概括
刺激细胞的去极化增加了它们的质子透性,挑战了关于细胞内pH调节的先前假设. 这一发现揭示了穿越细胞膜的质子运输的新途径.
科学领域:
- 神经科学是一个神经科学.
- 细胞生理学 细胞生理学
- 生物物理学的生物物理.
背景情况:
- 细胞内pH (pHi) 调节对于可刺激细胞至关重要.
- 以前,人们只知道去极化会导致细胞质酸化.
- 由于电中性调节机制,膜电位和pHi之间的联系尚不清楚.
研究的目的:
- 为了研究膜去极化对可刺激细胞的细胞内pH (pHi) 的影响.
- 测试脱极化增加质子 (H+) 离子透性的假设.
- 探索这种潜在的新途径的生理意义.
主要方法:
- 在软体动物神经元上利用电压技术.
- 在受控条件下进行精确的细胞内pH值 (pHi) 测量.
- 在膜去极化过程中分析了质子导电率的变化.
主要成果:
- 在细胞脱极化时,证明了质子透率的显著增加.
- 在去极化软体动物神经元中观察到质子导电率的大幅增加.
- 提供了与H+离子与膜电位处于平衡的概念相矛盾的证据.
结论:
- 脱极化活跃地提高了细胞膜中质子的透性.
- 这种增加的质子导电率可能解释了以前在神经元中观察到的"非特异性"电流.
- 确定了一种新的生理途径,用于激发性细胞中的质子运输.
相关概念视频
Action Potentials
Overview
The Resting Membrane Potential
Overview
Resting Membrane Potential
The relative difference in electrical charge, or voltage, between the inside and the outside of a cell membrane, is called the membrane potential. It is generated by differences in permeability of the membrane to various ions and the concentrations of these ions across the membrane.
The Inside of a Neuron is More Negative
The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular fluid. The...
The Inside of a Neuron is More Negative
The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular fluid. The...
The Role of Ion Channels in Neuronal Computation
A postsynaptic neuron usually receives numerous impulses from several other presynaptic neurons. The axon hillock of the postsynaptic neuron integrates all these signals and determines the likelihood of firing an action potential.
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
Electrochemical Gradient and Channel Proteins: An Overview
An electrochemical gradient is a fundamental concept in biology and chemistry. It regulates the movement of ions across cell membranes. This movement is influenced by two factors:
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell. This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to the...
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell. This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to the...
Action Potential: Phases of Stimulation
The action potential is a complex electrical event that occurs in excitable cells, such as neurons and muscle cells. It consists of several distinct phases, each with specific characteristics.
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...


