Recreational drugs, CNS and aggression Flashcards
intro
the CNS is made up of the Brian, spinal cord and a complex network of neurones which work together to send messages across the body through a process called synaptic transmission which involves the release of NT’s across the synapse to he receiving neurone, to transport these messages around thee body, recreational drugs can micmic the role of NT’s and change the transmission process which influences out thoughts, feelings and behaviours which in the long term can damage out CNS
point 1 - cocaine
cocaine works by blocking reuptake receptors of dopamine back into the presynaptic neurone, therefore, the synaptic gap becomes flooded with dopamine, which creates a euphoric effect in the short term, it can also lead to increased heart rate, blood pressure and confidence which can lead to more risk taking behaviour.
in the long term, abuse of cocaine can lead to damage to receptors leading to a desensitisation of dopamine receptors meaning more cocaine will be needed to create the same euphoric effect, this can lead to desensitisation addiction
cocain also effects the PFC which controls impulses from the amygdala which can lead to impulsive and impaired decision making
strength: VOLKOW et al used PET scans to track the activity of dopamine during a cocaine induced high. he found a positive correlation between the level of dopamine and the course of the high. when the high was intensified, dopamine flooded the pathways whereas when the high slowed down, the level of dopamine reduced, demonstrating how cocain blocks dopamine receptors which leads to feelings of euphoria- high.
weakness: evidence is correlational, other factors, circular argument, no direct cause and effect
point 2 - heroin
heroin binds to presynaptic neurones which use dopamine as their NT;s, it changes the reward pathway of dopamine releasing more dopamine than usual, morphine binds to recptors used to inhibit dopamine, GABA dopamine neurones- leading to increased dopamine in synaptic cleft - euphoria
same effects as cociane
Dianne marines used rats and PET scans to demonstrate how heroin changes action of dopamine- found that heroin causes a significant increase in dopamine in reward related areas- supports above findings
although Alexander suggests heroin addiction isn’t caused by biology but social influences.
gave rats morphine for 57 consecutive days and then gave them a choice between water or morphine hydrochloride, most chose water demonstrating addiction caused by social pressures and therefore heroin doesn’t impact the CNS leading to an addiction
application
if we can understand how an addiction is formed we can reverse it. addiction formed because reward pathway associates taking the drug with pleasurable feelings reinforcing the use of the drug. Drug replacement therapy provides patients with a replacement that provides similar feelings of euphoria but in a controlled way and the dosage can be decreased gradually
