Roman Benacka

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Forced inspiratory efforts resembling the sniff-like aspiration reflex (AR) were evoked by single-shocks or trains of electrical impulses to the dorsal pharyngeal and nasal mucosal surfaces in 12 anaesthetized spontaneously breathing cats. The strongest ARs determined by diaphragmatic (DIA) EMG and peak-inspiratory flows were elicited from the dorsolateral(More)
Re-evaluation of our earlier c-Fos-like immuno-reactive studies and brainstem transection/lesion experiments in over 40 anaesthetized, non-paralyzed cats allowed comparison of two distinct airway defensive reflexes with the distinct generators for inspiration (I) and expiration (E), described recently in juvenile rats. The spiration reflex (AspR) is(More)
Respiratory effects of electrical stimulation of the upper airways (UAW) before and during apnoeic episodes induced by nitrogen inhalation were studied in 9 anaesthetized cats. In eupnoeic animals these electrically-evoked reflexes comprise rapid and powerful inspiratory efforts characterized by strong maximal airway occlusion pressures (Pmax = 635 +/- 39(More)
Various cardiorespiratory and electrophysiological parameters were analysed in a model of acute respiratory failure induced by inhalation of pure nitrogen in approximately 150 anaesthetized cats. Initial hyperventilation leading to apnoea was characterized by extreme hypoxaemia, marked bradycardia and flattening of electrocortical (ECoG) activity.(More)
Various flow and timing characteristics of breathing as well as electrocorticographic (ECoG) records were analysed in a model of reversible respiratory failure induced by N2 inhalation in 27 anaesthetized cats. During the first minute of respiratory arrest, nasopharyngeal stimulation by an elastic nylon fibre elicited a typical sniff- or gasp-like(More)
BACKGROUND Apnoeic events are often accompanied by various disturbances in electric cardiac activity, the character and development as well as mechanism of which remain broadly unknown suggesting both direct metabolic defects as well as neurogenous autonomic influences. METHODS Changes in ECG and heart rate induced by repeated short-lasting inhalation of(More)
The aim of the study was to determine the dependence of changes in the electrical stability of the heart on the light-dark cycle (LD cycle) in disorders of pulmonary ventilation. The ventricular arrhythmia threshold (VAT) was measured in female Wistar rats (adaptation to the light regime 12:12 h, ketamine/xylazine anesthesia 100 mg/15 mg/kg, i.m., open(More)
Cardiorespiratory decompensation or even death may result from dysfunction of upper airway reflexes during sleep. This could manifest, for example, as a lack of pharyngeal dilation in obstructive sleep apnoea or failure of autoresuscitation by gasping in sudden infant death syndrome. Data obtained from experiments in anaesthetized cats suggest several(More)
Mechanical stimulation of the pharyngeal mucosa in cats and some other mammals evokes the 'aspiration reflex' (AR) characterized by rapid and strong inspiratory efforts not followed by active expirations. It resembles other spasmodic inspiratory acts such as the sniff, the gasp, and the sigh in several aspects, e.g. reflex or semireflex triggering from the(More)