A mitochondrion is a double-membrane-bound organelle found in most eukaryotic organisms.
Interconnected mitochondria are also found in neuronal cell bodies, but in order to enter the axon, a mitochondrion must undergo a fission reaction that frees it from the reticulum.
Majorly, the mitochondria in nerve cells are involved in redox signaling, regulation of Ca2+, developmental and synaptic plasticity along with the mediation of cell survival and death.
It is said that nearly 2 million mitochondria are found in a cell.