Respiratory rhythms arise from neurons situated in the ventral medulla. We are investigating their spatial and functional relationships optically by measuring changes in intracellular calcium using the fluorescent, calcium-sensitive dye Oregon Green 488 BAPTA-1 AM while simultaneously recording the regular firing of motoneurons in the phrenic nerve in isolated brainstem/spinal cord preparations of E17 to E19 mice. Responses of identified cells are associated breath by breath with inspiratory and expiratory phases of respiration and depend on CO(2) and pH levels. Optical methods including two-photon microscopy are being developed together with computational analyses. Analysis of the spatial pattern of neuronal activity associated with respiratory rhythm, including cross-correlation analysis, reveals a network distributed in the ventral medulla with intermingling of neurons that are active during separate phases of the rhythm. Our experiments, aimed at testing whether initiation of the respiratory rhythm depends on pacemaker neurons, on networks or a combination of both, suggest an important role for networks.
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http://dx.doi.org/10.1098/rstb.2009.0070 | DOI Listing |
J Neurophysiol
January 2025
Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington.
The persistent Na current (I) is thought to play important roles in many brain regions including the generation of inspiration in the ventral respiratory column (VRC) of mammals. The characterization of the slow inactivation of I requires long-lasting voltage steps (>1 s), which will increase intracellular Na and activate the Na/K-ATPase pump current (I). Thus, I may contribute to the previously measured slow inactivation of I and the generation of the inspiratory bursting rhythm.
View Article and Find Full Text PDFAust Crit Care
January 2025
Intensive Care Medicine Department, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile; Department of Intensive Care, Erasmus MC University Medical Centre, Rotterdam, the Netherlands.
Background: Sleep and circadian rhythms are markedly altered in intensive care unit (ICU) patients. Numerous factors related to the patient and the ICU environment affect the ability to initiate and maintain sleep. Therefore, nonpharmacological interventions could play an essential role in improving sleep and circadian rhythm.
View Article and Find Full Text PDFCureus
January 2025
Oncologic Sciences, University of South Florida Morsani College of Medicine, Tampa, USA.
Obesity is a complex and non-communicable disease with a pandemic entity. Currently, multiple causes can lead to obesity, and it is not always easy to create a direct relationship between physical inactivity, poor quality of nutrients consumed, and calculation of excess calories. Among the associated comorbidities, obesity creates a dysfunctional environment of respiratory rhythms at the central and peripheral levels, with functional, morphological, and phenotypic alteration of the diaphragm muscle.
View Article and Find Full Text PDFERJ Open Res
January 2025
Department of Otolaryngology-Head and Neck Surgery, University of California, Los Angeles, Los Angeles, CA, USA.
Background: Chronic rhinosinusitis (CRS) and olfactory dysfunction (OD) are prevalent disease complications in people with cystic fibrosis. These understudied comorbidities significantly impact quality of life. The impact of highly effective modulator therapy (HEMT) in young children with cystic fibrosis (YCwCF) on these disease complications is unknown.
View Article and Find Full Text PDFSci Rep
January 2025
Departments of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, USA.
Approaches to mitigate the severity of infections and of immune responses are still needed for the treatment of cystic fibrosis (CF) even with the success of highly effective modulator therapies. Previous studies identified reduced levels of melatonin in a CF mouse model related to circadian rhythm dysregulation. Melatonin is known to have immunomodulatory properties and it was hypothesized that treatment with melatonin would improve responses to bacterial infection in CF mice.
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