Lecture 2. Lets talk brainy neurotransmission 2025

Neurotransmission

The process by which signaling molecules called neurotransmitters are released by a neuron and bind to specific receptors on target cells, thereby transmitting messages across the synapse.

Neuron

A nerve cell that transmits signals throughout the body, consisting of a cell body (soma), dendrites, and an axon.

Soma

The cell body of a neuron, containing the nucleus and organelles.

Dendrite

Branch-like structures of a neuron that receive signals from other neurons.

Axon

The long, slender projection of a neuron that conducts electrical impulses away from the cell body.

Action potential

A temporary shift in membrane potential that occurs when a neuron is activated, resulting in the transmission of a signal down the axon.

Resting membrane potential

The voltage difference across the neuronal membrane when the neuron is not actively signaling, typically around -65 mV.

Equilibrium potential (Eion)

The electrical potential that exactly balances an ionic concentration gradient, resulting in no net movement of ions across the membrane.

Synaptic cleft

The small gap between the presynaptic terminal and the postsynaptic cell where neurotransmitters are released.

Neurotransmitter

A chemical messenger that transmits signals from a nerve cell across the synapse to a target cell, such as another nerve cell, muscle cell, or gland cell.

Excitatory neurotransmitter

A neurotransmitter that leads to depolarization of the postsynaptic cell and promotes the likelihood of action potentials.

Inhibitory neurotransmitter

A neurotransmitter that leads to hyperpolarization of the postsynaptic cell and reduces the likelihood of action potentials.

Ion channel

Proteins embedded in the neuronal membrane that allow specific ions to flow in and out of the neuron, influencing its electrical potential.

Saltatory conduction

The process of action potential propagation along myelinated axons, where impulses jump from one node of Ranvier to the next.

Receptor

A protein molecule in the postsynaptic membrane that binds neurotransmitters and initiates a cellular response.

Agonist

A substance that enhances or mimics the action of a neurotransmitter, facilitating neurotransmission.

Antagonist

A substance that blocks or inhibits the action of a neurotransmitter, reducing neurotransmission.

Glial cells

Supportive cells in the nervous system that provide insulation, nutrients, and support to neurons, categorized as astrocytes, oligodendrocytes, and microglia.

Efferent neuron

A motor neuron that transmits signals from the central nervous system to effector organs such as muscles or glands.

Afferent neuron

A sensory neuron that carries signals from sensory receptors to the central nervous system.

Membrane potential (Vm)

The voltage difference across a cell's membrane at any moment.

Neuropharmaceuticals

Chemical substances that can affect neurotransmission, acting as agonists or antagonists to alter synaptic communication.