neurotrans. and synap.

Neurotransmitter (NT)

A chemical messenger that neurons use to communicate with other cells.

Receptor

A protein that recognizes and binds to a specific chemical, allowing the cell to respond.

Binding

When a chemical attaches to a receptor.

Ion

A particle with an electrical charge, such as sodium (Na⁺).

Ion channel

A tiny passageway in a cell membrane that allows certain ions to pass through.

Ionotropic receptor

A receptor that opens an ion channel when a neurotransmitter binds to it. This usually produces a fast response.

Metabotropic receptor

A receptor that activates processes inside the cell rather than directly opening an ion channel. This usually produces a slower response.

Ligand

Any chemical that binds to a receptor.

Agonist

A chemical that binds to and activates a receptor.

Antagonist

A chemical that binds to a receptor and blocks its activation.

Reuptake

When a neuron takes a neurotransmitter back up after releasing it.

Synaptic cleft

The tiny gap between communicating cells where neurotransmitters are released.

Acetylcholine (ACh)

A neurotransmitter involved in muscle movement, attention, learning, and memory.

Cholinergic

Relating to acetylcholine or neurons that use it.

Nicotinic receptor

A type of ACh receptor that is ionotropic. When activated, it opens an ion channel. It's important for skeletal muscle contraction.

Muscarinic receptor

A type of ACh receptor that is metabotropic. It activates processes inside the cell and is important for functions such as slowing the heart rate.

Skeletal muscle

Muscle attached to the skeleton that allows you to move voluntarily.

Autonomic nervous system

The part of the nervous system that regulates automatic body functions, such as heart rate and digestion.

Sympathetic division

The autonomic division associated with the fight-or-flight response.

Parasympathetic division

The autonomic division associated with rest-and-digest functions.

Acetylcholinesterase

The enzyme that breaks down acetylcholine.

Acetylcholinesterase inhibitor

A substance that blocks this enzyme, allowing ACh to remain available in the synapse longer.

CNS (central nervous system)

The brain and spinal cord.

PNS (peripheral nervous system)

The nerves outside the brain and spinal cord.

Excitatory

Makes a neuron more likely to fire an electrical signal.

Inhibitory

Makes a neuron less likely to fire an electrical signal.

Monoamine

A class of neurotransmitters made through chemical modification of a single amino acid precursor.

Catecholamines

A subgroup of monoamines that includes dopamine, norepinephrine, and epinephrine.

Precursor

A starting substance used to make another substance.

Co-release

When a neuron releases more than one type of chemical messenger.

Neuropeptide

A neurotransmitter or signaling molecule made from a chain of amino acids.

Neuroplasticity

The brain's ability to change its connections and functioning.

Neurogenesis

The formation of new neurons.

BDNF

Brain-derived neurotrophic factor, a protein that supports neurons and their connections.