Tonic firing

In this cell, the tonic firing of the neuron during this behavior is increased by amphetamine. This result is consistent with our finding that neostriatal units projecting to the pars reticulata are inhibited by amphetamine. The resulting disinhibition of these nigral units may, in turn, increase their tonic inhibitory control over their target stmetures, such as the deep layers of the superior colliculis (Chevalier et al. 1985). the thalamus (Deniau and Chevalier 1985) and the PPN. These output stmetures are known to affect the motor behaviors that amphetamine influences (Di Chiara et al. 1979). 

Zhang ZW. Serotonin induces tonic firing in layer V pyramidal neurons of rat prefrontal cortex during postnatal development. J Neurosci 2003 23 (8) 3373-3384. 

Fig. 7.9 Computer simulations of a neuronal network (lOx 10 neurons) with nearest neighbor gap-junction coupling (see equations). The diagrams show the local mean field potentials (LFP) which are calculated as the mean potential values V of all neurons during continuously increasing coupling strength gc- Insets illustrate the different types of patterns in which the neurons originally operate (with randomly set initial values), (a) The network of tonic firing...

Fig. 7.10 Computer simulation of two gap-junction coupled neurons which originally are operating at different dynamic states, one in the tonic firing regime and the other one in the bursting regime (also indicated in Fig. 6.8b by the points T and B, respectively with the arrow S pointing on the completely synchronized state), (a) Bifurcation diagrams of interspike intervals (ISI) of the originally...

Reynolds. J, N., Hyland. B. L, and Wickens, J. R. (2004). Modulation of an afterhyperpolarization by the. substantia nigra induces pauses in the tonic firing of. striatal cholinergic imerncurotis, J. Neurosci. 24,9870-9877,... 

Also within the brain stem is another type of saccade neuron called the omnipause neuron (OPN). The OPN fires tonicaUy at approximately 200 Hz during periods of fixation, and is silent during saccades. The OPN stops filing approximately 10 to 12 msec before a saccade and resumes tonic firing approximately 10 msec before the end of the saccade. The OPN are known to inhibit the MLBN, and are inhibited by the LLBN. The OPN activity is responsible for the precise timing between groups of neurons that causes a saccade. 

The ipsilateral LLBN and EBN are stimulated by the contralateral SC burst cells. The LLBN then inhibits the tonic firing of the OPN. The contralateral FN also stimulates the ipsilateral LLBN and... 

Contralateral Fastigial Nucleus 20 ms 200 Hz Pulse ends with pause approx. 10 ms before saccade ends, resumes tonic firing approx. 10 ms after saccade ends... 

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