Which of the following is not true w.r.t electrical synapse?

Options

A. Transmission of impulse across an electrical synapse is faster as compared to chemical synapse
B. Electrical synapse is rare in human nervous system
C. Two neurons having electrical synapse communicate via tight junctions
D. Synaptic cleft is greatly reduced in electrical synapse

Answer

To determine which statement is not true with respect to electrical synapses, we will analyze each option provided in the question.

1. **Transmission of impulse across an electrical synapse is faster as compared to chemical synapse.**
- This statement is true. Electrical synapses allow for direct electrical communication between neurons, which results in faster transmission of impulses compared to chemical synapses that rely on neurotransmitter release and binding.

2. **Electrical synapses are rare in the human nervous system.**
- This statement is also true. While electrical synapses do exist, they are much less common than chemical synapses in the human nervous system.

3. **Two neurons having electrical synapse communicate via tight junction.**
- This statement is not true. Neurons that are connected by electrical synapses communicate through gap junctions, not tight junctions. Tight junctions serve to create barriers between cells, preventing the passage of ions and small molecules, whereas gap junctions allow for direct electrical communication.

4. **Synaptic cleft is greatly reduced in electrical synapse.**
- This statement is true. In electrical synapses, the synaptic cleft is either very small or absent, allowing for the rapid transmission of electrical signals between the pre- and post-synaptic neurons.

Based on this analysis, the statement that is not true regarding electrical synapses is:

**Answer: Two neurons having electrical synapse communicate via tight junction.**