Meditation V Sudhakara Rao Editor-in-Chief Health Scan Series-6 The Science of Yoga and health In the previous issue  ‘Understanding Consciousness and thought as an integrated approach’, was discussed Meditation The  art  of  meditation  has been,  often  associated  with  religion and  spiritualism for long time.  However, it has been established by modern science that ‘Meditation & Yoga’   would influence the biological functions of the body. This indicates that they can influence   ‘Thoughts’ and in turn can influence health.  Meditation is known for its ability to help relax and de-stress the mind and body. This shows that brain chemistry undergoes some changes due to meditation. Neurotransmitters   The nervous system processes sensory information and controls behaviour by performing an enormous number of computations. This task is achieved by ‘Neurotransmitters’.  Neurotransmitters are  chemical messengers  used by the nervous system to transmit messages between neurons  or from neurons to muscles to perform their work.  If a neurotransmitter stimulates the target cell to an action, then it is called  as an ‘Excitatory’ neurotransmitter and if  it decreases stimulation  it is an ‘Inhibitory’ neurotransmitter.  Neuromodulators modulate the signals. There are more than 40 neurotransmitters in the human nervous system; Key Neurotransmitters and their role: Acetylcholine  •	It is found in both the central and peripheral nervous systems; it is the primary neurotransmitter associated with motor neurons. •	Stimulates muscle contraction  •	Functions in the autonomic nervous system and sensory neurons •	Organises release of a few hormones •	Controls Wakefulness and sleep cycle.  •	Regulates thirst •	Regulates emotions like Anger, aggression, irritability etc •	Controls Libido drive •	Learning and memory functionality •	Low levels are indicated in Alzheimers disease  Dopamine Basically, dopamine is a Neuromodulator. Dopamine is commonly  associated  with  reward-motivated behavior. Dopamine levels increase when people achieve success, reach expected goals, eat foods that they like too much or involve in pleasure seeking activities. Schizophrenics have too much dopamine.  Parkinson's patients have too little dopamine. And addiction mechanism such as alcohol or smoking is related to dopamine.  Endorphins  They inhibit pain signals and create an energized, euphoric feeling. They are also the body’s natural pain relievers. Epinephrine It acts as a transmitter as well as hormone. It is involved in the body’s “fight or flight” response. GABA Gamma-aminobutyric acid (GABA) is an inhibiary transmitter. It is a mood regulator. Low levels of GABA can cause anxiety, irritability, and restlessness.   In particular, decreased  GABA  activity is seen   in  the  hippocampus,  lingual  gyrus, middle  temporal  gyrus,  visual  cortex    orbital  cortex  and insula     in  patients  with  panic  disorder.  If GABA is lacking in certain parts of the brain, epilepsy results GLUTAMATE It is  commonly found excitatory neurotransmitter in the brain.  It is involved in functions like  cognition, memory and learning.  MELATONIN  Melatonin is produced by the pineal gland, a small endocrine gland located in the center of the brain,  but outside the Blood–Brain barrier.  Regulates: the sleep-wake cycle and  acts as Antioxidant, regulates Immune system. Its role in Autism: Children with autism spectrum disorder (ASD) often experience problems with getting to sleep as well as sleep maintenance.  This poor sleep quality  affects  daytime behavior, memory, and learning. One of the possible reasons for the sleep issues is disturbance  in them is low levels of melatonin. People with Parkinsons disease, MS, other neuro disorders often have low lelvels of melatonin.  Nor-epinephrine (noradrenaline) It is a primary neurotransmitter as well as stress hormone, in the sympathetic nervous system  and involves in controlling blood pressure, heart rate, liver function and many other functions. It triggers the release of glucose (sugar) into the blood to counter stress related situations.  It is Involved in sleep, wakefulness, attention and feeding behavior.  Its excessive release leads to  excessive alertness, sleeplessness  and it increases body’s speed of response. Very low  levels of this substance can lead to dullness, lethargy, depression, lack of interest  in regular activities, sleepy tendency, dizziness, sense of fainting and  even low BP etc. Serotonin It is called happy mood transmitter. That’s why it plays important role in mind health.  Its deficiency can lead to poor mental functions and depression. Serotonin is a neurotransmitter as well as hormone. To understand  the way meditation affects brain-mind mechanism, it is essential to further understand crucial brain chemicals called Neurotransmitters  and  brain waves Otto Loewi, an Austrian scientist, discovered the first neurotransmitter: acetylcholine  in 1921 Thoughts can   Heal or Steal  health Contd…next issue 18
Health Scan - March 2020 -