Synapses and Their Functions

This set of flashcards covers key terms and concepts related to synapses, their structure, function, and types as discussed in the provided lecture notes.

Synapse

An anatomically specialized junction between two neurons, where the electrical activity in one neuron influences the activity in another.

Presynaptic Neuron

The neuron that sends the signal and is located before the synaptic cleft.

Postsynaptic Neuron

The neuron that receives the signal and is located after the synaptic cleft.

Synaptic Cleft

The gap between presynaptic and postsynaptic neurons through which neurotransmitters travel.

Neurotransmitter

Chemical messengers released from presynaptic neurons to transmit signals to postsynaptic neurons.

Action Potential

A short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, signaling transmission.

Dendrite

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

Axon Terminal

The end part of an axon that releases neurotransmitters into the synaptic cleft.

Ionotropic Receptor

A receptor that directly opens ion channels in response to neurotransmitter binding, leading to rapid synaptic responses.

Metabotropic Receptor

A receptor that activates a signaling cascade through G-proteins when bound by a neurotransmitter, leading to slower, longer-lasting effects.

EPSP (Excitatory Postsynaptic Potential)

A depolarizing change in the postsynaptic neuron's membrane potential that brings it closer to firing an action potential.

IPSP (Inhibitory Postsynaptic Potential)

A hyperpolarizing change in the postsynaptic neuron's membrane potential that makes it less likely to fire an action potential.

Cotransmitter

An additional neurotransmitter released alongside a primary neurotransmitter, acting on different receptors.

Nonsynaptic Communication

A method of intercellular signaling where chemicals diffuse far to send messages without involving direct synaptic transmission.

Autoreceptors

Receptors located on the same cell that released the neurotransmitter, regulating its own synthesis and release.

Electrical Synapses

Synapses that transmit signals rapidly through gap junctions, allowing direct flow of ionic currents between neurons.

Termination of Synaptic Signal

Processes that clear neurotransmitters from the synaptic cleft to end the signal transmission.