A5014179885- Zebrafish Biomedical Research Applications
- Neural dynamics and brain function
- Neuroscience and Neuropharmacology Research
- Neuroscience and Neural Engineering
- Neurobiology and Insect Physiology Research
- Neurogenesis and neuroplasticity mechanisms
- Spinal Cord Injury Research
- Muscle activation and electromyography studies
- Vestibular and auditory disorders
- Tissue Engineering and Regenerative Medicine
- stochastic dynamics and bifurcation
- Ion channel regulation and function
- Transcranial Magnetic Stimulation Studies
- Metabolism and Genetic Disorders
- Fish Ecology and Management Studies
- Botulinum Toxin and Related Neurological Disorders
- Neuroscience of respiration and sleep
- Motor Control and Adaptation
- Advanced Memory and Neural Computing
- Spinal Dysraphism and Malformations
- Effects of Environmental Stressors on Livestock
- Folate and B Vitamins Research
- EEG and Brain-Computer Interfaces
- Photoreceptor and optogenetics research
- Sleep and Wakefulness Research
University of Ottawa
2016-2025
MIND Research Institute
2016-2021
Dalhousie University
2009-2014
Queen's University
2003-2010
Canadian Institutes of Health Research
2003-2010
Cornell University
1987
Pyridoxine-dependent epilepsy (PDE) is a rare disease characterized by mutations in the lysine degradation gene
Biallelic pathogenic variants in PLPBP (formerly called PROSC) have recently been shown to cause a novel form of vitamin B6-dependent epilepsy, the pathophysiological basis which is poorly understood. When left untreated, disease can progress status epilepticus and death infancy. Here we present 12 previously undescribed patients six PLPBP. Suspected clinical diagnoses prior identification included mitochondrial encephalopathy (two patients), folinic acid-responsive epilepsy (one patient)...
The spinal cord has the capacity to coordinate motor activities such as locomotion. Following transection, functional activity can be regained, a degree, following training. To identify microcircuits involved in this recovery, we studied population of mouse interneurons known receive direct afferent inputs and project intermediate ventral regions cord. We demonstrate that while dI3 are not necessary for normal locomotor activity, circuits rhythmically inhibit them activate these circuits....
In the presence of neuromodulators such as serotonin and noradrenaline, motoneurons exhibit persistent inward currents (PICs) that serve to amplify synaptic inputs. A major component these PICs is mediated by L-type Ca(2+) channels. Estimates based on electrophysiological studies indicate channels are located dendrites, but immunohistochemical their precise distribution have yielded different results. Our goal was determine using computational methods. theoretical analysis activation a...
Spasticity is a common comorbidity of spinal cord injury (SCI), disrupting motor function and resulting in significant discomfort. While elements post-SCI spasticity can be assessed using pre-clinical SCI models, the robust measurement severity difficult due to its periodic spontaneous appearance. Electrical stimulation sensory afferents elicit spasticity-associated responses, such as spasms; however, placing surface electrodes on hindlimbs awake animals induce stress or encumbrance that...
Spinal cord injury (SCI) is a debilitating neurological condition with far-reaching consequences for patients, including loss of motor function and significant limitations to quality life. Implantable biomaterials have emerged as therapeutic strategy modulate the SCI microenvironment facilitate regeneration axons. In this study, plant-derived cellulose scaffolds coated poly-L-ornithine (PLO) are shown support locomotor recovery neural tissue repair in rat model spinal injury. Upon complete...
In spinal motoneurons, activation of dendritically located depolarizing conductances can lead to amplification synaptic inputs and the production plateau potentials. Immunohistochemical computational studies have implicated dendritic Ca V 1.3 channels in this suggest that motoneurons may be organized clusters tree. Our goal was provide physiological evidence for presence multiple discrete voltage-gated calcium explore spatial arrangement these We recorded currents from slices mature mouse...
A single spinal motoneuron receives tens of thousands synapses. The neurotransmitters released by many these synapses act on iontotropic receptors and alter the driving potential neighboring This interaction introduces an intrinsic nonlinearity in input-output properties where response to two simultaneous inputs is less than linear sum responses each input alone. Our goal was determine impact this current delivered soma during activation predetermined numbers distributions excitatory...
The ability of inhibitory synaptic inputs to dampen the excitability motoneurons is augmented when persistent inward currents (PICs) are activated. This amplification could be due an increase in driving potential synapses or deactivation channels underlying PICs. Our goal was determine which mechanism leads by To reach this goal, we measured postsynaptic (IPSCs) decerebrate cats during somatic voltage-clamp steps. These IPSCs were generated tonic activation Renshaw cells. exhibited a rapid...
In some motoneurons, L-type Ca2+ channels that partly mediate persistent inward currents (PICs) have been estimated to be arranged in 50- 200-microm-long discrete regions the dendrites, centered 100 400 microm from soma. As a consequence of this nonuniform distribution, interaction between synaptic inputs motoneurons and these may vary according distribution synapses. For instance, >93% synapses Renshaw cells observed located 65 470 away cell body motoneurons. Our goal was assess whether are...
In the presence of monoamines, L-type Ca(2+) channels on dendrites motoneurons contribute to persistent inward currents (PICs) that can amplify synaptic inputs two- sixfold. However, exact location is controversial, and importance as a means regulating input-output properties unknown. this study, we used computational strategy developed previously estimate dendritic test hypothesis varies function motoneuron size. Compartmental models were constructed based trees five ranged in size from...
Many spinal circuits dedicated to locomotor control have been identified in the developing zebrafish. How these operate together generate various swimming movements during development remains be clarified. In this study, we iteratively built models of zebrafish coupled simplified musculoskeletal that reproduce coiling and movements. The neurons were based upon morphologically or genetically populations cord. We simulated intact as well with silenced altered synaptic transmission better...
The morphological and electrotonic properties of 4 motoneurons, 8 Ia inhibitory interneurons, Renshaw cells were compared. analysis, based on 3-D reconstructions the cells, revealed that dendrites motoneurons are longer more extensively branched. have shorter simpler in structure. Dendrites interneurons could be as long those but branching structure resembled cells. Compartmental models used to determine paths from each dendritic terminal soma. attenuations steady-state voltage changes 3 7...
Neural stem cell (NSC)-based therapies are at the forefront of regenerative medicine strategies for various neural defects and injuries such as stroke, traumatic brain injury, spinal cord injury. For several clinical applications, NSC require biocompatible scaffolds to support survival direct differentiation. Here, we investigate decellularized plant tissue a novel scaffold three-dimensional (3D), in vitro culture NSCs. Plant cellulose were shown attachment proliferation adult rat...
Primitive reflexes are evident shortly after birth. Many of these disappear during postnatal development as part the maturation motor control. This study investigates changes connectivity related to sensory integration by spinal dI3 interneurons time in which palmar grasp reflex gradually disappears mice pups. Our results reveal an increase GAD65/67-labeled terminals perisomatic Vglut1-labeled inputs contacting cervical and lumbar between day 3 25. In contrast, there were no number other...
Previous studies show that the activation of voltage-dependent channels is dependent on local density synapses in dendritic region containing channels. We hypothesized selective innervation excitatory vestibulospinal (VST) neurons medial dendrites contralateral splenius motoneurons designed to enhance persistent inward currents (PICs) mediated by L-type Ca(2+) Using compartmental models we compared synaptic current reaching soma response input generated with two different distribution...