Video Experimental Relacionado
Updated: Aug 14, 2026
08:38
Vibrodissociation of Neurons from Rodent Brain Slices to Study Synaptic Transmission and Image Presynaptic Terminals
Published on: May 25, 2011
Un canal de Ca activado por baja tensión y totalmente inactivo en las neuronas sensoriales de los vertebrados
Nature
|August 9, 1984
Resumen
Los investigadores descubrieron un nuevo canal de calcio en las neuronas sensoriales de pollitos y ratas. Este canal exhibe propiedades únicas dependientes del tiempo y la tensión, lo que explica la inactivación de la conductividad del calcio en las membranas excitables.
Área de la Ciencia:
- La neurociencia es la neurociencia.
- Fisiología celular Fisiología celular.
- Biología del canal iónico Biología del canal iónico.
Sus antecedentes:
- Los canales de calcio son críticos para las funciones celulares en las membranas excitables.
- Los modos de disparo de ráfagas neuronales están influenciados por la conductividad del calcio, a menudo inactivados en potenciales de reposo pero activados por hiperpolarización.
Objetivo del estudio:
- Identificar y caracterizar un nuevo tipo de canal de calcio responsable del comportamiento de inactivación en las neuronas sensoriales.
- Para investigar las propiedades dependientes del tiempo y la tensión de este nuevo canal de calcio.
Principales métodos:
- Registros electrofisiológicos de parches de membrana aislados de neuronas sensoriales de pollitos y ratas.
- Técnicas de abrazadera de tensión para estudiar la cinética de los canales de calcio y las propiedades de inactivación.
Principales resultados:
- Evidencia de un nuevo canal de calcio con distintas propiedades dependientes del tiempo y la tensión.
- Este canal exhibe aberturas de 3-6 ms entre -50 y +10 mV, que ocurren en ráfagas.
- La inactivación se caracteriza por cierres prolongados después de los pasos de voltaje despolarizante, lo que lo distingue de un canal coexistente, menos sensible a la tensión con aberturas más cortas.
Conclusiones:
- Se ha identificado un nuevo tipo de canal de calcio, probablemente responsable de la inactivación de la conductividad del calcio, en las neuronas sensoriales.
- Este descubrimiento proporciona nuevos conocimientos sobre los mecanismos que controlan la excitabilidad neuronal y los cambios de estado funcional.
Videos de Conceptos Relacionados
01:21The Resting Membrane Potential
Overview
01:24Resting 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...
01:19The 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.
01:26Voltage-gated Ion Channels
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
01:30Ligand-Gated Ion Channel Receptor: Gating Mechanism
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
01:26Voltage-gated Ion Channels
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...