A transient change in the postsynaptic membrane potential that makes it more likely for a neuron to fire an action potential. This graded potential arises from the influx of positive ions, such as sodium or calcium, into the postsynaptic cell, thereby depolarizing the membrane. For example, when a neurotransmitter like glutamate binds to receptors on a postsynaptic neuron, it can open ion channels that allow sodium ions to enter the cell, shifting the membrane potential closer to the threshold required for an action potential.
This process is crucial for neural communication and underlies many brain functions, including learning, memory, and sensory processing. By increasing the probability of action potential generation, these events facilitate the transmission of signals across synapses, allowing for complex information processing within neural circuits. Understanding the mechanisms and modulation of these potential changes is fundamental to comprehending neural plasticity and the effects of various drugs and neurological disorders.
