Figure 3. Neurons directly and indirectly interact with tumor cells.

Neurons can form bona fide synapses or respond to local neurotransmitters to regulate tumor cell growth, which can be propagated between adjacent tumor cells through tumor microtubes, thus creating interconnected electrically coupled syncytia. Aberrant expression of ion channels on cancer cells can additionally modulate tumor expansion, and neurons can also directly synapse onto tumor microtubes.