Adaptation to Space Flight

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Adaptation to Space Flight

• Richard P. Brown, MD
• Associate Professor of Psychiatry
• Columbia University

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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

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Effects of Stressors

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

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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)

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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

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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

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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

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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

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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

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Neurophysiological Model of Vagus Nerve
Stimulation Pathways
Stimulation Hyperventilation Thalamic
Nuclei Diffuse Cortical Areas Electronic
Thalamic Generators Frontal
quiet, ? worry Sudarshan Kriya (SKY)
Parieto-occipital SMR calm
relaxed ?
attention vigilance Vagus Nerve ? NTS ?
PBN ? MRS

Anterior Limbic Cortex PRS reward, satiety,
pleasure
Limbic Pathways
Hypothalamus Amygdala Stria
Terminalis
Emotion Memories reward oxytocin
receptors
Pituitary Release
Prolactin, Vasopressin Oxytocin - bonding
_________________________________________________
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NTS nucleus tractus solitarius PBN
parabrachial nucleus MRS mesolimbic reward
system SMR sensori-motor rhythm PRS
post-reinforcement synchronization 
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Sudarshan Kriya Yoga

• Ujjayi Breathing
• Bhastrika
• Sudarshan Kriya
• Chanting
• Meditation

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Ujjayi Breathing

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

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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

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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

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Chanting

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

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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

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The effects of hyperventilation require an intact
thalamus and vagal afferents to the brain.
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Vagal Nerve Stimulation

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

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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

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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

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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

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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

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Oxytocin

• cuddle hormone
• Released in bonding behaviors, delivery, sexual
  activity
• Low in depression
• Stimulated by SSRIs
• Parasympathetic enhancement

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Antidepressant Effect HRSD
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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)

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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)

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