Neurotransmission and Synaptic Function

These flashcards cover key terms and definitions related to neurotransmission and synaptic function based on the lecture notes.

Postsynaptic density

A specialized area containing proteins that are involved in neurotransmitter signaling.

Synaptic cleft

The 10 to 20 nm extracellular space separating presynaptic and postsynaptic neurons.

Neurotransmitter

Chemical messengers released from presynaptic axon terminals that transmit signals across the synaptic cleft.

Cotransmitter

An additional neurotransmitter released simultaneously with the primary neurotransmitter from an axon.

Excitatory synapse

A synapse that brings the membrane of a postsynaptic cell closer to threshold.

Inhibitory synapse

A synapse that prevents a postsynaptic cell from nearing threshold by hyperpolarizing or stabilizing its membrane potential.

Electrical synapses

Synapses consisting of gap junctions that allow current to flow between adjacent cells.

Chemical synapses

Synapses where neurotransmitters are released by a presynaptic axon terminal into the synaptic cleft.

SNARE proteins

Proteins that facilitate the docking and fusion of vesicles with the presynaptic membrane.

Synaptotagmins

Proteins that trigger vesicle membrane fusion and neurotransmitter release in response to calcium ions.

Kiss-and-run fusion

A mechanism where vesicles briefly fuse with the membrane to release neurotransmitter and then reseal.

EPSP (Excitatory Postsynaptic Potential)

The electrical response in a postsynaptic cell at an excitatory chemical synapse, typically causing depolarization.

IPSP (Inhibitory Postsynaptic Potential)

The electrical response in a postsynaptic cell at an inhibitory synapse, usually causing hyperpolarization.

Temporal summation

Summed potential created by multiple EPSPs and/or IPSPs arriving at a single synapse in quick succession.

Spatial summation

Summed potential created by multiple EPSPs and/or IPSPs arriving together at different synapses on a postsynaptic membrane.

Synaptic strength

The effectiveness of a synapse, which can be modified by pre- and postsynaptic mechanisms.

Presynaptic inhibition

Inhibitory action by one neuron on another's axon terminal, reducing neurotransmitter release.

Presynaptic facilitation

Stimulatory action by one neuron's axon terminal on another's terminal, increasing neurotransmitter release.