Synapse 2D: Neurotransmitter Release & Receptor Binding in a 2D Model

Overview of Synapse Function

A synapse is the junction between two neurons where chemical signaling occurs. When an action potential reaches the presynaptic terminal, it triggers the release of neurotransmitters into the synaptic cleft. These molecules then diffuse across the gap and bind to receptors on the postsynaptic neuron, initiating a response that can be either excitatory or inhibitory.

In this 2D model, you can observe these processes in real-time, adjusting parameters such as neurotransmitter type, release amount, and receptor density to see how they affect synaptic transmission.

Mechanisms of Neurotransmitter Release

Neurotransmitters are stored in vesicles within the presynaptic neuron. Upon an action potential reaching the terminal, voltage-gated calcium channels open, allowing calcium ions to enter the cell. The influx of calcium triggers exocytosis, a process where vesicles fuse with the plasma membrane and release their contents into the synaptic cleft.

In the simulation, you can control the amount of neurotransmitter released per action potential by adjusting the 'Release Amount' slider, which directly influences the intensity of the postsynaptic response.

Diffusion and Binding Dynamics

Once released into the synaptic cleft, neurotransmitters diffuse according to Brownian motion. The rate of diffusion is influenced by factors such as the size of the synaptic cleft and the concentration gradient between the presynaptic and postsynaptic compartments.

The simulation models this process accurately, allowing you to observe how changes in 'Cleft Width' or 'Receptor Density' affect the number of neurotransmitters that successfully bind to their respective receptors.

Postsynaptic Effects

Neurotransmitter binding to postsynaptic receptors can either excite or inhibit the target neuron, depending on the type of receptor and neurotransmitter involved. Excitatory neurotransmitters like glutamate typically lead to an influx of sodium ions, depolarizing the cell membrane and potentially triggering another action potential.

Inhibitory neurotransmitters such as GABA cause hyperpolarization by allowing chloride ions into the cell, making it less likely for an action potential to occur. In the simulation, you can observe these effects by adjusting parameters like 'Reuptake Rate' or adding a receptor antagonist.

Frequently asked questions

Try it live

Everything above runs in your browser — open Synapse 2D: Neurotransmitter Release & Receptor Binding (2D) and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.