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In order to adapt to the education of the professional who work in thecurrent medical lab,we set up the course of'Experimental Technology of Medical Function'. It is a required subject for the professional with laboratory skill. This article explores the curriculum sys-tem,teaching contents,teaching methods and examination.
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Objective To investigate the biophysical properties of mechanosensitive(MS) channels in cultured dorsal root ganglion neurons of neonatal rats. Methods MS channels current of cultured dorsal root ganglion neurons of neonatal rats were recorded using cell-attached and inside-out patch-clamp technique.The biophysical properties such as pressure response relationship,current voltage relationship,channel kinetics and ion selectivity were analyzed.Membrane stretch was achieved by the application of negative pressure(suction) to a patch-clamp electrode. Results One type of MS non-selective cation ion channels in the membrane patches tested in cultured dorsal root ganglion neurons of neonatal rats were recorded. Those channels were activated rapidly when suction was applied, and kept active during sustained application of negative pressure and quickly turned off when the suction was released.The MS channels exhibited a nearly linear current voltage relationship in the balance solution.The outward chord conductance was (96.2?3.6)pS (mV is between +40 mV and +60 mV) and the inward slope conductance was (62.5?0.4)pS (mV is between -60 mV and 0 mV). This kind of channels appeared to be outward rectifier.The average reversal potential was (-2.3?0.8)mV.The channel kinetics analysis indicated that suction could significantly increase the duration of short-openings and long-openings and decrease that of long-closings,with no effects on short-closings. Conclusion The results of this study could serve as a reference to the understanding of electric activity of DRG neurons.
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Objective To investigate the electrophysiological and morphological properties of the single ventral neuron in the medial geniculate body (MGBv) in rats. Methods The basic electrophysiological properties and action potentials at different levels of membrane potentials were recorded by whole cell patch clamp technique. Morphological properties of ventral neurons in the medial geniculate body were studied by biocytin staining. Results Nissl and biocytin stainings indicated that MGBv neurons were composed of oval shaped cell bodies, and the dendritic branches were tufted. In current clamp recordings, the resting membrane potential was (-54.92?10.85) mV, the input resistance (945.67?507.80) M?, the membrane capacitance (5.37?1.98) pF, and the time constant (2 109 87 ?2 496 01) ?s. Action potentials under different current inputs were various. Spontaneous discharge could be recorded by voltage clamp and current clamp. Conclusion MGBv dendritic trees are fairly dense with bushy tufted neurons and variety of action potentials under different current inputs in ventral neurons of the medial geniculate body. Spontaneous activities recorded by current clamp are similar to the action potential, which may be the spontaneous action potential due to the exceeding of membrane potential over liminal value.
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Objective: To study the activities of ion channels in macrophages collected from wound. Methods:Using patch clamp technique to study the activities of ion channels.Results:The spontaneous occurrence of channel-induced currents in macrophage collected from wound can be recorded. These currents include cation-selective channel current carried by potassium and anion-selective channel current carried by chloridion. The physiologic function of these ion channels in macrophage collected from wound was discussed in this paper.
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Objective To study the physiological properties of a potassium channel in the basolateral membrane (BLM) of proximal tubule. Methods Nephrons were dissected from rat kidney under a stereoscopic microscope. The standard configuration for single channel tight seal patch clamp technique was used to record channel currents from the BLM. Results A kind of potassium channel with low conductance and inward rectification was easily recorded in the BLM of the proximal tubule. The channel current occurred spontaneously in 81% seals made on the BLM. In the patches, with no spontaneous channel activity, the channel current occurred when the pressure increased. In the inside out configuration, run down was present in channel activity. The open dwelling time constants of the potassium channel were 0.524 ms and 5.087 ms, while the closed dwelling time constants were 1.029 ms and 16.500 ms. Conclusion A type of potassium channels with low conductance, stretch sensibility and chemistry sensibility, presenting kinetic properties as two opening and two closing states, are widely distributed in the basolateral membrane of proximal tubule.