1. Neurotransmitters: Acetylcholine and Dopamine
Ms. Carmelitano

2. Acetylcholine
First Neurotransmitter to be identified and most common in the human body
Function:
Helps control muscle contraction
Plays a role in the development of memory of the hippocampus
Hippocampus: Part of the brain responsible for converting short-term memory into long-term memory

3. Acetylcholine Acetylcholine and memory formation
It is still not fully understood how memory formation occurs
However, research has shown that when a short-term memory is converted into long-term storage in the hippocampus, neurons in the brain help to synthesize protein molecules and new connections between neurons are formed

4. Acetylcholine So, what does this have to do with psychology you ask??
Over or underproduction can cause us to act in certain ways!

5. Malfunction of Acetylcholine
Underproduction on Memory
Because acetylcholine plays a huge role in memory, an underproduction can cause memory loss or inhibit the formation of new memories
It has been discovered that people who suffer Alzheimer's have a deterioration in the dendrites in neurons that play a role in memory, and therefore a deterioration in the amount of acetylcholine

6. Can you solve the maze? Martinez and Kesner (1991)
Aim: To investigate the role of Acetylcholine on memory
Procedure:
1. Rats were trained to go through a maze and get to the end, where they received food.
Can you solve the maze?

7. Martinez and Kesner (1991) Procedure:
2. Once the rats were able to do this, the researchers injected one group of rats with scopolamine, which blocks acetylcholine receptor sites decreasing available acetylcholine.
3. Then the second group of rats was injected with physostigmine, which blocks the production of cholinesterase which does the “clean-up” of acetylcholine from the synapse and returns the neuron to its “resting state”
4.The third group, control group, were not given any injections.

8. Second Place
WINNER!

9. Martinez and Kesner (1991) Findings:
The rats that were injected with scopolamine were slower at finding their way round the maze and made the most errors
The physostigmine group ran through the maze and found the food more quickly and took fewer wrong turns.
The researchers concluded that acetylcholine played an important role in creating a memory of the maze.

10. Nicotine and Acetylcholine
When a person smokes a cigarette, they will put nicotine into their system
Nicotine will stimulate neurons to release more acetylcholine
The overproduction of Acetylcholine will give a person an “energized” feeling, muscles react faster and the brain functions faster
Smokers become addicted, and need a cigarette in the morning to “wake-up”

11. Dopamine Function: voluntary muscle movement Learning
Feelings of emotion: pleasure

12. Dopamine Dopamine and voluntary muscle movement
When the body reacts to a stimuli that calls for muscle movement (example: I hear a noise and turn my head to see what it was) Dopamine will be released over the synapses of nerve cells.
The Dopamine will bind with receptors that cause a chemical reaction to move smooth muscles in the basil ganglia – the portion of the brain that coordinates smooth muscle movement

13. Dopamine Dopamine and learning and emotion
Dopamine controls the transfer of messages in the frontal cortex of the brain which controls memory, attention, and problem solving ability
When dopamine is released, it creates a “feel-good” feeling within the individual
The individual learns what behaviors will create this feel good feeling
They will learn that if they continue this behavior, the feeling will continue

14. Malfunction of Dopamine
Malfunction of Dopamine and muscle movement
When dopamine receptors are blocked, or not enough dopamine is produced, a person will find muscle coordination difficult
People who do not produce enough dopamine develop Parkinson
Parkinson is degenerative – this means that it progressively gets worse. A person with Parkinson's Disease will gradually produce less and less dopamine over time

15. Malfunction of Dopamine
Malfunction of Dopamine in learning and emotion
Because Dopamine regulates connections between neurons responsible for concentration in the frontal lobe, a person without enough dopamine may develop ADD
Low dopamine may also cause dementia because the neurotransmitter helps make connection with learning and memory. This usually occurs with age as the neurons that produce dopamine begin to degrade
Low dopamine may also be a reason for depression, low dopamine will decrease the pleasure feeling

16. Malfunction of Dopamine and Schizophrenia
Schizophrenia is a mental illness
People suffering from Schizophrenia report feeling paranoid, having hallucinations, and even hearing voices that are not there
An overproduction of Dopamine in one area of the brain has been linked to Schizophrenia. This overproduction of Dopamine can cause the hallucinations linked to Schizophrenia

17. Drugs and Dopamine
Drugs prescribed to help people with ADD concentrate increase the amount of dopamine that is released in the brain
People with Schizophrenia will be given drugs to inhibit dopamine production, however, as a side effect, this makes it hard for the person to concentrate, reduce feelings of pleasure, and reduce motor function

18. Drugs and Dopamine
Most drugs, such as alcohol, cocaine, and amphetamines increase the production of dopamine in the brain
This is why people get addicted to drugs
They feel good when they take them
They become used to the over production of dopamine in their brain, and find it hard to concentrate or feel pleasure without the drug as they become dependent on it

19. Cardinal et al (2001) Procedure:
Researchers gave a set of rats choices between bowls of food containing large and small portions
Rats chose the larger consistently
The researchers split the rats into two groups
Lesioned their nucleus accumbens (Where Dopamine and Serotonin is produced) This caused excess Dopamine to be produced
One group received an anti-psychotic on did not
When presented a choice between large and small portions of food, the rats were more impulsive and simply chose the bowl closer to them. They appeared hyper-active

20. Findings:
Excess Dopamine in the brain lead the rats to be more impulsive
This could be why drug addicts are impulsive

21. Laurelle et al (1996) Procedure:
Researchers gathered participants who were and were not diagnosed with Schizophrenia
Researchers gave participants an amphetamine, a drug, that increased levels of dopamine in the brain
Researchers observed patients and interviewed them about how they were feeling

22. Findings:
Observations and interviews confirmed that the “healthy” patients began to experience symptoms of Schizophrenia when their Dopamine levels were forced to rise
Patients tested who were diagnosed with Schizophrenia had their symptoms worsen