BIOLOGICAL IMPLICATIONS Review of anatomy and physiology of the nervous system: Central nervous system Brain - Cerebrum.. Frontal lobe.. Parietal lobe.. Temporal lobe.. Occipital lobe 1 _ . 2 3 DIENCEPHALON -Diencephalon.. Thalamus: integrates all sensory input (except smell ) on its way to the cortex. It has some involvement with emotion and mood.. 4 _ . Hypothalamus: It regulates appetite and temperature.. Limbic system: ( emotional brain )is associated with fear and anxiety; anger and aggression;love,joy, and hope;and sexuality and social behavior 5 _ . Medulla: It contains vital centers that regulates heart rate, BP, and respiration and reflex centers for swallowing sneezing, coughing, and vomiting. Cerebellum: Functions of the cerebellum are concerned with involuntary movement, such as muscular tone and coordination, and the maintenance of posture and equilibrium. 6 _ . . Synapse: Is the junction between tow neurons Synaptic cleft : Is the small space between the axon terminals of one neuron and the cell body or dendrites of another 7 _ . 8 9 10 _ . 11 _ . 12 _ . 13 _ . 14 _ . 15 _ . 16 _ . 17 _ . 18 NEUROTRANSMITTERS Chemicals called neurotransmitters (NT) s tored in the axon terminals of presynaptic neurons Electrical impulses cause the release of these chemicals into the synaptic cleft NT combines with receptor sites on the post synaptic neuron, resulting in a determination of whether another electrical impulse is generated NT responsible for essential functions in the role of human emotions and behavior. NT s are the target for the mechanism of action of many of the psychotropic medications _ . The Two Key Amino Acids Your Brain Uses to Make Neurotransmitters From -- Phenylalanine* is an essential amino acid, meaning that if you're not getting it from your diet then your brain isn't getting what it needs to make the transmitters that cause you to feel happy, loving and motivated. Phenylalanine is found in protein-rich foods, such as milk, cheese, nuts, seeds, poultry and fish. It's also found in diet foods, such as diet soda, which contains aspartame. Phenylalanine isn't a problem for most people. 19 _ . The other amino acid, Glutamine, is a conditionally essential amino acid. It is used to make neurotransmitters which keep you feeling calm, focused and in control, but during periods of stress the body cannot make its own supply of glutamine and needs an outside source, diet or otherwise 20 _ . The dietary sources of glutamine includes especially the protein-rich foods like beef, chicken, fish, dairy products, eggs, vegetables like beans, beets, cabbage, spinach, carrots, parsley, vegetable juices and also in wheat, papaya, brussel sprouts, celery, These are the natural food sources for L-Glutamine. But this may constitute only 4-8% of the requirement of the body and hence the supplement form is a requisite at some situations. 21 _ . Types of Neurotransmitters The Inhibitory System is the brains braking system, it prevents the signal from continuing. The inhibitory system slows things down. The Excitatory Neurotransmitter System can be related to your car's accelerator. It allows the signal to go. When the excitatory neurotransmitter system is in drive your system gets all revved up for action. Without a functioning inhibitory system to put on the brakes, things (like your mood) can get out of control 22 _ . EXCITATORY Acetylcholine Aspartate Dopamine Histamine Norepinephrine Epinephrine Glutamate Serotonin INHIBITORY GABA Glycine 23 _ . 24 _ . 25 _ . 26 After a neurotransmitter has performed its function in the synaptic cleft, it either returns to the vesicles in the axon terminals to be stored and used again/or it is in activated and dissolved by enzymes. The process of being stored for reuse is called reuptake _ . 27 _ . 28 _ . Major neurotransmitters that regulate mood are: Serotonin: Serotonin imbalance is one of the most common contributors to mood problems. Serotonin is key to our feelings of happiness and very important for our emotions because it helps defend against both anxiety and depression. You may have a shortage of serotonin if you have a sad depressed mood, anxiety, panic attacks, low energy, migraines, sleeping problems, obsession or compulsions, feel tense and irritable, crave sweets, and have a reduced interest in sex Moreover, daily stress can greatly reduce your serotonin supplies. 29 _ . Dopamine: is responsible for motivation, interest, and drive. It is associated with positive stress states such as being in love, exercising, listening to music, and sex. When we don't have enough of it we don't feel alive, we have difficulty initiating or completing tasks, poor concentration, no energy, and lack of motivation. Dopamine also is involved in muscle control and function. Low Dopamine levels can drive us to use drugs (self medicate), alcohol, smoke cigarettes, gamble, and/or overeat. High dopamine has been observed in patients with poor GI function, autism, mood swings, psychosis, and children with attention disorders. 30 _ . GABA (Gamma amino butyric acid): is the major inhibitory neurotransmitter in the central nervous system. It helps the neurons recover after transmission, reduces anxiety and stress. It regulates norepinephrine, adrenaline, dopamine, and serotonin, it is a significant mood modulator. 31 _ . Norepinephrine: also known as noradrenaline is a excitatory neurotransmitter that is produced by the adrenal medulla or made from dopamine. High levels of norepinephrine are linked to anxiety, stress, high blood pressure, and hyperactivity. Low levels are linked to lack of energy, focus, and motivation. 32 _ . Acetylcholine: Acetylcholine was the first neurotransmitter to be discovered. It is the neurotransmitter that is released by stimulation of the vagus nerve, which alters heart muscle contractions. It is important for the movement of other muscles as well. Acetylcholine induces movement by the locomotion of an impulse across a nerve that causes it to release neurotransmitter molecules onto the surface of the next cell. neurotransmitter 33 _ . Acetylcholine ( cont): This causes a stimulation of that next cell. After this process has been completed, the acetylcholine is then broken into acetate and choline. These travel back to the first cell to be recycled into acetylcholine and start the process over again. 34 _ . Epinephrine also known as adrenaline: is a neurotransmitter and hormone essential to metabolism. It regulates attention, mental focus, arousal, and cognition. It also inhibits insulin excretion and raises the amounts of fatty acids in the blood. Epinephrine is made from norepinephrine and is released from the adrenal glands. 35 _ . Low levels of Epinephrine can result in fatigue, lack of focus, and difficulty losing weight. High levels of Epinephrine have been linked to sleep problems, anxiety and Attention Deficit and Hyperactivity Disorder ADHD. 36 _ . PEA Beta-phenylethylamine is an excitatory neurotransmitter derived from the amino acid phenylalanine is an excitatory neurotransmitter made from phenylalanine. It is important in focus and concentration. High PEA are observed in individuals experiencing "mind racing", sleep problems, anxiety, and schizophrenia. Low PEA is associated with difficulty paying attention or thinking clearly, and in depression. 37 _ . 38 _ . 39 CATEGORIES OF NEUROTRANSMITTERS Cholinergics Monoamines Amino acids Neuropeptides _ . 40 Cholinergics Acetylcholine: was the first chemical to be identified and proven as a neurotransmitter. Functions: involved in sleep, arousal, pain perception, the modulation and coordination of movement, and memory acquisition and retention. Implications in mental illness: Parkinsons disease,Alzheimers disease.. Increased level result in depression _ . 41 Monoamines Norepinephrine: associated with flight-or-fight syndrome of symptoms that occurs in response to stress. Functions: - regulation of mood, cognition, perception, sleep and arousal Implications: - decreased level in depression and increased in mania, anxiety states, schizophrenia _ . 42 Dopamine: derived from amino acid tyrosine Functions: involved in the regulation of movements and coordination,emotions, and voluntary decision making ability, it inhibits the release of prolactin. Implications: - decreased levels depression, and parkinsons disease - increased levels. Mania and schizophrenia _ . 43 Serotonin: is derived from amino acid tryptophan, - the selective serotonin reuptake inhibitors (SSRIs) antidepressants block the reuptake of serotonin to increase levels in the brain. Functions: sleep and arousal,libido,appetite,mood,aggression,pain perception. Implications: - Increased levelmania & anxiety states - decreased level depression _ . 44 Amino acids Gamma aminobutyric acid (GABA): Functions: GABA interrupts the progression of the electrical impulse at the synaptic junction, producing a significant slowdown of body activity. Implications: - decreased level of GABA etiology of anxiety disorders,movement disorders( Huntingtons Chorea), some form of epilepsy _ . 45 Glycine: inhibitory aminoaci, high concentration in brainstem and spinal cord Functions: involved in the recurrent inhibition of motor neurons within the spinal cord and possibly involved in the regulation of spinal and brain stem reflexes. Implications: some form of spastic disorders, high concentration of glycine can produce glycine encephalopathy _ . 46 NEUROPEPTIDES Endorphins and Enkaphalins (Opioid peptides): Function: with their natural morphinelike properties, they are thought to have a role in pain modulation. Implication: modulation of dopamine activity by opioid peptides may indicate some link to the symptoms of schizophrenia. _ . 47 THE NEUROENDOCRINE SYSTEM Thyroid stimulating hormone: - increased levels insomnia,anxiety,emotional lability. - decreased level depression fatigue Adrenocorticotropic hormone: - increased levelmood disorders, psychosis - decreased level depression, apathy, fatigue Prolactin: - increased leveldepression, anxiety, decreased libido, irritability. _ . 48 Gonadotropic hormone: - Decreased levels depression, anorexia nervosa,increased sexual behavior,and aggressiveness. Melanocyte-stimulating hormone: - increased levels depression _ . 49 DIAGNOSTIC PROCEDURES USED TO DETECT ALTERED BRAIN FUNCTION Electroencephalograph (EEG); Computerized EEG maping Computed tomographic scan( CT) Magnetic Resonance Imaging (MRI) Positron Emission Tomography (PET) Single Photon Emission Computed Tomography(SPECT) _ . 50 _ .