Final answer:
Continuous neural stimulation is prevented by disinhibition, disynaptic connections, and cellular processes including ligand-gated ion channels, ion pumps, reuptake, and enzymatic degradation of neurotransmitters.
Step-by-step explanation:
Continuous stimulation of a neuron on the distal side of a junction is prevented by several mechanisms ensuring the proper function of neural signaling. These mechanisms include disinhibition, a disynaptic connection, and various cellular processes that regulate the movement of ions and neurotransmitters.
A disynaptic connection involves two synapses, where the first synapse inhibits the second cell, which in turn stops inhibiting the final target. This mechanism serves to modulate and limit overstimulation. Regarding ion movement, specific factors such as the membrane's selective permeability to ions, closed ligand-gated ion channels, and the sodium-potassium pump work together to prevent the unchecked influx of Na+ ions despite the concentration gradient and Coulomb force that would otherwise drive them into the cell.
Furthermore, processes like neurotransmitter reuptake by the presynaptic neuron, enzymatic degradation, and diffusion help reduce neurotransmitter levels in the synaptic cleft, terminating the signal and preventing continuous stimulation. Additionally, strategies to block neurotransmitter transmission, such as glutamatergic, are not simplistic solutions due to the self-regulating mechanism of synapses known as homeostatic plasticity.