(2000). Action potential-evoked Ca2+ signals and calcium channels in axons of developing rat cerebellar interneurones. J. Physiol. 527, 33-48.Forti L, Pouzat C, Llano I (2000) Action potential-evoked Ca 2+ signals and calcium channels in axons of developing rat cerebellar interneurones . J...
When the presynaptic membrane is depolarized by an action potential, the calcium voltage-gated channels open. This leads to an influx of calcium, which changes the state of certain membrane proteins in the presynaptic membrane, and results with exocitosis of the neurotransmitter in the synaptic ...
这种效应来自BK(large conductance calcium-activated potassium channels),由于BK带来的强大钾离子同通透性,使得封闭钙离子的净效益是去极化。BK和Cav1.2、Cav2.2、Cav2.1都有空间上的共定位,这对其快速反应性可能有贡献。BK强烈地影响动作电位形状,因而长的动作电位(如Purkinje neurons)并不一定意味着高的钙离子内流。
At the same time, fast sodium channels and (L-type) slow calcium channels are closed, so Na+ and Ca++ inward currents are very low. When these cells are rapidly depolarized to a threshold voltage of about -70 mV by an action potential in an adjacent cell, this triggers a rapid ...
Most neurons have large calcium currents carried by multiple types of calcium channels. The calcium current is largest during the falling phase of the action potential but is often outweighed by calcium-activated potassium current, activated by extremely rapid coupling to calcium entry. Potassium channe...
During sleep, their hyperpolarized membrane potential allows activation of the T-type calcium channels, promoting rhythmic high-frequency burst firing that reduces sensory information transfer. In contrast, in the waking state thalamic neurons mostly exhibit action potentials at low frequency (i.e., ...
The function of Ca 2+ at the time of the action potential is being revealed by experimental techniques of increasing sophistication. The development of these methods and possible associated artefacts are considered. 展开 关键词: Chara action potentials calcium concentration cytoplasmic streaming ...
Membrane Calcium Channels Play a Special Role in Cardiac Muscle Fig. 19.5 depicts a cardiac muscle cell action potential, aligned in time with graphs of the sequence of changes in K+, Na+, and Ca2+ permeability that are responsible for the action potential. As the time line begins (on the...
opening, in the terminals, of the voltage-operated calcium channels that have an essential role in transmitter release (seeChapter 3). Influx of Ca2+causes further depolarization, but voltage-operated gated channels are also opened and K+efflux restores the membrane potential to the resting value....
A time-dependent outward K current in colon cells was observed which appeared to be dependent upon entry of calcium ions (Ca 2+ ) through voltage-dependent Ca-channels, since it was blocked by cadmium and low concentrations of nifedipine. The majority of cells did not exhibit transient outward...