A5056913077- Neural dynamics and brain function
- Neuroscience of respiration and sleep
- stochastic dynamics and bifurcation
- Neurobiology and Insect Physiology Research
- Neuroendocrine regulation and behavior
- Sleep and Wakefulness Research
- Bat Biology and Ecology Studies
- Nonlinear Dynamics and Pattern Formation
- Heart Rate Variability and Autonomic Control
- Circadian rhythm and melatonin
- Neonatal Respiratory Health Research
- Neuroscience and Neuropharmacology Research
- Robotic Locomotion and Control
- Photoreceptor and optogenetics research
- Motor Control and Adaptation
- Economics of Agriculture and Food Markets
- Winter Sports Injuries and Performance
- Economic theories and models
- Neuropeptides and Animal Physiology
- Muscle activation and electromyography studies
- Neural and Behavioral Psychology Studies
- Neurotransmitter Receptor Influence on Behavior
- Ion channel regulation and function
- Neuroscience and Neural Engineering
- Receptor Mechanisms and Signaling
Indiana University – Purdue University Indianapolis
2021-2023
University of Indianapolis
2021-2023
Georgia State University
2013-2022
McMaster University
1990-1993
University of Nebraska at Kearney
1989
Western University
1977-1988
Baylor University
1958
The circuit organization within the mammalian brainstem respiratory network, specifically and between pre-Bötzinger (pre-BötC) Bötzinger (BötC) complexes, roles of these circuits in pattern generation are continuously debated. We address issues with a combination optogenetic experiments modeling studies. used transgenic mice expressing channelrhodopsin-2 under VGAT-promoter to investigate perturbations activity by site-specific photostimulation inhibitory neurons pre-BötC or BötC....
The retrotrapezoid nucleus (RTN) contains chemosensitive cells that distribute CO2-dependent excitatory drive to the respiratory network. This facilitates function of central pattern generator (rCPG) and increases sympathetic activity. It is also evidenced during hypercapnia, late-expiratory (late-E) oscillator in parafacial group (pFRG) activated determines emergence active expiration. However, it remains unclear microcircuitry responsible for distribution signals pFRG rCPG conditions high...
The dynamics of different ionic currents shape the bursting activity neurons and networks that control motor output. Despite being ubiquitous in all animal cells, contribution Na(+)/K(+) pump current to such has not been well studied. We used monensin, a Na(+)/H(+) antiporter, examine role on oscillator heart interneurons leeches. When we stimulated with period these decreased significantly, an effect was prevented or reversed when h-current blocked by Cs(+). could also occur if inhibited...
Coordination of respiratory pump and valve muscle activity is essential for normal breathing. A hallmark response to hypercapnia hypoxia the emergence active exhalation, characterized by abdominal pumping during late one-third expiration (late-E phase). Late-E has been attributed activation expiratory neurons located within parafacial group (pFRG). However, mechanisms that control its silencing in restful breathing, are not completely understood. We hypothesized inputs from Kölliker-Fuse...
The motor cortex controls behaviors by generating movement-specific signals and transmitting them through spinal cord circuits motoneurons to the muscles. Precise well-coordinated muscle activation patterns are necessary for accurate movement execution. Therefore, activity of cortical neurons should correlate with parameters. To investigate specifics such correlations among activities cortex, network muscles, we developed a model neural control goal-directed reaching movements that simulates...
This work was produced as part of the activities FAPESP Research, Disseminations and Innovation Center for Neuromathematics (grant 2013/07699-0, S. Paulo Research Foundation). NLK is supported by a FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR partially supported a CNPq 306251/2014-0).
Contraction of abdominal muscles at the end expiration during metabolic challenges (such as hypercapnia and hypoxia) improves pulmonary ventilation. The emergence this active expiratory pattern requires recruitment oscillator located on ventral surface medulla oblongata. Here we show that an inhibitory circuitry in Bötzinger complex is important source drive to oscillator. This circuitry, mediated by GABAergic glycinergic synapses, provides inhibition restrains under resting condition...
Flexibility in neuronal circuits has its roots the dynamical richness of their neurons. Depending on membrane properties single neurons can produce a plethora activity regimes including silence, spiking and bursting. What is less appreciated that these coexist with each other so transient stimulus cause persistent change given neuron. Such multistability dynamics been shown variety under different modulatory conditions. It play either functional role or present substrate for diseases. We...
It is widely accepted that the basal ganglia (BG) play a key role in action selection and reinforcement learning. However, despite considerable number of studies, BG architecture function are not completely understood. Action learning facilitated by activity dopaminergic neurons, which encode reward prediction errors when outcomes higher or lower than expected. The thought to select proper motor responses gating appropriate actions, suppressing inappropriate ones. direct striato-nigral (GO)...
The dynamics of individual neurons are crucial for producing functional activity in neuronal networks. An open question is how temporal characteristics can be controlled bursting and transient responses to synaptic input. Bifurcation theory provides a framework discover generic mechanisms addressing this question. We present family organized around global codimension-2 bifurcation. cornerstone bifurcation located at the intersection border between spiking silence. These borders correspond...
In this study, we explore the functional role of striatal cholinergic interneurons, hereinafter referred to as tonically active neurons (TANs), via computational modeling; specifically, investigate mechanistic relationship between TAN activity and dopamine variations how changes in affect reinforcement learning striatum. TANs pause their tonic firing after excitatory stimuli from thalamic cortical response a sensory event or reward information. During concentration excursions are observed....
Motor adaptation to perturbations is provided by learning mechanisms operating in the cerebellum and basal ganglia. The normally performs motor through supervised using information about movement error visual feedback. However, if feedback critically distorted, system may disengage cerebellar error-based switch reinforcement mediated Yet, exact conditions of ganglia involvement remain unknown. We use mathematical modeling simulate control planar reaching movements that relies on both...
Variability in blood pressure has become an important metric to consider as more is learned about the link between excessive variability and adverse health outcomes. In this study using slow deep breathing human subjects, we found that heart rate pulse variations have comparable effects on amplitude of waves, it common action two defines phase relationship respiration oscillations.
New Findings Cardio-ventilatory coupling refers to the onset of inspiration occurring at a preferential latency following last heartbeat (HB) in expiration. According cardiac-trigger hypothesis, pulse pressure initiates an via baroreceptor activation. However, central neural substrate mediating this remains undefined. Using combination animal data, human data and mathematical modelling, study tests hypothesis that HB, by way pulsatile baroreflex activation, controls initiation occurs through...
Central pattern generators (CPGs), specialized oscillatory neuronal networks controlling rhythmic motor behaviors such as breathing and locomotion, must adjust their patterns of activity to a variable environment changing behavioral goals. Neuromodulation adjusts these by orchestrating changes in multiple ionic currents. In the medicinal leech, endogenous neuromodulator myomodulin speeds up heartbeat CPG reducing electrogenic Na<sup>+</sup>/K<sup>+</sup> pump current increasing h-current...
The present study examined the localization and characterization of [125I]vasoactive intestinal polypeptide (VIP) binding to synaptosomes enterocyte membranes using preparations made from homogenized canine mucosa compared it [3H]saxitoxin VIP-immunoreactive content (markers for synaptosomes). highest [125I]VIP was located in P2 fraction correlated with locations maximal content. This correlation indicates that VIP receptors are on small mucosa. A enriched contained a high density saturable...
Abstract Third-generation navel orangeworm ( Amyelois transitella) damage to almond Prunus dulcis Mill.) kernels is a serious problem in the California industry. An early harvest one means of reducing losses and increasing crop quality. A successful was accomplished 2 3 weeks before normal date, with no perceptible effect on kernel Percent hullsplit correlated nut removal, providing field guide acceptable maturity. Within defined limits, yield, drying rate, hullability harvested almonds were...
Our previous study of cat locomotion demonstrated that lateral displacements the centre mass (COM) were strikingly similar to those human walking and resembled behaviour an inverted pendulum (Park et al. 2019 J. Exp. Biol. 222 , 14. (doi:10.1242/jeb.198648)). Here, we tested hypothesis frontal plane dynamics quadrupedal are consistent with model. We developed a simple mathematical model balance control in based on compared four cats locomoting split-belt treadmill. The accurately reproduced...