Neurotransmitters are chemicals in the brain to allow an impulse from one nerve cell to pass to another. There 50 neurotransmitters. Some of them are acetylcholine,norepinephrine,dopamine, serotonin and gamma aminobutyric acid (GABA).Excitatory neurotransmitters-acetylcholine and norepinephrine. inhibitory neurotransmitters – dopamine, serotne and GABA. neurotransmitter can directly / indirectly influence neurons at a specific site of the brain, this affects behavior.
Dopamine main function is decision making and to control thoughts. In the article journal of computational neurology explains dopamine is the driving force. Dr. Chudler explaihow dopamine related to certain disorder like schizophrenia. Dopamine plays important role is motivation. Substantia nigrans controls the sensation of pleasure. Pleasurable sensation cause dpamine relesase causing neurons to become active.
Types of behavior
5.learning and memory
6. Addictive behavior
1. Adrenergic: alpha1A, 1b,1c
2. Dopaminergic:D1, D2, D3
a. Muscle contraction
b. Affects memory in hippocampus
a. Voluntary movement
c. Stimulation of sympathetic nervous system
Behaviors or diseases related to neurotransmitters
1. Acetylcholine – learning and memory: Alzheimer’s disease
2. Dopamine – parkinson’s disease
3.norepinephrine- arousal, depression
Acetylcholine – Ach
It activates muscles for initiation of motor behaviour
These are found in CNS and PNS
By lowering Ach muscle movement is prevented by botox
Ach synthesised from choline
Acetyl coA by the choline acetyltransferase enzyme
These are synthesized in presynaptic nerve terminal.
Alzheimer’s disease is due to deficiency of acetylcholine.
This diseasedestroys memory and ability to learn
In this disease protein clumps are formed
Clumps-amyloid plaques and tau tangles.
Protein strand twist and damage brain cell.
Brain cell die and brain shrink
Symptoms – agression, lack of restrain, difficulty im self care
Medication – cognition enhancing medication
Stages of Alzheimer
There are 7 stages
2.normal age firgetfulness
3. Mild cognitive impairment
4. Mild Alzheimer’s disease
5. Moderate Alzheimer’s disease
6. Moderately severe Alzheimer’s disease
7. Severe Alzheimer’s disease
Is degenarative, progressive disorder
This affects basal ganglia and substantia nigra
These substantia nigra is responsible for production of dopamine
Low dopamine level- parkinson’s disease
Dopamine generating cells-dopaminergic neurons
Norepinephrine – mood depression
This norepinephrine occurs normally in body.
This acts as neurotransmitter and stress hormone.
Stressful event – released into blood as stress hormone.
1.increase heart rate
2.trigger the release of glucose into blood
3. Increase blood flow to muscles
Norepinephrine increase alertness
Low conc – ADHD, depression, hypotension
Medication for increasing norepinephrine and dopamine
4. Strattera only for norepinephrine
Depression people take SNRI
These drug raise level of serotonin and norepinephrine
Other drug-tricyclic antidepressant increase norepinephrine level
These also causes sideeffects such as sedation weigt gain, dry mouth
Levophed – that is given for hypotension