John E Remmers , Cory Torgerson , Michael Harris , Steven F Perry , Konstantinon Vasilakos , Richard J.A Wilson
{"title":"Evolution of central respiratory chemoreception: a new twist on an old story","authors":"John E Remmers , Cory Torgerson , Michael Harris , Steven F Perry , Konstantinon Vasilakos , Richard J.A Wilson","doi":"10.1016/S0034-5687(01)00291-2","DOIUrl":"10.1016/S0034-5687(01)00291-2","url":null,"abstract":"<div><p>Evolution of central respiratory chemosensitivity has been linked traditionally to the need for carbon dioxide regulation that accompanied the evolution of air breathing in terresterial animals. We examined the validity of this linkage by investigating the possibility of central chemoreception in air breathing fish that diverged from the amphibian lineage long before the appearance of terrestriality. We showed that the isolated brainstem preparation of the long nose gar (<em>Lepisosteus osseus</em>) produces a putative motor pattern for lung ventilation, which is responsive to CO<sub>2</sub>. These findings, together with more inferential evidence, suggest an association between air breathing and central chemosensitivity in aquatic animals that spans the major branches in vertebrate phylogeny. Furthermore, developmental observations in tadpoles suggest that the neural substrates for central chemoreception exist in proximity to that for rhythm generation. We postulate that a primitive ancestral CPG, sensitive to CO<sub>2</sub> is conserved and is evidenced in the intrinsic coupling of respiratory CPG and central chemoreception in modern tetrapods.</p></div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":"129 1","pages":"Pages 211-217"},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00291-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82484907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christina M Spengler , David Gozal , Steven A Shea
{"title":"Chemoreceptive mechanisms elucidated by studies of congenital central hypoventilation syndrome","authors":"Christina M Spengler , David Gozal , Steven A Shea","doi":"10.1016/S0034-5687(01)00294-8","DOIUrl":"10.1016/S0034-5687(01)00294-8","url":null,"abstract":"<div><p>Humans born with the condition of central hypoventilation during non-rapid eye movement sleep, termed congenital central hypoventilation syndrome (CCHS), invariably have absent or greatly diminished central hypercapnic ventilatory chemosensitivity. Genetic and pathological studies of CCHS may enable identification of the genes or areas of the central nervous system involved in the syndrome and thus implicated in central hypercapnic ventilatory chemosensitivity. Functional studies of CCHS permit a more quantitative assessment of the importance of ventilatory chemosensitivity in the regulation of breathing during wakefulness and sleep. The experimental evidence suggests that central hypercapnic ventilatory chemosensitivity is crucial in regulating alveolar ventilation during non-rapid eye movement sleep but not during rapid eye movement sleep or during many of the behaviors occurring during wakefulness. Presumably, other neural drives to breathe supervene to enable adequate ventilation. However, although physiological studies in CCHS subjects have been greatly instructive, their accurate interpretation will have to await future determination of the potential genetic and/or neuroanatomic basis of the syndrome.</p></div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":"129 1","pages":"Pages 247-255"},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00294-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76988012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M.J Morrell , P Heywood , S.H Moosavi , J Stevens , A Guz
{"title":"Central chemosensitivity and breathing asleep in unilateral medullary lesion patients: comparisons to animal data","authors":"M.J Morrell , P Heywood , S.H Moosavi , J Stevens , A Guz","doi":"10.1016/S0034-5687(01)00296-1","DOIUrl":"10.1016/S0034-5687(01)00296-1","url":null,"abstract":"<div><p>The rostro-ventrolateral medulla (RVLM) is a site of chemosensitivity in animals; such site(s) have not been defined in humans. We studied the effect of unilateral focal lesions in the rostrolateral medulla (RLM) of man, on the ventilatory CO<sub>2</sub> sensitivity and during awake and sleep breathing. Nine patients with RLM lesions (RLM group), and six with lesions elsewhere (non-RLM group) were studied. The ventilatory CO<sub>2</sub> sensitivity was lower in the RLM compared with the non-RLM group (mean (S.D.), RLM, 1.4 (0.9), non-RLM 3.0 (0.6) L min<sup>−1</sup> mmHg<sup>−1</sup>). In both groups resting breathing was normal. During sleep all RLM patients had frequent arousals, four had significant sleep disordered breathing (SDB), only one non-RLM patient had SDB. Our findings in humans resemble those in animals with focal RVLM lesions. This review provides evidence that in humans there is an area of chemosensitivity in the RLM. We propose that in humans, dorsal displacement of the RVLM area of chemosensitivity in animals, arises from development of the olive plus the consequences of the evolution of the cerebellum/inferior peduncle.</p></div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":"129 1","pages":"Pages 269-277"},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00296-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78254763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M.A. Haxhiu , F. Tolentino-Silva , G. Pete , P. Kc , S.O. Mack
{"title":"Monoaminergic neurons, chemosensation and arousal","authors":"M.A. Haxhiu , F. Tolentino-Silva , G. Pete , P. Kc , S.O. Mack","doi":"10.1016/S0034-5687(01)00290-0","DOIUrl":"10.1016/S0034-5687(01)00290-0","url":null,"abstract":"<div><p>In recent years, immense progress has been made in understanding central chemosensitivity at the cellular and functional levels. Combining molecular biological techniques (early gene expression as an index of cell activation) with neurotransmitter immunohistochemistry, new information has been generated related to neurochemical coding in chemosensory cells. We found that CO<sub>2</sub> exposure leads to activation of discrete cell groups along the neuraxis, including subsets of cells belonging to monoaminergic cells, noradrenaline-, serotonin-, and histamine-containing neurons. In part, they may play a modulatory role in the respiratory response to hypercapnia that could be related to their behavioral state control function. Activation of monoaminergic neurons by an increase in CO<sub>2</sub>/H<sup>+</sup> could facilitate respiratory related motor discharge, particularly activity of upper airway dilating muscles. In addition, these neurons coordinate sympathetic and parasympathetic tone to visceral organs, and participate in adjustments of blood flow with the level of motor activity. Any deficit in CO<sub>2</sub> chemosensitivity of a network composed of inter-related monoaminergic nuclei might lead to disfacilitation of motor outputs and to failure of neuroendocrine and homeostatic responses to life-threatening challenges (e.g. asphyxia) during sleep.</p></div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":"129 1","pages":"Pages 191-209"},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00290-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81005246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Central chemosensitivity, sleep, and wakefulness","authors":"Eugene E Nattie","doi":"10.1016/S0034-5687(01)00295-X","DOIUrl":"10.1016/S0034-5687(01)00295-X","url":null,"abstract":"<div><p>Neurons in many regions of the lower brain are chemosensitive in vitro. Focal acidification of these same and other regions in vivo can stimulate breathing indicating the presence of chemoreception. Why are there so many sites for central chemoreception? This review evaluates data obtained from unanesthetized rats at three central chemoreceptor sites, the retrotrapezoid nucleus (RTN), the medullary raphé, and the nucleus tractus solitarius (NTS) and extends ideas concerning two hypotheses, which were recently formulated (Nattie, E., 2000. Respir. Physiol. 122, 223–235). (1) The high overall sensitivity of the respiratory control system in the unanesthetized state to small increases in arterial CO<sub>2</sub> relies on an additive or greater effect of these multiple chemoreceptor sites. (2) Chemoreceptor sites can vary in effectiveness dependent on the state of arousal. These ideas fit into a more speculative and general hypothesis that central chemoreceptors are organized in a hierarchical manner as proposed for temperature sensing and thermoregulation (Satinoff, E., 1978. Science 201, 16–22). The presence of a number of chemosensitive sites with varying thresholds, sensitivity, and arousal dependence provides finely tuned control and stability for breathing.</p></div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":"129 1","pages":"Pages 257-268"},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00295-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90407206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Central chemosensitivity of respiration: a brief overview","authors":"David Ballantyne, Peter Scheid","doi":"10.1016/S0034-5687(01)00297-3","DOIUrl":"https://doi.org/10.1016/S0034-5687(01)00297-3","url":null,"abstract":"<div><p>In this introductory article we make use of the work reviewed in detail by a number of contributors to this Special Issue (Respir. Physiol., 2001) to provide an outline of current approaches to identifying brainstem CO<sub>2</sub>/pH-chemosensitive neurones. The section headings which we have adopted are intended to reflect particular issues rather than experimental techniques, though some of these issues arise out of the choice of preparation and the advantages and limitations which follow from such a choice. We have also considered whether, in spite of the diversity in the kinds of neurones usually considered to be chemosensitive, there are any indications for shared or uniform features. Again, this is based on the material published together in this volume. Finally, and more speculatively, we suggest that the dendritic organization of chemosensitive neurones may play an important role in chemoreception, not simply as a means of sampling the stimulus but also as a way of compartmentalizing the effects of pH in relation to other aspects of a neurone's activity.</p></div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":"129 1","pages":"Pages 5-12"},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00297-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91663194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Central chemosensitivity of respiration: a brief overview.","authors":"D. Ballantyne, P. Scheid","doi":"10.1016/S0034-5687(01)00297-3","DOIUrl":"https://doi.org/10.1016/S0034-5687(01)00297-3","url":null,"abstract":"","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":"41 1","pages":"5-12"},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81355947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"From low arterial- to low tissue-oxygenation strategy. An evolutionary theory","authors":"J.-C Massabuau","doi":"10.1016/S0034-5687(01)00305-X","DOIUrl":"10.1016/S0034-5687(01)00305-X","url":null,"abstract":"<div><p>The primitive atmosphere where aerobic life started on earth was hypoxic and hypercapnic. Remarkably, an adaptation strategy whereby O<sub>2</sub> partial pressure, P<sub>O<sub>2</sub></sub>, in the arterial blood is maintained within a low and narrow range of 1–3 kPa, largely independent of inspired P<sub>O<sub>2</sub></sub>, has also been reported in modern water-breathers. In mammalian tissues, including brain, the most frequently measured P<sub>O<sub>2</sub></sub> is in the same low range. Based on the postulate that basic cellular machinery has been established since the early stages of evolution, we propose that this similarity in oxygenation status is the consequence of an early adaptation strategy which, subsequently throughout the course of evolution, maintained cellular oxygenation in the same low and primitive range independent of environmental changes. The rational for such an evolutionary theory is discussed in terms of an equilibrium between physiological and pathological reactions associated with O<sub>2</sub> excess vs O<sub>2</sub> lack and emerging concepts about the importance of cellular O<sub>2</sub>-dependent mechanisms in the low but physiological P<sub>O<sub>2</sub></sub> range.</p></div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":"128 3","pages":"Pages 249-261"},"PeriodicalIF":0.0,"publicationDate":"2001-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00305-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77129705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ageing and the free radical theory","authors":"Andrew P Wickens","doi":"10.1016/S0034-5687(01)00313-9","DOIUrl":"https://doi.org/10.1016/S0034-5687(01)00313-9","url":null,"abstract":"<div><p>The free radical theory proposes that ageing is the cumulative result of oxidative damage to the cells and tissues of the body that arises primarily as a result of aerobic metabolism. Several lines of evidence have been used to support this hypothesis including the claims that: (1) variation in species life span is correlated with metabolic rate and protective antioxidant activity; (2) enhanced expression of antioxidative enzymes in experimental animals can produce a significant increase in longevity; (3) cellular levels of free radical damage increases with age; and (4) reduced calorie intake leads to a decline in the production of reactive oxygen species and an increase in life span. The free radical theory may also be used to explain many of the structural features that develop with ageing including the lipid peroxidation of membranes, formation of age pigments, cross-linkage of proteins, DNA damage and decline of mitochondrial function. Despite this, many uncertainties concerning the role of oxidative damage in ageing remain and alternative explanations cannot be ruled out. Free radicals only occur in trace quantities in biological tissues, their cellular levels and actions cannot be measured in vivo, and definitive proof that oxidised molecules are the primary cause of ageing is lacking. Moreover, ageing is also likely to be a multifactorial process and not reducible to any one single cause. Thus, despite its positive features, the evidence for the free radical theory is either correlative or inconclusive.</p></div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":"128 3","pages":"Pages 379-391"},"PeriodicalIF":0.0,"publicationDate":"2001-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00313-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91743755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tissue oxygen sensor function of NADPH oxidase isoforms, an unusual cytochrome aa3 and reactive oxygen species.","authors":"T. Porwol, W. Ehleben, V. Brand, H. Acker","doi":"10.1016/S0034-5687(01)00310-3","DOIUrl":"https://doi.org/10.1016/S0034-5687(01)00310-3","url":null,"abstract":"","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":"10 1","pages":"331-48"},"PeriodicalIF":0.0,"publicationDate":"2001-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86570571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}