Which of the following best describes how neurons convey information using both electrical and chemical signals?

• A. Neurons generate action potentials in the dendrites, which are then converted directly into muscle contractions.
• B. Neurons transmit electrical impulses along their axons, and at synapses, these impulses trigger the release of neurotransmitters that carry the signal to the next cell.
• C. Neurons rely solely on chemical diffusion through gap junctions to transmit information.
• D. Neurons use only electrical signals to communicate, with no involvement of chemical messengers.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the structure and function of neurons. Neurons are specialized cells in the nervous system that transmit information. They consist of dendrites (which receive signals), a cell body, and an axon (which sends signals).
2. Step 2: Learn about action potentials. Neurons use electrical signals called action potentials to transmit information along their axons. These are rapid changes in membrane potential caused by the movement of ions (e.g., Na⁺ and K⁺) across the cell membrane.
3. Step 3: Explore synaptic transmission. At the end of the axon, the electrical signal reaches the synapse, a junction between two neurons or between a neuron and another cell (e.g., muscle cell). Here, the electrical signal triggers the release of chemical messengers called neurotransmitters.
4. Step 4: Understand the role of neurotransmitters. Neurotransmitters diffuse across the synaptic cleft and bind to receptors on the target cell, initiating a response in the next cell. This is how neurons use chemical signals to communicate.
5. Step 5: Compare the options provided in the problem. Based on the above understanding, the correct description is: 'Neurons transmit electrical impulses along their axons, and at synapses, these impulses trigger the release of neurotransmitters that carry the signal to the next cell.' This highlights the dual use of electrical and chemical signals in neuronal communication.