Question

Explain how information is passed from a presynaptic neuron to a postsynaptic cell (p. 372).

A) Information is transmitted from the presynaptic neuron to the postsynaptic cell through direct electrical connections between the two cells.
B) Information is conveyed from the presynaptic neuron to the postsynaptic cell by the release of neurotransmitters from the axon terminal into the synaptic cleft.
C) Information is passed through the exchange of genetic material between the presynaptic neuron and the postsynaptic cell.
D) Information is relayed from the presynaptic neuron to the postsynaptic cell by the flow of blood carrying specific signals.

Answer 1

Information is transmitted from the presynaptic neuron to the postsynaptic cell through the release of neurotransmitters into the synaptic cleft, which then bind to receptors on the postsynaptic neuron. Option B) Information is conveyed from the presynaptic neuron to the postsynaptic cell by the release of neurotransmitters from the axon terminal into the synaptic cleft.is the correct answer.

Step-by-step explanation:

Information is conveyed from the presynaptic neuron to the postsynaptic cell by the release of neurotransmitters from the axon terminal into the synaptic cleft. This process is known as synaptic transmission. Synaptic vesicles within the axon terminal of the presynaptic neuron release neurotransmitters into the synapse, a small gap between the presynaptic and postsynaptic cells. These molecules then travel across the gap and bind to receptors on the postsynaptic neuron's membrane, thereby transmitting the signal.

The action potential arriving at the axon terminal triggers the influx of calcium ions, which in turn prompts the synaptic vesicles to merge with the neuron's membrane, releasing their neurotransmitter contents into the synaptic cleft. The quick diffusion of these neurotransmitters across the synaptic cleft allows them to bind to specific receptors on the postsynaptic cell. The binding can either excite or inhibit the postsynaptic neuron, depending on the type of neurotransmitter and the receptors present. After performing their function, neurotransmitters are cleared from the synapse through enzymatic degradation, reuptake mechanisms, or by glial cells.

There are two types of synapses: chemical synapses, which involve neurotransmitter release as described, and electrical synapses, where a direct electrical connection allows ions to pass directly between cells. However, the description provided pertains to chemical synapses, which are the most common form by which a presynaptic neuron transfers information to a postsynaptic cell. The correct option that describes this process is 'Information is conveyed from the presynaptic neuron to the postsynaptic cell by the release of neurotransmitters from the axon terminal into the synaptic cleft.'