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G W Lü

Publications and source records attributed to G W Lü.

9 recordsLinked to original sources
PubMed1993

The functional linkage among the "ZSL"-spinal dorsal horn-SN.

Electrical stimulation of the Zusanli point (ZSL) and solitary tract nucleus (SN) as well as microelectrode recording from the laminae III-V of the lumbar spinal dorsal horn have been used on the pentobarbital anesthetized rats, finding and identifying 57 spinal neurons responding to the stimulations of both ZSL and SN. Among them, 34 responded antidromically to SN; the others responded orthodromically to SN. Among them, the low-threshold mechano-receptive (LTM) neurons and wide-dynamic-range (WDR) neurons were 50 percent respectively. The results indicate that (i) a single spinal dorsal horn neuron receives somatic afferent input and then conveys it to the visceral sensory nucleus-SN; (ii) some spinal dorsal horn neurons receive, in turn, innervation from the SN; (iii) the convergence and integration between somatic and visceral sensory inputs might occur in the spinal dorsal horn neurons and/or SN.

Acupuncture Points↗
PubMed1991

The projection linkage between the spinal dorsal horn neurons and both the solitary tract and dorsal column nuclei.

Electrical stimulation of the solitary tract nucleus (SN) and dorsal column nuclei (DCN) as well as microelectrode recording from the lumbal spinal dorsal horn have been used to find and identify the axonal projection of and the afferent innervation on the spinal neurons of pentobarbital-anesthetized rats. A total of 92 neurons was recorded and identified mainly in laminae III-V of the lumbar spinal dorsal horn. Of them, 38 neurons were activated antidromically from stimulation of both the SN and DCN. The other 54 neurons responded synaptically to both the SN and DCN stimulations. The initial antidromic responses of 8 neurons in the first group were followed by one or more responses synaptically driven from the SN and/or DCN stimulation. Conduction velocities were in the range of A delta fibers, but faster in the antidromic responses and slower in the synaptic responses. These results indicate that (i) some spinal neurons issue branched axons of larger-sized A delta fibers and double project to both the SN and DCN; (ii) some of these double projection neurons receive in turn smaller A delta fiber innervation from the SN and/or DCN; and (iii) some other neurons in the spinal cord are dually innervated by smaller A delta fibers originating from both nuclei.

Animals↗
PubMed1990

[Digital and electromagnetically controlled pinchers for spinal cord injury].

A kind of noval digital and electromagnetically controlled pinchers is developed from its original type for more quantitatively pinching the spinal cord. The instrument is designed based on electromagnetic theory and principle of equilibrium in mechanics and composed of a timer, a current regulator and meter, control circuits and two-arm pinchers. The interarm distance, the pinch force, duration, and direction of left and/or right arm can be set up and adjusted. The current flowing through one or two pinching arms can be displayed and hold digitally on a screen. The machine is characterized not only by its convenience and correctness in operation but also by its directness and accuracy in reading. The setup is applicable to produce different kind and extent of spinal cord injury in many species of animals.

Animals↗
PubMed1990

Developmental studies of electrical properties in cultured rat brain neurons.

The rat brain neurons isolated from 15--17-day embryos were grown in dissociated cell culture and maintained in vitro for 3 weeks. The developmental process of the neurons was observed from the early stage of development in terms of passive and active electrical parameters and their changes induced by perfusion of ionic channel blockers. The neurons' development could be morphologically divided into stages I (from seedling to 6 days), II (7-11 days), III (12-20 days) and IV (21-22 days). The relative values of resting membrane potentials (RMP) for stages I, II, III and IV were 1, 3.46, 4.07 and 6.54, respectively; the corresponding values of input resistance (Rin) were 1, 1.48, 2.53 and 4.56, respectively. The current-voltage relationship in stages II and III was exponential in the direction of depolarization and the Rin's change with time was nearly linear. Spontaneous activities increased with prolongation of culture and the amplitude of evoked action potentials reached the maximum during stages III and IV. The RMP and Rin were markedly decreased by perfusion of TEA while no change was seen in TTX perfusion group. The results indicate that potassium ionic channels develop slower in stages II and IV, faster in stages I and III and mature by the end of stage IV.

Animals↗
PubMed1989

The property of peripheral input of projection neurons in the spinal cord dorsal horn.

Antidromic and orthodromic responses of the projection neurons in the dorsal horn of the spinal cord have been recorded by a glass microelectrode in anesthetized and paralyzed cats. Furthermore, the effect of cervical segment antidromic stimulation to orthodromic response of the projection neurons has been observed by way of conditioning-test stimulation. Among all the spinocervical tract neurons (SCT), the dorsal column postsynaptic neurons (DCPS) and the spinocervical tract-dorsal column postsynaptic neurons (SCT-DCPS), which were identified by cervical segment antidromic stimulation, 46% are low-threshold mechanoreceptive (LTM) and 54% are wide-dynamic-range (WDR) neurons. Most LTM neurons can evoke the same response to both 10 times (10 T) and 50 times (50 T) the threshold stimulation on the peroneal nerve. Most WDR neurons to 50 T intensity stimulation are stronger than the 10 T stimulation. Under the antidromic-cervical segment conditioning stimulation, the amount of orthodromic-discharging in most WDR and few LTM neurons reduced significantly. The result shows that both LTM and WDR projection neurons in the spinal cord can respond to all peripheral A beta fibers and part of the A delta fibers; there are some inhibitional descending fibers which affect the projection neurons in the cervical segment dorsal column and dorsolateral funiculi.

Animals↗
PubMed1986

Electrophysiological studies on the termination sites of double projection spinal dorsal horn neurons in the cat.

Some projection neurons in laminae III, IV and V of the feline lumbar dorsal horn have been found to be antidromically driven from stimulation of both the ipsilateral cervical dorsal and dorsolateral funiculi that are well-dissected and insulated from one another. No detectable responses can be evoked from these neurons when stimulation is applied to sites rostral to the lateral cervical nucleus and the dorsal column nuclei, suggesting that the dorsal and dorsolateral funicular branches of these neuron's axons terminate in the lateral cervical nucleus and the dorsal column nuclei, respectively. The results indicate that these neurons are an intersection set of the spinal cervical tract (SCT) and dorsal column postsynaptic (DCPS) neurons and have been thus named spinal cervical tract-dorsal column postsynaptic (SCT-DCPS) neurons.

Animals↗
PubMed1985

Intraspinal connections of dorsal column postsynaptic neurons in the cat--a physiological analysis.

Dorsal column postsynaptic (DCPS) neurons in the dorsal horn of the spinal cord have been identified by antidromic stimulation and intracellularly recorded in anesthetized cats. In about one-half of the cells, the antidromic stimulus evokes only an antidromic potential. This potential sometimes has an atypical shape due to penetration-induced depolarization. Atypical potentials are converted into typical antidromic spike potentials after intracellular injection of hyperpolarizing current. In the other one-half, the antidromic potentials are followed by postsynaptic activity. Intracellular analysis indicates that this postsynaptic activity is generated largely by activation of the intraspinal collaterals of A-beta primary afferents that are ascending the dorsal columns. Part of this postsynaptic activity has been produced monosynaptically. Polysnaptic responses are also evident; these are thought to be initiated by A-beta axons, desending axons from neurons in the dorsal column nuclei, or the local collaterals of the DCPS axons themselves. The results indicate that the DCPS system is nonlemniscal in nature and may be involved in those pain modulation systems that are activated by A-beta afferents.

Action Potentials↗