Final answer:
The process where the neuron membrane allows positively charged ions in and negatively charged ions out, leading to a neural signal, is called an action potential.
Step-by-step explanation:
The part of the process that occurs during the firing of a neuron where part of the neural membrane opens to allow positively charged ions inside the cell and negatively charged ions out is known as an action potential. During an action potential, sodium (Na+) channels open first, allowing positively charged Na+ ions to enter the neuron, which leads to membrane depolarization. Following this influx, potassium (K+) channels open, allowing K+ ions to exit, which results in repolarization of the membrane. The ion flows during action potentials are an essential part of neural communication, allowing neurons to send signals rapidly along their axons to communicate with other neurons or muscles.