Brain ’noise' keeps nerve connections young

Adult Drosophila motor terminals ( green ) and muscles ( red ) progressively degenerate with age © Laboratory of Neural Genetics and Disease / EPFL - Researchers have found that a form of neuron-to-neuron communication that has long been dismissed as 'background noise' is required to keep nerve junctions intact as animals age. The finding suggests that defects in this type of neural communication could contribute to neurodegenerative disorders and other brain conditions. Neurons communicate through rapid electrical signals that regulate the release of neurotransmitters, the brain's chemical messengers. Once transmitted across a neuron, electrical signals cause the juncture with another neuron, known as a synapse, to release droplets filled with neurotransmitters that pass the information on to the next neuron. This type of neuron-to-neuron communication is known as evoked neurotransmission. However, some neurotransmitter-packed droplets are released at the synapse even in the absence of electrical impulses. These miniature release events - or minis - have long been regarded as 'background noise', says Brian McCabe, Director of the Laboratory of Neural Genetics and Disease and a Professor in the EPFL Brain Mind Institute.