We tested the hypothesis that intermittent hypoxia (IH) and/or continuous hypoxia (CH) would enhance the ventilatory response to acute hypoxia (HVR), thereby altering blood pressure (BP) and cerebral perfusion. Seven healthy volunteers were randomly selected to complete 10-12 days of IH (5-min hypoxia to 5-min normoxia repeated for 90 min) before ascending to mild CH (1,560 m) for 12 days. Seve...

Exposure to chronic hypoxia (CH; 3-28 days at 380 Torr) induces adaptation in mammalian carotid body such that following CH an acute hypoxic challenge elicits an abnormally large increase in carotid sinus nerve impulse activity. The current study examines the hypothesis that CH initiates an immune response in the carotid body and that chemoreceptor hyperexcitability is dependent on the expressi...

BACKGROUND Endothelin (ET)-1 is a 21-amino-acid peptide with potent vasoactive properties, which increases intrahepatic resistance in patients with chronic hepatitis (CH) or cirrhosis. ET-1 concentrations have not been investigated in dogs with CH. HYPOTHESIS/OBJECTIVES This study compared hepatic and plasma ET-1 levels in healthy dogs and in dogs with CH, and examined the relationship betwee...

The ‘simulation hypothesis’ is an intriguing explanation for cognition, and holds that ‘thinking consists of simulated interaction with the environment’ ([4], p.242). However, the neuroscientific proof for a simulation mechanism in the brain is indirect. In this paper we present a minimal-model approach to investigate the ‘simulation hypothesis’. Our minimal model is called ACP? and is an exten...

Fractal dimensionality (FD) measures the complexity within folds and ridges of cortical subcortical structures. We tested degree that FD might provide a new perspective on atrophy-compensation hypothesis: age or disease-related atrophy causes compensatory neural response in form increased brain activity prefrontal cortex to maintain cognition. Brain structural functional data were collected fro...

This paper discusses the relevance of the discovery of mirror neurons in monkeys and of the mirror neuron system in humans to a neuroscientific account of primates' social cognition and its evolution. It is proposed that mirror neurons and the functional mechanism they underpin, embodied simulation, can ground within a unitary neurophysiological explanatory framework important aspects of human ...