Continuous subcellular resolution three-dimensional imaging on intact macaque brain

To decipher the organizational logic of complex brain circuits,it is important to chart long-distance path-ways while preserving micron-level accuracy of local ...     

Activation of protein kinase C augments evoked transmitter release

In view of the emerging role of the phosphoinositide system in cellular communication we examined its involvement in quantal-transmitter release, which is a key element in synaptic transmission. Transmitter release is normally activated by an increase in intracellular calcium, achieved either by entry of calcium ions through the presynaptic membrane or by intracellular calcium liberation. One of the targets of the phosphoinositide signalling system is the enzyme protein kinase C (PKC), which can be activated experimentally by tumour promoting phorbol esters, including 12-O-tetradecanoylphorbol-13-acetate (TPA). Such activation of PKC may be implicated in transmitter release in two ways. First, phorbol esters were found to increase secretion and enhance calcium currents; it might therefore be expected that they would increase synaptic transmitter release. But phorbol esters also inhibit the calcium current in dorsal root ganglion neurones. We report that the phorbol ester TPA augments synaptic transmission at the neuromuscular junction by increasing transmitter liberation. Activation of PKC also depends synaptic depression.     

温度对二硫苏糖醇释放马脾铁蛋白铁的影响

用光谱法检测了二硫苏糖醇(DTT)在不同温度下对马脾铁蛋白(HSF)铁核铁的释放过程.在空气(21%O2)、DTT浓度为1.67mmol/L和反应时间为2h条件下,37℃时铁释放量是5℃时的19.43倍,25℃时铁释放量是5℃时的16.91倍,37℃时铁释放量仅是25℃时的1.15倍.这说明HSF分子在不同的温度下其蛋白壳结构发生了柔性改变.这种改变使HSF亲水通道在5℃时变得更为狭窄,从而使DTT进入HSF变得困难.     

温度对二硫苏糖醇释放马脾铁蛋白铁的影响

用光谱法检测了二硫苏糖醇(DTT)在不同温度下对马脾铁蛋白(HSF)铁核铁的释放过程。在空气(21%O2)、DTT浓度为1.67mmol/L和反应时间为2h条件下,37°C时铁释放量是5°C时的19.43倍,25°C时铁释放量是5°C时的16.91倍,37°C时铁释放量仅是25°C时的1.15倍。这说明HSF分子在不同的温度下其蛋白壳结构发生了柔性改变。这种改变使HSF亲水通道在5°C时变得更为狭窄,从而使DTT进入HSF变得困难。     

Effect of electroacupuncture in Weijing points on gastrointestinal interdigestive migrating motor complex and brain gut peptides release in dogs

Interdigestive gastrointestinal migrating motor complex (MMC) activities were recorded by strain gauge implanted on the serosa in 7 conscious dogs. We studied the effects of electroacupuncture (EAP) Weijing points Zusanli (S36), Tianshu (S25), Liangmen (S21) on MMC and release of motilin and gastrin, and compared them with that of EAP Pangguangjing points. The results indicated that EAP Weijing points could not only strengthen MMC contractions in antrum, duodenum and proximal jejunum, but also increase plasma concentration of motilin and gastrin. Anti-motilin serum, proglumide, atropine, or hexamethonium could markedly block the effect of EAP on reinforcing MMC contraction and release of motilin and gastrin. We could get the conclusions that such enhancing effect of EAP Weijing points on MMC and brain-gut peptides release is mediated by motilin and gastrin, on which both cholinergic nerve and sympathetic nerve play important roles.