September 15, 2009

Neuron integration method studied

U.S. scientists say a new study of neurons supports one of several competing models that attempt to explain how neurons integrate synaptic inputs.

Northwestern University researchers in Evanston, Ill., say a neuron is a very complex structure, with dendrites integrating thousands of inputs before it sends a signal to a central axon. Synapses constantly deal with information, deciding whether to send a nerve impulse to drive a certain action.

The Northwestern scientists say their study supports the two-layer integration model, in which each dendritic branch of a neuron receives and integrates thousands of electrical inputs, deciding on just one signal to send to the axon. The axon then receives signals from all the dendrites and a final decision is made. The result could be an output in the form of an impulse, or action potential, or no action at all.

There are more than 100 billion neurons in the human brain, so detailed knowledge of individual neurons will lead to a better understanding of how the brain works, including the processes of learning and memory, said Professor Nelson Spruston, who led the research.

The study that included Professor William Kath, Yael Katz, Vilas Menon, Daniel Nicholson and Yuri Geinisman appears in the journal Neuron.