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Data
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Dopaminergic cell bursting model (Kuznetsov et al 2006)
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Dopaminergic neurons of the midbrain fire spontaneously at rates
<10/s and ordinarily will not exceed this range even when driven with
somatic current injection. During spontaneous
bursting of dopaminergic neurons in vivo, bursts related to reward
expectation in behaving animals, and bursts generated by dendritic
application of N-methyl-D-aspartate (NMDA) agonists, transient firing
attains rates well above this range. We suggest a way such highfrequency
firing may occur in response to dendritic NMDA receptor
activation. We have extended the coupled oscillator model of the
dopaminergic neuron, which represents the soma and dendrites as
electrically coupled compartments with different natural spiking frequencies,
by addition of dendritic AMPA (voltage-independent) or
NMDA (voltage-dependent) synaptic conductance. Both soma and
dendrites contain a simplified version of the calcium-potassium mechanism
known to be the mechanism for slow spontaneous oscillation
and background firing in dopaminergic cells. We show that because of its voltage dependence,
NMDA receptor activation acts to amplify the effect on the
soma of the high-frequency oscillation of the dendrites, which is
normally too weak to exert a large influence on the overall oscillation
frequency of the neuron.
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Neuron or other electrically excitable cell Show
Other
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Kuznetsov AS, Kopell NJ, Wilson CJ (2006) Show
Other
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tmm46@email.med.yale.edu
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