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Self-Organized Near-Zero-Lag Synchronization Induced by Spike-Timing Dependent Plasticity in Cortical Populations.

Matias FS, Carelli PV, Mirasso CR, Copelli M - PLoS ONE (2015)

Bottom Line: We show that STDP can promote auto-organized zero-lag synchronization in unidirectionally coupled neuronal populations.We also find synchronization regimes with negative phase difference (AS) that are stable against plasticity.Finally, we show that the interplay between negative phase difference and STDP provides limited synaptic weight distribution without the need of imposing artificial boundaries.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Física, Universidade Federal de Alagoas, Maceió AL 57072-970, Brazil.

ABSTRACT
Several cognitive tasks related to learning and memory exhibit synchronization of macroscopic cortical areas together with synaptic plasticity at neuronal level. Therefore, there is a growing effort among computational neuroscientists to understand the underlying mechanisms relating synchrony and plasticity in the brain. Here we numerically study the interplay between spike-timing dependent plasticity (STDP) and anticipated synchronization (AS). AS emerges when a dominant flux of information from one area to another is accompanied by a negative time lag (or phase). This means that the receiver region pulses before the sender does. In this paper we study the interplay between different synchronization regimes and STDP at the level of three-neuron microcircuits as well as cortical populations. We show that STDP can promote auto-organized zero-lag synchronization in unidirectionally coupled neuronal populations. We also find synchronization regimes with negative phase difference (AS) that are stable against plasticity. Finally, we show that the interplay between negative phase difference and STDP provides limited synaptic weight distribution without the need of imposing artificial boundaries.

No MeSH data available.


Neuronal firing patterns in the DS and AS regimes due to STDP.(a)-(d) Raster plots of each population in the DS and AS regimes. Black dots are neurons from the Master population. Red dots are neurons from the Slave-Interneuron population. Neurons 0 to 399 are excitatory, whereas neurons 400 to 499 are inhibitory. (e) Histogram of the time delay between the closest spikes in each cycle of all coupled pairs whose pre-synaptic neuron is in the M population and the post-synaptic neuron is in the S population. The blue distribution represents a DS regime and the red distribution represents an AS regime. The inhibitory conductances in the S population is set to gIS = 16 nS in the DS regime, and gIS = 4 nS in the AS regime.
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pone.0140504.g003: Neuronal firing patterns in the DS and AS regimes due to STDP.(a)-(d) Raster plots of each population in the DS and AS regimes. Black dots are neurons from the Master population. Red dots are neurons from the Slave-Interneuron population. Neurons 0 to 399 are excitatory, whereas neurons 400 to 499 are inhibitory. (e) Histogram of the time delay between the closest spikes in each cycle of all coupled pairs whose pre-synaptic neuron is in the M population and the post-synaptic neuron is in the S population. The blue distribution represents a DS regime and the red distribution represents an AS regime. The inhibitory conductances in the S population is set to gIS = 16 nS in the DS regime, and gIS = 4 nS in the AS regime.

Mentions: Although synchronized oscillations are collective phenomena, the DS and AS regimes can also be represented at the neuronal level. The raster plots in Fig 3(a)–3(d) illustrate the oscillatory behavior of the coupled populations. Black (red) dashed lines indicate the time of peak average activity of the Master (Slave-Interneuron) population (see Methods for more details). In the DS regime the darker regions in the Slave-Interneuron population occur shortly after the ones in the Master population (see Fig 3(a) and 3(b)). On the contrary, in the AS regime, the darker regions in the Slave-Interneuron population occur before the ones in the Master population (see Fig 3(c) and 3(d)). However, there is a fraction of the neurons in the Master population which spikes before the peak of the Slave-Interneuron activity. The histograms in Fig 3(e) show the probability density of spike-timing intervals between each spike from neurons in the S population and the nearest spike from their respective pre-synaptic neurons in the M population. Although there are positive and negative values for the spike-timing intervals in both regimes, the peak and the mean of the distribution have positive values in the DS regime (blue, gIS = 16 nS) and negative values in the AS regime (red, gIS = 4 nS).


Self-Organized Near-Zero-Lag Synchronization Induced by Spike-Timing Dependent Plasticity in Cortical Populations.

Matias FS, Carelli PV, Mirasso CR, Copelli M - PLoS ONE (2015)

Neuronal firing patterns in the DS and AS regimes due to STDP.(a)-(d) Raster plots of each population in the DS and AS regimes. Black dots are neurons from the Master population. Red dots are neurons from the Slave-Interneuron population. Neurons 0 to 399 are excitatory, whereas neurons 400 to 499 are inhibitory. (e) Histogram of the time delay between the closest spikes in each cycle of all coupled pairs whose pre-synaptic neuron is in the M population and the post-synaptic neuron is in the S population. The blue distribution represents a DS regime and the red distribution represents an AS regime. The inhibitory conductances in the S population is set to gIS = 16 nS in the DS regime, and gIS = 4 nS in the AS regime.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4608682&req=5

pone.0140504.g003: Neuronal firing patterns in the DS and AS regimes due to STDP.(a)-(d) Raster plots of each population in the DS and AS regimes. Black dots are neurons from the Master population. Red dots are neurons from the Slave-Interneuron population. Neurons 0 to 399 are excitatory, whereas neurons 400 to 499 are inhibitory. (e) Histogram of the time delay between the closest spikes in each cycle of all coupled pairs whose pre-synaptic neuron is in the M population and the post-synaptic neuron is in the S population. The blue distribution represents a DS regime and the red distribution represents an AS regime. The inhibitory conductances in the S population is set to gIS = 16 nS in the DS regime, and gIS = 4 nS in the AS regime.
Mentions: Although synchronized oscillations are collective phenomena, the DS and AS regimes can also be represented at the neuronal level. The raster plots in Fig 3(a)–3(d) illustrate the oscillatory behavior of the coupled populations. Black (red) dashed lines indicate the time of peak average activity of the Master (Slave-Interneuron) population (see Methods for more details). In the DS regime the darker regions in the Slave-Interneuron population occur shortly after the ones in the Master population (see Fig 3(a) and 3(b)). On the contrary, in the AS regime, the darker regions in the Slave-Interneuron population occur before the ones in the Master population (see Fig 3(c) and 3(d)). However, there is a fraction of the neurons in the Master population which spikes before the peak of the Slave-Interneuron activity. The histograms in Fig 3(e) show the probability density of spike-timing intervals between each spike from neurons in the S population and the nearest spike from their respective pre-synaptic neurons in the M population. Although there are positive and negative values for the spike-timing intervals in both regimes, the peak and the mean of the distribution have positive values in the DS regime (blue, gIS = 16 nS) and negative values in the AS regime (red, gIS = 4 nS).

Bottom Line: We show that STDP can promote auto-organized zero-lag synchronization in unidirectionally coupled neuronal populations.We also find synchronization regimes with negative phase difference (AS) that are stable against plasticity.Finally, we show that the interplay between negative phase difference and STDP provides limited synaptic weight distribution without the need of imposing artificial boundaries.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Física, Universidade Federal de Alagoas, Maceió AL 57072-970, Brazil.

ABSTRACT
Several cognitive tasks related to learning and memory exhibit synchronization of macroscopic cortical areas together with synaptic plasticity at neuronal level. Therefore, there is a growing effort among computational neuroscientists to understand the underlying mechanisms relating synchrony and plasticity in the brain. Here we numerically study the interplay between spike-timing dependent plasticity (STDP) and anticipated synchronization (AS). AS emerges when a dominant flux of information from one area to another is accompanied by a negative time lag (or phase). This means that the receiver region pulses before the sender does. In this paper we study the interplay between different synchronization regimes and STDP at the level of three-neuron microcircuits as well as cortical populations. We show that STDP can promote auto-organized zero-lag synchronization in unidirectionally coupled neuronal populations. We also find synchronization regimes with negative phase difference (AS) that are stable against plasticity. Finally, we show that the interplay between negative phase difference and STDP provides limited synaptic weight distribution without the need of imposing artificial boundaries.

No MeSH data available.