Dysfunctions of brainstem regions responsible for central CO2 chemoreception have been proposed as an underlying pathophysiology of Sudden Infant Death Syndrome (SIDS). We recorded respiratory motor output and intracellular pH (pHi) from chemosensitive neurons in an in vitro tadpole brainstem during normocapnia and hypercapnia. Flash photolysis of the H+ donor nitrobenzaldehyde was used to induce focal decreases in pHi alone. Hypercapnia and flash photolysis significantly decreased pHi from normocapnia. In addition, chemoreceptors did not regulate pHi during hypercapnia, but demonstrated significant pHi recovery when only pHi was reduced by flash photolysis. Respiration was stimulated by decreases in pHi (hypercapnia and flash photolysis) by decreases in burst cycle. These data represent our ability to load the brainstem with nitrobenzaldehyde without disrupting the respiration, to quantify changes in chemoreceptor pHi recovery, and to provide insights regarding mechanisms of human health conditions with racial/ethnic health disparities such as SIDS and Apnea of Prematurity (AOP).
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4372124 | PMC |
http://dx.doi.org/10.1353/hpu.2011.0168 | DOI Listing |
J Phys Chem B
January 2025
Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznanskiego 8, 61-614 Poznan, Poland.
In the course of 266 nm nanosecond laser flash photolysis of carbazole (CBL) in acetonitrile, we discovered a new transient absorption band centered at 360 nm that has been heretofore unreported despite numerous reports on similar topics. To put some limits on possible transients responsible for this absorption band and thus to solve the mechanism of CBL photolysis, we employed the strategy of selectively blocking the CBL active sites by various modifications in the structure. This strategy was supported by the use of the solvent effect and triplet quenching by molecular oxygen.
View Article and Find Full Text PDFChemphyschem
January 2025
Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt am Main, Max-von-Laue-Straße 7, 60438, Frankfurt, Germany.
The light-sensing activity of phytochromes is based on the reversible light-induced switching between two isomerization states of the bilin chromophore. These photo-transformations may not necessarily be only unidirectional, but could potentially branch back to the initial ground state in a thermally driven process termed shunt. Such shunts have been rarely reported, and thus our understanding of this process and its governing factors are limited.
View Article and Find Full Text PDFMacromol Rapid Commun
December 2024
Paris-Est Creteil University, CNRS, ICMPE, UMR 7182, Thiais, 94320, France.
The design of a new visible-light methacrylated-based kraft lignin photosensitizer (MAcL) of iodonium salt (Iod) for the free-radical polymerization (FRP) of polyethylene glycol dimethacrylate (PEGDMA) under LEDs@405, 455, 470, 505, and 530 nm is reported. As demonstrated by laser flash photolysis (LFP) and electron paramagnetic resonance spin-trapping (EPR ST) experiments, the combination of MAcL with an electron acceptor (Iod) and trimethylolpropane tris(3-mercaptopropionate) (TT) used as a crosslinker, leads to the formation of highly efficient initiating radicals, i.e.
View Article and Find Full Text PDFPhotochem Photobiol Sci
December 2024
Instituto Universitario Mixto de Tecnología Química (UPV-CSIC), Universitat Politècnica de València, Consejo Superior de Investigaciones Científicas, Avda de los Naranjos s/n, 46022, Valencia, Spain.
Photophysical and photochemical studies were carried out to examine the photoreactivity of etheno adducts, 1,N-ethenoadenine (εdA) and 1,N-ethenoguanine (εdG), in the presence of two well-known photosensitizers acting by Type I and/or Type II mechanisms such as 4-carboxybenzophenone (CBP) and rose Bengal (RB), respectively. Steady-state photolysis experiments combined with HPLC and mass spectroscopy measurements lead to photoproducts that correspond to the repaired nucleosides. To determine the mechanism of this photooxidation processes, phosphorescence spectroscopy, direct detection of singlet oxygen luminescence and laser flash photolysis were carried out.
View Article and Find Full Text PDFCells
November 2024
Neuroscience & Mental Health Program, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore.
The claustrum is a small but densely interconnected brain structure that is innervated by axons containing serotonin (5-HT), a neuromodulator that has been implicated in control of sleep and in the actions of psychedelic drugs. However, little is known about how 5-HT influences the claustrum. We have combined whole-cell patch-clamp measurements of ionic currents, flash photolysis, and receptor pharmacology to characterize the 5-HT responses of individual claustral projection neurons (PNs) in mouse brain slices.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!