Wiktor A. Janczewski

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Inspiration and active expiration are commonly viewed as antagonistic phases of a unitary oscillator that generates respiratory rhythm. This view conflicts with observations we report here in juvenile rats, where by administration of fentanyl, a selective mu-opiate agonist, and induction of lung reflexes, we separately manipulated the frequency of(More)
Current consensus holds that a single medullary network generates respiratory rhythm in mammals. Pre-Bötzinger Complex inspiratory (I) neurons, isolated in transverse slices, and preinspiratory (pre-I) neurons, found only in more intact en bloc preparations and in vivo, are each proposed as necessary for rhythm generation. Opioids slow I, but not pre-I,(More)
Delineating neurons that underlie complex behaviors is of fundamental interest. Using adeno-associated virus 2, we expressed the Drosophila allatostatin receptor in somatostatin (Sst)-expressing neurons in the preBötzinger Complex (preBötC). Rapid silencing of these neurons in awake rats induced a persistent apnea without any respiratory movements to rescue(More)
We report that after spontaneous breathing movements are stopped by administration of opioids (opioid-induced apnoea) in neonatal rats, abdominal muscles continue to contract at a rate similar to that observed during periods of ventilation. Correspondingly, in vitro bath application of a mu opioid receptor agonist suppresses the activity of the fourth(More)
In the mammalian respiratory central pattern generator, the preBötzinger complex (preBötC) produces rhythmic bursts that drive inspiratory motor output. Cellular mechanisms initiated by each burst are hypothesized to be necessary to determine the timing of the subsequent burst, playing a critical role in rhythmogenesis. To explore mechanisms relating(More)
Ablation of preBötzinger complex (preBötC) neurons, critical for respiratory rhythm generation, resulted in a progressive, increasingly severe disruption of respiratory pattern, initially during sleep and then also during wakefulness in adult rats. Sleep-disordered breathing is highly prevalent in elderly humans and in some patients with neurodegenerative(More)
The preBötzinger Complex (preBötC) contains neural microcircuitry essential for normal respiratory rhythm generation in rodents. A subpopulation of preBötC neurons expresses somatostatin, a neuropeptide with a modulatory action on breathing. Acute silencing of a subpopulation of preBötC neurons transfected by a virus driving protein expression under the(More)
Data from perinatal and juvenile rodents support our hypothesis that the preBötzinger complex generates inspiratory rhythm and the retrotrapezoid nucleus-parafacial respiratory group (RTN/pFRG) generates active expiration (AE). Although the role of the RTN/pFRG in adulthood is disputed, we hypothesized that its rhythmogenicity persists but is typically(More)
Among the most rewarding moments in scientific discovery are when the pieces of a puzzle provided by different laboratories start to fall into place, forming a coherent and new view of the world. Several years ago, a consensus was emerging that respiratory rhythm in mammals arose from a single medullary site. Then suddenly several observations suggested(More)
Postsynaptic inhibition is a key element of neural circuits underlying behavior, with 20-50% of all mammalian (nongranule) neurons considered inhibitory. For rhythmic movements in mammals, e.g., walking, swimming, suckling, chewing, and breathing, inhibition is often hypothesized to play an essential rhythmogenic role. Here we study the role of fast(More)