On the development of spinal circuits during the maturation of movements

Topcu E, Roussel Y, and and Bui TV. SiliFish: A desktop application to model swimming behavior in developing zebrafish (Danio rerio), STAR Protocols, Jan 3;4(1):101973. doi: 10.1016/j.xpro.2022.101973, 2023.

Laliberte AM, Farah C, Steiner KR, Tariq O, and Bui TV. Changes in Sensorimotor Connectivity to dI3 Interneurons in Relation to the Postnatal Maturation of Grasping. Frontiers in Neural Circuits, 2022.

Roussel Y, Gaudreau SF, Kacer ER, Sengupta M, and Bui TV. Modelling spinal locomotor circuits for movements in developing zebrafish. eLife, 2021;10:e67453, DOI: 10.7554/eLife.67453

Roussel Y, Paradis M, Gaudreau SF, Lindsey BW, and Bui TV. Spatiotemporal Transition in the Role of Synaptic Inhibition to the Tail Beat Rhythm of Developing Larval Zebrafish. eNeuro, 31 January 2020, 7 (1) ENEURO.0508-18.2020; DOI: https://doi.org/10.1523/ENEURO.0508-18.2020

On dI3 interneurons and hand control

Bui TV, Stifani N, Panek I, and Farah C. Genetically identified spinal interneurons integrating tactile afferents for motor control. Journal of Neurophysiology, jn.00522.2015. doi: 10.1152/jn.00522.2015, 2015.

Panek I, Bui T, Wright AT, and Brownstone RM. Cutaneous afferent regulation of motor function. Acta Neurobiologica Experimentalis (Warsaw), 74(2):158-71, 2014.

Bui TV, Akay T, Loubani O, Hnasko TS, Jessell TM, and Brownstone RM. Circuits for grasping: spinal dI3 interneurons mediate cutaneous control of motor behavior. Neuron, 78: 191-204, 2013.

This paper shows that dI3 interneurons form a microcircuit linking sensory neurons innervating tactile receptors and spinal motoneurons. Using transgenic strategies, electrophysiological recordings and immunohistochemistry, this paper is the first to demonstrate the critical role of such a circuit in a specific facet of hand control, the regulation of hand grasp.

On spinal interneurons and spinal cord injury

Bui TV (co-first author), Stifani N (co-first author), Akay T, and Brownstone R. Spinal microcircuits comprising dI3 interneurons are necessary for motor functional recovery following spinal cord transection. eLife, Dec 15;5. pii: e21715. doi: 10.7554/eLife.21715, 2016.

This study shows that silencing dI3 interneurons compromises the ability of spinal cord injured mice to recover their locomotor function through treadmill training. In the process, this study is the first to identify a population of spinal neurons that is important for the recovery of locomotion following a complete spinal cord injury in mice.

Lalonde NR, Bui TV. Do spinal circuits still require gating of sensory information by presynaptic inhibition after spinal cord injury?. Current Opinion in Physiology, February; 19: 113-118. https://doi.org/10.1016/j.cophys.2020.10.001, 2021.

On sensorimotor integration

Bui TV and Roussel Y. Choosing sides: making decisions in an escape response. Journal of Physiology, 593: 4303-4, 2015.

Bui TV and Brownstone RM. Sensory-evoked perturbations of locomotor activity by sparse sensory input: A computational study. Journal of Neurophysiology, 113:2824-39, 2015.

On locomotion

Brownstone RM and Bui TV. Spinal locomotor inputs to the final common pathway. Progress in Brain Research,  187: 81-95, 2010

This review paper synthesizes a large body of knowledge on the many neurons that project to motoneurons and the role of these projections in the control of locomotion

Laliberte AM, Goltash S, Lalonde NR, and Bui TV. Propriospinal Neurons: Essential Elements of Locomotor Control in the Intact and Possibly the Injured Spinal Cord Front. Cell. Neurosci., 12 November 2019 | https://doi.org/10.3389/fncel.2019.00512

This review paper describes the latest and most seminal work studying the role of propriospinal neurons to locomotor control in the intact and injured spinal cord

On motor learning

Brownstone RM, Bui TV, and Stifani N. Spinal circuits for motor learning. Current Opinion in Neurobiology,  33: 166-173, 2015

This review paper proposes that spinal circuits may have characteristics usually associated with cerebellar circuits that drive motor learning.

On the electrophysiological properties of spinal motoneurons

Grande G, Bui TV, and Rose PK. Distribution of vestibulospinal contacts on the dendrites of ipsilateral splenius motoneurons: an anatomical substrate for push-pull interactions during vestibulocollic reflexes. Brain Research, 1333:9-27, 2010.

Carlin KP*, Bui TV*, Dai Y, and Brownstone RM. Staircase currents in motoneurons: insight into the spatial arrangement of calcium channels in the dendritic tree. Journal of Neuroscience; 29(16): 5343-53, 2009.

This paper combined electrophysiological recordings and computational modelling to demonstrate that L-type Calcium channels, which provide a powerful source of intrinsic depolarization to motoneurons, are distributed in small domains (or hot spots) in dendritic areas away from the cell body

Bui TV, Grande G, and Rose PK. Multiple modes of amplification of synaptic inhibition to motoneurons by persistent inward currents. Journal of Neurophysiology, 99(2): 571-82, 2008.

This study combined electrophysiological recordings and computational modelling to show that the recurrent inhibition to motoneurons from a population of spinal neurons known as Renshaw cells was amplified by the presence of persistent inward currents, partially mediated by L-type Calcium channels. It demonstrated that depending on the ability of Renshaw cell inhibition to deactivate these persistent inward currents, the shape of the inhibitory synaptic current could be modified as well

Bui TV, Grande G, and Rose PK. Relative location of inhibitory synapses and persistent inward currents determines the magnitude and mode of synaptic amplification in motoneurons. Journal of Neurophysiology, 99(2): 583-94, 2008.

Rose PK, Cushing S, Grande G, and Bui T. Functional diversity of motoneuron dendrites: by accident or design? Archives of Italian Biology, 145(3-4):175-91, 2007.

Grande G, Bui TV, and Rose PK. Effect of localized innervation of the dendritic trees of feline motoneurons on the amplification of synaptic input: a computational study. Journal of Physiology, 583(Pt 2): 611-30, 2007.

Grande G, Bui TV, and Rose PK. Estimates of the location of L-type Ca2+ channels in motoneurons of different sizes: a computational study. Journal of Neurophysiology, 97(6):4023-35, 2007.

Bui TV, Ter-Mikaelian M, Bedrossian D, and Rose PK. Computational estimation of the distribution of L-type Ca(2+) channels in motoneurons based on variable threshold of activation of persistent inward currents. Journal of Neurophysiology, 95(1)225-41, 2005.

Cushing S, Bui T,  and Rose PK. Effect of nonlinear summation of synaptic currents on the input-output properties of spinal motoneurons. Journal of Neurophysiology, 94(5):3465-78, 2005.

Bui TV, Cushing S, Dewey D, Fyffe RE, and Rose PK. Comparison of the morphological and electrotonic properties of Renshaw cells, Ia inhibitory interneurons, and motoneurons in the cat. Journal of Neurophysiology, 90(5):2900-18, 2003.