Neurons

Main thing

A neuron is a specialized cell that transmits information through electrical and chemical signals in the nervous system. Neurons play a crucial role in enabling humans to perceive, think, learn, remember, and control their movements. A neuron consists of three main parts:

1. Cell body (soma): Contains the nucleus and other organelles necessary for the neuron's survival and function.

2. Dendrites: Branch-like structures that receive signals from other neurons.

3. Axon: A long, thin fiber that conducts electrical impulses away from the cell body to other neurons or cells.

   • Axon terminal: The end of the axon where neurotransmitters are released to communicate with other neurons or cells.

   • Myelin sheath: An insulating layer that surrounds the axon to speed up signal transmission.

Neurons communicate with each other through synapses. When a signal reaches the end of an axon, it triggers the release of neurotransmitters, which cross the synaptic gap and bind to receptors on the dendrites of the receiving neuron. This causes changes in the electrical potential of the receiving neuron, which can lead to the generation of a new electrical signal if the threshold is reached. This process allows neurons to transmit information throughout the nervous system.

Terms

• Synapse: A junction between two neurons where signals are transmitted. Example: A synapse between two neurons in the brain allows communication.

• Nervous system: A complex network of neurons and other cells that transmits signals throughout the body. Example: The central nervous system includes the brain and spinal cord.

• Neurotransmitter: A chemical substance released by neurons to transmit signals across synapses. Example: Serotonin is a neurotransmitter that regulates mood and sleep.

• Electrical potential: The difference in electrical charge across a neuron's membrane. Example: When a neuron is at rest, it has a negative electrical potential.

An analogy

Neurons are like a city's postal system. The dendrites are like mailboxes that receive letters (signals), the cell body is like the post office that processes the letters, and the axon is like the postal worker who delivers the letters to other houses (cells). Just as a postal system allows communication between people in a city, neurons allow communication between cells in the body.

A main misconception

Many people believe that we are born with all the neurons we will ever have and that they cannot regenerate. However, research has shown that new neurons can form in certain parts of the adult brain, such as the hippocampus, through a process called neurogenesis. This means that the brain can adapt and change throughout life.

The history

1. 1873: Camillo Golgi discovers the silver staining method to visualize neurons

2. 1888: Santiago Ramón y Cajal proposes the neuron doctrine

3. 1897: Charles Sherrington coins the term "synapse"

4. 1952: Alan Hodgkin and Andrew Huxley describe the ionic basis of the action potential

5. 1998: Peter Eriksson and Fred Gage provide evidence for neurogenesis in the adult human brain

Three cases how to use it right now

1. A student can apply their knowledge of neurons to create effective study strategies. By taking breaks, getting enough sleep, and engaging in mentally stimulating activities, they can promote healthy neuron function and improve their learning.

2. A person with a neurological disorder can work with their doctor to develop a treatment plan that supports neuron health. This may include medications, therapy, and lifestyle changes like exercise and stress management.

3. A teacher can design lessons that incorporate movement, novelty, and social interaction to stimulate neuron activity in their students' brains. This can lead to better engagement, memory, and learning outcomes.

Interesting facts

• The human brain contains about 86 billion neurons.

• The longest neuron in the human body is the sciatic nerve, which can be up to 1 meter long.

• Neurons can transmit signals at speeds up to 120 meters per second.

• A single neuron can have up to 10,000 synaptic connections with other neurons.

• The human brain uses about 20% of the body's total energy supply.