Dendritic spines are small protrusions that extend from which neuronal process?

Dendritic spines are small protrusions that extend from which neuronal process?

• A. Axons
• B. Dendrites
• C. Soma
• D. Myelin

Answer: (B)

Spines extend from dendrites, serving as the postsynaptic sites of most excitatory synapses. Dendrites are the receptive branches of a neuron, so these tiny protrusions on them provide specialized, high-surface-area locations where incoming signals from other neurons are received and processed. Their structure helps localize and regulate calcium signaling and synaptic strength, which is key for learning and memory. Axons carry signals away from the neuron and form synapses onto dendrites or the soma, but they don’t sprout spines themselves. The soma is the cell body; while it can receive inputs, dendritic spines are not extensions of the soma. Myelin insulates axons and does not bear spines.

Spines extend from dendrites, serving as the postsynaptic sites of most excitatory synapses. Dendrites are the receptive branches of a neuron, so these tiny protrusions on them provide specialized, high-surface-area locations where incoming signals from other neurons are received and processed. Their structure helps localize and regulate calcium signaling and synaptic strength, which is key for learning and memory.

Axons carry signals away from the neuron and form synapses onto dendrites or the soma, but they don’t sprout spines themselves. The soma is the cell body; while it can receive inputs, dendritic spines are not extensions of the soma. Myelin insulates axons and does not bear spines.