Name: glial cells and nervous system support
Uploaded: 2025-10-23T11:49:28.000Z
Duration: 1 min 4 s
Channel: JoVE

- [Instructor] Las células
gliales son las células de apoyo

de los sistemas nerviosos.

El sistema nervioso central, o SNC,

contiene diferentes
variedades de células gliales.

El tipo más grande y abundante
es el de los astrocitos.

Estas células tienen varias funciones.

Una de ellas es la de mantener

la barrera hematoencefálica.

Otro tipo es el de los
oligodendrocitos, que son células más

pequeñas y tienen menor
cantidad de procesos,

que forma la cubierta de mielina a

lo largo de la longitud de los axones.

Las células más pequeñas
y menos numerosas son

las microglías, que se involucran
en procesos fagocíticos,

patógenos de recubrimiento
y suciedad celular.

Además, el sistema
nervioso periférico, o SNP,

incluye células satelitales
que rodean células neuronales

y funcionan como astrocitos
encontrados en el SNC.

De forma similar, las
células de Schwann son las

que actúan como oligodendrocitos,

que forman la cubierta alrededor
de los axones periféricos.

Como la investigación continúa,
queda claro que las células

gliales no son un simple
pegamento en el sistema nervioso.

Zuchero, J. Bradley y Ben A. Barres. "La glía en el desarrollo y la enfermedad de los mamíferos". Development (Cambridge, Inglaterra) 142, no. 22 (15 de noviembre de 2015): 3805–9. [<a href="https://doi.org/10.1242/dev.129304" target="__blank">Fuente</a>]

células gliales

<h4>Descripción general</h4> Las células gliales son uno de los dos tipos principales de células del sistema nervioso. Las células gliales comprenden astrocitos, oligodendrocitos, microglía y células ependimarias en el sistema nervioso central, y células satélite y de Schwann en el sistema nervioso periférico. Estas células no se comunican mediante señales eléctricas como lo hacen las neuronas, pero contribuyen prácticamente a todos los demás aspectos de la función del sistema nervioso. En los humanos, la cantidad de células gliales es aproximadamente igual a la cantidad de neuronas en el cerebro. <h4>Células gliales del sistema nervioso central</h4> La glía en el sistema nervioso central (SNC) incluye astrocitos, oligodendrocitos, microglía y células ependimarias. Los astrocitos son el tipo más abundante de célula glial y se encuentran en patrones organizados y no superpuestos en todo el cerebro, donde se asocian estrechamente con neuronas y capilares. Los astrocitos desempeñan numerosas funciones en la función cerebral, incluida la regulación del flujo sanguíneo y los procesos metabólicos, la homeostasis de los iones sinápticos y el pH y el mantenimiento de la barrera hematoencefálica. Otra célula glial especializada, el oligodendrocito, forma la vaina de mielina que rodea a los axones neuronales en el SNC. Los oligodendrocitos extienden largos procesos celulares que envuelven los axones varias veces para formar este recubrimiento. La vaina de mielina es necesaria para la conducción adecuada de la señalización neuronal y aumenta considerablemente la velocidad a la que viajan estos mensajes. La microglía,conocida como macrófagos del SNC, es el tipo de célula glial más pequeña y se especializa en la fagocitosis tanto de patógenos como de desechos. Protegen el SNC de agentes infecciosos y toxinas, y apoyan las sinapsis durante el desarrollo. Aunque la microglía se considera células gliales, tiene un origen único y separado en comparación con otros tipos de células gliales. Los astrocitos y oligodendrocitos son producidos por la glía radial, aunque la microglía se origina en el saco vitelino y migra al embrión en las primeras etapas del desarrollo embrionario. Por último, las células ependimarias son células en forma de cubo con protuberancias similares a cilios que recubren los ventrículos, donde producen líquido cefalorraquídeo (LCR). Las células ependimarias forman una barrera entre el cerebro y el LCR, filtrando sustancias potencialmente dañinas. Al igual que los astrocitos y los oligodendrocitos, las células ependimarias se originan a partir de la glía radial que se encuentra cerca de los ventrículos laterales. <h4>Células gliales del sistema nervioso periférico</h4> En el sistema nervioso periférico (SNP), existen tipos similares pero distintos de células gliales. Por ejemplo, las funciones realizadas por los astrocitos del SNC se realizan en el SNP principalmente mediante células satélite, células gliales que proporcionan estructura, amortiguación y nutrientes a los cuerpos neuronales con los que se asocian. Otra célula glial del SNP, la célula de Schwann, funciona como oligodendrocitos del SNC formando una vaina de mielina alrededor de los axones neuronales. Al igual que la mielinización en el SNC, la mielinización de los axones del SNP proporciona el aislamiento y la conductividad necesarios para la transmisión adecuada de señales eléctricas. <h4>Importancia de la glía en la salud y la enfermedad</h4> Las células gliales son protectoras y reguladoras críticas del sistema nervioso. No sólo mantienen condiciones homeostáticas y contribuyen al funcionamiento rutinario del cerebro, sino que también responden a lesiones, infecciones y enfermedades del sistema nervioso. Además, la glía realiza funciones críticas durante el desarrollo embrionario del sistema nervioso. Estas células incluso contribuyen a la eliminación de conexiones neuronales innecesarias, un proceso llamado poda sináptica. Debido a la importancia de la glía en numerosos aspectos de la función cerebral, los defectos en una o más poblaciones de células gliales pueden provocar afecciones neurológicas graves y debilitantes, incluidos trastornos del desarrollo, enfermedad de Alzheimer, enfermedad de Parkinson, esclerosis múltiple y muchas otras. Durante el desarrollo, las células gliales proporcionan un andamiaje para que las neuronas migren adecuadamente y desarrollen sus axones. Más adelante en la vida, los traumatismos o las enfermedades neurodegenerativas pueden provocar la pérdida de conexiones neuronales que no pueden regenerarse, lo que provoca un deterioro del funcionamiento o parálisis.

Células gliales

Visión general

Las células gliales son uno de los dos tipos principales de células del sistema nervioso. Las células gliales comprenden astrocitos, oligodendrocitos, microglía y ...

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Biology

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Biología Humana

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Sistema nervioso

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

Glial Cells

glial cells and nervous system support

Glial cells support the nervous system and work alongside neurons. They are one of the two main cell types in the nervous system. Unlike neurons, glia do not send electrical signals, but they help with nearly every other part of nervous system function. In humans, glial cells are about as numerous as neurons in the brain.

In the central nervous system, glia include astrocytes, oligodendrocytes, microglia, and ependymal cells. Astrocytes are the most common glial cells. They form organized, non-overlapping patterns in the brain and stay close to neurons and capillaries. They help regulate blood flow, support metabolism, maintain ion and pH balance around synapses, and help maintain the blood-brain barrier.

Oligodendrocytes make the myelin sheath in the central nervous system. This sheath wraps around neuronal axons many times and acts as insulation. Myelin helps nerve signals travel correctly and much faster. Microglia are the smallest glial cells and are known as the macrophages of the CNS. They remove pathogens and debris by phagocytosis and also help prune synapses during development. Unlike other glia, microglia come from the yolk sac and enter the embryo early in development.

Ependymal cells are cube-shaped cells with cilia-like projections that line the ventricles. They produce cerebrospinal fluid, or CSF, and form a barrier between the brain and the CSF. This barrier helps filter out harmful substances. Like astrocytes and oligodendrocytes, ependymal cells come from radial glia near the lateral ventricles.

The peripheral nervous system also has glial cells. Satellite cells support the neuronal cell bodies they surround by providing structure, cushioning, and nutrients. Schwann cells do for peripheral axons what oligodendrocytes do in the CNS. They form myelin around axons and help insulation and conductivity for electrical signaling.

Glia are important for health, development, and disease. They protect the nervous system, keep internal conditions stable, and respond to injury, infection, and disease. They also help guide neuron migration and axon growth during embryonic development. Because they help remove extra neuronal connections through synaptic pruning, problems in glial cells can contribute to developmental disorders, Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and other serious conditions. Damage later in life can also lead to lost connections that are difficult or impossible to replace, which may cause impaired function or paralysis.

Glial Cells and Nervous System Support

what is a nervous system?

Nervous System Parts and Control

The nervous system is a network of specialized cells that keeps the body working and helps it respond to the world around it. It controls essential functions such as heart rate and breathing. It also supports movement that helps an organism escape danger. In vertebrates, the nervous system has two major parts: the central nervous system, or CNS, and the peripheral nervous system, or PNS. The CNS includes the brain, spinal cord, and retina, which is the sensory tissue of the visual system. The...

the parasympathetic nervous system

Rest and Digest: Parasympathetic Control

The parasympathetic nervous system helps the body stay calm and return to a rested state. It is one of the two major divisions of the autonomic nervous system, which controls many unconscious functions such as heart rate and digestion. Its neurons are found in the brain and the peripheral nervous system, and they send axons to muscles, organs, and glands. This system is often called the “rest and digest” system because it supports body processes that restore homeostasis. It is most active...

the sympathetic nervous system

Sympathetic Stress Response and Body Changes

The sympathetic nervous system helps the body respond to stress and danger. It is one of the two main divisions of the autonomic nervous system. When it turns on, it prepares the body for action and puts lower-priority functions, such as digestion, on hold. This response is often called the fight-or-flight system. A surprise exam can trigger it, and students may notice a tight stomach, a dry mouth, and a fast heartbeat. In a real threat, the system shifts blood away from the digestive system...

the blood-brain barrier

How the Blood-Brain Barrier Works

The blood-brain barrier is a specialized system of blood vessels that helps control what enters the brain. It delivers nutrients from the blood while tightly regulating ions, molecules, pathogens, and other substances. This semipermeable barrier protects the brain and also makes it harder to deliver some therapies. The blood-brain barrier includes several cellular parts, especially endothelial cells and astrocytes. These cells share a common basement membrane and regulate movement between the...

neuron structure

How Neurons Send Signals

Neurons send signals through a clear set of structures that let them receive, process, and pass on information. They are the main cells of the nervous system and use electrochemical signals to communicate. Neurons also talk to other cells through neurotransmitters at junctions called synapses. Most neurons share three main parts: a cell body, also called the soma, dendrites, and an axon. The soma holds the nucleus and other organelles needed for cell function. Dendrites usually receive...

glial cells

Glial cells support the nervous system and work alongside neurons. They are one of the two main cell types in the nervous system. Unlike neurons, glia do not send electrical signals, but they help with nearly every other part of nervous system function. In humans, glial cells are about as numerous as neurons in the brain. In the central nervous system, glia include astrocytes, oligodendrocytes, microglia, and ependymal cells. Astrocytes are the most common glial cells. They form organized,...

action potentials

How Nerve Signals Travel in Axons

Neurons send signals through action potentials, the rapid electrical changes that move along the axon. These signals lead to neurotransmitter release at axon terminals, which passes information through the nervous system. An action potential is an all-or-none change in membrane potential, the voltage across a cell membrane. A neuron usually has a resting membrane potential of about -70 millivolts. When it receives signals from neurotransmitters or sensory input, the membrane can become more...

the resting membrane potential

How Neurons Keep a Negative Resting Charge

Neurons keep a negative resting charge across their membrane. This electrical difference, called the membrane potential, comes from how ions move and how the membrane lets them pass. In a resting neuron, the inside is typically around -70 millivolts and is more negative than the outside, so the cell is polarized. Two main factors create this resting state. First, the membrane is selectively permeable, which means most ions and molecules cannot cross the lipid bilayer without help from ion...

long-term potentiation

Synaptic Strengthening in Learning and Memory

Long-term potentiation, or LTP, is a form of synaptic strengthening in the brain. It changes the strength of chemical synapses over time between pre- and postsynaptic neurons. LTP works against long-term depression, or LTD, which weakens synapses. Together, LTP and LTD are major mechanisms behind learning and memory. LTP can happen when a presynaptic neuron fires again and again and keeps stimulating a postsynaptic neuron. This is called Hebbian LTP, based on Donald Hebb’s idea that neurons...

long-term depression

Synaptic Pruning in Long-term Depression

Long-term depression, or LTD, is a form of synaptic plasticity that weakens chemical synapses over time. It acts between presynaptic and postsynaptic neurons. LTD works in opposition to long-term potentiation, or LTP, which strengthens synapses. Together, LTD and LTP are two of the main mechanisms behind learning and memory. LTD helps the brain avoid staying locked in a fully strengthened state. If synapses were always maximally strengthened, the brain would become less efficient and it would...

the synapse

How Neurons Signal at Synapses

Neurons communicate through synapses, the points where two neurons meet to pass on signals. At a synapse, the sending neuron is the presynaptic cell, and the receiving neuron is the postsynaptic cell. Most neurons can serve in both roles because they send and receive information. Electrical synapses move signals directly between cells. The presynaptic and postsynaptic cells are linked by gap junctions, which are proteins that physically connect them. This type of synapse can pass electrical...

key terms and concepts

Learn how astrocytes, oligodendrocytes, microglia, ependymal cells, satellite cells, and Schwann cells support neurons in the CNS and PNS.

Glial Cells and Nervous System Support | JoVE K12

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Glial Cells and Nervous System Support

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