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Goal Directed Behavior

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There are two main components involved in goal-directed behavior, which is defined as the behavior directed towards accomplishing a specific goal. The first is to select a proper course of action and the second is to learn to adjust the behavior depending on the surrounding conditions. Studies have shown that the basal ganglia is the brain region largely responsible for the selection and initiation of these ‘willed’ movements. That is to say, the main function of the basal ganglia is in controlling voluntary movements. Within the basal ganglia of the brain, there is an important input structure called the dorsal striatum, which plays a vital role in the reward system of the brain. Moreover, the dorsal striatum is made up of 2 opponent pathways …show more content…

For instance, when the researchers activated the population of neurons in the direct pathway (dMSNs), it caused the mice to accelerate and push the joystick at a faster rate on future movements. In contrast, when the researchers activated the population of neurons in the indirect pathway (iMSNs), it caused the mice to decelerate and push the joystick at a slower rate on future movements. These results were consistent with the wide-held belief that separate population of neurons in the basal ganglia promote and suppress movement. However, contrary to popular belief, Yttril and Dudman found that this is not always the case as they discovered that stimulation of dMSNs of the direct pathway can also slow movement, while stimulation of iMSNs of the indirect pathway can also speed movement. Interestingly, this result only seemed to occur in situations where the researchers activated a population of neurons at a moment the mouse was making a slow movement of the joystick. This was different from the first case, in which researchers activated a population of neurons at a moment the mouse was making a fast movement of the joystick. Additionally, the researchers discovered that stimulation of either population of neurons did not have any impact on the rate of movement initiation or on the rate of water licking by the mice, thus indicating that movement initiation and motivation are not affected by activation of the neurons. Lastly, Yttril and Dudman attempted to stimulate the loss of the chemical dopamine in mice in order to help determine the effect of dopamine on the movement speed of the mice pushing the joystick. Dopamine is a neurotransmitter, a chemical messanger released by neurons in the brain, that plays a vital role in reward-motivated

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