猫扣带回前部内脏伤害感受神经元的膜电学特性

目的 :研究猫扣带回前部内脏大神经刺激相关神经元的膜电生理特性 ,以便从神经元水平进一步了解大脑皮质内脏伤害感受的特性及机制 ,为痛觉理论“特异性学说”提供新的实验依据。方法 :应用在体玻璃微电极细胞内电位记录技术及细胞内注入极化电流的方法 ,测量和计算神经元的膜电学参数。结果 :将 2 0只猫扣带回前部 1 76个内脏大神经刺激相关神经元 ,分为内脏伤害 (1 4 8个 )和非伤害 (2 8个 )感受神经元。发现它们在膜电阻、时间常数、膜电容及I V曲线等方面存在差异。注入去极化电流引发的放电幅值及频率也存在差异。结论 :扣带回前部内脏伤害与非伤害感受神经元可能在细胞膜结构。

猫扣带回前部内脏与躯体伤害感受神经元膜电学特性的对比研究

目的对比研究猫扣带回前部内脏伤害感受神经元与躯体伤害感受神经元膜电学特性,从膜电学方面为阐明内脏痛与躯体痛具有不同感受特性的机制提供实验依据。方法选择成龄猫77只,体质量2.0~3.5 kg,雄雌不限。根据在体微电极记录的扣带回前部神经元对电刺激内脏大神经或隐神经产生的诱发反应的特点及吗啡对该诱发反应的影响,检出具有长潜伏期(≥50 ms)的内脏伤害感受神经元或躯体伤害感受神经元。应用在体微电极向内脏伤害感受神经元或躯体伤害感受神经元内注入波宽50 ms、不同强度(-5 n A^+5 n A)的一系列极化电流,记录神经元膜电学反应,计算膜电学参数。结果在扣带回前部记录了254个内脏伤害感受神经元和172个躯体伤害感受神经元。内脏伤害感受神经元的内脏大神经诱发反应阈值比躯体伤害感受神经元的隐神经诱发反应阈值高;与躯体伤害感受神经元相比,内脏伤害感受神经元的膜电阻、膜电容、时间常数较大。结论扣带回前部内脏伤害感受神经元与躯体伤害感受神经元的膜电学特性存在差异,可能是内脏痛与躯体痛具有不同感受特性的膜电学基础。

猫扣带回前部躯体伤害性与非伤害性感受神经元膜电学特性的对比

应用在体微电极胞内电位记录技术分别向猫扣带回前部躯体伤害性感受神经元与非伤害性感受神经元内注入波宽50ms、不同强度(-5 n A^+5 n A)的系列超级化或去极化电流,记录神经元的膜电学反应,计算膜电学参数。通过对比躯体伤害性与非伤害性感受神经元的膜电学特性,从该侧面为深入了解该脑区躯体伤害性感受的特性及机制提供实验依据。在57只猫扣带回前部共记录了188个神经元,其中172个为躯体伤害性感受神经元(91.5%),另外16个为躯体非伤害性感受神经元(8.5%)。结果表明:躯体伤害性与非伤害性感受神经元的注入电流(I)-膜电位(V)曲线都为"S"型;注入电流强度的绝对值≤1n A时,躯体伤害性与非伤害性感受神经元I-V曲线的I与V均呈线性相关(r都为0.99);而注入电流强度的绝对值>1 n A时,两者均呈现内向或外向整流作用;但是,与躯体非伤害性感受神经元相比,躯体伤害性感受神经元的整流作用较大,对刺激的适应性较低,诱发放电的频率较高(P<0.01),并且,随注入的去极化电流强度的逐渐增大,放电频率变化也较大;另外,躯体伤害性感受神经元的膜电阻、膜电容、时间常数也明显大于躯体非伤害性感受神经元(P<0.05或P<0.01)。这些结果提示扣带回前部躯体伤害性与非伤害性感受神经元在直径大小、细胞膜结构等方面存在差异。

Study on the growth of honeycomb-like film of basic zinc carbonate induced by bovine serum albumin LB film template

Honeycomb-like films of basic zinc carbonate were successfully prepared on FTO(SnO_(2):F)conductive glass using bovine serum albumin(BSA)as a template at room temperature.After low-temperature annealing,a high-specific-surface-area porous ZnO film with excellent electron mobility was obtained.The surface morphology,crystallization performance,and photoluminescence characteristics of basic zinc carbonate thin films and annealed ZnO thin film were analyzed by scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),photoluminescence spectroscopy(PL)and UV-Visible spectroscopy(UV-vis).By comparing with those samples prepared without any protein,it was determined that the complexation between BSA molecules and Zn^(2+)ions was the primary factor in the synthesis of porous films of basic zinc carbonate.The experimental results showed that the ZnO thin film samples prepared with this method had high specific surface area and broadband luminescence characteristics in the near ultraviolet range.

Fabrication and Electrical Properties of Titanium Oxide by Thermally Oxidizing Titanium on Silicon

Polycrystalline titanium oxide films are fabricated on silicon by thermally oxidizing titanium.The current- voltage and capacitance- voltage characteristics of the Ag/Ti Ox/Si/Ag capacitors are m easured.The thickness of the titanium oxide films arranges from15 0 nm to2 5 0 nm,and their dielectric constants are within40～ 87.As the oxida- tion tim e is shortened,the fixed charges of the titanium oxide films become less and the leakage current characteris- tics becom e better.

Effect of Film Thickness on Properties of a-Si∶H Films

The a-Si∶H films with different thickness smaller than 1 μm were deposited by plasma enhanced chemical vapor deposition (PECVD) under the optimum deposition conditions. The effect of different thickness on film properties is analyzed.The results show that,with the increase of the film thickness,the dark conductivity, photoconductivity and threshold voltage increase, the optical gap and peak ratio of TA to TO in the Raman spectra decrease, the refractive index keeps almost constant, and the optical absorption coefficient and current ratio of on/off state first maximize and then reduce.

Preparation and electronic characteristics of anionic perylene bisimide films

Neutral perylene bisimides(PBI) are well-known n-type organic semiconductors, with number of challenging electronic properties in their neutral and reduced states. We report the characteristic electronic properties of PBI anionic films. We unexpectedly discovered that pristine PBI dianion film showed p-type character, while oxidized dianion film(dominant neutral state with few radical anions) showed normal n-type semiconductor character based on Seebeck effect measurements. Both kinds of films exhibit high electrical conductivity with a potential for thermoelectric applications. The mechanism of polarity reversal is proposed.