Nucleus of the solitary tract neuronal degeneration and impaired hypoxia response in a model of Parkinson's disease.

Parkinson's disease (PD) involves the degeneration of dopaminergic neurons in the substantia nigra (SNpc) and manifests with both classic and non-classic motor symptoms, including respiratory failure. Our study aims to investigate the involvement of the commissural and intermediate nucleus of the solitary tract (cNTS and iNTS) in the attenuated respiratory response to hypoxia in PD. Using a PD rat model induced by bilateral injection of 6-hydroxydopamine (6-OHDA) into the striatum of male Wistar rats, we explored potential alterations in the population of Phox2b neurons or hypoxia-activated neurons in the NTS projecting to the retrotrapezoid nucleus (RTN).

Autoregulation of blood flow drives early hypotension in a rat model of systemic inflammation induced by bacterial lipopolysaccharide.

Uncontrolled vasodilation is known to account for hypotension in the advanced stages of sepsis and other systemic inflammatory conditions, but the mechanisms of hypotension in earlier stages of such conditions are not clear. By monitoring hemodynamics with the highest temporal resolution in unanesthetized rats, in combination with ex-vivo assessment of vascular function, we found that early development of hypotension following injection of bacterial lipopolysaccharide is brought about by a fall in vascular resistance when arterioles are still fully responsive to vasoactive agents. This approach further uncovered that the early development of hypotension stabilized blood flow.

mutation mediated by expression impaired respiratory rhythm and ventilatory responses to hypoxia and hypercapnia.

Mutations in the transcription factor cause congenital central hypoventilation syndrome (CCHS). The syndrome is characterized by hypoventilation and inability to regulate breathing to maintain adequate O and CO levels. The mechanism by which CCHS impact respiratory control is incompletely understood, and even less is known about the impact of the non-polyalanine repeat expansion mutations (NPARM) form.

Respiratory deficits in a female rat model of Parkinson's disease.

New Findings: What is the central question of this study? How does the 6-hydroxydopamine (6-OHDA)-induced Parkinson's disease model affect the respiratory response in female rats? What effect does ovariectomy have on that response? What is the main finding and its importance? The results suggest a protective effect of ovarian hormones in maintaining normal neuroanatomical integrity of the medullary respiratory nucleus in females. It was observed that ovariectomy alone reduced neurokinin-1 density in the pre-Bötzinger complex and Bötzinger complex, and there was an incremental effect of 6-OHDA and ovariectomy on retrotrapezoid nucleus neurons.

Abstract: Emerging evidence indicates that the course of Parkinson's disease (PD) includes autonomic and respiratory deficiencies in addition to the classical motor symptoms.

Chronic apnea during REM sleep increases arterial pressure and sympathetic modulation in rats.

Study Objectives: Obstructive sleep apnea can induce hypertension. Apneas in REM may be particularly problematic: they are independently associated with hypertension. We examined the role of sleep stage and awakening on acute cardiovascular responses to apnea.

Increased sympathetic responses induced by chronic obstructive sleep apnea are caused by sleep fragmentation.

Obstructive sleep apnea (OSA) is often associated with sympathetic overactivity and hypertension. These associations are mainly attributed to hypoxia acting on arterial chemoreceptors. However, the contribution of arousal from sleep is unclear.

Airway obstruction produces widespread sympathoexcitation: role of hypoxia, carotid chemoreceptors, and NTS neurotransmission.

Obstructive sleep apnea (OSA) is the most common respiratory disturbance of sleep and is closely associated to cardiovascular diseases. In humans, apnea increases respiratory effort and elevates muscle sympathetic nerve activity (SNA), but the primary stimulus for the SNA activation has not been identified. We recently developed a model of apnea in rodents using acute airway obstruction.

Resistance of Hydraulic Calcium Silicate Cements to Dislodgment in Short- and Long-term Assessment.

Purpose: To investigate the resistance to dislodgment produced by Biodentine (Septodont) and White-MTA (Angelus) after immersion in phosphate-buffered saline (PBS) for different durations.

Materials And Methods: Dentin disks 1 ± 0.1 mm thick were obtained from the middle third of the roots of 6 human maxillary canines.