Changes

=== Concept of Sleep ===

=== Concept of Sleep ===

The age-old concepts of sleep (''nidra'') and its different stages such as ''jagrata'', ''swapana'' and ''sushupti'' are comparable to the current concept of sleep and its stages. The problems and pattern of sleep are assessed by observing the activity of brain through Electroencephalogram (EEG) pattern.<ref>Dement, William; Kleitman, Nathaniel (1 November 1957). "Cyclic variations in EEG during sleep and their relation to eye movements, body motility, and dreaming". Electroencephalography and Clinical Neurophysiology9 (4): 673–690. doi:10.1016/0013-4694(57)90088-3. PMID 13480240. </ref> It is pointed out that wakefulness and stages of sleep have a specific EEG pattern. The wakefulness is associated with Beta and Gama waves frequencies in EEG pattern, which depends on pleasurable or painful stressors of surrounding environment. Stage 1 non-rapid eye movement (NREM) sleep is characterized by slowing down of Beta and Gama wave frequencies, reached to slow down the Alpha wave, and finally reached to Theta wave frequencies in EEG pattern.  At a higher stage of NREM and REM, these brain wave frequencies in EEG pattern gradually decreases, and the person falls into sleep. By observing overall brain activity in EEG pattern, we can say that frequencies of sleep waves are low in wakefulness and it is gradual increases in different stages of sleep. Sleep spindles and K-complexes appeared in EEG pattern in Stage 2 of sleep, while more sleep spindles are observed in Stage 3 of sleep.  The slow wave sleep is also known as high amplitude Delta wave, which is commonly observed in Stages 3 and 4 of sleep in EEG pattern. Low amplitude, mixed frequency waves- a sawtooth wave in EEG pattern observed at REM stage of sleep.<ref> 71. BARKER, W; BURGWIN, S (1948 Nov-Dec). "Brain wave patterns accompanying changes in sleep and wakefulness during hypnosis." Psychosomatic Medicine10 (6): 317–26. PMID 18106841. </ref> <ref>Jankel, WR; Niedermeyer, E (January 1985). "Sleep spindles.". Journal of clinical neurophysiology: official publication of the American Electroencephalographic Society2 (1): 1–35. PMID 3932462. </ref> <ref>Loomis, A. L.; Harvey, E. N.; Hobart, G. A (1938). "Distribution of disturbance-patterns in the human electroencephalogram with special reference to sleep". Journal of Neurophysiology1: 413–430. </ref>(verse 35)

The age-old concepts of sleep ([[nidra]]) and its different stages such as ''jagrata'', ''swapana'' and ''sushupti'' are comparable to the current concept of sleep and its stages. The problems and pattern of sleep are assessed by observing the activity of brain through Electroencephalogram (EEG) pattern.<ref>Dement, William; Kleitman, Nathaniel (1 November 1957). "Cyclic variations in EEG during sleep and their relation to eye movements, body motility, and dreaming". Electroencephalography and Clinical Neurophysiology9 (4): 673–690. doi:10.1016/0013-4694(57)90088-3. PMID 13480240. </ref> It is pointed out that wakefulness and stages of sleep have a specific EEG pattern. The wakefulness is associated with Beta and Gama waves frequencies in EEG pattern, which depends on pleasurable or painful stressors of surrounding environment. Stage 1 non-rapid eye movement (NREM) sleep is characterized by slowing down of Beta and Gama wave frequencies, reached to slow down the Alpha wave, and finally reached to Theta wave frequencies in EEG pattern.  At a higher stage of NREM and REM, these brain wave frequencies in EEG pattern gradually decreases, and the person falls into sleep. By observing overall brain activity in EEG pattern, we can say that frequencies of sleep waves are low in wakefulness and it is gradual increases in different stages of sleep. Sleep spindles and K-complexes appeared in EEG pattern in Stage 2 of sleep, while more sleep spindles are observed in Stage 3 of sleep.  The slow wave sleep is also known as high amplitude Delta wave, which is commonly observed in Stages 3 and 4 of sleep in EEG pattern. Low amplitude, mixed frequency waves- a sawtooth wave in EEG pattern observed at REM stage of sleep.<ref>BARKER, W; BURGWIN, S (1948 Nov-Dec). "Brain wave patterns accompanying changes in sleep and wakefulness during hypnosis." Psychosomatic Medicine10 (6): 317–26. PMID 18106841. </ref> <ref>Jankel, WR; Niedermeyer, E (January 1985). "Sleep spindles.". Journal of clinical neurophysiology: official publication of the American Electroencephalographic Society2 (1): 1–35. PMID 3932462. </ref> <ref>Loomis, A. L.; Harvey, E. N.; Hobart, G. A (1938). "Distribution of disturbance-patterns in the human electroencephalogram with special reference to sleep". Journal of Neurophysiology1: 413–430.</ref>[verse 35]

==== Sleep regulation ====

==== Sleep regulation ====

It is presumed that the sleep physiology is controlled by the hypothalamus and the suprachiasmatic nucleus (SCN) in the brain, which regulates mechanism of homeostatic and circadian rhythm respectively of the body. The actual mechanism of the physiology of sleep is still evolving in biomedical sciences. The sleep is initiated and begins by projections from the SCN to the brain stem. Borbely called projections as Process S (homeostatic) and Process C (Circadian) respectively, who first proposed these two process models in 1982. He pointed out that maximum sleep is the outcome of significant differences between homeostatic and circadian rhythm.<ref name=ref74>Saper, Clifford B.; Scammell, Thomas E.; Lu, (Jun (27 October 2005)): "Hypothalamic regulation of sleep and circadian rhythms". Nature437 (7063): 1257–1263. doi:10.1038/nature04284. PMID 16251950.</ref>(verse 39-43)

It is presumed that the sleep physiology is controlled by the hypothalamus and the suprachiasmatic nucleus (SCN) in the brain, which regulates mechanism of homeostatic and circadian rhythm respectively of the body. The actual mechanism of the physiology of sleep is still evolving in biomedical sciences. The sleep is initiated and begins by projections from the SCN to the brain stem. Borbely called projections as Process S (homeostatic) and Process C (Circadian) respectively, who first proposed these two process models in 1982. He pointed out that maximum sleep is the outcome of significant differences between homeostatic and circadian rhythm.<ref name=ref74>Saper, Clifford B.; Scammell, Thomas E.; Lu, (Jun (27 October 2005)): "Hypothalamic regulation of sleep and circadian rhythms". Nature437 (7063): 1257–1263. doi:10.1038/nature04284. PMID 16251950.</ref>[verse 39-43]

==== Effects of sleep  ====

==== Effects of sleep  ====

Recent conventional evidence suggests that seasonal variation can have an impact on sleep/wake cycle, which is quite interesting and proven the age-old concept of [[Ayurveda]]. Recent evidence shows that core temperature of body and secretion of melatonin hormone levels are slightly greater in the month of summer due to prolong the length of light exposure, which imparts significant role in daytime sleep in summer. This is the reason people go to bed early at night and wake up early in the morning in the month of summer.  Sunlight exposure in the morning hours may affect internal biological clock, shifting the timing of the sleep window. The need and function of sleep are the most lacking areas of sleep research in biomedical sciences. Some of the important ones are- restoration and recovery of body systems, energy conservation, memory consolidation, protection from predation, brain development, and discharge of emotions.<ref name=ref74/> <ref>Krueger, James M.; Obál, Ferenc; Fang, Jidong. "Why we sleep: a theoretical view of sleep function". Sleep Medicine Reviews3 (2): 119–129. doi:10.1016/S1087-0792(99)90019-9. </ref> <ref>KRUEGER, JAMES M.; OBÄL, FERENC (1 June 1993). "A neuronal group theory of sleep function". Journal of Sleep Research2 (2): 63–69. doi:10.1111/j.1365-2869.1993.tb00064.x. </ref> <ref>Friborg, O., Bjorvatn, B., Amponsah, B., Pallesen, S. (2012). Associations between seasonal variations in day length (photoperiod), sleep timing, sleep quality and mood: a comparison between Ghana (5°) and Norway (69°). Journal of Sleep Research, 21(2), 176-184.) </ref>(verse 36-38 and 44-49)

Recent conventional evidence suggests that seasonal variation can have an impact on sleep/wake cycle, which is quite interesting and proven the age-old concept of [[Ayurveda]]. Recent evidence shows that core temperature of body and secretion of melatonin hormone levels are slightly greater in the month of summer due to prolong the length of light exposure, which imparts significant role in daytime sleep in summer. This is the reason people go to bed early at night and wake up early in the morning in the month of summer.  Sunlight exposure in the morning hours may affect internal biological clock, shifting the timing of the sleep window. The need and function of sleep are the most lacking areas of sleep research in biomedical sciences. Some of the important ones are- restoration and recovery of body systems, energy conservation, memory consolidation, protection from predation, brain development, and discharge of emotions.<ref name=ref74/> <ref>Krueger, James M.; Obál, Ferenc; Fang, Jidong. "Why we sleep: a theoretical view of sleep function". Sleep Medicine Reviews3 (2): 119–129. doi:10.1016/S1087-0792(99)90019-9. </ref> <ref>KRUEGER, JAMES M.; OBÄL, FERENC (1 June 1993). "A neuronal group theory of sleep function". Journal of Sleep Research2 (2): 63–69. doi:10.1111/j.1365-2869.1993.tb00064.x. </ref> <ref>Friborg, O., Bjorvatn, B., Amponsah, B., Pallesen, S. (2012). Associations between seasonal variations in day length (photoperiod), sleep timing, sleep quality and mood: a comparison between Ghana (5°) and Norway (69°). Journal of Sleep Research, 21(2), 176-184.) </ref>[verse 36-38 and 44-49]

==== Sleep about ''atisthula'' and ''atikrisha'' ====

==== Sleep about [[atisthula]] and [[atikrisha]] ====

Recent evidence suggests that a good sleep plays an important role in the regulation of neuroendocrine, hormonal and metabolic function in the body. Since last few decades, the timing and quality of sleep is gradually hampered due to the affliction of modernization in many ways. At present, the adult and children progressively reduce bedtimes and increases times for other activities, which affect the metabolic functions in many ways. The ''atisthula'' and ''atikrisha'' are also the outcome of excessive sleep and lack of sleep and vice-versa. Evidence shows that sleep loss for prolong period may provoke the risk of weight gain and morbid obesity. Further, sleep reduction in young adults affects metabolic and endocrine functions in various ways such as- insulin resistance, hyperglycemia, elevated sympathovagal activity, an elevated level of serum glucocorticoid hormone, increased levels of ghrelin, and decreased the level of leptin. Due to improper and lack of good quality of sleep in adolescents may be important factors to consider in the prevention of childhood obesity.<ref>Neeraj K. Gupta,William H. Mueller,Wenyaw Chan, Janet C. Meininger (2002).: Is obesity associated with poor sleep quality in adolescents?. Am. J. Hum. Biol.; 14:762–768, 2002.  </ref> Probably this is the reason that sleep is mentioned in ''ashṭoninditiya'' chapter by Charak about ''atisthula'' and ''atikrisha'' like other dietary and lifestyle intervention.(verse 51)

Recent evidence suggests that a good sleep plays an important role in the regulation of neuroendocrine, hormonal and metabolic function in the body. Since last few decades, the timing and quality of sleep is gradually hampered due to the affliction of modernization in many ways. At present, the adult and children progressively reduce bedtimes and increases times for other activities, which affect the metabolic functions in many ways. The [[atisthula]] and [[atikrisha]] are also the outcome of excessive sleep and lack of sleep and vice-versa. Evidence shows that sleep loss for prolong period may provoke the risk of weight gain and morbid obesity. Further, sleep reduction in young adults affects metabolic and endocrine functions in various ways such as- insulin resistance, hyperglycemia, elevated sympathovagal activity, an elevated level of serum glucocorticoid hormone, increased levels of ghrelin, and decreased the level of leptin. Due to improper and lack of good quality of sleep in adolescents may be important factors to consider in the prevention of childhood obesity.<ref>Neeraj K. Gupta,William H. Mueller,Wenyaw Chan, Janet C. Meininger (2002).: Is obesity associated with poor sleep quality in adolescents?. Am. J. Hum. Biol.; 14:762–768, 2002.  </ref> Probably this is the reason that sleep is mentioned in the present chapter by Charak about [[atisthula]] and [[atikrisha]] like other dietary and lifestyle intervention.(verse 51)

==== Insomnia or sleeplessness  ====

==== Insomnia or sleeplessness  ====

Improper sleep has a harmful impact on carbohydrate metabolism and endocrine function. Besides, it also reduces the metabolic activity in the brain with prolonging lack of sleep. The effects are similar to those seen in normal aging and, therefore, sleep debt may increase the severity of age-related chronic disorders. <ref name=ref85>Van Dongen, HP; Maislin, G; Mullington, JM; Dinges, DF (2003-03-15). "The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation.". Sleep26 (2): 117–26.</ref> Lack of sleep for prolonged period has been shown to affect cognitive functions of people involved in versatile activities along with interfering in mood and emotion. This is one of reason to increased tendency to fear, depression, and rage in the people having a deficiency in sleep. The mechanism and effects of sleep deficit are still evolving in the pathophysiology of sleep deficit.<ref>Karine Spiegel, Rachel Leproult, BS, Eve Van Cauter.: Impact of sleep debt on metabolic and endocrine function. The lancet, Volume 354, Issue 9188, 23 October 1999, Pages 1435–1439. </ref>  <ref name=ref85/> <ref>Chee, MW; Chuah, LY (August 2008). "Functional neuroimaging insights into how sleep and sleep deprivation affect memory and cognition.". Current Opinion in Neurology21 (4): 417–23.  </ref>

Improper sleep has a harmful impact on carbohydrate metabolism and endocrine function. Besides, it also reduces the metabolic activity in the brain with prolonging lack of sleep. The effects are similar to those seen in normal aging and, therefore, sleep debt may increase the severity of age-related chronic disorders. <ref name=ref85>Van Dongen, HP; Maislin, G; Mullington, JM; Dinges, DF (2003-03-15). "The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation.". Sleep26 (2): 117–26.</ref> Lack of sleep for prolonged period has been shown to affect cognitive functions of people involved in versatile activities along with interfering in mood and emotion. This is one of reason to increased tendency to fear, depression, and rage in the people having a deficiency in sleep. The mechanism and effects of sleep deficit are still evolving in the pathophysiology of sleep deficit.<ref>Karine Spiegel, Rachel Leproult, BS, Eve Van Cauter.: Impact of sleep debt on metabolic and endocrine function. The lancet, Volume 354, Issue 9188, 23 October 1999, Pages 1435–1439. </ref>  <ref name=ref85/> <ref>Chee, MW; Chuah, LY (August 2008). "Functional neuroimaging insights into how sleep and sleep deprivation affect memory and cognition.". Current Opinion in Neurology21 (4): 417–23.  </ref>

The concept of ''Nidra'' in  [[Ayurveda]] is quite comparable to the sleep of biomedical sciences. The ''nidra'' is so important for the maintenance of health and sustaining the life. This is true in the light of contemporary scientific knowledge too. According to  [[Ayurveda]], ''kapha'' and ''tamas'' are responsible for ''nidra'' even as modern studies attribute the occurrence of sleep to many factors including stimulation of certain areas of the brain. [[Ayurveda]] classifies the ''nidra'' based on the mode of origin while modern classification of sleep based on physiological variations seen in association with the different types of sleep. Some factors like food, activities, external stimuli, etc. affect ''nidra'' or sleep. Any variation in the normal sleep pattern is not at all desirable, and they may cause serious health problems that demand proper medical attention.(verse 52-54)

The concept of [[nidra]] in  [[Ayurveda]] is quite comparable to the sleep of biomedical sciences. The [[nidra]] is so important for the maintenance of health and sustaining the life. This is true in the light of contemporary scientific knowledge too. According to  [[Ayurveda]], [[kapha]] and [[tamas]] are responsible for [[nidra]] even as modern studies attribute the occurrence of sleep to many factors including stimulation of certain areas of the brain. [[Ayurveda]] classifies the [[nidra]] based on the mode of origin while modern classification of sleep based on physiological variations seen in association with the different types of sleep. Some factors like food, activities, external stimuli, etc. affect [[nidra]] or sleep. Any variation in the normal sleep pattern is not at all desirable, and they may cause serious health problems that demand proper medical attention.[verse 52-54]

=== Conclusion ===

=== Conclusion ===