I Timofeev

Summary

Country: Canada

Publications

  1. pmc Cortical hyperpolarization-activated depolarizing current takes part in the generation of focal paroxysmal activities
    Igor Timofeev
    Laboratory of Neurophysiology, Faculty of Medicine, Laval University, Quebec City, QC, Canada G1K 7P4
    Proc Natl Acad Sci U S A 99:9533-7. 2002
  2. ncbi request reprint Neocortical focus: experimental view
    Igor Timofeev
    Centre de recherche de l Institut universitaire en santé mentale de Québec CRIUSMQ, Universite Laval, Quebec, Canada Department of Psychiatry and Neuroscience, Universite Laval, Quebec, Canada Electronic address
    Int Rev Neurobiol 114:9-33. 2014
  3. pmc Modeling thalamocortical cell: impact of ca channel distribution and cell geometry on firing pattern
    Reza Zomorrodi
    Department of Physics, Laval University Quebec, Canada
    Front Comput Neurosci 2:5. 2008
  4. pmc Origin of active states in local neocortical networks during slow sleep oscillation
    Sylvain Chauvette
    Department of Psychiatry and Neuroscience, The Centre de Recherche Université Laval Robert Giffard CRULRG, Laval University, Quebec, PQ, Canada
    Cereb Cortex 20:2660-74. 2010
  5. ncbi request reprint Local origin of slow EEG waves during sleep
    Igor Timofeev
    Centre de Recherche Université Laval Robert Giffard CRULRG, Universite Laval, Quebec, Canada
    Zh Vyssh Nerv Deiat Im I P Pavlova 63:105-12. 2013
  6. pmc Regulation of AMPA and NMDA receptor-mediated EPSPs in dendritic trees of thalamocortical cells
    Francis Lajeunesse
    Centre de Recherche de l Institut Universitaire en Santé Mentale de Québec, Laval University, Quebec, Canada
    J Neurophysiol 109:13-30. 2013
  7. ncbi request reprint Thalamocortical oscillations: local control of EEG slow waves
    Igor Timofeev
    Department of Psychiatry and Neuroscience, Laval University, Quebec, Canada
    Curr Top Med Chem 11:2457-71. 2011
  8. pmc Short- and medium-term plasticity associated with augmenting responses in cortical slabs and spindles in intact cortex of cats in vivo
    Igor Timofeev
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, Canada G1K 7P4
    J Physiol 542:583-98. 2002
  9. pmc Posttraumatic epilepsy: the roles of synaptic plasticity
    Igor Timofeev
    Laval University, Medical School, Centre de Recherche, Université Laval Robert Giffard, Quebec, Canada
    Neuroscientist 16:19-27. 2010
  10. ncbi request reprint Neocortical seizures: initiation, development and cessation
    I Timofeev
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, Canada G1K 7P4
    Neuroscience 123:299-336. 2004

Collaborators

Detail Information

Publications55

  1. pmc Cortical hyperpolarization-activated depolarizing current takes part in the generation of focal paroxysmal activities
    Igor Timofeev
    Laboratory of Neurophysiology, Faculty of Medicine, Laval University, Quebec City, QC, Canada G1K 7P4
    Proc Natl Acad Sci U S A 99:9533-7. 2002
    ..Computational models showed how, after the increased [K(+)](o), the interplay between I(h), I(K(Ca)), and a persistent Na(+) current, I(Na(P)), could organize paroxysmal oscillations at a frequency of 2-3 Hz...
  2. ncbi request reprint Neocortical focus: experimental view
    Igor Timofeev
    Centre de recherche de l Institut universitaire en santé mentale de Québec CRIUSMQ, Universite Laval, Quebec, Canada Department of Psychiatry and Neuroscience, Universite Laval, Quebec, Canada Electronic address
    Int Rev Neurobiol 114:9-33. 2014
    ..Therefore, we define these areas as the seizure focus. In this zone, neuronal connectivity and excitability are moderately enhanced, lowering the threshold for seizure generation. ..
  3. pmc Modeling thalamocortical cell: impact of ca channel distribution and cell geometry on firing pattern
    Reza Zomorrodi
    Department of Physics, Laval University Quebec, Canada
    Front Comput Neurosci 2:5. 2008
    ....
  4. pmc Origin of active states in local neocortical networks during slow sleep oscillation
    Sylvain Chauvette
    Department of Psychiatry and Neuroscience, The Centre de Recherche Université Laval Robert Giffard CRULRG, Laval University, Quebec, PQ, Canada
    Cereb Cortex 20:2660-74. 2010
    ....
  5. ncbi request reprint Local origin of slow EEG waves during sleep
    Igor Timofeev
    Centre de Recherche Université Laval Robert Giffard CRULRG, Universite Laval, Quebec, Canada
    Zh Vyssh Nerv Deiat Im I P Pavlova 63:105-12. 2013
    ....
  6. pmc Regulation of AMPA and NMDA receptor-mediated EPSPs in dendritic trees of thalamocortical cells
    Francis Lajeunesse
    Centre de Recherche de l Institut Universitaire en Santé Mentale de Québec, Laval University, Quebec, Canada
    J Neurophysiol 109:13-30. 2013
    ..The variability of response amplitude between cells was much larger than the variability within cells. This suggests possible functional segregation of TC neurons of different size...
  7. ncbi request reprint Thalamocortical oscillations: local control of EEG slow waves
    Igor Timofeev
    Department of Psychiatry and Neuroscience, Laval University, Quebec, Canada
    Curr Top Med Chem 11:2457-71. 2011
    ..The last part offers a detailed review on sleep slow oscillation describing its properties in the thalamocortical system, proposing a mechanism of generation of active states and a description of their propagation...
  8. pmc Short- and medium-term plasticity associated with augmenting responses in cortical slabs and spindles in intact cortex of cats in vivo
    Igor Timofeev
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, Canada G1K 7P4
    J Physiol 542:583-98. 2002
    ..These data suggest that augmenting responses elicited by stimulation, as well as spontaneously occurring spindles, may induce short- and medium-term plasticity of neuronal responses...
  9. pmc Posttraumatic epilepsy: the roles of synaptic plasticity
    Igor Timofeev
    Laval University, Medical School, Centre de Recherche, Université Laval Robert Giffard, Quebec, Canada
    Neuroscientist 16:19-27. 2010
    ..These changes develop progressively, and after several weeks their synergetic action leads to epilepsy...
  10. ncbi request reprint Neocortical seizures: initiation, development and cessation
    I Timofeev
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, Canada G1K 7P4
    Neuroscience 123:299-336. 2004
    ....
  11. ncbi request reprint Contribution of intrinsic neuronal factors in the generation of cortically driven electrographic seizures
    Igor Timofeev
    Laboratory of Neurophysiology, Faculty of Medicine, Laval University, Quebec G1K 7P4, Canada
    J Neurophysiol 92:1133-43. 2004
    ..We conclude that intrinsic cellular factors have significant role in the generation of depolarizing and hyperpolarizing components of seizures...
  12. pmc Disfacilitation and active inhibition in the neocortex during the natural sleep-wake cycle: an intracellular study
    I Timofeev
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, QC, Canada G1K 7P4
    Proc Natl Acad Sci U S A 98:1924-9. 2001
    ....
  13. pmc Neuronal plasticity and thalamocortical sleep and waking oscillations
    Igor Timofeev
    The Centre de Recherche Université Laval Robert Giffard CRULRG, Laval University, Quebec, Canada
    Prog Brain Res 193:121-44. 2011
    ..However, prolonged and profound shift from this homeostatic balance could lead to development of paroxysmal hyperexcitability and seizures as in the case of brain trauma...
  14. ncbi request reprint The role of chloride-dependent inhibition and the activity of fast-spiking neurons during cortical spike-wave electrographic seizures
    I Timofeev
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, QC, Canada G1K 7P4
    Neuroscience 114:1115-32. 2002
    ....
  15. ncbi request reprint Mircea Steriade (1924-2006)
    I Timofeev
    Department of Anatomy and Physiology, Universite Laval, Centre de Recherche Universite Laval Robert Giffard, 2601 de la Canardiere, Quebec, G1J 2G3, Canada
    Neuroscience 142:917-20. 2006
    ..Dr. Mircea Steriade passed away at age 82. In this obituary I briefly describe some of the most important achievements of his remarkable life and I express deepest sympathies to his family members, collaborators and trainees...
  16. ncbi request reprint Impact of intrinsic properties and synaptic factors on the activity of neocortical networks in vivo
    I Timofeev
    Laboratory of Neurophysiology, Department of Anatomy and Physiology, School of Medicine, Laval University, PQ G1K 7P4, Quebec, Canada
    J Physiol Paris 94:343-55. 2000
    ....
  17. ncbi request reprint Spontaneous field potentials influence the activity of neocortical neurons during paroxysmal activities in vivo
    F Grenier
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, QC, Canada G1K 7P4
    Neuroscience 119:277-91. 2003
    ..We propose a mechanism for seizure initiation involving these phenomena...
  18. ncbi request reprint Focal synchronization of ripples (80-200 Hz) in neocortex and their neuronal correlates
    F Grenier
    Laboratoire de Neurophysiologie, , , Quebec G1K 7P4, Canada
    J Neurophysiol 86:1884-98. 2001
    ..The mechanisms of generation and synchronization, and the possible functions of neocortical ripples in plasticity processes are discussed...
  19. ncbi request reprint Natural waking and sleep states: a view from inside neocortical neurons
    M Steriade
    Laboratoire de Neurophysiologie, Faculte de Medicine, Universite Laval, Quebec G1K 7P4, Canada
    J Neurophysiol 85:1969-85. 2001
    ..In view of the high firing rates in the functionally disconnected state of slow-wave sleep, we suggest that neocortical neurons are engaged in processing internally generated signals...
  20. ncbi request reprint Callosal responses of fast-rhythmic-bursting neurons during slow oscillation in cats
    Y Cisse
    Department of Anatomy and Physiology, Laval University, Centre de Recherche Universite Laval Robert Giffard, 2601 de la Canardiere, Quebec, Canada G1J 2G3
    Neuroscience 147:272-6. 2007
    ..Our data show that callosal volleys excite and lead to spiking in fast-rhythmic-bursting neurons during prolonged hyperpolarizations, thus enabling them to transmit information within intracortical networks during slow-wave sleep...
  21. ncbi request reprint Synaptic responsiveness of neocortical neurons to callosal volleys during paroxysmal depolarizing shifts
    Y Cisse
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, Canada G1K 7P4
    Neuroscience 124:231-9. 2004
    ....
  22. pmc Membrane bistability in thalamic reticular neurons during spindle oscillations
    Pablo Fuentealba
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, G1K 7P4, Canada
    J Neurophysiol 93:294-304. 2005
    ....
  23. ncbi request reprint Selective amplification of neocortical neuronal output by fast prepotentials in vivo
    S Crochet
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, Canada G1K 7P4
    Cereb Cortex 14:1110-21. 2004
    ..We suggest that FPPs represent attenuated spikes generated in hot spots of the dendritic arbor and constitute a powerful mechanism to reinforce the functional connections between specific elements of the cortical networks...
  24. pmc Neocortical post-traumatic epileptogenesis is associated with loss of GABAergic neurons
    Sinziana Avramescu
    Laval University Medical School, Centre de Recherche Universite Laval Robert Giffard, Quebec, QC G1J 2G3, Canada
    J Neurotrauma 26:799-812. 2009
    ....
  25. doi request reprint Cortical and thalamic components of neocortical kindling-induced epileptogenesis in behaving cats
    Dragos A Nita
    Department of Anatomy and Physiology, Laval University, Centre de Recherche Universite Laval Robert Giffard, 2601 Ch de la Canardiere, Quebec, Canada G1J 2G3
    Exp Neurol 211:518-28. 2008
    ..Following PPT/LC stimulation the burst firing of thalamocortical neurons was replaced by tonic firing. We conclude that the thalamus is involved in the mechanism of generation of OA but that it does not play an exclusive role...
  26. ncbi request reprint Synaptic plasticity in local cortical network in vivo and its modulation by the level of neuronal activity
    Sylvain Crochet
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, Canada G1K 7P4
    Cereb Cortex 16:618-31. 2006
    ..Our results demonstrate that high levels of neuronal activity in the cortical network promote potentiation and insure the stability of synaptic connections...
  27. doi request reprint Synaptic strength modulation after cortical trauma: a role in epileptogenesis
    Sinziana Avramescu
    Centre de Recherche Universite Laval Robert Giffard, Quebec, Canada
    J Neurosci 28:6760-72. 2008
    ..We suggest that homeostatic synaptic plasticity compensating the decreased activity in the undercut cortex leads to an uncontrollable cortical hyperexcitability and seizure generation...
  28. ncbi request reprint Hyperexcitability of intact neurons underlies acute development of trauma-related electrographic seizures in cats in vivo
    Lisa Topolnik
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, Canada G1K 7P4, Canada
    Eur J Neurosci 18:486-96. 2003
    ..Our results suggest that trauma-induced electrographic seizures first arise in cortical fields that are closest to the site of injury and such seizures do not require long-term neuronal reorganization...
  29. ncbi request reprint Synaptic interactions between thalamic and cortical inputs onto cortical neurons in vivo
    Pablo Fuentealba
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec G1K 7P4, Canada
    J Neurophysiol 91:1990-8. 2004
    ..These results suggest a short-lasting but strong shunting between thalamocortical and cortical inputs onto cortical neurons...
  30. ncbi request reprint Neocortical very fast oscillations (ripples, 80-200 Hz) during seizures: intracellular correlates
    Francois Grenier
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec G1K 7P4, Canada
    J Neurophysiol 89:841-52. 2003
    ....
  31. ncbi request reprint Waking-sleep modulation of paroxysmal activities induced by partial cortical deafferentation
    Dragos A Nita
    Laboratory of Neurophysiology, Faculty of Medicine, Laval University, Quebec, Canada G1K 7P4
    Cereb Cortex 17:272-83. 2007
    ....
  32. ncbi request reprint EPSP depression following neocortical seizures in cat
    Dragos A Nita
    Department of Anatomy and Physiology, Laval University, Centre de Recherche Universite Laval Robert Giffard, Quebec, Canada
    Epilepsia 49:705-9. 2008
    ..Data demonstrate a long-lasting decreased synaptic responsiveness following generalized spike-wave seizures slowly recovering in time...
  33. ncbi request reprint Modulation of synaptic transmission in neocortex by network activities
    Sylvain Crochet
    Department of Anatomy and Physiology, Laval University, Quebec, G1K 7P4, Canada
    Eur J Neurosci 21:1030-44. 2005
    ....
  34. pmc Prolonged hyperpolarizing potentials precede spindle oscillations in the thalamic reticular nucleus
    Pablo Fuentealba
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, QC, Canada G1K 7P4
    Proc Natl Acad Sci U S A 101:9816-21. 2004
    ..These data are further arguments for the generation of spindles within the thalamic RE nucleus...
  35. doi request reprint Analysis of morphological features of thalamocortical neurons from the ventroposterolateral nucleus of the cat
    Reza Zomorrodi
    Department of Physics, Laval University, Quebec, Quebec G1V 0A6, Canada
    J Comp Neurol 518:3541-56. 2010
    ..We also found that the dendritic branching pattern of each subtree of the cell had a wide range in symmetry index, whereas the mean path length did not show a large variation through the dendritic arborizations...
  36. pmc Neuronal mechanisms mediating the variability of somatosensory evoked potentials during sleep oscillations in cats
    Mario Rosanova
    Department of Anatomy and Physiology, School of Medicine, Laval University, Quebec, Canada G1K 7P4
    J Physiol 562:569-82. 2005
    ..However the reduced firing ability of the cortical neurones during the silent state may contribute to impair sensory processing during sleep...
  37. ncbi request reprint Increased propensity to seizures after chronic cortical deafferentation in vivo
    Dragos A Nita
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, Canada
    J Neurophysiol 95:902-13. 2006
    ..The increased amplitudes of both slow oscillation and SW seizures, and their enhanced synchrony expressed by shorter time of propagation, are ascribed to increased neuronal and network excitability after cortical undercut...
  38. ncbi request reprint Generators of ictal and interictal electroencephalograms associated with infantile spasms: intracellular studies of cortical and thalamic neurons
    M Steriade
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec, Canada G1 K 7P4
    Int Rev Neurobiol 49:77-98. 2002
  39. ncbi request reprint Neuronal plasticity in thalamocortical networks during sleep and waking oscillations
    Mircea Steriade
    Laboratoire de Neurophysiologie, Faculte de Medicine, Universite Laval, Quebec, Canada G1K 7P4
    Neuron 37:563-76. 2003
    ..Similar phenomena occur as a consequence of fast oscillations during brain-activated states...
  40. ncbi request reprint [Cellular basis of transition between sleep and electrographic seizures]
    Mircea Steriade
    Laboratoire de Neurophysiologie, Département d anatomie et physiologie, Faculte de Medecine, Universite Laval, Quebec, G1K 7P4 Canada
    Med Sci (Paris) 19:999-1002. 2003
    ..Simultaneously, thalamocortical neurons are steadily inhibited and cannot relay signals from the outside world to cortex. This may explain the unconsciousness during certain types of epilepsy...
  41. ncbi request reprint Synaptic enhancement induced through callosal pathways in cat association cortex
    Youssouf Cisse
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec G1K 7P4, Canada
    J Neurophysiol 92:3221-32. 2004
    ..These data suggest that callosal activities occurring within low-frequency and fast-frequency oscillations play a role in cortical synaptic plasticity...
  42. ncbi request reprint Electrophysiological properties and input-output organization of callosal neurons in cat association cortex
    Youssouf Cisse
    Laboratory of Neurophysiology, Faculty of Medicine, Laval University, Quebec G1K 7P4, Canada
    J Neurophysiol 89:1402-13. 2003
    ..Data are discussed in relation to the commissural spread of fast and slow normal oscillations as well as paroxysmal activities...
  43. ncbi request reprint Partial cortical deafferentation promotes development of paroxysmal activity
    Lisa Topolnik
    Laboratoire de Neurophysiologie, Faculte de Medecine, Universite Laval, Quebec G1K 7P4, Canada
    Cereb Cortex 13:883-93. 2003
    ..These results indicate that alterations in neuronal synchrony following neuronal trauma can be a critical factor triggering electrographic seizures...
  44. pmc Experimental evidence and modeling studies support a synchronizing role for electrical coupling in the cat thalamic reticular neurons in vivo
    Pablo Fuentealba
    Laboratory of Neurophysiology, Faculty of Medicine, Laval University, Quebec City, Canada G1K 7P4
    Eur J Neurosci 20:111-9. 2004
    ..These experimental and modeling data suggest that electrotonic coupling within the RE nucleus plays an important role in the generation and synchronization of low-frequency (spindling) activities in the thalamus...
  45. doi request reprint State-dependent slow outlasting activities following neocortical kindling in cats
    Dragos A Nita
    Department of Anatomy and Physiology, Laval University, Centre de Recherche Universite Laval Robert Giffard, 2601 de la Canardiere, Quebec, Canada G1J 2G3
    Exp Neurol 211:456-68. 2008
    ..Our results suggest that such rhythmic long-lasting oscillatory activity outlasting seizures are the key factor of epileptogenesis, leading to epilepsy...
  46. doi request reprint Subcellular distribution of low-voltage activated T-type Ca2+ channel subunits (Ca(v)3.1 and Ca(v)3.3) in reticular thalamic neurons of the cat
    Krisztina Kovacs
    Centre de Recherche Universite Laval Robert Giffard, Quebec, Quebec, Canada
    J Neurosci Res 88:448-60. 2010
    ..Our results demonstrate a higher density of low-threshold Ca(2+) channels in distal dendrites and provide further evidence of the role of RE neuron dendrites in the generation of prolonged, low-threshold spike bursts...
  47. pmc Homeostatic synaptic plasticity can explain post-traumatic epileptogenesis in chronically isolated neocortex
    Arthur R Houweling
    The Salk Institute, Computational Neurobiology Laboratory, La Jolla, CA 92037, USA
    Cereb Cortex 15:834-45. 2005
    ..Our results support a role for homeostatic synaptic plasticity as a novel mechanism of post-traumatic epileptogenesis...
  48. pmc Frequency-selective augmenting responses by short-term synaptic depression in cat neocortex
    Arthur R Houweling
    Computational Neurobiology Laboratory, The Salk Institute, La Jolla, CA 92037, USA
    J Physiol 542:599-617. 2002
    ..These results suggest that short-term plasticity of cortical synapses could shape the dynamics of synchronized oscillations in the brain...
  49. ncbi request reprint Model of thalamocortical slow-wave sleep oscillations and transitions to activated States
    Maxim Bazhenov
    The Salk Institute, Howard Hughes Medical Institute, Computational Neurobiology Laboratory, La Jolla, California 92037, USA
    J Neurosci 22:8691-704. 2002
    ..The model describes many essential features of SWS and activated states in the thalamocortical system as well as the transition between them...
  50. ncbi request reprint Inhibition determines membrane potential dynamics and controls action potential generation in awake and sleeping cat cortex
    Michelle Rudolph
    Integrative and Computational Neuroscience Unit, Centre National de la Recherche Scientifique, 91198 Gif sur Yvette, France
    J Neurosci 27:5280-90. 2007
    ....
  51. ncbi request reprint Role of network dynamics in shaping spike timing reliability
    Maxim Bazhenov
    Salk Institute, 10010 North Torrey Pines Road, La Jolla, California 92037, USA
    Phys Rev E Stat Nonlin Soft Matter Phys 72:041903. 2005
    ..The underlying dynamical mechanisms of reliability enhancement are discussed...
  52. ncbi request reprint Precise long-range synchronization of activity and silence in neocortical neurons during slow-wave oscillations [corrected]
    Maxim Volgushev
    Department of Neurophysiology, Ruhr University Bochum, D 44780 Bochum, Germany
    J Neurosci 26:5665-72. 2006
    ..Revealing this yet unknown large-scale mechanism, which switches network activity to silence, will aid our understanding of the origin of brain rhythms in normal function and pathology...
  53. ncbi request reprint Detection of active and silent states in neocortical neurons from the field potential signal during slow-wave sleep
    Mikhail Mukovski
    Department of Neurophysiology, Ruhr University Bochum, Bochum, Germany
    Cereb Cortex 17:400-14. 2007
    ..These results open new perspectives for studying differential operation of neural networks during periods of activity and silence, which rapidly alternate on the subsecond scale...
  54. pmc Slow state transitions of sustained neural oscillations by activity-dependent modulation of intrinsic excitability
    Flavio Frohlich
    The Salk Institute for Biological Studies, Computational Neurobiology Laboratory, Howard Hughes Medical Institute, La Jolla, California 92037, USA
    J Neurosci 26:6153-62. 2006
    ..We therefore predict that extracellular potassium dynamics can cause alternating episodes of fast and slow oscillatory states in both normal and epileptic neocortical networks...