When neurotransmitter molecules bind to the receptors on post postsynaptic membrane, triggering an action potential in the postsynaptic neuron, by causing changes in its

Explanation

The permeability of a cell membrane to specific ions is crucial for establishing the resting membrane potential and generating action potentials. At rest, the membrane is primarily permeable to potassium ions (K⁺), leading to a negative resting potential of around -70 to -90 mV. Upon stimulation, voltage-gated sodium channels open, increasing permeability to sodium ions (Na⁺) and causing rapid depolarization as Na⁺ floods into the cell. At the peak of the action potential, Na⁺ channels inactivate, and voltage-gated K⁺ channels open, increasing K⁺ permeability and leading to repolarization as K⁺ exits the cell. This process may result in after-hyperpolarization before returning to the resting potential, ensuring efficient signal transmission in neurons and muscle cells.