Synaptic Transmission

Chemical Synapse

A junction where a neurotransmitter is released from the presynaptic neuron and diffuses to the postsynaptic neuron.

Electrical Synapse

A connection where neurons directly touch each other, allowing for faster impulse conduction and bidirectional transmission.

Neurotransmitter

A chemical released from neurons that transmits information across synapses, often resulting in complex decision making.

Synaptic Vesicles

Structures that contain neurotransmitters, found in the axon terminal, which fuse with the membrane to release their contents.

Active Zones

Locations in the axon terminal where synaptic vesicles are released, characterized by pyramidal structures due to specific proteins.

Synaptic Cleft

The gap between pre- and post-synaptic neurons filled with extracellular fluid, where neurotransmitters diffuse.

Type 1 Synapse (Gray's Type 1)

A synapse usually associated with EPSPs, characterized by asymmetrical distribution of proteins.

Type 2 Synapse (Gray's Type 2)

A synapse with symmetrical distribution of proteins, predominantly associated with IPSPs.

Exocytosis

The process through which synaptic vesicles release neurotransmitters into the synaptic cleft.

Calcium-Calmodulin Complex

A complex formed when calcium binds to calmodulin, which activates signaling pathways leading to neurotransmitter release.

Small Molecule Neurotransmitters

Simple neurotransmitters like ACh, dopamine, and serotonin, synthesized in the axon terminal.

Neuropeptides

Larger neurotransmitters synthesized from amino acids that require extensive processing and are typically found farther from the active zones.

Axoaxonic Synapse

A type of synapse where one axon synapses onto another axon, requiring minimal neurotransmitter to produce an action potential.

CRF Synthesis

The process of producing Corticotropin-Releasing Factor, which is triggered during stress and involves transcription and translation of specific genes.

ACh Synthesis

The formation of Acetylcholine from precursor molecules by the enzyme Choline acetyltransferase, without the involvement of gene expression.