Which statement describes the neuron doctrine?

• A. The brain is a continuous network of fibers.
• B. Neuronal signaling occurs only through electrical conduction.
• C. The nervous system is composed of individual, discrete cells called neurons.
• D. The brain lacks distinct functional units.

Answer: (C)

The neuron doctrine is the idea that the nervous system is built from individual, discrete cells called neurons, and that communication between these cells occurs at specialized gaps called synapses rather than through a continuous web. This means neurons are the basic signaling units that process and transmit information, typically sending signals across synapses to other neurons via chemical neurotransmitters, while electrical signaling occurs along the neuron itself. This view emerged in contrast to the older notion of a uniform, uninterrupted network of fibers. The statement that the nervous system is composed of individual, discrete cells called neurons captures this fundamental idea. The other descriptions—imagining the brain as a continuous network of fibers, claiming signaling happens only through electrical conduction, or asserting there are no distinct functional units—would imply a different organization and mode of communication than what the neuron doctrine describes.