Nervous System Physiology Essentials 3

The connection between a neuron and another cell allowing information exchange.

The neuron sending the signal across the synapse.

The cell receiving the signal from the synapse.

A synapse where the presynaptic neuron connects to a dendrite of the postsynaptic neuron.

A synapse where the presynaptic neuron connects to the cell body of the postsynaptic neuron.

A synapse where the presynaptic neuron connects to the axon of the postsynaptic neuron.

A synapse where the presynaptic neuron releases a neurotransmitter that excites the postsynaptic neuron, making it more likely to fire.

A synapse where the presynaptic neuron releases a neurotransmitter that inhibits the postsynaptic neuron, making it less likely to fire.

The arrival of an action potential (AP) at the presynaptic terminal of a neuron triggers a series of events culminating in neurotransmitter release into the synaptic cleft.

Voltage-gated calcium (Ca2+) channels open in the presynaptic terminal membrane, allowing Ca2+ ions to flow into the neuron. This influx of Ca2+ triggers the release of neurotransmitters from synaptic vesicles.

Synaptic vesicles, filled with neurotransmitters, are docked near the presynaptic membrane. They release their contents into the synaptic cleft via exocytosis.

The neurotransmitter acetylcholine (ACh) binds to nicotinic acetylcholine receptors (nAcHR) located on the postsynaptic membrane. This activates the receptors, allowing for the flow of ions across the membrane.

The binding of acetylcholine to its receptors leads to a localized depolarization of the postsynaptic membrane, called the motor end plate potential (MEPP). This depolarization is a type of graded potential.

Glutamate is a primary excitatory neurotransmitter in the central nervous system (CNS). It facilitates the transmission of signals between neurons, playing a crucial role in learning and memory.

Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the CNS. It calms down the firing of neurons, preventing overstimulation and contributing to anxiety control.

Neurotransmitters, like chemical messengers, are released from presynaptic neurons to communicate with postsynaptic neurons. They carry information across synapses and play vital roles in brain function.

A neurotransmitter responsible for initiating muscle contractions and involved in learning and memory in the central nervous system (CNS). It's found in both the CNS and the peripheral nervous system (PNS).

A type of synapse where the transmission of signals is carried out directly through the flow of ions between two neurons. It's characterized by a narrow synaptic gap, no synaptic delay, and bidirectional transmission.

A type of synapse where the transmission of signals is carried out through the release of neurotransmitters into the synaptic gap. It's characterized by a wide synaptic gap, a synaptic delay, and unidirectional transmission.

A type of SNARE protein located on the surface of a vesicle that helps it bind to the target cell or organelle membrane. It's essential for the release of neurotransmitters.

A type of SNARE protein located on the target cell or organelle membrane that helps the vesicle bind to it. It collaborates with V-SNAREs for successful neurotransmitter release.

A complex formed by the interaction of V-SNARE and T-SNARE proteins. This complex plays a crucial role in bringing the vesicle and target membrane close together, leading to the release of neurotransmitters.

A powerful neurotoxin produced by the bacterium Clostridium botulinum. It blocks the release of neurotransmitters from synaptic vesicles, causing paralysis in the muscles.

SNARE proteins are a family of proteins that play crucial roles in the process of vesicle fusion and neurotransmitter release. Major players include synaptobrevin, syntaxin, SNAP-25, and synaptotagmin.

A type of signal that travels across a synapse and makes the postsynaptic neuron more likely to generate an action potential.

A type of signal that travels across a synapse and makes the postsynaptic neuron less likely to generate an action potential.

The sum of all EPSPs and IPSPs reaching a postsynaptic neuron at a given time.

When a neuron receives input from multiple presynaptic neurons.

When a neuron sends signals to multiple postsynaptic neurons.

The process where repeated stimulation of a synapse enhances its strength, making it more likely to trigger an action potential in the postsynaptic neuron.

A chemical that blocks the action of acetylcholine at the neuromuscular junction, leading to muscle paralysis.

An enzyme that breaks down acetylcholine in the synaptic cleft.

Botulinum toxin specifically targets and destroys SNAP-25, synaptobrevin, and syntaxin, key proteins responsible for neurotransmitter release at the synapse.

Botulinum toxin blocks the release of acetylcholine, a neurotransmitter essential for muscle contraction.

Curare is a natural compound that has muscle relaxant properties. It works by blocking acetylcholine receptors, preventing muscle activation. This effect is similar to that of botulinum toxin, but curare acts on the postsynaptic side.

The bacterium Clostridium botulinum produces botulinum toxin, which can be found in soil, water, and some food products.

Tetanus toxin specifically targets and destroys synaptobrevin in inhibitory interneurons, leading to overactivity of motor neurons and spastic paralysis.

The anaerobic bacterium Clostridium tetani, found in soil, produces tetanus toxin. It causes spastic paralysis by blocking the release of inhibitory neurotransmitters, leading to overactive motor neurons.

Lambert-Eaton syndrome is a rare autoimmune disorder caused by autoantibodies that attack voltage-gated calcium channels, reducing acetylcholine release at the neuromuscular junction.

Myasthenia gravis is an autoimmune disease that involves the production of antibodies against acetylcholine receptors, leading to impaired muscle function.