It has been shown that chronic repetitive ambient hypoxia, simulating pulmonary gas disturbances observed in apnoea, leads to systemic hypertension in rats. However, the relative roles of hypoxia (HO), hypercapnia (HC), gas stress and vigilance on the cardiovascular changes have not yet been demonstrated. The aim of this study was to investigate the acute haemodynamic changes observed during th...

Abstract Introduction In the words of Michel Salmon, " Between anatomy and physiology there is room for a functional physiologic “. This concept was applied to analyze our (1) Sleep Research 21, 1992,341 (2) 22, 1993, 363, (3) SLEEP 31, 2008, A219 publications on patients with Hypersomnia who had intracranial extracranial blood flow evaluations. Methods For “Functional Anatomy”, Intracranial ce...

This paper describes the development of a computer-controlled system that controls inspired CO2 or end-tidal PCO2 (PETCO2) to follow preprogrammed functions such as step, sinusoid, and pulse, under normoxic, hyperoxic, and hypoxic conditions. The system uses a proportional-integral (PI) controller that was optimized by adjusting the PI parameters so as to minimize the integral-time of absolute ...

TARGET AUDIENCE – Neuroscientists using ASL/BOLD MRI for CO2 cerebrovascular reactivity measurements or quantitative BOLD PURPOSE – Cerebrovascular reactivity (CVR) due to CO2 inhalation is believed to be a measure of the capacity of the cerebral blood vessels to match the cerebral blood flow (CBF) to the metabolic needs of the brain. CO2 CVR has been shown to be disturbed in many neurological ...

UNLABELLED Carbon dioxide (CO2) rebreathing has been recognised as a concern regarding respirator use and is related to symptoms of discomfort, fatigue, dizziness, headache, muscular weakness and drowsiness. Previous investigations are limited by small sample size and have not evaluated the relationship between CO2 inhalation and phonic respiration (breathing during speech) in respiratory prote...

The present study tested several predictions of a context-sensitivity panic vulnerability model emphasizing the interaction between threat context and threat sensitivities. Participants without a history of panic (N=47) completed both global and domain-specific panic relevant sensitivity measures and were then randomized to undergo a 35% CO2 inhalation challenge in the presence or absence of a ...

OBJECTIVE We aim to determine if a treatment with a dose of clonazepam--2 mg/day, for 6 weeks, blocks spontaneous panic attacks and the ones induced by the inhalation of 35% carbon dioxide (CO2) in panic disorder (PD) patients. The CO2 challenge-test may be a useful addition tool for measuring the pharmacological response during the initial phase (6 weeks) in the treatment of PD. METHOD Eight...