Neurobiology: Dopamine, GABA, Serotonin, Acetylcholine
Dr. Dawn-Elise Snipes PhD, LPC-MHSP, LMHC
Executive Director, AllCEUs.com
Objectives
~ Define Neurobiology
~ For the following neurotransmitters, Dopamine, GABA, Serotonin, Acetylcholine, identify
~ Their mechanism of action/purpose
~ Where they are found
~ Symptoms of excess & insufficiency
~ Nutritional building blocks
~ Medications
~ Neurological changes over the lifespan
What is Neurobiology
~ Neurobiology is the study of the brain and nervous system which generate sensation, perception, movement, learning, emotion, and many of the functions that make us human
Dopamine
~ Mechanism of action/purpose
~ Movement
~ Memory
~ Pleasurable reward
~ Behavior and cognition
~ Attention
~ Sleep
~ Mood
~ Learning
Dopamine
~ Mechanisms of Action
~ Precursor, L-DOPA is synthesized in brain and kidneys
~ Dopamine functions in several parts of the peripheral nervous system
~ In blood vessels, it inhibits norepinephrine release and acts as a vasodilator (relaxation)
~ In the pancreas, it reduces insulin production
~ In the digestive system, it reduces gastrointestinal motility and protects intestinal mucosa
~ In the immune system, it reduces lymphocyte activity.
Dopamine
~ Symptoms of excess
~ Unnecessary movements, repetitive tics
~ Psychosis
~ Hypersexuality
~ Nausea
~ Most antipsychotic drugs are dopamine antagonists
~ Dopamine antagonist drugs are also some of the most effective anti-nausea agents
Dopamine
~ Symptoms of insufficiency
~ Insufficient dopamine
~ Negative symptoms of schizophrenia
~ Pain
~ Parkinsonās Disease
~ Restless legs syndrome
~ Attention deficit hyperactivity disorder (ADHD)
~ Neurological symptoms that increase in frequency with age, such as decreased arm swing and increased rigidity.
~ Changes in dopamine levels may also cause age-related changes in cognitive flexibility.
Dopamine
~ Symptoms of excess & insufficiency
~ Insufficient dopamine
~ Lack of motivation
~ Fatigue
~ Apathy, Inability to feel pleasure
~ Procrastination
~ Low libido
~ Sleep problems
~ Mood swings
~ Hopelessness
~ Memory loss
~ Inability to concentrate
Dopamine: Age Related Changes
~ Dopamine levels decline by around 10% per decade from early adulthood and have been associated with declines in cognitive and motor performance
~ Dopamine levels are also impacted by availability of estrogen
Dopamine
~ Nutritional building blocks
~ Eating a diet high in magnesium and tyrosine rich foods will ensure youāve got the basic building blocks needed for dopamine production.
~ Hereās a list of foods known to increase dopamine:
Dopamine
~ Medications
~ Most common dopamine antagonists (positive symptoms)
~ Risperdone, Haldol, Zyprexa
~ Metoclopramide (Reglan) is an antiemetic and antipsychotic
~ Most common dopamine AGONISTs (Parkinsonās, Restless Legs) (negative symptoms)
~ Mirapex & Requip
Glutamate
~ Is an amino acid (present in most high protein foods)
~ Most prevalent excitatory neurotransmitter
~ Used to make GABA (teeter-totter)
~ Facilitates learning and memory
~ Excess glutamate is associated with
~ Panic attacks / anxiety
~ Impulsivity
~ OCD
~ Depression
Glutamate
~ Availability declines with age
~ Affected by serotonin availability
~ Insufficient
~ Agitation
~ Memory loss
~ Sleeplessness
~ Low energy level
~ Depression
GABA
~ Mechanism of action/purpose
~ Anti-anxiety, Anti-convulsant
~ GABA is made from glutamate
~ GABA functions as an inhibitory neurotransmitter
~ GABA does the opposite and tells the adjoining cells not to āfireā
~ Where is it found
~ Close to 40% of the synapses in the human brain work with GABA and therefore have GABA receptors.
GABA
~ Symptoms of excess
~ Excess sleepiness
~ Shallow breathing
~ *Increased blood pressure
~ Symptoms of insufficiency
~ Anxiety
~ Depression
~ Difficulty concentrating
~ Insomnia
~ Seizure disorders
GABA
~ Nutritional building blocks
~ Fermented foods sauerkraut, yogurt, kefir
~ Almonds & walnuts
~ Cherry tomatoes
~ Bananas
~ Brown rice
~ Potatoes
~ Oats
~ Lentils, navy & lima beans
~ Vitamin B6, if deficient, may impair the production of GABA as it is a cofactor nutrient.
GABA
~ Medications
~ Drugs that increase the available amount of GABA typically have relaxing, anti-anxiety, and anti-convulsive effect
~ Gabapentin (neurontin) is a GABA analogue used to treat epilepsy and neurologic pain.
~ Benzodiazepines and Barbiturates including GHB, Valium, Xanax
Serotonin
~ Mechanism of action/purpose
~ Helps regulate
~ Mood
~ Cardiovascular functioning
~ Memory
~ Intestinal motility
~ Sleep patterns
~ Appetite
~ Pain
Serotonin
~ Where is it found
~ Brain
~ Gut/Intestines
~ Symptoms of excess (Serotonin Syndrome)
~ Shivering
~ Diarrhea
~ Muscle rigity
~ Fever
~ Seizures
~ Irregular heartbeat
Serotonin
~ Symptoms of excess
~ Depression
~ Apathy, Emotional flatness or dullness
~ Passivity
~ Insomnia and other sleep problems
~ Difficulty concentrating and learning
~ Poor memory; amnesia
~ Difficulty making decisions and acting on them
~ Sexual dysfunction
Serotonin
~ Insufficiency
~ Depression
~ Anxiety
~ Pain sensitivity
~ Appetite disturbance
~ Sleep disturbances
Serotonin
~ Nutritional building blocks
~ Foods rich in tryptophan, an amino acid that converts to serotonin in the brain.
~ Whole-wheat
~ Potatoes
~ Brown rice
~ Lentils
~ Oats
~ Beans
Serotonin
~ Medications
~ SSRIs
~ SNRIs
~ 5-HTP
~ SAM-e
Serotonin Age Related Changes
~ Serotonin goes down when estrogen or testosterone go down (Dr. Jacques Lorrain. (1994) Comprehensive Management of Menopause)
~ Melatonin doesnāt decline as we age, unless serotonin declines significantly
Acetylcholine
~ Mechanism of action/purpose
~ In lower amounts, ACh can act like a stimulant by releasing norepinephrine (NE) and dopamine (DA)
~ Memory
~ Motivation
~ Higher-order thought processes
~ Sexual desire and activity
~ Sleep
Acetylcholine
~ Symptoms of excess
~ Depression (all symptoms)
~ Nightmares
~ Mental Fatigue
~ Anxiety
~ Inverse relationship between serotonin and acetylcholine
Acetylcholine
~ Insufficiency
~ Alzheimerās/dementia
~ Parkinsonās
~ Impaired cognition, attention, and arousal
Acetylcholine
~ Nutritional building blocks
~ Foods high in choline
~ Meats
~ Dairy
~ Poultry
~ Chocolate
~ Peanut butter
~ Wheat germ
~ Brussels sprouts and broccoli
Acetylcholine
~ Anticholinergic drugs are used to treat a variety of conditions:
~ Gastrointestinal disorders (e.g., gastritis, diarrhea, diverticulitis, ulcerative colitis, nausea, and vomiting)
~ Genitourinary disorders (e.g., cystitis, urethritis, prostatitis)
~ Respiratory disorders (e.g., asthma, chronic bronchitis, and chronic obstructive pulmonary disease [COPD])
~ Insomnia, although usually only on a short-term basis.
Acetylcholine
~ Medications
~ Anticholinergics
~ Atropine
~ Benzatropine (Cogentin)
~ Chlorpheniramine (Chlor-Trimeton)
~ Dimenhydrinate (Dramamine)
~ Diphenhydramine (Benadryl, Sominex, Advil PM, Unisom)
~ Hydroxyzine (Atarax, Vistaril)
~ Bupropion (Zyban, Wellbutrin)
~ Dextromethorphan – Cough suppressant
Summary
~ There are a variety of different neurotransmitters involved in addiction and mental health disorders
~ It is not always about increasing a neurotransmitter. Sometimes you need to decrease it or increase another neurotransmitter to facilitate it.
~ Human brains try to maintain homeostasis and too much or too little can be bad
~ A balanced diet will provide the brain the necessary nutrients in synergystic combinations
References
~ Res Nurs Health. 2014 Jun;37(3):185-93. doi: 10.1002/nur.21595. Epub 2014 Apr 3. Neurobehavioral effects of aspartame consumption.Lindseth GN1, Coolahan SE, Petros TV, Lindseth PD.
~ http://www.smithsonianmag.com/science-nature/could-diet-soda-cause-clinical-depression-586801/?no-ist
~ Understanding our Bodies: Dopamine and Its Rewards http://nutritionwonderland.com/2009/07/understanding-our-bodies-dopamine-rewards/
~ http://nutritionwonderland.com/2009/06/understanding-bodies-serotonin-connection-between-food-and-mood/
References
~ Myo-inositol content of common foods: development of a high-myo-inositol diet. http://ajcn.nutrition.org/content/33/9/1954.abstract
~ Neuroscience. 2002;111(2):231-9. GABA mechanisms and sleep. Gottesmann C.
~ Biofactors. 2006;26(3):201-8. Relaxation and immunity enhancement effects of gamma-aminobutyric acid (GABA) administration in humans. Abdou AM1, Higashiguchi S, Horie K, Kim M, Hatta H, Yokogoshi H.
References
~ Neuropsychopharmacology: The Fifth Generation of Progress Editors: Kenneth L. Davis et. Al. Publisher Lippincott, Williams, & Wilkins, Philadelphia, Pennsylvania, 2002 http://www.acnp.org/publications/neuro5thgeneration.aspx