|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
* To whom correspondence should be addressed. E-mail: rsachdev{at}utsa.edu.
Changes in spontaneous activity within the cortex recognized by sub-threshold fluctuations of the membrane potential of cortical neurons modified the response of cortical neurons to sensory stimuli. Sensory stimuli occurring in the hyperpolarized "Down" state evoked a larger depolarization and were more effective in evoking action potentials than stimuli occurring in the depolarized "Up" state. Direct electrical stimulation of the thalamus showed the same dependence on the cell's state at the time of the stimulus, ruling out a strictly thalamic mechanism. Stimuli were more effective at triggering action potentials in the Down state even during moderate depolarization or hyperpolarization of the somatic membrane potential. The PSP evoked from the Down state was larger than the Up state PSP, but achieved about the same peak membrane potential, which was also near the reversal potential of the PSP (about -51 mV). Chloride loading shifted the reversal potentials of both the Up state and the whisker-evoked PSP toward a more depolarized membrane potential. In addition, the threshold for action potentials evoked from the Down state was lower than for spikes evoked in the Up state. Thus the larger PSP from the Down state may be caused by its larger driving force, and the state-dependence of action potential generation in response to whisker stimulation may in part be related to a shift in threshold. Different mechanisms are therefore responsible for the state-dependence of PSP amplitude and the spike frequency response to the whisker stimulus.
This article has been cited by other articles:
![]() |
M. Diaz-Quesada and M. Maravall Intrinsic Mechanisms for Adaptive Gain Rescaling in Barrel Cortex J. Neurosci., January 16, 2008; 28(3): 696 - 710. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. A. Milojkovic, W.-L. Zhou, and S. D. Antic Voltage and calcium transients in basal dendrites of the rat prefrontal cortex J. Physiol., December 1, 2007; 585(2): 447 - 468. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Hasenstaub, R. N. S. Sachdev, and D. A. McCormick State Changes Rapidly Modulate Cortical Neuronal Responsiveness J. Neurosci., September 5, 2007; 27(36): 9607 - 9622. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Haider, A. Duque, A. R. Hasenstaub, Y. Yu, and D. A. McCormick Enhancement of Visual Responsiveness by Spontaneous Local Network Activity In Vivo J Neurophysiol, June 1, 2007; 97(6): 4186 - 4202. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Berger, A. Borgdorff, S. Crochet, F. B. Neubauer, S. Lefort, B. Fauvet, I. Ferezou, A. Carleton, H.-R. Luscher, and C. C. H. Petersen Combined Voltage and Calcium Epifluorescence Imaging In Vitro and In Vivo Reveals Subthreshold and Suprathreshold Dynamics of Mouse Barrel Cortex J Neurophysiol, May 1, 2007; 97(5): 3751 - 3762. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Kepecs and S. Raghavachari Gating Information by Two-State Membrane Potential Fluctuations J Neurophysiol, April 1, 2007; 97(4): 3015 - 3023. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Mukovski, S. Chauvette, I. Timofeev, and M. Volgushev Detection of Active and Silent States in Neocortical Neurons from the Field Potential Signal during Slow-Wave Sleep Cereb Cortex, February 1, 2007; 17(2): 400 - 414. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Haslinger, I. Ulbert, C. I. Moore, E. N. Brown, and A. Devor Analysis of LFP Phase Predicts Sensory Response of Barrel Cortex J Neurophysiol, September 1, 2006; 96(3): 1658 - 1663. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Waters and F. Helmchen Background synaptic activity is sparse in neocortex. J. Neurosci., August 9, 2006; 26(32): 8267 - 8277. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. M. Davies, G. L. Gerstein, and S. N. Baker Measurement of Time-Dependent Changes in the Irregularity of Neural Spiking J Neurophysiol, August 1, 2006; 96(2): 906 - 918. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Hentschke, F. Haiss, and C. Schwarz Central Signals Rapidly Switch Tactile Processing in Rat Barrel Cortex during Whisker Movements Cereb Cortex, August 1, 2006; 16(8): 1142 - 1156. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. F. Civillico and D. Contreras Integration of Evoked Responses in Supragranular Cortex Studied With Optical Recordings In Vivo J Neurophysiol, July 1, 2006; 96(1): 336 - 351. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Fujisawa, N. Matsuki, and Y. Ikegaya Single Neurons Can Induce Phase Transitions of Cortical Recurrent Networks with Multiple Internal States Cereb Cortex, May 1, 2006; 16(5): 639 - 654. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Haider, A. Duque, A. R. Hasenstaub, and D. A. McCormick Neocortical network activity in vivo is generated through a dynamic balance of excitation and inhibition. J. Neurosci., April 26, 2006; 26(17): 4535 - 4545. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Massimini, F. Ferrarelli, R. Huber, S. K. Esser, H. Singh, and G. Tononi Breakdown of Cortical Effective Connectivity During Sleep Science, September 30, 2005; 309(5744): 2228 - 2232. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Fontanini and J. M. Bower Variable Coupling Between Olfactory System Activity and Respiration in Ketamine/Xylazine Anesthetized Rats J Neurophysiol, June 1, 2005; 93(6): 3573 - 3581. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Rosanova and I. Timofeev Neuronal mechanisms mediating the variability of somatosensory evoked potentials during sleep oscillations in cats J. Physiol., January 15, 2005; 562(2): 569 - 582. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |