SOURCE;
https://www.drugabuse.gov/publications/ ... dependence
Brain regions mediating the development of morphine dependence
- The development of dependence to morphine also involves specific areas of the brain, separate from the reward pathway. In this case, point to the thalamus and the brainstem (green dots). The parts of the reward pathway involved in heroin or morphine addiction are shown for comparison. Many of the withdrawal symptoms from heroin or morphine are generated when the opiate receptors in the thalamus and brainstem are deprived of morphine.
https://www.drugabuse.gov/publications/ ... ing-develo
Definition of Dependence
- With repeated use of heroin, dependence also occurs. Dependence develops when the neurons adapt to the repeated drug exposure and only function normally in the presence of the drug. When the drug is withdrawn, several physiologic reactions occur. These can be mild (e.g., for caffeine) or even life threatening (e.g., for alcohol). This is known as the withdrawal syndrome. In the case of heroin, withdrawal can be very serious and the abuser will use the drug again to avoid the withdrawal syndrome.
https://www.drugabuse.gov/publications/ ... dependence