|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Center for Computational Science, Tulane University, New Orleans, Louisiana, USA
2 Department of Psychology, University of New Orleans, New Orleans, Louisiana, USA
3 Department of Neurology, Oregon Health Sciences University, Portland, Oregon, USA
* To whom correspondence should be addressed. E-mail: ccanavie{at}uno.edu.
Midbrain dopaminergic (DA) neurons in vivo exhibit two major firing patterns: single-spike firing and burst firing. The firing pattern expressed is dependent upon both the intrinsic properties of the neurons and their excitatory and inhibitory synaptic inputs. Experimental data suggest that the activation of NMDA and GABAA receptors is a crucial contributor to the initiation and suppression of burst firing, respectively, and that blocking Ca2+-activated potassium SK channels can facilitate burst firing. A multi-compartmental model of a DA neuron with a branching structure was developed and calibrated based on in vitro experimental data, in order to explore the effects of different levels of activation of NMDA and GABAA receptors, as well as the modulation of the SK current on the firing activity. The simulated tonic activation of GABAA receptors was calibrated by taking into account the difference in the electrotonic properties in vivo versus in vitro. Although NMDA evoked currents are required for burst generation in the model, currents evoked by GABAA-receptor activation can also regulate the firing pattern. For example, the model predicts that increasing the level of NMDA receptor activation can produce excessive depolarization that prevents burst firing, but a concurrent increase in the activation of GABAA receptors can restore burst firing. Another prediction of the model is that blocking the SK channel current in vivo will facilitate bursting, but not as robustly as blocking the GABAA receptors.
This article has been cited by other articles:
![]() |
L. S. Zweifel, J. G. Parker, C. J. Lobb, A. Rainwater, V. Z. Wall, J. P. Fadok, M. Darvas, M. J. Kim, S. J. Y. Mizumori, C. A. Paladini, et al. From the Cover: Feature Article: Disruption of NMDAR-dependent burst firing by dopamine neurons provides selective assessment of phasic dopamine-dependent behavior PNAS, May 5, 2009; 106(18): 7281 - 7288. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Migliore, C. Cannia, and C. C. Canavier A Modeling Study Suggesting a Possible Pharmacological Target to Mitigate the Effects of Ethanol on Reward-Related Dopaminergic Signaling J Neurophysiol, May 1, 2008; 99(5): 2703 - 2707. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. C. Canavier, S. A. Oprisan, J. C. Callaway, H. Ji, and P. D. Shepard Computational Model Predicts a Role for ERG Current in Repolarizing Plateau Potentials in Dopamine Neurons: Implications for Modulation of Neuronal Activity J Neurophysiol, November 1, 2007; 98(5): 3006 - 3022. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. W. Hopf, M. Martin, B. T. Chen, M. S. Bowers, M. M. Mohamedi, and A. Bonci Withdrawal From Intermittent Ethanol Exposure Increases Probability of Burst Firing in VTA Neurons In Vitro J Neurophysiol, October 1, 2007; 98(4): 2297 - 2310. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. C. Canavier and R. S. Landry An Increase in AMPA and a Decrease in SK Conductance Increase Burst Firing by Different Mechanisms in a Model of a Dopamine Neuron In Vivo J Neurophysiol, November 1, 2006; 96(5): 2549 - 2563. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. S. Kuznetsov, N. J. Kopell, and C. J. Wilson Transient High-Frequency Firing in a Coupled-Oscillator Model of the Mesencephalic Dopaminergic Neuron J Neurophysiol, February 1, 2006; 95(2): 932 - 947. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Soto-Trevino, P. Rabbah, E. Marder, and F. Nadim Computational Model of Electrically Coupled, Intrinsically Distinct Pacemaker Neurons J Neurophysiol, July 1, 2005; 94(1): 590 - 604. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. A. McClung, K. Sidiropoulou, M. Vitaterna, J. S. Takahashi, F. J. White, D. C. Cooper, and E. J. Nestler Regulation of dopaminergic transmission and cocaine reward by the Clock gene PNAS, June 28, 2005; 102(26): 9377 - 9381. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |