Which of the following steps occurs immediately after dendrites receive a message in a neuron?

• A. Reuptake of neurotransmitters by the presynaptic neuron
• B. Generation of a graded potential at the cell body
• C. Release of neurotransmitters into the synaptic cleft
• D. Propagation of the action potential along the axon

Answer: (B)

Verified step by step guidance

1. Understand the structure and function of a neuron: Neurons are specialized cells that transmit electrical and chemical signals. Key parts include dendrites (which receive signals), the cell body (soma), the axon (which propagates signals), and the synaptic terminals (which release neurotransmitters).
2. Recognize the sequence of events in neuronal communication: When dendrites receive a message, it typically involves the binding of neurotransmitters to receptors, leading to changes in the membrane potential of the cell body.
3. Learn about graded potentials: After dendrites receive a message, the cell body generates a graded potential. This is a localized change in the membrane potential that depends on the strength of the stimulus. It occurs before an action potential is triggered.
4. Differentiate between graded potentials and action potentials: Graded potentials are small, localized changes in voltage, while action potentials are large, rapid changes that propagate along the axon. Graded potentials must reach a threshold to initiate an action potential.
5. Understand the role of neurotransmitters and synaptic cleft: The release of neurotransmitters into the synaptic cleft and their reuptake by the presynaptic neuron occur later in the process, after the action potential has traveled down the axon and reached the synaptic terminals.