Purpose: The present study tested the hypothesis that connexin-36 (Cx36) and gap junctions between photoreceptor cells contribute to the circadian rhythm of the photopic electroretinogram (ERG) b-wave amplitude.
Methods: Cone-specific disruption of Cx36 was obtained in mice with a floxed Gjd2 gene and human red/green pigment promoter (HRGP)-driven Cre recombinase. Standard ERG, spectral-domain optical coherence tomography (SD-OCT) and histochemical methods were used.
Results: HRGPcreGjd2fl/fl mice had a selective reduction in Cx36 protein in the outer plexiform layer; no reduction in Cx36 was observed in the inner plexiform layer. Cx36 disruption had no effect on the number of cones, the thickness of the photoreceptor layer, or the scotopic ERG responses. However, there was a reduction of the photopic ERG circadian rhythm, with b-wave amplitudes in the day and the night locked in the daytime, light-adapted state. In HRGPcreGjd2+/+and Gjd2fl/fl controls, the circadian rhythm of light-adapted ERG persisted, similar to that in wild type mice.
Conclusions: Cx36 regulation contributes to the circadian rhythm of light-adapted ERG; in the absence of photoreceptor gap junctions, mice appear to be in a fully light-adapted state regardless of the time of day. The higher amplitudes and reduced circadian regulation of the b-wave of HRGPcreGjd2fl/fl mice may be due to increased synaptic strength at the cone to ON bipolar cell synapse due to electrotonic isolation of the terminals lacking gap junctions.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7415284 | PMC |
| http://dx.doi.org/10.1167/iovs.61.6.24 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Hypo-osmotic stress shifts transcription of circadian genes.
Biophys J
January 2025
Dept. of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Rd. Worcester, MA 01609. Electronic address:
Cells respond to hypo-osmotic stress by initial swelling followed by intracellular increases in the number of osmolytes and initiation of gene transcription that allow cells to adapt to the stress. Here, we have studied the genes that change expression under mild hypo-osmotic stress for 12 and 24 hours in rat cultured smooth muscle cells (WKO-3M22). We find shifts in the transcription of many genes, several of which are associated with circadian rhythm, such as per1, nr1d1, per2, dbp, and Ciart.
View Article and Find Full Text PDFMaternal shift work during pregnancy and cardiovascular health impacts on mother and offspring.
J Mol Cell Cardiol
December 2024
Department of Physiology and Pathophysiology, Rady College of Medicine, Max Rady Faculty of Health Sciences, University of Manitoba, The Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, Manitoba, Canada. Electronic address:
Cardiovascular disease (CVD) is the leading cause of death for women worldwide. One of the risk factors for CVD in women is complications during pregnancy. Pregnancy complications include a wide arena of pathologies, including hypertension, preeclampsia, gestational diabetes, preterm delivery and miscarriage.
View Article and Find Full Text PDFComplex gene-dependent and-independent mechanisms control daily rhythms of hematopoietic cells.
Biomed Pharmacother
January 2025
Department of Experimental Medicine, Sapienza University of Rome, Rome 00161, Italy. Electronic address:
The abundance and behaviour of all hematopoietic components display daily oscillations, supporting the involvement of circadian clock mechanisms. The daily variations of immune cell functions, such as trafficking between blood and tissues, differentiation, proliferation, and effector capabilities are regulated by complex intrinsic (cell-based) and extrinsic (neuro-hormonal, organism-based) mechanisms. While the role of the transcriptional/translational molecular machinery, driven by a set of well-conserved genes (Clock genes), in nucleated immune cells is increasingly recognized and understood, the presence of non-transcriptional mechanisms remains almost entirely unexplored.
View Article and Find Full Text PDFDim blue light at night worsens high-fat diet-induced kidney damage via increasing corticosterone levels and modulating the expression of circadian clock genes.
Ecotoxicol Environ Saf
January 2025
National Key Laboratory of Veterinary Public Health Security, College of Veterinary Medicine, China Agricultural University, Haidian, Beijing 100193, China. Electronic address:
Obesity is a contributing factor that increases the likelihood of developing chronic kidney disease. In recent years, studies have found that light pollution worldwide promoted obesity, which was known to be a consequence of circadian rhythm disruption. Nevertheless, the impact of light pollution on kidney disease associated with obesity remains mostly unknown, and potential processes have been minimally investigated.
View Article and Find Full Text PDFTranscriptomic DN3 clock neuron subtypes regulate sleep.
Sci Adv
January 2025
Howard Hughes Medical Institute, Brandeis University, Waltham, MA 02453, USA.
Circadian neurons within animal brains orchestrate myriad physiological processes and behaviors, but the contribution of these neurons to the regulation of sleep is not well understood. To address this deficiency, we leveraged single-cell RNA sequencing to generate a comprehensive census of transcriptomic cell types of clock neurons. We focused principally on the enigmatic DN3s, which constitute most fly brain clock neurons and were previously almost completely uncharacterized.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!