Which channels maintain the resting membrane potential?

The resting membrane potential is primarily maintained by ungated channels, also known as leak channels. These channels allow specific ions, such as potassium (K+) and sodium (Na+), to flow across the cell membrane continuously, according to their concentration gradients.

Ungated channels are always open, permitting the passive movement of ions. Their permeability characteristics significantly contribute to the cell’s resting potential by allowing a higher concentration of K+ to move out of the cell while limiting the entry of Na+. This movement of ions helps establish a negative charge inside the cell relative to the outside, typically around -70 mV in neurons, which is essential for the proper function of nerve and muscle cells, as well as maintaining homeostasis.

In contrast, other types of channels such as voltage-gated channels and ligand-gated channels play critical roles in generating action potentials and facilitating synaptic transmission but do not contribute to the establishment of the resting membrane potential. Transmembrane channels is a broader term that can include various types of channels, but it does not specifically indicate the channels responsible for maintaining resting membrane potential. Thus, ungated channels are key players in sustaining the resting membrane potential by permitting the ongoing diffusion of ions to balance the electrochemical gradients.