... brain. It was found that shocks to the Median Forebrain bundle and the Ventral Tegmantal Area, were most desirable, and stimulating, the levers would be pressed more frequently when the shocks were associated with the stimulation in these parts of the brain. It was found that the stimulation by shocks was more pleasurable and 'rewarding' to the rats than any other stimuli, for example food or water. The self-stimulation by shocks in rats is comparable to self-stimulation by humans who use drugs, or are addictive to substances. Immediate affects of drugs on the brain, and as a result the rest of the body, result in variations on biochemical activity in certain regions of the brain. These variations result in changes in how a person feels, for example elevation of moods or hallucinations. Variations in levels of dopamine (DA) in various regions of the brain have been linked with intakes of ...

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