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Neurobiology" Understanding Dopamine Serotonin & GABA

Jan 14, 2017



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Neurobiology: Dopamine, GABA, Serotonin, Acetylcholine

Neurobiology: Dopamine, GABA, Serotonin, AcetylcholineDr. Dawn-Elise Snipes PhD, LPC-MHSP, LMHC, NCC, CCDCExecutive Director,

Define NeurobiologyFor the following neurotransmitters, Dopamine, GABA, Serotonin, Acetylcholine, identifyTheir mechanism of action/purposeWhere they are foundSymptoms of excess & insufficiencyNutritional building blocksMedicationsObjectives

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 humanWhat is Neurobiology

Mechanism of action/purposemovementmemorypleasurable rewardbehavior and cognitionattentioninhibition of prolactin productionsleepmoodlearningDopamine

Mechanism of action/purposeAltered dopamine neurotransmission is implicated in Cognitive control (racing thoughts)Attentional controlImpulse controlWorking memoryDopamine

Where is it foundPrecursor, L-DOPA is synthesized in brain and kidneysDopamine functions in several parts of the peripheral nervous system In blood vessels, it inhibits norepinephrine release and acts as a vasodilator (relaxation)In the kidneys, it increases sodium and urine excretion In the pancreas, it reduces insulin productionIn the digestive system, it reduces gastrointestinal motility and protects intestinal mucosaIn the immune system, it reduces lymphocyte activity.Dopamine

Symptoms of excess & insufficiencyExcess of dopamineUnnecessary movements, repetitive ticsPsychosisHypersexualityNauseaMost antipsychotic drugs are dopamine antagonists Dopamine antagonist drugs are also some of the most effective anti-nausea agentsDopamine

Symptoms of excess & insufficiencyInsufficient dopamineNegative symptoms of schizophreniaPainParkinsons DiseaseRestless 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 & insufficiencyInsufficient dopamineLack of motivationFatigueApathy, Inability to feel pleasureProcrastinationLow libidoSleep problemsMood swingsHopelessnessMemory lossInability to concentrateDopamine

Nutritional building blocksEating a diet high in magnesium and tyrosine rich foodswill ensure youve got thebasic building blocks needed for dopamine production.Heres a list of foods known to increase dopamine:

DopamineChickenAlmondsApplesAvocadoBananasBeets ChocolateGreen leafy vegetablesGreen teaLima beansOatmealSesame & pumpkin seedsTurmericWatermelonWheat germ

MedicationsDopamine in blood is unable to cross the blood-brain barrier to reach the brain. Levodopa-Carbidopa combination is actually converted to dopamine in the brain


MedicationsMost common dopamine antagonists (positive symptoms)Risperdone, Haldol, ZyprexaMetoclopramide (Reglan) is an antiemetic and antipsychoticMost common dopamine AGONISTs (Parkinsons, Restless Legs) (negative symptoms)Mirapex & Requip


Patients with schizophrenia do not typically show measurably increased levels of brain dopamine activityOther dissociative drugs, notably ketamine and phencyclidine that act on glutamate NMDA receptors (and not on dopamine receptors) can produce psychotic symptoms.Those drugs that do reduce dopamine activity are a very imperfect treatment for schizophrenia: they only reduce a subset of symptoms, while producing severe short-term and long-term side effectsDopamine Hypothesis

Mechanism of action/purposeAnti-anxiety, Anti-convulsantGABA is made from glutamateGABA functions as an inhibitory neurotransmitter Glutamate acts as an excitatory neurotransmitter GABA does the opposite and tells the adjoining cells not to fireGABA

Where they are foundClose to 40% of the synapses in the human brain work with GABA and therefore have GABA receptors.GABA

Symptoms of excessExcess sleepinessShallow breathing*Increased blood pressureSymptoms of insufficiencyAnxietyDepressionDifficulty concentratingInsomniaSeizure disordersGABA

Nutritional building blocksFermented foods sauerkraut, yogurtAlmonds & WalnutsCherry TomatoesBananaBrown ricePotatoOatsLentilsVitamin B6, if deficient, may impair the production of GABA as it is a cofactor nutrient.GABA

Nutritional building blocksInositol (Vitamin B-8)Wheat germBrown riceGreen leafy vegetablesNutsNavy and Lima beansGABA

MedicationsDrugs that act as allosteric modulators of GABA receptors (known as GABA analogues or GABAergic drugs) or increase the available amount of GABA typically have relaxing, anti-anxiety, and anti-convulsive effectGabapentin (neurontin) is a GABA analogue used to treat epilepsy and neurotic pain. Benzodiazepines and Barbiturates including GHB, Valium, XanaxGABA

Mechanism of action/purposeHelps regulate MoodSleep patternsAppetitePainSerotonin

Where is it foundBrainGut/IntestinesSerotonin

Symptoms of excessShiveringDiarrheaMuscle rigityFeverSeizuresIrregular heartbeat


Symptoms of excessDepressionApathy, Emotional flatness or dullnessPassivityInsomnia and other sleep problemsDifficulty concentrating and learningPoor memory; amnesiaDifficulty making decisions and acting on themSexual dysfunction


InsufficiencyDepressionAnxietyPain sensitivity


Nutritional building blocksFoods rich in tryptophan, an amino acid that converts to serotonin in the brain. Whole-wheat PotatoesBrown riceLentilsOatsBeansSerotonin



Their mechanism of action/purposeIn lower amounts, ACh can act like a stimulant by releasing norepinephrine (NE) and dopamine (DA).MemoryMotivationHigher-order thought processesSexual desire and activitySleepAcetylcholine

Symptoms of excessDepression (all symptoms)NightmaresMental FatigueAnxietyInverse relationship between serotonin and acetylcholine


InsufficiencyAlzheimers/dementiaParkinsonsImpaired cognition, attention, and arousal Cholinergic and GABAergic pathways are intimately connected in the hippocampus and basal forebrain complex. Acetylcholine

Nutritional building blocksFoods high in cholineMeatsDairyPoultryChocolatePeanut butterWheat germBrussels sprouts and broccoliAcetylcholine

MedicationsCholinergicsUsed for glaucoma, bladder control and severe muscle weaknessAnticholinergicsMay worsen GERDUsed for extrapyrimadal symptoms is treating schizophreniaMuscular spasmsAkathisia: A feeling of internal motor restlessness, tension, nervousness, or anxiety[ Drug-induced parkinsonism Tardive dyskinesia: involuntary muscle movements in the lower face and distal extremities


MedicationsAnticholinergicsAtropine Benzatropine (Cogentin) Chlorpheniramine (Chlor-Trimeton) Dimenhydrinate (Dramamine) Diphenhydramine (Benadryl, Sominex, Advil PM, Unisom)Hydroxyzine (Atarax, Vistaril)Bupropion (Zyban, Wellbutrin) Dextromethorphan - Cough suppressantAcetylcholine

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.


Higher ACh and NE, together with lower SE, produces Anxiety, emotional lability, irritability, anger, aggressiveness, negative rumination, impatience, and impulsiveness When NE, DA, and SE are low and acetylcholine is highThe result is simply depression. Increasing serotonin lowers acetylcholine levels, and norepinephrine and dopamine.Homeostasis

There are a variety of different neurotransmitters involved in addiction and mental health disordersIt is not always about increasing a neurotransmitter. Sometimes you need to decrease it.Human brains try to maintain homeostasis and too much or too little can be badA balanced diet will provide the brain the necessary nutrients in synergystic combinationsSummary

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. our Bodies: Dopamine and Its Rewards


Myo-inositol content of common foods: development of a high-myo-inositol diet. 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.


Neuropsychopharmacology: The Fifth Generation of Progress Editors: Kenneth L. Davis et. Al. Publisher Lippincott, Williams, & Wilkins, Philadelphia, Pennsylvania, 2002