Question

1. Excess neurotransmitter is typically released into the synaptic cleft. What are two mechanisms used by cells to prevent the excess neurotransmitter from causing excessive post-synaptic cell stimulation ?

Answer 1

Ans) Neurotransmitters are chemicals that neurons use to communicate. Presynaptic neurons release neurotransmitters when an action potential reaches the terminal. The neurotransmitter diffuses across the synapse and binds to receptors on the post-synaptic cell. The excess neurotransmitters are removed either through two ways either digested by enzymes or reuptake through transporters. :-

First method is Enzymatic degradation – special biocatalyst called enzymes break down or degrade neurotransmitter. Astrocytes are the cells which absorb the excessive neurotransmitters and pass them to enzymes or pump them directly into the presynaptic neuron.

And second method to remove excess neurotranmitter is Reuptake in which reabsorption of a neurotransmitter from synaptic cleft to the axon terminal of presynaptic neuron(storage site of neurotransmitter)   though the transporters, or membrane transport proteins, pump neurotransmitters take place.