Final answer:
The microscopic cells that store and release electrical charges are neuronal cells, which generate a potential difference across their membrane to produce action potentials for neural communication.
Step-by-step explanation:
The layer of microscopic cells that actively stores and releases electrical charges in the context of biology refers to nerve cells or neurons. This occurs across the cell membrane, where the separation of charge creates a potential difference of 70 to 90 mV. Such voltages are essential for the generation of electrical signals, including action potentials.
When nerve or muscle cells are at rest, the cell membrane's semipermeable nature separates differently concentrated electrically neutral fluids of ions like Na+, K+, and Cl-. Due to diffusion and the Coulomb force, this creates a layer of positive and negative charges on the outside and inside of the cell membrane. Consequently, a small voltage is generated across the cell membrane. This voltage is maintained by the cells, which consume a significant portion of energy to balance the concentration of these ions.
In response to stimuli that alter the permeability of the membrane, electric currents can travel along the cell membrane creating an action potential, which is the basis for neural communication. The very slight potential differences across the neuronal membrane play a crucial role in how nerve cells communicate and generate electrical currents for the body to function properly.