Biology subjects

Palandira, S. P.

Publications and source records attributed to Palandira, S. P..

3 recordsLinked to original sources

bioRxiv2026

Cholinergic impairment in the dorsal motor nucleus of the vagus during experimental Alzheimer's disease

Cholinergic neurons in the dorsal motor nucleus of the vagus (DMN) in the brainstem are a key source of efferent vagus nerve fibers that regulate vital functions, including heart rate and inflammation. Whether the integrity of DMN cholinergic neurons is affected during Alzheimer's disease (AD) remains unknown. Here, in female and male mice with experimental AD (5xFAD), which exhibit age-dependent memory impairment, basal forebrain cholinergic neurodegeneration, and microglial alterations, we observe a reduction in cholinergic neuron density in the DMN at 6 and 10 months of age. Furthermore, while an important physiological function of DMN cholinergic signaling, such as suppression of heart rate, is preserved in control mice upon electrical DMN stimulation, the extent of suppression diminishes with age in both female and male 5xFAD mice. In addition, while electrical DMN stimulation lowers pro-inflammatory cytokine levels in control mice subjected to endotoxemia, this anti-inflammatory effect is diminished with age in 5xFAD mice, with females showing earlier dysfunction at 6 months. These results reveal previously unrecognized age-dependent cholinergic deficits in the DMN and disrupted brain - to - periphery vagus nerve circuits in experimental AD. These findings advance our understanding of AD mechanisms and are of interest for the development of conceptually novel therapies.

physiology↗

bioRxiv2025

The cholinergic drug galantamine ameliorates acute and subacute peripheral and brain manifestations of acute respiratory distress syndrome in mice

Acute respiratory distress syndrome (ARDS) is a life-threatening form of acute lung injury (ALI), which is a common cause of respiratory failure and high mortality in critically ill patients. Long-term mortality and brain dysfunction have been documented in ARDS patients after hospital discharge. Inflammation plays a key role in ALI/ARDS pathogenesis. Neural cholinergic signaling regulates cytokine responses and inflammation. Here, we studied the effects of galantamine, an approved cholinergic drug (for Alzheimers disease) on ALI/ARDS severity and inflammation in mice, using a clinically relevant mouse model induced by intratracheal administration of hydrochloric acid and lipopolysaccharide. Mice were treated 30 mins prior to each insult with vehicle or galantamine (4 mg/kg, i.p.). Galantamine treatment significantly decreased bronchoalveolar lavage (BAL) and serum TNF, IL-1{beta}, and IL-6 levels, as well as BAL total protein and myeloperoxidase and lung histopathology in ALI/ARDS mice. In addition, galantamine improved the functional state of mice with ALI/ARDS during a 10-day monitoring and attenuated lung injury and indices of brain inflammation at 10 days. These findings support further studies utilizing this approved cholinergic drug in therapeutic strategies for ARDS and its subacute sequelae.

physiology↗

bioRxiv2023

Electrical stimulation of the dorsal motor nucleus of the vagus regulates inflammation without affecting the heart rate

BackgroundThe vagus nerve plays an important role in neuroimmune interactions and in the regulation of inflammation. A major source of efferent vagus nerve fibers that contribute to the regulation of inflammation is the brainstem dorsal motor nucleus of the vagus (DMN) as recently shown using optogenetics. In contrast to optogenetics, electrical neuromodulation has broad therapeutic implications, but the anti-inflammatory efficacy of electrical DMN stimulation (eDMNS) was not previously investigated. Here, we examined the effects of eDMNS on heart rate (HR) and cytokine levels in murine endotoxemia as well as the cecal ligation and puncture (CLP) model of sepsis. MethodsAnesthetized male 8-10-week-old C57BL/6 mice on a stereotaxic frame were subjected to eDMNS using a concentric bipolar electrode inserted into the left or right DMN or sham stimulation. eDMNS (50, 250 or 500 A and 30 Hz, for 1 min) was performed and HR recorded. In endotoxemia experiments, sham or eDMNS utilizing 250 A or 50 A was performed for 5 mins and was followed by LPS (0.5 mg/kg) i.p. administration. eDMNS was also applied in mice with cervical unilateral vagotomy or sham operation. In CLP experiments sham or left eDMNS was performed immediately post CLP. Cytokines and corticosterone were analyzed 90 mins after LPS administration or 24h after CLP. CLP survival was monitored for 14 days. ResultsEither left or right eDMNS at 250 A and 500 A decreased HR, compared with pre- and post-stimulation. This effect was not observed at 50 A. Left side eDMNS at 50 A, compared with sham stimulation, significantly decreased serum and splenic levels of the pro-inflammatory cytokine TNF and increased serum levels of the anti-inflammatory cytokine IL-10 during endotoxemia. The anti-inflammatory effect of eDMNS was abrogated in mice with unilateral vagotomy and were not associated with serum corticosterone alterations. Right side eDMNS suppressed serum TNF levels but had no effects on serum IL-10 and on splenic cytokines. In mice with CLP, left side eDMNS suppressed serum TNF and IL-6, as well as splenic IL-6 and increased splenic IL-10 and significantly improved the survival rate of CLP mice. ConclusionsFor the first time we show that a regimen of eDMNS which does not cause bradycardia alleviates LPS-induced inflammation and these effects require an intact vagus nerve and are not associated with corticosteroid alterations. eDMNS also decreases inflammation and improves survival in a model of polymicrobial sepsis. These findings are of interest for further studies exploring bioelectronic anti-inflammatory approaches targeting the brainstem DMN.

physiology↗