How the brain triggers action

21. EPFL scientists have identified specific neurons in the striatum that contribute to driving motivated behaviors like movement. The work may help in designing new ways of treating disorders like Parkinson's disease in the long term. Perhaps the brain's most important function is to process sensory information and make behavioral decisions based on it, like moving to grasp an object. One part of the brain that does this is the "striatum", a large area in the middle of brain. Using cutting-edge techniques, neuroscientists at EPFL have now discovered how a specific type of neuron in the striatum contributes to a simple goal-directed sensorimotor behavior. The findings add a missing piece in the puzzle of the brain, contributing to our fundamental understanding of a brain area that is intimately involved in neurodegenerative disorders like Parkinson's and Huntington's disease. The work is published in Neuron . The striatum is often described as the "coordination center" for different higher cognitive activities including motor and action planning, decision-making, motivation, reinforcement, and reward perception. To do all this, the striatum must first integrate incoming information from other parts of the brain and then respond accordingly. The striatum thus integrates TWO sensorimotor and reward signals to guide motivated behavior. Incoming sensory and motor information reaches the striatum mostly through neurons coming from the brain's largest, and external part, the neocortex. These neurons use glutamate to transmit their signals. On the other hand, reward information comes to the striatum mostly through neurons using dopamine as their transmitter. What does what?