"The neuron is the main component of nervous tissue in all animals except sponges and placozoa."
The basic functions of neurons and how they communicate with each other through synapses.
Neuron anatomy: The structure and parts of a neuron including the soma, axon, dendrites, and synapse.
Resting potential: The difference in electrical charge between the inside and outside of a neuron when it is not transmitting a signal.
Action potential: The rapid change in electrical charge that occurs when a neuron is stimulated and sends a signal down its axon.
Ion channels: The channels in the cell membrane that allow ions to flow in and out of the neuron, contributing to the resting potential and action potential.
Neurotransmitters: The chemicals released by neurons at the synapse that transmit signals to other neurons or to muscles or glands.
Synaptic transmission: The process by which neurotransmitters are released and bind to receptors on the dendrites of other neurons.
Excitatory and inhibitory neurotransmitters: Neurotransmitters that either increase or decrease the likelihood that a neuron will fire an action potential.
Receptors: The molecules on the surface of neurons that bind to neurotransmitters or other chemicals.
Neuroplasticity: The ability of the brain and nervous system to change and adapt in response to experience and environmental feedback.
Neural networks: The interconnected networks of neurons that perform complex functions such as perception, cognition, and behavior.
Lateralization: The specialization of the two hemispheres of the brain for different cognitive and perceptual functions.
Neural development: The growth and maturation of neurons and neural networks, from conception through adulthood.
Neurological disorders: Conditions that affect the nervous system and result in cognitive or motor dysfunction, including Alzheimer's disease, Parkinson's disease, and epilepsy.
Sensory Neurons: These neurons are responsible for transmitting signals from sensory receptors to the central nervous system (CNS). They are activated by stimuli such as light, sound, touch, and temperature.
Motor Neurons: These neurons are responsible for transmitting signals from the CNS to the muscles or glands, causing them to contract or secrete. They play a vital role in movement and reflexes.
Interneurons: These neurons connect sensory and motor neurons, forming the connections and circuits that allow for complex behavior and decision-making.
Mirror Neurons: These neurons fire both when an individual performs an action and when they observe another individual doing the same action. They play a role in empathy, imitation, and learning.
Dopaminergic Neurons: These neurons release the neurotransmitter dopamine, which is involved in motivation, reward, and addiction.
Serotonergic Neurons: These neurons release the neurotransmitter serotonin, which regulates mood, appetite, and sleep.
GABAergic Neurons: These neurons release the inhibitory neurotransmitter GABA, which regulates neural activity and prevents neurons from firing excessively.
Glutamatergic Neurons: These neurons release the excitatory neurotransmitter glutamate, which is involved in learning and memory.
Cholinergic Neurons: These neurons release the neurotransmitter acetylcholine, which is involved in attention, arousal, and memory.
Myelinated Neurons: These neurons have a myelin sheath, which increases the speed and efficiency of signal transmission.
Unmyelinated Neurons: These neurons lack a myelin sheath and have a slower signal transmission speed.
Action Potential: An electrical impulse that travels down the axon of a neuron when it is activated.
Synaptic Transmission: The process by which a message is transmitted from one neuron to another across a synapse.
Neurotransmitters: Chemical messengers that are released from the presynaptic neuron and bind to receptors on the postsynaptic neuron, conveying the signal.
Excitatory Postsynaptic Potential (EPSP): A depolarization of the postsynaptic neuron that makes it more likely to fire an action potential.
Inhibitory Postsynaptic Potential (IPSP): A hyperpolarization of the postsynaptic neuron that makes it less likely to fire an action potential.
Reuptake: The reabsorption of neurotransmitters by the presynaptic neuron, terminating their effects on the postsynaptic neuron.
Modulation: The process by which the effects of neurotransmitters on the postsynaptic neuron are enhanced or inhibited by other factors, such as hormones or drugs.
"Neurons communicate with other cells via synapses - specialized connections that commonly use minute amounts of chemical neurotransmitters to pass the electric signal from the presynaptic neuron to the target cell through the synaptic gap."
"Neurons are typically classified into three types based on their function. Sensory neurons respond to stimuli such as touch, sound, or light, Motor neurons receive signals from the brain and spinal cord to control muscle contractions and glandular output, and Interneurons connect neurons to other neurons within the same region of the brain or spinal cord."
"Neurons are special cells which are made up of some structures that are common to all other eukaryotic cells such as the cell body (soma), a nucleus, smooth and rough endoplasmic reticulum, Golgi apparatus, mitochondria, and other cellular components."
"Additionally, neurons have other unique structures such as dendrites, and a single axon. The soma is a compact structure, and the axon and dendrites are filaments extruding from the soma."
"Dendrites typically branch profusely and extend a few hundred micrometers from the soma. The axon leaves the soma at a swelling called the axon hillock and travels for as far as 1 meter in humans or more in other species."
"At the farthest tip of the axon's branches are axon terminals, where the neuron can transmit a signal across the synapse to another cell."
"Neurons may lack dendrites or have no axon. The term neurite is used to describe either a dendrite or an axon, particularly when the cell is undifferentiated."
"At the majority of synapses, signals cross from the axon of one neuron to a dendrite of another. However, synapses can connect an axon to another axon or a dendrite to another dendrite."
"If the voltage changes by a large enough amount over a short interval, the neuron generates an all-or-nothing electrochemical pulse called an action potential."
"Synaptic signals may be excitatory or inhibitory, increasing or reducing the net voltage that reaches the soma."
"In most cases, neurons are generated by neural stem cells during brain development and childhood."
"Neurogenesis largely ceases during adulthood in most areas of the brain."
"The axon leaves the soma at a swelling called the axon hillock."
"Sensory neurons respond to stimuli such as touch, sound, or light that affect the cells of the sensory organs, and they send signals to the spinal cord or brain."
"Motor neurons receive signals from the brain and spinal cord to control everything from muscle contractions to glandular output."
"Interneurons connect neurons to other neurons within the same region of the brain or spinal cord."
"However, synapses can connect an axon to another axon or a dendrite to another dendrite."
"Non-animals like plants and fungi do not have nerve cells."
"Neurons communicate with other cells via synapses - specialized connections that commonly use minute amounts of chemical neurotransmitters to pass the electric signal from the presynaptic neuron to the target cell through the synaptic gap."