Robustness effect of gap junctions between Golgi cells on cerebellar cortex oscillations
نویسندگان
چکیده
BACKGROUND Previous one-dimensional network modeling of the cerebellar granular layer has been successfully linked with a range of cerebellar cortex oscillations observed in vivo. However, the recent discovery of gap junctions between Golgi cells (GoCs), which may cause oscillations by themselves, has raised the question of how gap-junction coupling affects GoC and granular-layer oscillations. To investigate this question, we developed a novel two-dimensional computational model of the GoC-granule cell (GC) circuit with and without gap junctions between GoCs. RESULTS Isolated GoCs coupled by gap junctions had a strong tendency to generate spontaneous oscillations without affecting their mean firing frequencies in response to distributed mossy fiber input. Conversely, when GoCs were synaptically connected in the granular layer, gap junctions increased the power of the oscillations, but the oscillations were primarily driven by the synaptic feedback loop between GoCs and GCs, and the gap junctions did not change oscillation frequency or the mean firing rate of either GoCs or GCs. CONCLUSION Our modeling results suggest that gap junctions between GoCs increase the robustness of cerebellar cortex oscillations that are primarily driven by the feedback loop between GoCs and GCs. The robustness effect of gap junctions on synaptically driven oscillations observed in our model may be a general mechanism, also present in other regions of the brain.
منابع مشابه
Identification of an Inhibitory Circuit that Regulates Cerebellar Golgi Cell Activity
Here we provide evidence that revises the inhibitory circuit diagram of the cerebellar cortex. It was previously thought that Golgi cells, interneurons that are the sole source of inhibition onto granule cells, were exclusively coupled via gap junctions. Moreover, Golgi cells were believed to receive GABAergic inhibition from molecular layer interneurons (MLIs). Here we challenge these views by...
متن کاملSpatiotemporal network coding of physiological mossy fiber inputs by the cerebellar granular layer
The granular layer, which mainly consists of granule and Golgi cells, is the first stage of the cerebellar cortex and processes spatiotemporal information transmitted by mossy fiber inputs with a wide variety of firing patterns. To study its dynamics at multiple time scales in response to inputs approximating real spatiotemporal patterns, we constructed a large-scale 3D network model of the gra...
متن کاملInferior olive hypertrophy and cerebellar learning are both needed to explain ocular oscillations in oculopalatal tremor.
A new model of cerebellar learning explains how the cerebellum can generate arbitrary output waveforms to adjust output timing in the classical delay conditioning. This model can also reproduce the low frequency ocular oscillations seen in oculopalatal tremor (OPT). A novel circuit in the cerebellum uses both interneurons (INs) and Purkinje cells (PC) to control timing. Brain lesions that cause...
متن کاملFunctional Properties of Dendritic Gap Junctions in Cerebellar Golgi Cells
The strength and variability of electrical synaptic connections between GABAergic interneurons are key determinants of spike synchrony within neuronal networks. However, little is known about how electrical coupling strength is determined due to the inaccessibility of gap junctions on the dendritic tree. We investigated the properties of gap junctions in cerebellar interneurons by combining pai...
متن کاملNeocortical networks entrain neuronal circuits in cerebellar cortex.
Activity in neocortex is often characterized by synchronized oscillations of neurons and networks, resulting in the generation of a local field potential (LFP) and electroencephalogram. Do the neuronal networks of the cerebellum also generate synchronized oscillations and are they under the influence of those in the neocortex? Here we show that, in the absence of any overt external stimulus, th...
متن کامل