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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.


STDP in a microcircuit of three neurons.(a) Three neurons coupled by chemical synapses in the master-slave-interneuron (MSI) configuration. The excitatory synaptic weight gMS may change through STDP rules. (b)-(d) Left: membrane potential of the master (M, black), the slave with no plasticity (S, grey) and the slave with STDP (SSTDP, red). Right: The synaptic weight gMS as a function of time. The vertical arrow indicates the moment at which plasticity rules were switched on. The system can exhibit synchronized regimes with positive time delay (delayed synchronization, DS) or negative time delay (anticipated synchronization, AS) and a phase-drift (PD) regime. (b) The system initiates in the DS regime and remains in it. The synaptic weight increases from the initial value to the upper boundary. (c) The system initiates in the AS regime, then gMS decreases to values smaller than 6 nS and the phase-drift (PD) regime is reached. (d) The system initiates in the PD regime and ends in a different PD regime. (e) Without STDP, the time delay τ between M and S is a smooth function of the weight gMS. If we turn on STDP, the DS region (gMS > 32 nS) leads to LTP whereas the AS region (6 < gMS < 32 nS) leads to LTD. For gMS < 6 nS the system exhibits a PD regime.
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pone.0140504.g001: STDP in a microcircuit of three neurons.(a) Three neurons coupled by chemical synapses in the master-slave-interneuron (MSI) configuration. The excitatory synaptic weight gMS may change through STDP rules. (b)-(d) Left: membrane potential of the master (M, black), the slave with no plasticity (S, grey) and the slave with STDP (SSTDP, red). Right: The synaptic weight gMS as a function of time. The vertical arrow indicates the moment at which plasticity rules were switched on. The system can exhibit synchronized regimes with positive time delay (delayed synchronization, DS) or negative time delay (anticipated synchronization, AS) and a phase-drift (PD) regime. (b) The system initiates in the DS regime and remains in it. The synaptic weight increases from the initial value to the upper boundary. (c) The system initiates in the AS regime, then gMS decreases to values smaller than 6 nS and the phase-drift (PD) regime is reached. (d) The system initiates in the PD regime and ends in a different PD regime. (e) Without STDP, the time delay τ between M and S is a smooth function of the weight gMS. If we turn on STDP, the DS region (gMS > 32 nS) leads to LTP whereas the AS region (6 < gMS < 32 nS) leads to LTD. For gMS < 6 nS the system exhibits a PD regime.

Mentions: The simplest biophysical neuronal model which exhibits AS is the 3-neuron motif shown in Fig 1(a) [7]. It consists of three identical Hodgkin-Huxley neurons spiking periodically: the master (M), the slave (S), and the interneuron (I), coupled by chemical synapses. They are connected via two excitatory synapses, from M to S (gMS) and from S to I (gSI), as well as an inhibitory synapse from I to S (gIS, see Methods for more details). The time delay τ = tS − tM is defined as the spike timing difference between the S and M neurons. It was shown that without plasticity, this motif may present two phase-locking regimes: DS (τ > 0) and AS (τ < 0), as well as a phase-drift (PD) regime [7]. The membrane potentials of M and S shown in Fig 1(b)–1(d)) illustrate each regime.


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)

STDP in a microcircuit of three neurons.(a) Three neurons coupled by chemical synapses in the master-slave-interneuron (MSI) configuration. The excitatory synaptic weight gMS may change through STDP rules. (b)-(d) Left: membrane potential of the master (M, black), the slave with no plasticity (S, grey) and the slave with STDP (SSTDP, red). Right: The synaptic weight gMS as a function of time. The vertical arrow indicates the moment at which plasticity rules were switched on. The system can exhibit synchronized regimes with positive time delay (delayed synchronization, DS) or negative time delay (anticipated synchronization, AS) and a phase-drift (PD) regime. (b) The system initiates in the DS regime and remains in it. The synaptic weight increases from the initial value to the upper boundary. (c) The system initiates in the AS regime, then gMS decreases to values smaller than 6 nS and the phase-drift (PD) regime is reached. (d) The system initiates in the PD regime and ends in a different PD regime. (e) Without STDP, the time delay τ between M and S is a smooth function of the weight gMS. If we turn on STDP, the DS region (gMS > 32 nS) leads to LTP whereas the AS region (6 < gMS < 32 nS) leads to LTD. For gMS < 6 nS the system exhibits a PD regime.
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pone.0140504.g001: STDP in a microcircuit of three neurons.(a) Three neurons coupled by chemical synapses in the master-slave-interneuron (MSI) configuration. The excitatory synaptic weight gMS may change through STDP rules. (b)-(d) Left: membrane potential of the master (M, black), the slave with no plasticity (S, grey) and the slave with STDP (SSTDP, red). Right: The synaptic weight gMS as a function of time. The vertical arrow indicates the moment at which plasticity rules were switched on. The system can exhibit synchronized regimes with positive time delay (delayed synchronization, DS) or negative time delay (anticipated synchronization, AS) and a phase-drift (PD) regime. (b) The system initiates in the DS regime and remains in it. The synaptic weight increases from the initial value to the upper boundary. (c) The system initiates in the AS regime, then gMS decreases to values smaller than 6 nS and the phase-drift (PD) regime is reached. (d) The system initiates in the PD regime and ends in a different PD regime. (e) Without STDP, the time delay τ between M and S is a smooth function of the weight gMS. If we turn on STDP, the DS region (gMS > 32 nS) leads to LTP whereas the AS region (6 < gMS < 32 nS) leads to LTD. For gMS < 6 nS the system exhibits a PD regime.
Mentions: The simplest biophysical neuronal model which exhibits AS is the 3-neuron motif shown in Fig 1(a) [7]. It consists of three identical Hodgkin-Huxley neurons spiking periodically: the master (M), the slave (S), and the interneuron (I), coupled by chemical synapses. They are connected via two excitatory synapses, from M to S (gMS) and from S to I (gSI), as well as an inhibitory synapse from I to S (gIS, see Methods for more details). The time delay τ = tS − tM is defined as the spike timing difference between the S and M neurons. It was shown that without plasticity, this motif may present two phase-locking regimes: DS (τ > 0) and AS (τ < 0), as well as a phase-drift (PD) regime [7]. The membrane potentials of M and S shown in Fig 1(b)–1(d)) illustrate each regime.

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.