Question

Where are neurotransmitter receptors located?

(A) the nuclear membrane

(B) the nodes of Ranvier

(C) the postsynaptic membrane

(D) synaptic vesicle membranes

Short answer

(A) The option“the nuclear membrane” is false.

(B) The option “the nodes of Ranvier” is false.

(C) The option “the postsynaptic membrane” is true.

(D) The option “synaptic vesicle membrane” is false.

Step-by-step solution

Chemical synapse

In neurophysiology, the term synapse relates to the chemical or electrical connections formed between two neuronal cells or one neuronal cell and a target cell. A chemical synapse comprises three components: a presynaptic cell and a postsynaptic cell physically drifted by a space called the synaptic cleft.

Explanation of option ‘(A)’

The term nuclear membrane refers to the plasma membrane that demarks the interior region of a neuronal cell from the extracellular environment. This structure relates to the membrane of the axon, dendrites, and the cell body.

Thus, the nuclear membrane is located throughout the neuron, and neurotransmitter receptors are only present at the signal receiving terminals.

Therefore, the given option is false.

Explanation of option ‘(B)’

The node of Ranvier refers to the portion of axonal fiber which is deprived of the myelinating sheath. Action potentials are produced at this zone, and these are concerned with rapid signal propagation.

Thus, the nodes of Ranvier do not contain neurotransmitter receptors.

Therefore, the given option is false.

Explanation of option ‘(C)’

A postsynaptic membrane refers to the nuclear membrane of the synapse’s postsynaptic terminal (the region where a signal is propagated). It comprises receptors for neurotransmitters so that signals released by the presynaptic end in chemical form (as neurotransmitters) can be detected by the postsynaptic cell.

Thus, the presence of receptors for neurotransmitters at the postsynaptic membrane facilitates signal transmission.

Therefore, the given option is true.

Explanation of option ‘(D)’

The synaptic vesicles are membrane-bound structures present within the presynaptic end; these structures store the molecules of neurotransmitters. During signal transmission, the synaptic vesicle membrane fuses with the presynaptic neuron’s membrane and helps in their release via exocytosis.

Thus, the synaptic vesicle membrane is the membranous covering of the structure that stores neurotransmitters.

Therefore, the given option is false.