# Presentation: 100438

## Adaptation to Space Flight

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

## 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

## Effects of Stressors

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

## 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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## Slide 6

## 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

## 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

## 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

## 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

## 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

## Neurophysiological Model of Vagus Nerve Stimulation Pathways

**Neurophysiological Model of Vagus Nerve Stimulation Pathways**

**Anterior Limbic Cortex**
**PRS** – reward, *satiety, pleasure*

-    Prolactin, Vasopressin     Oxytocin - *bonding*
- _________________________________________________________________________________________________
-    NTS = nucleus tractus solitarius; PBN = parabrachial nucleus; MRS = mesolimbic reward system
-   SMR = sensori-motor rhythm; PRS = post-reinforcement synchronization

**	****	****Hypothalamus      Amygdala         Stria Terminalis**

*Emotion & Memories*           *reward & oxytocin receptors*

-    **Pituitary Release**

**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

-     **Limbic Pathways**

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## Sudarshan Kriya Yoga

- 			Ujjayi Breathing
- 			Bhastrika
- 			Sudarshan Kriya
- 			Chanting
- 			Meditation

## Ujjayi Breathing

- _Vagal_ stimulation
- Enhances _parasympathetic_ system
- Slow breathing rate 4/minute
- High volume avoids hypercapnia/hypocapnia

## 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

## 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

## Chanting

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

## 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

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

## Vagal Nerve Stimulation

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

## 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_

## 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

## 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

## 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

## Oxytocin

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

## Antidepressant Effect: HRSD 

## 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)

## 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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