Final answer:
Stimulating neurons in the nucleus of the solitary tract that receive input from arterial baroreceptors leads to a decrease in sympathetic stimulation and an increase in parasympathetic stimulation. This helps maintain homeostasis in response to increased blood pressure.
Step-by-step explanation:
If you stimulate the neurons in the nucleus of the solitary tract that receive input from the arterial baroreceptors, you would expect to observe a decrease in sympathetic stimulation and an increase in parasympathetic stimulation. This is because the baroreceptors signal an increase in blood pressure, which triggers the cardiovascular center in the medulla oblongata to initiate a reflex to maintain homeostasis. The reflex includes decreasing sympathetic stimulation, which causes vasodilation and a decrease in heart rate, and increasing parasympathetic stimulation, which also decreases heart rate.