What term is used for the process that combines the effects of excitatory and inhibitory signals to determine if an action potential will be generated?

The process that combines the effects of excitatory and inhibitory signals to determine whether an action potential will be generated is known as summation. In the context of neuronal activity, when a neuron receives signals from various other neurons, it integrates these inputs. Excitatory signals promote the depolarization of the neuron's membrane potential, often making it more likely for an action potential to occur. Conversely, inhibitory signals decrease the likelihood that an action potential will be fired, typically by hyperpolarizing the membrane potential or stabilizing it.

Summation can occur in two forms: temporal and spatial. Temporal summation involves multiple excitatory signals from a single presynaptic neuron occurring close enough in time to overlap and influence the postsynaptic potential. Spatial summation occurs when multiple presynaptic neurons fire simultaneously, contributing their excitatory or inhibitory potentials to create a combined effect on the postsynaptic neuron.

This integration process is crucial as it allows the neuron to evaluate the net input it receives and decide whether the overall signal is strong enough to reach the threshold needed to initiate an action potential. Understanding this concept is fundamental in neurophysiology as it underlines how neurons process information and communicate within the nervous system.