Neural energy
From Memory Alpha, the free Star Trek reference.
Neural energy (or neurogenic energy) is the energy contained within a lifeform's nervous system.
During operation of a transporter, an individual's neural energy is stored within the transporter buffer. The energy pattern occupies a massive amount of computer memory and so cannot be stored for long.
In 2372, a transporter accident forced Deep Space 9 to preserve Benjamin Sisko, Jadzia Dax, Kira Nerys, Miles O'Brien, and Worf's neural energy. However, Michael Eddington discovered that there was insufficient memory on the entire station to store the neural energy of all the officers. Faced with the prospect of losing them, he ordered the computer to wipe all data necessary in order to save the energy signatures before the buffer lost coherence. (DS9: "Our Man Bashir")
When Kes returned to USS Voyager in 2376, she gave off high levels of neurogenic energy. (VOY: "Fury")
