This study examined the effects of hypomorphic p75 neurotrophin receptor (p75NTR) expression and high levels of nerve growth factor (NGF) on trkA phosphorylation and downstream activation of p44/42 mitogen-activated protein kinase (MAPK). Post-ganglionic sympathetic neurons from postnatal day 1 p75NTR exon III null mutant (p75(-/-)) and 129/SvJ mice were cultured in the presence of 50 ng/mL NGF and analysed by Western blotting. Levels of phosphorylated trkA are increased in p75(-/-) neurons compared with 129/SvJ neurons, and these higher levels are maintained with continuous exposure to NGF. MAPK is also phosphorylated to a greater extent in p75(-/-) neurons than in 129/SvJ neurons, both within 10 min of exposure to NGF, and with continuous NGF treatment for 5 days. These data provide new insight into the mechanism underlying enhanced neurite outgrowth in p75(-/-) neurons, demonstrating that trkA and MAPK signalling in sympathetic neurons are increased when p75NTR function is disrupted.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1111/j.0953-816X.2004.03381.x | DOI Listing |
Neurol Int
December 2024
Department of Human Studies, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
The purpose of this review is to compile and discuss available evidence in humans on the efficacy of YHM supplementation on performance in different exercise modalities. Yohimbine (YHM) is a naturally occurring alkaloid that induces increases in sympathetic nervous system (SNS) activation effectively initiating "fight or flight" responses. In supplement form, YHM is commonly sold as an isolated product or combined into multi-ingredient exercise supplements and is widely consumed in fitness settings despite the lack of empirical support until recently.
View Article and Find Full Text PDFBiomed Pharmacother
December 2024
Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND 58102, United States. Electronic address:
Neurogenic hypertension (NH) is characterized by heightened sympathetic activity mediated by angiotensin II in specific brain areas including the paraventricular nucleus and circumventricular organs. While strategies targeting sympathetic activity have shown effectiveness in managing NH, their invasive nature hinders their widespread clinical adoption. Conversely, nose-to-brain drug delivery is emerging as a promising approach to access the brain with reduced invasiveness.
View Article and Find Full Text PDFJACC Clin Electrophysiol
November 2024
Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia, USA; Pauley Heart Center, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA. Electronic address:
Background: The mechanisms underlying postoperative atrial fibrillation (POAF) remain unclear.
Objectives: The aim of this study was to test the hypothesis that targeted chemical ganglionated plexi (GP) modulation of all major left atrial-pulmonary vein GP using novel nanoformulated calcium chloride (nCaCl) can reverse postoperative neuroelectrical remodeling by suppressing vagosympathetic nerve activity and the localized inflammatory process, both critical substrates of POAF.
Methods: In a novel canine model of POAF with serial thoracopericardiotomies, sympathetic nerve activity (SNA), vagal nerve activity (VNA) and GP nerve activity (GPNA) were recorded; spontaneous and in vivo AF vulnerability were assessed; and atrial and circulating inflammatory markers and norepinephrine (NE) were measured to determine the neuroelectrical remodeling that promotes POAF and its subsequent modulation with nCaCl GP treatment (n = 6) vs saline sham controls (n = 6).
J Integr Med
December 2024
College of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei 230012, Anhui Province, China; Institute of Health and Medicine, Hefei Comprehensive National Scicence Center, Hefei 230051, Anhui Province, China. Electronic address:
Objective: Acupuncture therapies are known for their effectiveness in treating a variety of gastric diseases, although the mechanisms underlying these effects are not fully understood. This study tested the effectiveness of electroacupuncture (EA) at acupoints Zhongwan (RN12) and Weishu (BL21) for managing gastric motility disorder (GMD) and investigated the underlying mechanisms involved.
Methods: A GMD model was used to evaluate the impact of EA on various aspects of gastric function including the amplitude of gastric motility, electrogastrogram, food intake, and the rate of gastric emptying.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!