*Synaptic Transmission

Synaptic Transmission

  • Definition: Synaptic transmission refers to how a neuron releases neurotransmitters and communicates with the next neuron across a synapse.

Flow of Synaptic Transmission

  1. Neurotransmitters are made

  2. They are transported down the axon.

  3. They are released into the synapse.

  4. They bind to receptors on the postsynaptic neuron.

  5. They detach from the receptors.

  6. They are reuptaken or recycled.

Step-by-Step Process of Synaptic Transmission

1. Synthesis of Neurotransmitter

  • Produced in the cell body of the neuron.

  • Neurotransmitters are packaged into vesicles (tiny bubbles) for transport.

2. Transport of Neurotransmitter Down the Axon

  • Vesicles containing neurotransmitters travel down the axon to the axon terminal.

3. Release of Neurotransmitter (Exocytosis)

  • When electrical signals reach the axon terminal:

    • The vesicles fuse with the membrane,

    • Neurotransmitters are released into the synaptic cleft.

4. Interaction with Receptor (Postsynaptic Neuron)

  • The released neurotransmitter binds to receptors on the postsynaptic neuron.

    • This binding can excite (increase firing rate) or inhibit (decrease firing rate) the postsynaptic neuron.

5. Separation from Receptors

  • Neurotransmitters detach from the receptors, signaling the end of interaction.

    • Continuous signaling without separation can lead to chaos in neuronal communication.

6. Reuptake of Neurotransmitter (Recycling)

  • Neurotransmitters are transported back to the presynaptic neuron.

    • They may either be recycled for future use or broken down if no longer needed.