ipsilateral plantar nerve. Traditional manual acupuncture delivered at the local acupoints Zusanli, Chengshan, Kunlun and Yongquan induced a strong inhibition or the C-fiber response. in 19 of 42 neurons obtained but did not after the A-fibre response of the neurons. The inhibition of the fibre response outlasted the period of acupuncture for more than 30 min. Neither Anor C-fibre responses in the remaining 23 neurous could be affected by manual acupuncture. These results suggest that the acupuncture stimulation specifically influences nociceptive nociceptive transmission,maybe through a presynaptic action,Furthermore, the fact that the inhibitory effect outlasts the stimulation by more than 30 min indicates that either a neuromodulatory ,presumably peptidergic action is at hand or that a temporary synaptic modification occurs in the spinal dorsal horn.
基金Project supported by the National Natural Science Foundation of China.
文摘Antidromic and orthodromic responses of the projection neurons in the dorsal horn ofthe spinal cord have been recorded by a glass microelectrode in anesthetized and paralyz-ed cats. Furthermore, the effect of cervical segment antidromic stimulation to orthodromicresponse of the projection neurons has been observed by way of conditioning-test stimulation. Among all the spinocervical tract neurons (SCT), the dorsal column postsynaptic neu-rons (DCPS) and the spinocervical tract-dorsal column postsynaptic neurons (SCT-DCPS),which were identified by cervical segment antidromic stimulation, 46% are low-thresholdmechanoreceptive (LTM) and 54% are wide-dynamic-range (WDR) neurons. Most LTMneurons can evoke the same response to both 10 times (10 T) and 50 times (50 T) the thresh-old stimulation on the peroneal nerve. Most WDR neurons to 50 T intensity stimulation arestronger than the 10 T stimulation. Under the antidromic-cervical segment conditioningstimulation, the amount of orthodromic-discharging in most WDR and few LTM neuronsreduced significantly. The result shows that both LTM and WDR projection neurons in the spinal cord canrespond to all peripheral Aβ fibers and part of the Aδ fibers; there are some inhibitionaldescending fibers which affect the projection neurons in the cervical segment dorsal col-umn and dorsolateral funiculi.
