Models of Innate Neural Attractors and Their Applications for Neural Information Processing.

In this work we reveal and explore a new class of attractor neural networks, based on inborn connections provided by model molecular markers, the molecular marker based attractor neural networks (MMBANN). Each set of markers has a metric, which is used to make connections between neurons containing the markers. We have explored conditions for the existence of attractor states, critical relations between their parameters and the spectrum of single neuron models, which can implement the MMBANN.

Tonic and phasic drive to medullary respiratory neurons during periodic breathing.

It is unknown how central neural activity produces the repetitive termination and restart of periodic breathing (PB). We hypothesized that inspiratory and expiratory neural activities would be greatest during the waxing phase and least during the waning phase. We analyzed diaphragmatic and medullary respiratory neural activities during PB in intact unanesthetized adult cats.

Effect of hypercapnia on sleep and breathing in unanesthetized cats.

Objectives: In this study, we looked at the effect of hypercapnia on sleep architecture and breathing. We characterized the effect of hypercapnia on duration, frequency, and latency of NREM and REM sleep. We described state-specific patterns of breathing as well.

Precise rhythmicity in activity of neocortical, thalamic and brain stem neurons in behaving cats and rabbits.

Rhythmic discharges of neurons are believed to be involved in information processing in both sensory and motor systems. However their fine structure and functional role need further elucidation. We employed a pattern-based approach to search for episodes of precisely rhythmic activity of single neurons recorded in different brain structures in behaving cats and rabbits.

Medullary respiratory neural activity during hypoxia in NREM and REM sleep in the cat.

Intact unanesthetized cats hyperventilate in response to hypocapnic hypoxia in both wakefulness and sleep. This hyperventilation is caused by increases in diaphragmatic activity during inspiration and expiration. In this study, we recorded 120 medullary respiratory neurons during sleep in hypoxia.

Hypocapnia decreases the amount of rapid eye movement sleep in cats.

Context: Sleep is disturbed at high altitudes. Low PO2 levels at high altitude cause hyperventilation, which results in secondary hypocapnia (low PaCO2 levels). Thus, although sleep disruption at high altitudes is generally assumed to be caused by hypoxia, it may instead be the result of hypocapnia.

Ventilatory response of the cat to hypoxia in sleep and wakefulness.

This study characterized ventilation, the airflow waveform, and diaphragmatic activity in response to hypoxia in the intact adult cat during sleep and wakefulness. Exposure to hypoxia for up to 3 h caused sustained hyperventilation during both wakefulness and sleep. Hyperventilation resulted from significant increases in minute ventilation due to increases in both tidal volume and frequency.