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Comparison and regulation of neuronal synchronization for various STDP rules.

Ruan Y, Zhao G - Neural Plast. (2009)

Bottom Line: We discuss effects of various experimentally supported STDP learning rules on frequency synchronization of two unidirectional coupled neurons systematically.First, we show that synchronization windows for all STDP rules cannot be enhanced compared to constant connection under the same model.Thus, we give some explanations by analyzing the synchronization mechanisms for various STDP rules finally.

View Article: PubMed Central - PubMed

Affiliation: Institute of Complex Bio-dynamics, Jiangxi Blue Sky University, Nanchang, Jiangxi 330098, China.

ABSTRACT
We discuss effects of various experimentally supported STDP learning rules on frequency synchronization of two unidirectional coupled neurons systematically. First, we show that synchronization windows for all STDP rules cannot be enhanced compared to constant connection under the same model. Then, we explore the influence of learning parameters on synchronization window and find optimal parameters that lead to the widest window. Our findings indicate that synchronization strongly depends on the specific shape and the parameters of the STDP update rules. Thus, we give some explanations by analyzing the synchronization mechanisms for various STDP rules finally.

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Four pictures are obtained from the same values of parameters and model of Figure 3. The front four pictures take the function of tanh to limit synaptic strength for c-STDP and dc-STDP rules. Figures 7(a)  and 7(c)  show the average spike time interval of postneuron's and preneuron's spike time for c-STDP and dc-STDP over some time after a period time of coupling, respectively. Figures 7(b)  and 7(d)  present the average synaptic strength for c-STDP and dc-STDP rule, respectively. Each subplot has two dash lines what indicate the boundary of synchronization window.
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fig7: Four pictures are obtained from the same values of parameters and model of Figure 3. The front four pictures take the function of tanh to limit synaptic strength for c-STDP and dc-STDP rules. Figures 7(a) and 7(c) show the average spike time interval of postneuron's and preneuron's spike time for c-STDP and dc-STDP over some time after a period time of coupling, respectively. Figures 7(b) and 7(d) present the average synaptic strength for c-STDP and dc-STDP rule, respectively. Each subplot has two dash lines what indicate the boundary of synchronization window.

Mentions: Figures 7(a) and 7(b) show the average Δt = tpostspike − tprespike, and synaptic strength after an episode of coupling time for c-STDP rule. Parameters in Figure 7 are same as those in Figure 3. There are two types of behavior for Δt when synchronization occurs (Figure 7(a)). In a section of constant Δt, the synaptic strength does not achieve the maximal value. Apparently, in this situation, postsynaptic neuron achieves synchronization with the pre-synaptic neuron depending on the balance between potentiation and depression of synaptic conductance. In the rest part of synchronization window, the synaptic strength achieves the maximal value (Figure 7(b)). It indicates that for larger T2, postsynaptic neuron achieves synchronization depending on the effect of maximal synaptic conductance. For dc-aSTDP rule, the synchronization mechanisms are similar to c-STDP rule. When the post-synaptic neuron synchronizes with the pre-synaptic neuron under small T2, the change of synaptic potentiation and depression cancel each other. However, for the small portion of synchronization window at the right side, synaptic conductance gets the maximum at the stationary synchronized state.


Comparison and regulation of neuronal synchronization for various STDP rules.

Ruan Y, Zhao G - Neural Plast. (2009)

Four pictures are obtained from the same values of parameters and model of Figure 3. The front four pictures take the function of tanh to limit synaptic strength for c-STDP and dc-STDP rules. Figures 7(a)  and 7(c)  show the average spike time interval of postneuron's and preneuron's spike time for c-STDP and dc-STDP over some time after a period time of coupling, respectively. Figures 7(b)  and 7(d)  present the average synaptic strength for c-STDP and dc-STDP rule, respectively. Each subplot has two dash lines what indicate the boundary of synchronization window.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2712720&req=5

fig7: Four pictures are obtained from the same values of parameters and model of Figure 3. The front four pictures take the function of tanh to limit synaptic strength for c-STDP and dc-STDP rules. Figures 7(a) and 7(c) show the average spike time interval of postneuron's and preneuron's spike time for c-STDP and dc-STDP over some time after a period time of coupling, respectively. Figures 7(b) and 7(d) present the average synaptic strength for c-STDP and dc-STDP rule, respectively. Each subplot has two dash lines what indicate the boundary of synchronization window.
Mentions: Figures 7(a) and 7(b) show the average Δt = tpostspike − tprespike, and synaptic strength after an episode of coupling time for c-STDP rule. Parameters in Figure 7 are same as those in Figure 3. There are two types of behavior for Δt when synchronization occurs (Figure 7(a)). In a section of constant Δt, the synaptic strength does not achieve the maximal value. Apparently, in this situation, postsynaptic neuron achieves synchronization with the pre-synaptic neuron depending on the balance between potentiation and depression of synaptic conductance. In the rest part of synchronization window, the synaptic strength achieves the maximal value (Figure 7(b)). It indicates that for larger T2, postsynaptic neuron achieves synchronization depending on the effect of maximal synaptic conductance. For dc-aSTDP rule, the synchronization mechanisms are similar to c-STDP rule. When the post-synaptic neuron synchronizes with the pre-synaptic neuron under small T2, the change of synaptic potentiation and depression cancel each other. However, for the small portion of synchronization window at the right side, synaptic conductance gets the maximum at the stationary synchronized state.

Bottom Line: We discuss effects of various experimentally supported STDP learning rules on frequency synchronization of two unidirectional coupled neurons systematically.First, we show that synchronization windows for all STDP rules cannot be enhanced compared to constant connection under the same model.Thus, we give some explanations by analyzing the synchronization mechanisms for various STDP rules finally.

View Article: PubMed Central - PubMed

Affiliation: Institute of Complex Bio-dynamics, Jiangxi Blue Sky University, Nanchang, Jiangxi 330098, China.

ABSTRACT
We discuss effects of various experimentally supported STDP learning rules on frequency synchronization of two unidirectional coupled neurons systematically. First, we show that synchronization windows for all STDP rules cannot be enhanced compared to constant connection under the same model. Then, we explore the influence of learning parameters on synchronization window and find optimal parameters that lead to the widest window. Our findings indicate that synchronization strongly depends on the specific shape and the parameters of the STDP update rules. Thus, we give some explanations by analyzing the synchronization mechanisms for various STDP rules finally.

Show MeSH