Laser core

A laser core is a vital component of Transformer anatomy. If a Transformer's laser core is extinguished, the Transformer will cease functioning.

Divide and Conquer
Megatron sent Laserbeak to spy on the Autobot base to determine whether Optimus Prime's laser core was extinguished after he was badly damaged in a Decepticon attack.

The Autobot Run
After the Autobots regained their ability to transform, Megatron ordered the Constructicons to combine into Devastator, and then ordered Devastator to extinguish the Autobots' laser cores forever.

Laser core and Spark
It's been heavily debated what role the laser core and the spark play within a Transformer. Some fans have speculated that the laser core may be some sort of housing unit for the spark. Others have speculated that it may be a separate entity.

TFU MUX doesn't make references to "sparks" aside from casual slang.

Shattered Glass
In the Shattered Glass universe, the laser core is said to house the Transformer's "ember." Otherwise they function the same as the primary universe core.