Question

You are trying to understand the nature of the synapse between two neurons. You electrically stimulate the presynaptic neuron and cause the release of NTs while you measure the activity of the post-synaptic neuron. You measure a slight depolarization in the neuron after a short delay. What could be causing this delay? How would you test your hypothesis?

Answer 1

Transmission of signals from presynaptic neurons to postsynaptic neurons by the release of neurotransmitter (NT) is considered as chemical transmission. Generally, the chemical transmission is slower compared to electrical transmission. This causes a delay in the initiation of an action potential in the postsynaptic neuron.  Ther are many reasons causing this delay, such as.

1. Time taken by the NT to get released from the presynaptic neurons.

2. Time taken for diffusing of NT through the synaptic gaps.

3. Binding of the NT with the receptor might delay.

4. Some NT cannot activate receptors directly, instead activates a signaling pathway which in turn activates the receptor.