Final answer:
Maintaining a resting membrane potential of -70 mV is vital for neuron function, preventing overstimulation, and requiring energy investment in sodium-potassium pumps for nervous system health.
Step-by-step explanation:
Neurons expend a significant amount of energy maintaining a resting membrane potential of about -70 mV. This energy investment is crucial because it primes the neuron for action potentials, which are vital for nerve impulse transmission. If this potential were to shift more negative, to about -90 mV, neurons would be hyperpolarized, making it more difficult to reach the threshold for action potential initiation, possibly reducing neural responsiveness and impacting overall brain function.
If it were to shift more positive, to about -65 mV, neurons would be closer to the threshold and may become too excitable, increasing the likelihood of spontaneous action potentials, potentially leading to overstimulation of neural circuits.
The resting membrane potential is maintained through the action of sodium-potassium pumps and ion channels. Sodium-potassium pumps use ATP to exchange two K+ ions for three Na+ ions, creating a net negative charge inside the neuron. Potassium ions move more freely than sodium ions, which contributes to the negative charge inside relative to the outside. This balance is key for the proper function of neurons and, by extension, the entire nervous system.
Shifting the resting membrane potential could have profound implications for neuronal communication and the behavior of an organism. Extreme shifts can lead to neural dysfunction or overactivity, with corresponding behavioral effects. Therefore, despite the high energy cost, maintaining the resting membrane potential is essential for neuronal health and the adequate functioning of the nervous system.