Reticular activating system - Wikipedia - The Diigo Meta page

• 18 Jul 14
  

  jmcohen87
  • The reticular activating system (RAS), or extrathalamic control modulatory system, is a set of connected nuclei in the brains of vertebrates that is responsible for regulating arousal and sleep-wake transitions. As its name implies, its most influential component is the reticular formation.
  • Direct electrical stimulation of the reticular activating system produces pain responses in cats and educes verbal reports of pain in humans.
  • Intractable schizophrenic patients have a significant increase (> 60%) in the number of PPN neurons^[10] and dysfunction of NO signaling involved in modulating cholinergic output of the RAS.^[11]
  • There is a significant down-regulation of PPN output and a loss of orexin peptides, promoting the excessive daytime sleepiness that is characteristic of this disorder.^[12]
  • • Depression, autism, Alzheimer's disease, attention deficit disorder
     
     

     

    The exact role of the RAS in each of these disorders has not yet been identified. However, it is expected that in any neurological or psychiatric disease that manifests disturbances in arousal and sleep-wake cycle regulation, there will be a corresponding dysregulation of some elements of the RAS.^[10]

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• 02 Jul 13
  

  ralfrolf
  • ain function
  • modify and potentiate thalamic and cortical function
  • akefulness
  • st bu
  • ge fa
  • burst mode the EEG is synchronized
  • arge voltage slow wave
  • on-REM sleep.
  • tonic mode it is desynchronized.
  • hange from a state of deep sleep to wakefulness i
  • RAS.^[

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• 10 Jun 13
  

  marcella marcelli
  • The reticular activating system (RAS), or extrathalamic control modulatory system, is a set of connected nuclei in the brains of vertebrates that is responsible for regulating arousal and sleep-wake transitions.
  • most influential component is the reticular formation
• 01 Mar 13
  

  jonnycmw
  • nd, a series of “ascending relays from the reticular formation of the lower brain stem through the mesencephalic tegmentum, subthalamus and hypothalamus to the internal capsule.
  • ascending reticular activating system (ARAS
  • ow voltage fast burst brain waves (EEG desynchronization) are associated with wakefulness and REM sleep (which are electrophysiologically identical)
  • n burst mode the EEG is synchronized
  • esynchronized.
  • uring sleep, neurons in the RAS will have a much lower firing rate; conversely, they will have a higher activity level during the waking state
  • excitatory influence

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• 13 Dec 11
  

  Sue Peters

  Additionally, it appears that hypocretin/orexin neurons of the hypothalamus activate both the adrenergic and cholinergic components of the RAS and may coordinate activity of the entire system.[12]

  • Pathologies

     

    Given the importance of the RAS for modulating cortical changes, disorders of the RAS should result in alterations of sleep-wake cycles and disturbances in arousal.^[10] Some pathologies of the RAS may be attributed to age, as there appears to be a general decline in reactivity of the RAS with advancing years.^[20] Changes in electrical coupling have been suggested to account for some changes in RAS activity: If coupling were down-regulated, there would be a corresponding decrease in higher-frequency synchronization (gamma band). Conversely, up-regulated electrical coupling would increase synchronization of fast rhythms that could lead to increased arousal and REM sleep drive.^[9] Specifically, disruption of the RAS has been implicated in the following disorders:

     
     
    • Schizophrenia
     
     

     

    Intractable schizophrenic patients have a significant increase (> 60%) in the number of PPN neurons^[10] and dysfunction of NO signaling involved in modulating cholinergic output of the RAS.^[11]

     

     
     
    • Post-traumatic stress disorder, Parkinson’s Disease, REM behavior disorder
     
     

     

    Patients with these syndromes exhibit a significant (>50%) decrease in the number of locus coeruleus (LC) neurons, resulting is increased disinhibition of the PPN.^[10]

     

     
     
    • Narcolepsy
     
     

     

    There is a significant down-regulation of PPN output and a loss of orexin peptides, promoting the excessive daytime sleepiness that is characteristic of this disorder.^[12]

     

     
     
    • Progressive supranuclear palsy (PSP)
     
     

     

    Dysfunction of NO signaling has been implicated in the development of PSP.^[11]

     

     
     
    • Depression, autism, Alzheimer’s disease, attention deficit disorder
     
     

     

    The exact role of the RAS in each of these disorders has not yet been identified. However, it is expected that in any neurological or psychiatric disease that manifests disturbances in arousal and sleep-wake cycle regulation, there will be a corresponding dysregulation of some elements of the RAS.^[10]
• 12 Dec 11
  

  eemmann
  • ascending somatic and auditory paths
  • from the reticular formation of the lower brain stem through the mesencephalic tegmentum, subthalamus and hypothalamus to the internal capsule
  • Cats with mesancephalic interruptions to the RAS entered into a deep sleep and displayed corresponding brain waves
  • rostral intralaminar and thalamic nuclei
  • individuals with bilateral lesions of thalamic intralaminar nuclei are lethargic or somnolent
  • Mesencephalic Nucleus
  • Intralaminar nucleus
  • Hypothalamus
  • egmentum
  • cholinergic and adrenergic components
  • synergic as well as competitive actions
  • pedunculopontine nucleus (PPN)
  • laterodorsal tegmental nucleus (LDT),
  • active during waking and REM sleep
  • substantia nigra
  • descend throughout the reticular formation
  • thalamus
  • basal forebrain
  • cerebellum
  • . In addition to noradrenergic projections that parallel the aforementioned cholinergic paths
  • locus coeruleus
  • Unlike cholinergic neurons, the adrenergic neurons are active during waking and slow wave sleep but cease firing during REM sleep
  • This sustained activity may account for some of the time latency during changes of consciousness
  • NO diffusion from dendrites regulates regional blood flow in the thalamus,
  • Attention
  • in the midbrain reticular formation (MRF)
  • ncreased regional blood flow
  • thalamic intralaminar nuclei
  • Some pathologies of the RAS may be attributed to age, as there appears to be a general decline in reactivity of the RAS with advancing years

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• 29 Jan 09
  

  greg lindsey

  Nervous System Pharmacology

• 28 Jul 07
  

  elvisofdallas

  interaction mind wikipedia gtd nlp brain delicious

• 09 Jul 07
  

  Angela Lee

  Neuroplasticity

• 11 May 06
  

  Thomas Vander Wal

  During the 1970s in the "positive thinking" movement the reticular activating system was credited with providing people with the ability to discern items of interest from their subconscious in a world flooded with information and options for our attention

  cogsci cognition psycology mind interaction anatomy attention attraction

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