The subfornical organ (SFO) is a sensory circumventricular organ of the central nervous system and plays a key role in regulation of a number of homeostatic processes because of its ability to detect and respond to circulating signals and communication to homeostatic control centres. A previous study reported a change in expression of 687 transcripts in rat SFO following a 48h fast; of particular interest was the observed downregulation of the transcript encoding the Nav1.3 voltage-gated Na channel. Therefore, we carried out a study to examine the effects of a 48h fast on electrical properties of SFO neurons. First, we carried out an immunohistochemical analysis of rat SFO to confirm expression of Nav1.3 protein. Next, we carried out qPCR analysis of mRNA from SFO of sated rats and 48h fasted rats and confirm that a 48hr fast caused a downregulation of Nav1.3. Using patch clamp analysis of SFO neurons acutely isolated from rats following a 48h fast, a statistically significant decrease in peak Na current density, as well as shifts in voltage dependence of activation and inactivation, and a slowing to time dependent recovery from inactivation were observed. These changes were accompanied by a depolarization of the threshold to fire action potentials and a decrease in frequency of spontaneous action potentials. Together, these data show that the electrical properties of SFO neurons are altered by a 48hr fast, indicating SFO is a dynamic sensor of circulating signals.
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http://dx.doi.org/10.1016/j.bbrc.2024.151055 | DOI Listing |
Biochem Biophys Res Commun
December 2024
University of Manitoba, Department of Biological Sciences, Winnipeg, MB, Canada, R3X0B5. Electronic address:
The subfornical organ (SFO) is a sensory circumventricular organ of the central nervous system and plays a key role in regulation of a number of homeostatic processes because of its ability to detect and respond to circulating signals and communication to homeostatic control centres. A previous study reported a change in expression of 687 transcripts in rat SFO following a 48h fast; of particular interest was the observed downregulation of the transcript encoding the Nav1.3 voltage-gated Na channel.
View Article and Find Full Text PDFLife Sci
December 2024
Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, RJ, Brazil. Electronic address:
Aims: Investigate the impact of hypothyroidism on mitochondrial dynamics and mitophagy in the heart under fed and fasting conditions.
Methods: Hypothyroidism was induced in male Wistar rats with methimazole (0.03 %) for 21 days.
Reprod Biomed Online
December 2024
California Fertility Partners/Pinnacle Fertility, Los Angeles, CA 90025, USA.
Research Question: Can GV-oocytes serve as an effective model to test the efficacy of ultra-fast vitrification (UFV)/ rapid elution (RE) treatments to support reliable, high survival rates and sustained functionality?
Design: Prospective pilot cohort studies were performed to investigate the feasibility of non-equilibration, UFV to sustain cellular integrity and development in contrast to control vitrification (CV: 10-15min ES/ 1min VS). In Phase 1, we applied a 2 × 2 factorial design (n=25-30 eggs/group) to evaluate post-warming dilution treatments: conventional multi-step (CD) versus rapid elution (RE; one-step), including an apriori fresh egg control group. Phase 1/2 focused on survival and maturation assessments, including meiotic spindle formation (Phase 2).
Heliyon
September 2024
Department of Pathophysiology, Centre for Research on Nutrition, Metabolism and Diabetes, Third Faculty of Medicine, Charles University, Prague, Czech Republic.
Fasting induces significant shifts in substrate utilization with signs of acute insulin resistance (IR), while obesity is associated with chronic IR. Nonetheless, both states substantially influence adipose tissue (AT) function. Therefore, in this interventional study (NCT04260542), we investigated if excessive adiposity in premenopausal women alters insulin sensitivity and AT metabolic and endocrine activity in response to a 60-h fast and a subsequent 48-h refeeding period.
View Article and Find Full Text PDFiScience
September 2024
Department of Molecular, Cellular, Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, USA.
Autosomal-dominant polycystic kidney disease (ADPKD) is a common monogenic disease characterized by the formation of fluid-filled renal cysts, loss of mitochondrial function, decreased fatty acid oxidation, increased glycolysis, and likely renal failure. We previously demonstrated that inducing a state of ketosis ameliorates or reverses PKD progression in multiple animal models. In this study, we compare time-restricted feeding and 48-h periodic fasting regimens in both juvenile and adult Cy/+ rats.
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