Types of Synapses

Chemical Synapses - Structure and Function

Synapses are the fundamental communication points between neurons. Chemical synapses play a crucial role in transmitting signals via neurotransmitter release. They consist of presynaptic and postsynaptic components, separated by the synaptic cleft.

Structure of a Chemical Synapse

• Presynaptic Terminal: Contains synaptic vesicles loaded with neurotransmitters.
• Synaptic Cleft: The gap where neurotransmitters diffuse to reach the postsynaptic receptor sites.
• Postsynaptic Membrane: Features receptor proteins that bind neurotransmitters and initiate signal propagation.

Function of Chemical Synapses

Neurotransmitter release is triggered by an action potential arriving at the presynaptic terminal. Calcium ions mediate vesicle fusion with the membrane, leading to neurotransmitter exocytosis. The postsynaptic membrane binds these neurotransmitters, creating excitatory or inhibitory effects depending on the receptor type.