- Cocaine makes the user feel on top of the world, wide awake and confident. Getting a surge of energy.
- It takes 15 minutes to get into system but only lasts 10-20 minutes.
- Cocaine works on the reward pathway (Mesolimbic) & dopamine receptors. It releases additional dopamine into the synapse by using reserve supplies & blocks the binding sites of the reuptake of dopamine.
- This leads to excess dopamine in the synapse which overstimulates the post-synaptic receptors. This creates Euphoria feeling.
- When the effects wear off the user feels urge to take more. If in chronic dose there is LT affects where the brain won’t have enough dopamine to replenish previous state.
- In Chronic cocaine users the brain relies on drug to keep degree of pleasure associated with drug.
- Overstimulating receptors become damaged leading to desensitisation meaning addiction. With no cocaine sensitivity levels increase producing depression. If drug ceases dopamine levels return to normal.
- Nicotine is 1/4000 chemicals in tobacco. Is very addictive and this is ‘characterised’ by compulsive drug seeking & use with risk of negative effects.
- Small doses stimulate the CNS causing relaxation, mild euphoria, improve attention and problem solving while large doses depress the CNS (killing you)
- Nicotine affects both the CNS and the peripheral nervous system (PNS) Nicotine enters the lungs and passes to the blood via cell membrane.
- Works on the mesolimbic pathway (pleasure pathway) directly affecting dopamine receptors leading to addiction because individual will act to stimulate this pathway.
- Nicotine mimics behaviour of acetylcholine which is a natural neurotransmitter as it’s shaped like nicotine and binds to dopamine receptors.
- Nicotine binds with certain acetylcholine, causing receptors to create pulse of excitement through neurons causing action potential traveling to pleasure centre releasing more dopamine.
- Binding of nicotine damages receptors as they change shape, desensitisation and upbringing occurs where more receptors grow to meet normal levels.
| Strengths | Weaknesses |
| Brain scans – enable us to assess NT in ppl & animals, research can compare groups of drug users & non-druggies quantifying differences in their lvl of NT – has scientific status.
FMRI scans – used to monitor metabolic activity in selected regions of the brain as NT have unique distribution – areas with heightened or decreased lvls provide clues to NT involvement Internal validity – drug monitoring in lab, they can compare drug impact on NT & drug related behaviour with those who don’t in a controlled environment (control of EV) – can establish a cause & effect relation Application – drugs like cocaine done chronically damages receptors, overstimulating them, leading to desensitisation & addiction – can develop biological drugs to get off cocaine. |
Lack generalisability – Most of the research is done on animals which may have similar Nervous system but difference in development of brain areas – unable to compare to humans.
Low ethics – research would be unethical to be carried out on humans as doing an experiment with drugs and nicotine would cause harm – meaning theory is limited on human ppts
|