Breaking News
August 18, 2018 - Immigrants Not a Burden on U.S. Health Care: Study
August 18, 2018 - Women who eat fast food take longer to become pregnant
August 18, 2018 - Most YouTube videos on plastic surgery are misleading marketing campaigns
August 18, 2018 - The essential guide to make your laboratory more sustainable
August 18, 2018 - Researchers describe promising strategy to remove melanoma’s most powerful defenses
August 18, 2018 - Women with polycystic ovary syndrome dissatisfied with medical care
August 18, 2018 - Research discoveries reveal insights behind neurological degeneration
August 18, 2018 - Researchers win multi-million Euro award to conduct research into liver disease
August 18, 2018 - Survey highlights variations in practice of airway management in pediatric intensive care units
August 18, 2018 - UK students win sponsorship from Promega Corporation
August 18, 2018 - Janssen Reports Positive Topline Results for ATLAS Phase III Study of a Novel, Long Acting Injectable Two-Drug Regimen for the treatment of HIV-1
August 18, 2018 - PSD as a molecular platform for understanding synapse formation and plasticity
August 18, 2018 - Improved visual communication could help patients to make informed health-care decisions
August 18, 2018 - New algorithm helps identify and manage diabetic patients at increased fracture risk
August 18, 2018 - Microscopic insect odour detecting mechanisms discovered
August 18, 2018 - Researchers develop new approach to study how tuberculosis infects people
August 18, 2018 - FDA Approves Kalydeco (ivacaftor) for Cystic Fibrosis in Children Ages 12 to
August 18, 2018 - An ion channel differentiates newborn and mature neurons in the adult brain
August 18, 2018 - Socio-economic position associated with pregnant women’s exposure to environmental hazards
August 18, 2018 - Voters to settle dispute over ambulance employee break times
August 18, 2018 - AGA urges policymakers and stakeholders to improve affordability of drugs
August 18, 2018 - Increasing dietary protein may lower risk of diabetes in people with NAFLD
August 18, 2018 - New HIV therapy suppresses viral replication and increases immune cells in drug-resistant patients
August 18, 2018 - Broad Genetic Testing for NSCLC May Not Improve Survival
August 18, 2018 - Discovery opens door for synthetic opioids with less addictive qualities
August 18, 2018 - Transgenic rice plant extracts could help stop the spread of HIV
August 18, 2018 - Hologic’s Cynosure division partners with Porter Instrument to distribute nitrous oxide and oxygen system
August 18, 2018 - Two thyroid medications recalled by FDA
August 18, 2018 - Forecast Sees Abnormal Heat Worldwide Through 2022
August 18, 2018 - Childhood absence epilepsy – Genetics Home Reference
August 18, 2018 - Fearing hard Brexit, UK drugmakers stockpile to protect lives
August 18, 2018 - Discovery may help broaden the scope of defenses against HPV
August 18, 2018 - When they start thinking green, they see green
August 18, 2018 - Scientists introduce microfluidics-based chip for manipulation and analysis of single cells
August 18, 2018 - Researchers design new way to grow nose cells for treating spinal cord injuries
August 18, 2018 - New light shed on relationship between calorie-burning fat and muscle function
August 18, 2018 - Surgery Saturday Instagram series takes you inside Stanford’s OR
August 18, 2018 - Researchers uncover surprising new role for inhibition in the cerebellum
August 18, 2018 - Children have better nutrition when they live near forests, global study shows
August 18, 2018 - OHSU professor conducts clinical trial with artificial pancreas using Xeris’ liquid glucagon
August 18, 2018 - HSS takes young patients with physical challenges on a surfing trip
August 18, 2018 - Study shows electronic health records leave doctors and patients unsatisfied
August 18, 2018 - Study uncovers mechanism that affects multiplication of dengue virus lineage
August 18, 2018 - UTHealth safety expert talks about preparing for the most destructive hurricanes
August 18, 2018 - Theravance Biopharma Reports Positive Top-Line Four-Week Data from Phase 2 Trial of TD-9855 for the Treatment of Symptomatic Neurogenic Orthostatic Hypotension
August 18, 2018 - Animations prove effective in accurately measuring pain
August 18, 2018 - Three faculty members appointed to endowed positions | News Center
August 18, 2018 - New technique detects, measures, analyzes unevenly charged biomolecules
August 18, 2018 - Brief exposures to stressors can be beneficial to cells, shows study
August 18, 2018 - UTHealth-led survey shows much work remains to increase safety of e-health records
August 18, 2018 - Researchers use super-resolution microscope to unravel secrets of deadly Nipah virus
August 18, 2018 - Scientists identify pathways that reveal insights into mechanism of lung cancer etiology
August 18, 2018 - Rush’s health care IT leaders reach White House
August 18, 2018 - FDA approves marketing of brainsway deep transcranial magnetic stimulation system for OCD
August 17, 2018 - OUHSC gets $20 million grant to advance research and patient care for Oklahomans
August 17, 2018 - Sperm morphology differs depending on qualities of male bird
August 17, 2018 - Texas A&M researchers develop clay-based platform to grow blood vessels
August 17, 2018 - FDA Approves Expanded Indication for Orkambi (lumacaftor/ivacaftor) in Children Ages 2-5 Years
August 17, 2018 - Caring for Concussions | NIH News in Health
August 17, 2018 - Team explores diabetes drug’s ability to treat RSV infection
August 17, 2018 - New imaging technique can spot tuberculosis infection in an hour | News Center
August 17, 2018 - PolyU researchers design new self-fitting scaffold to induce bone regeneration
August 17, 2018 - CartiHeal and LSU Health successfully enroll first two patients in Agili-C IDE pivotal study
August 17, 2018 - Less-invasive options are slowing disease progression in glaucoma patients
August 17, 2018 - Researchers discover new promising target point for cancer and diabetes therapies
August 17, 2018 - Podcast: KHN’s ‘What the Health?’ See you in court!
August 17, 2018 - New mobile phone application enables early detection of cerebral ictus
August 17, 2018 - AJMC addresses role of community pharmacies in boosting adult vaccination rates
August 17, 2018 - UK’s leading sight loss charity invites applications from brightest minds in ophthalmic research
August 17, 2018 - Alternative devices can help when autoinjectors are unavailable
August 17, 2018 - Researchers produce artificial placenta model that closely resembles natural organ
August 17, 2018 - Study offers possibility of squelching a focal epilepsy seizure before symptoms appear
August 17, 2018 - FDA Alert: Temporary Total Artificial Heart Companion 2 Driver System by SynCardia Systems: Letter to Health Care Providers
August 17, 2018 - New statewide program in North Dakota aims to stem opioid misuse
August 17, 2018 - Researchers discover why sepsis from a staph infection causes organ failure
August 17, 2018 - Stony Brook University’s new medical students start a transformative journey
August 17, 2018 - Revealed: The molecular mechanism underlying hypertrophic cardiomyopathy | News Center
August 17, 2018 - New modeling studies highlight urgent need for effective drug policy reforms to prevent HIV
August 17, 2018 - Research explores relationship between personal history of infectious fever and cancer risk
August 17, 2018 - Study finds rise in cases of progressive massive fibrosis among U.S. coal miners
Inhaled carbon dioxide triggers group of neurons responsible for arousal

Inhaled carbon dioxide triggers group of neurons responsible for arousal

image_pdfDownload PDFimage_print

Breathing too much carbon dioxide can be deadly, but it can happen during sleep if a particular sleeping position causes an obstructed airway or because of a medical condition like sleep apnea. Fortunately, inhaled carbon dioxide normally triggers sensitive brain mechanisms that prevent suffocation. Researchers have long believed that inhaled carbon dioxide activates neurons responsible for breathing and the physical effect of increased deep breathing then triggers waking from sleep (arousal).

But a new study by researchers with the Iowa Neuroscience Institute at the University of Iowa challenges that idea. The UI study identifies a group of neurons responsible for arousal that are directly triggered by carbon dioxide and cause mice to wake up without any changes to breathing. The findings were published Jan. 29 in the Journal of Neuroscience.

“Carbon dioxide-induced arousal is critical to diseases like sleep apnea and sudden infant death syndrome (SIDS), and is probably important in sudden unexpected death in epilepsy (SUDEP). However, exactly how carbon dioxide triggers waking from sleep (arousal) has not been well understood,” says Gordon Buchanan, MD, PhD, senior study author and assistant professor of neurology at the UI Carver College of Medicine. “We show that neurons that should have nothing to do with breathing cause arousal from sleep when they are directly stimulated with carbon dioxide. This represents a departure from the previous thinking and may change preventive management of these diseases where disruption of carbon dioxide-induced arousal plays a role.”

Previous research by Buchanan and his colleagues showed that serotonin (5-HT) neurons are important for carbon dioxide-induced arousal, because mice without serotonin neurons do not wake up when they inhale carbon dioxide. However, there are two major groups of serotonin neurons: one in the midbrain involved in sleep-wake regulation and one in the medulla involved in the regulation of breathing. The new study separates the effects of these two groups of serotonin neurons.

The team showed that applying carbon dioxide-enriched artificial cerebrospinal fluid directly to the serotonin neurons in mice in an area of the midbrain known as the dorsal raphe nucleus (DRN) causes arousal from sleep. This arousal was lost if these midbrain serotonin neurons were blocked either by genetic manipulation or with chemical inhibitors. Moreover, applying the carbon dioxide-enriched artificial cerebrospinal fluid directly to the serotonin neurons in the medulla increased breathing but did not cause arousal in mice.

“We propose that serotonin neurons in the DRN can be activated directly by carbon dioxide to cause waking independently of respiratory activation,” Buchanan says. “A better understanding of the mechanisms that underlie this protective reflex of waking up when too much carbon dioxide is inhaled might improve strategies for reducing death and disability caused by sleep apnea and SIDS.”

Carbon dioxide-induced arousal plays a role in both SIDS and sleep apnea, but in the case of SIDS, the arousal mechanism is thought to be impaired, while in the sleep apnea the arousal mechanism works well, but that leads to a host of secondary health problems.

Babies that are susceptible to SIDS are not awakened by increased carbon dioxide when airway obstruction occurs. This might happen if the baby is sleeping face down, or their nose and mouth are covered by soft bedding, a plush toy, or a co-sleeping parent. In contrast, carbon-dioxide-induced arousal causes people with sleep apnea to awake frequently – in many cases hundreds of times during a night. This sleep disruption is associated with significant health problems, including poor cognitive function, excessive sleepiness, and cardiovascular and metabolic complications.

“While our findings are far from ready for clinical application, this work suggests that there should be ways to prevent apnea by maintaining normal carbon dioxide during sleep without causing arousal or to augment the arousal mechanisms in babies thought to be at higher risk for SIDS. Similar approaches might also help prevent SUDEP,” Buchanan says.

Source:

https://medicine.uiowa.edu/content/specific-neurons-trigger-waking-due-inhaled-co2

Tagged with:

About author

Related Articles