Final answer:
The 2nd-order neuron of the spinothalamic tract ascends contralaterally in the spinal cord.
Step-by-step explanation:
The statement is true. The 2nd-order neuron of the spinothalamic tract ascends contralaterally in the spinal cord. This means that the axons of the 2nd-order neurons cross over to the opposite side of the spinal cord.
For example, if a painful stimulus is sensed on the right side of the body, the sensation is transmitted to the left side of the brain. This decussation allows for the brain to receive information from both sides of the body.
Contrastingly, in the dorsal column system, which carries touch and proprioception information, the 2nd-order neuron decussates in the medulla, resulting in ipsilateral transmission to the brain.