Adaptation to Space Flight

1. Adaptation to Space Flight Richard P. Brown, MD Associate Professor of Psychiatry Columbia University

2. Stressors of Space Flight • Physical – lift off, microgravity, disorientation, space walks, strenuous work • Psychological – danger, confinement, mental fatigue, long hours, tedious work, crises • Social/Interpersonal – conflicts, misunderstandings, cultural and language differences • Radiation • Changes in atmosphere

3. Effects of Stressors • Anxiety, Depression • Insomnia • Irritability, interpersonal aggression • Poor judgment • Impaired attention and cognitive functions • Physical symptoms eg. cardiac arrhythmia

4. Stress Response System • Sympathetic Nervous System – • Epinephrine (adrenaline) and norepinephrine •  heart rate, blood pressure, respiration, energy expenditure, oxidative damage, prepare for fight or flight • Balanced by the Parasympathetic Nervous System -  heart rate, respirations, energy expenditure, calms brain, restore and repair • Hypothalamic-pituitary-adrenal axis (HPA)

7. Rhodiola rosea and Adaptogens • Rhodiola rosea root extract – high altitudes Caucuses, Siberia, Scandinavia • Long history – tonic,  energy, endurance for physical stress, cold, high altitudes, low oxygen, to treat infections, maintain memory in old age, fertility • 40 years scientific studies (classified Soviet Research) for physical and mental performance under stress. Tested in military, Olympic athletes, cosmonauts (on Mir 1994 Polyokov), students and scientists intellectual performance

8. Benefits of R. rosea and Adaptogen Formula • Studies demonstrate increase in physical performance, endurance, accuracy • Enhance intellectual performance under stress over long periods of time (12 hr and 24 hr tests) Improve accuracy, reduce errors in tracking and calculations, visualmotor,  eye strain • Improve morale, attitude, motivation, emotional stability under stress • Reduce irritability, frustration, anger • tolerance high altitude, disorientation in space

9. Mechanisms of Adaptogen Effects •  cellular energy production in mitochondria •  antioxidant • Protect against damage from stressors: physical (heat, cold), hypoxia (lack of oxygen or loss of blood supply), chemical (toxins, other medications), infection, radiation, psychological •  cellular repair •  parasympathetic tone

10. Adaptogens and Yogic Breathing • Reduce Stress &  stress resistance •  fatigue &  energy • Improve physical performance • Improve mental performance • Enhance social adaptation • Reduce anxiety, depression and aggression • Produce a Calm, Clear, Alert Mental State

11. Mechanisms of Yogic Breathing Effects •  parasympathetic tone and output to • Quiet cortex “worry centers” • Limbic System - Release emotional stress • Release oxytocin, vasopressin, prolactin “feel good, bonding, cuddle” and male protective hormones •  energy expenditure  production free radicals • Hypothalamus -  alertness, attention • Balance different areas of the cortex •  physical effects of stress on heart, muscle, gut

12. Neurophysiological Model of Vagus Nerve Stimulation Pathways Stimulation HyperventilationThalamic NucleiDiffuse Cortical Areas Electronic Thalamic Generators Frontal – quiet,  worry Sudarshan Kriya (SKY) Parieto-occipital SMR – calm + relaxed  attention + vigilance Vagus Nerve  NTS  PBN  MRS Limbic Pathways Anterior Limbic Cortex PRS– reward, satiety, pleasure Hypothalamus Amygdala Stria Terminalis Emotion & Memoriesreward & oxytocin receptors Pituitary Release Prolactin, Vasopressin Oxytocin - bonding _________________________________________________________________________________________________ NTS = nucleus tractus solitarius; PBN = parabrachial nucleus; MRS = mesolimbic reward system SMR = sensori-motor rhythm; PRS = post-reinforcement synchronization 

14. Sudarshan Kriya Yoga Ujjayi Breathing Bhastrika Sudarshan Kriya Chanting Meditation

15. Ujjayi Breathing • Vagal stimulation • Enhances parasympathetic system • Slow breathing rate 4/minute • High volume avoids hypercapnia/hypocapnia

16. Ujjayi Breathing • Although Ujjayi has not been studied in depth, “strained breathing” has in animals • Comes from hypothalamic vigilance area • Recharges animal for later fight or flight • Enhances attention and reflexes • Occurs when animal has surrendered but may be attacked

17. Bhastrika • Activates parieto-temporo-occiptal cortex • On EEG  wicket 12-17 hz sinusoidal 26-33 hz paroxysmal • Sympathetic stimulation • Integration of multiple areas • Subjectively stimulating

19. Chanting • Balances and enhances parasympathetic and sympathetic • Synchronizes breath/heart/brain flow cycles with medullary blood pressure cycle • Activates thalamus (internal attention)

20. Slow Breathing during Ujjayi, Chanting or Meditation • Enhances control of vagus nerve • Enhances baroreflex sensitivity • Decreases chemoreflex sensitivity • An “autonomic exercise” to enhance parasympathetic/sympathetic range and control

21. The effects of hyperventilation require an intact thalamus and vagal afferents to the brain.

22. Vagal Nerve Stimulation • Vagal Nerve Stimulation (left only) is used: treat epilepsy experimental treatment depression

23. Effects of Hyperventilation • Increases cardiac and renal output • At modest levels does not reduce brain metabolism or blood flow • Induces slow waves on EEG • Activates the thalamus (through the vagus) • Increases cortical excitability • Activates the limbic system

24. Sensori-motor Rhythm (SMR) • Similar to sleep spindles • Absent movement, reduced muscle tone • In humans, reduced eye movement • Resistance to seizures • Input from ventrobasal thalamus to sensorimotor area

25. Post-Reinforcement Synchronization (PRS) • Occurs with reward • “Edge of sleep” state (preverbal imagery) • From other areas of thalamus (to cortex) • Oscillates with SMR  resets system for next challenge

26. Possible Effects of Sudarshan Kriya • Activates the thalamus • Alternate or simultaneous: activates SMR and PRS • Shuts down frontal executive functions • Rebalance relationships between brain areas: R and L cerebral hemispheres; anterior and posterior; top to bottom • Releases stress hormones gently to calm stress response system • Releases pituitary hormones: enhance mood and social harmony

27. Oxytocin • “cuddle hormone” • Released in bonding behaviors, delivery, sexual activity • Low in depression • Stimulated by SSRIs • Parasympathetic enhancement

29. Antidepressant Effect: HRSD

30. Trials Summary of SKY in Consenting Depressives (NIMHANS Research) • Significant therapeutic effects in Dysthymia and Melancholia • Normalised sleep pattern (REM Latency & NREM states) • Corrected cerebral physiology (P3 amplitude) • Effect independent of pre-treatment dysfunction (P3 amplitude) • Prolactin response to SKY similar to ECT • Significant reduction in plasma cortisol (day 23) • No clinically detectable side-effects • Few contraindications (except in epileptics, bipolar disorder, pregnancy)

31. Yoga Breathing Uses • Enhance Well-Being • Stress Resilience/Stress Release • Memory, learning, cognition, attention • Physical Strength and Endurance • Depression, Anxiety, Irritability • Cardiac Function •  Energy,  Fatigue •  Interpersonal Conflict,  Bonding (team)