Structural constraints on the emergence of oscillations in multi-population neural networks

  1. Jie Zang
  2. Shenquan Liu  Is a corresponding author
  3. Pascal Helson
  4. Arvind Kumar  Is a corresponding author
  1. School of Mathematics, South China University of Technology, China
  2. Division of Computational Science and Technology, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Sweden
  3. Science for Life Laboratory, Sweden
5 figures, 11 tables and 1 additional file

Figures

Structural condition for oscillations: odd inhibitory cycle rule and its illustrations.

(a) Examples of oscillating motifs and non-oscillating motifs in Wilson-Cowan model. Motifs that cannot oscillate show features of Winner-take-all: the winner will inhibit other nodes with a high activity level. Inversely, the oscillatory ones all show features of winner-less competition, which may contribute to oscillation. (b) The odd inhibitory cycle rule for oscillation prediction with the sign condition of a network. (c) Illustrations of oscillation in complex networks. Based on the odd inhibitory cycle rule, Network I can’t oscillate, while Network II could oscillate by calculating the sums of their motifs. The red or black arrows indicate inhibition or excitation, respectively. Hollow nodes and solid nodes represent excitatory and inhibitory nodes, respectively.

The intuitive explanations of Theorem 1 and 2.

(a) A visual representation of why directed cycles are important in network oscillation. By rearranging all nodes, any network without directed cycles can be seen as a feed-forward network which will make the system reach a stable fixed point. (b) An intuitive explanation of the odd inhibitory cycle rule by showing the activities of two 6-node-loops. Odd inhibitory connections (bottom) can help the system oscillate, while even inhibitory connections has the opposite effect.

Figure 3 with 3 supplements
Influence of network properties on the oscillation frequency in motifs III and EII with Wilson-Cowan model.

(a) The changed network parameters are shown in the table. Red (green) connections are inhibitory (excitatory) and black arrows are the external inputs. (b-e) We systematically varied the synaptic delay time b, synaptic weights c, external input d, and self-connection e. These parameters were varied simultaneously for all the synapses i.e. in each simulation all synapses were homogeneous. Green, orange, red and turquoise respectively show the effect of synaptic delay, synaptic strength, external input and self-inhibition. See the Figure 3—figure supplement 1 and Figure 3—figure supplement 3 for more detailed results about III and EI network motifs.

Figure 3—figure supplement 1
Influence of III network properties on the oscillation frequency in Wilson-Cowan model.

The controlled properties in motif III, including delay time a, synaptic weights b, external input c, and self-connection d, are denoted successively by green, orange, red and blue. We controlled two factors once at a time to observe the reaction of oscillation frequency with sketch maps on the right as conclusions.

Figure 3—figure supplement 2
Effect of synaptic delays on motifs with even inhibition in the Wilson-Cowan model.

The synaptic delays are varied from 2ms to 10ms in motifs II, EEE, and EII, with corresponding external inputs to nodes being [4, 4], [2.2, 2, 1.8], and [3, 3, 3].

Figure 3—figure supplement 3
Influence of EI network properties on the oscillation frequency in Wilson-Cowan model.

The controlled properties in motif EI, including delay time a, synaptic weights b, external input c, and self-connection d, are denoted successively by green, orange, red and blue. We controlled two factors once at a time to observe the reaction of oscillation frequency with sketch maps on the right as conclusions.

Figure 4 with 6 supplements
Schematic of CBG network model with potential oscillators and the interaction between two oscillators in Wilson-Cowan model.

(a) CBG structure with red lines denoting inhibition and green lines denoting excitation, along with five potential oscillators based on the odd inhibitory cycle rule. (b) Oscillation in all BG motifs from 2 nodes to 6 nodes based on the odd inhibitory cycle rule. Each grid represents a separate motif. We use different colors to mark potential oscillators in each motif in BG, and each color means an oscillator from panel a. For more details, see Figure 4—figure supplements 16. (c) The reaction of oscillation frequency to different external inputs to D2 and STN in a BG subnetwork. External inputs to Proto and Arky are 1 and 3, respectively. (d) Same thing as c but ruining the connection from D2 to Proto. (e) Same thing as c but destroying the connections from STN and increasing the input to Proto from 1 to 4.

Figure 4—figure supplement 1
All 2-node-motifs in CBG network.

Potential oscillating motifs behind these subnetworks are marked with different colors. Yellow: motif Proto-STN; Orange: motif STN-GPi-Th-cortex; Blue: motif Proto-Arky-D2; Green: motif Proto-FSN-D2; Purple: motif Proto-GPi-Th-Cortex-D2.

Figure 4—figure supplement 2
All 3-node-motifs in CBG network.

Potential oscillating motifs behind these subnetworks are marked with different colors. Yellow: motif Proto-STN; Orange: motif STN-GPi-Th-cortex; Blue: motif Proto-Arky-D2; Green: motif Proto-FSN-D2; Purple: motif Proto-GPi-Th-Cortex-D2.

Figure 4—figure supplement 3
All 4-node-motifs in CBG network.

Potential oscillating motifs behind these subnetworks are marked with different colors. Yellow: motif Proto-STN; Orange: motif STN-GPi-Th-cortex; Blue: motif Proto-Arky-D2; Green: motif Proto-FSN-D2; Purple: motif Proto-GPi-Th-Cortex-D2.

Figure 4—figure supplement 4
All 5-node-motifs in CBG network.

Potential oscillating motifs behind these subnetworks are marked with different colors. Yellow: motif Proto-STN; Orange: motif STN-GPi-Th-cortex; Blue: motif Proto-Arky-D2; Green: motif Proto-FSN-D2; Purple: motif Proto-GPi-Th-Cortex-D2.

Figure 4—figure supplement 5
All 6-node-motifs in CBG network.

Potential oscillating motifs behind these subnetworks are marked with different colors. Yellow: motif Proto-STN; Orange: motif STN-GPi-Th-cortex; Blue: motif Proto-Arky-D2; Green: motif Proto-FSN-D2; Purple: motif Proto-GPi-Th-Cortex-D2. labelfig:bg6nodes.

Figure 4—figure supplement 6
All 7-node-motifs in CBG network.

Potential oscillating motifs behind these subnetworks are marked with different colors. Yellow: motif Proto-STN; Orange: motif STN-GPi-Th-cortex; Blue: motif Proto-Arky-D2; Green: motif Proto-FSN-D2; Purple: motif Proto-GPi-Th-Cortex-D2.

Oscillations in a leaky integrate-and-fire (LIF) spiking neuronal network model of specific BG motifs.

(a-b) Average peristimulus time histograms (PSTH) of all neurons in a Proto-FSN-D2 and (b) Proto-Arky-D2 motifs under Parkinson condition with power spectral density (PSD) at the top right. (c) PSTH of Proto and STN in a BG subnetwork with motif Proto-Arky-D2 as the oscillator during different STN inhibition. (d) Same thing as (c) but changing the oscillator from Proto-Arky-D2 to Proto-STN.

Tables

Table 1
Parameters of III network for Figure 3, Figure 3—figure supplement 1.
PopulationsSynaptic weightsExternal inputDelay
I1I2I3
I10(−20−0)0−15(−20−0)6(0−20)0(0−10)
I2−15(−20−0)0(−20−0)06(0−20)0(0−10)
I30−15(−20−0)0(−20−0)6(0−20)0(0−10)
  1. Note: The range in parentheses indicates the variety of parameters when controlled.

Table 2
Parameters of EII network for Figure 3.
PopulationsSynaptic weightsExternal inputDelay
E1I1I2
E100−15(−20−0)60(0−10)
I1−15(−20−0)0(−20−0)06(0−20)0(0−10)
I20−15(−20−0)0(−20−0)6(0−20)0(0−10)
  1. Note: The range in parentheses indicates the variety of parameters when controlled.

Table 3
Parameters for Figure 4 (Wilson-Cowan model).
PopulationsSynaptic weightsExternal inputDelay
(D2)(Arky)(Proto)(STN)
(D2)0−15004(0−20)2
(Arky)00−151532
(Proto)−150−8151/42
(STN)00−1554(0−20)2
  1. The external input to Proto is 1 in Figure 4c and 4d while it was changed into 4 in Figure 4e to help motif Proto-Arky-D2 oscillate.

Appendix 2—table 1
Parameters for the EI network in Figure 3 (Wilson-Cowan model).
PopulationsSynaptic Weights (E)Synaptic Weights (I)External InputDelay
E10 (0–20)–15 (−20–0)6 (0–20)2 (0–10)
I15 (0–20)–10 (−20–0)02 (0–10)
Appendix 2—table 2
Parameters of D2-SPN neurons (LIF model with conductance-based synapses).
NameValueDescription
Vreset–85.4 mVReset value for Vm after a spike
Vth–45 mVSpike threshold
τsynex0.3msRise time of excitatory synaptic conductance
τsynin2msRise time of inhibitory synaptic conductance
EL–85.4 mVLeak reversal potential
Eex0 mVExcitatory reversal potential
Ein–64 mVInhibitory reversal potential
Ie0 pAExternal input current
Cm157 pFMembrane capacitance
gL6.46 nSLeak conductance
tref2msDuration of the refractory period
Appendix 2—table 3
Parameters of FSN neurons (LIF model with conductance-based synapses).
NameValueDescription
Vreset–65 mVReset value for Vm after a spike
Vth–54 mVSpike threshold
τsynex0.3msRise time of excitatory synaptic conductance
τsynin2msRise time of inhibitory synaptic conductance
EL–65 mVLeak reversal potential
Eex0 mVExcitatory reversal potential
Ein–76 mVInhibitory reversal potential
Ie0 pAExternal input current
Cm700 pFMembrane capacitance
gL16.67 nSLeak conductance
tref2msDuration of the refractory period
Appendix 2—table 4
Parameters of STN neurons (LIF model with conductance-based synapses).
NameValueDescription
Vreset–70 mVReset value for Vm after a spike
Vth–64 mVSpike threshold
τsynex0.33msRise time of excitatory synaptic conductance
τsynin1.5msRise time of inhibitory synaptic conductance
EL–80.2 mVLeak reversal potential
Eex–10 mVExcitatory reversal potential
Ein–84 mVInhibitory reversal potential
Ie1 pAExternal input current
Cm60 pFMembrane capacitance
gL10 nSLeak conductance
tref2msDuration of the refractory period
Appendix 2—table 5
Parameters of Proto and Arky neurons (LIF model with AdEx).
NameProtoArkyDescription
a2.5 nS2.5 nSSubthresholded adaptation
b105 pA70 pASpike-triggered adaptation
ΔT2.55ms1.7msSlope factor
τw20ms20msAdaptation time constant
Vreset–60 mV–60 mVReset value for Vm after a spike
Vth–54.7 mV–54.7 mVSpike threshold
τsynex1 ms4.8msRise time of excitatory synaptic conductance
τsynin5.5ms1 msRise time of inhibitory synaptic conductance
EL–55.1 mV–55.1 mVLeak reversal potential
Eex0 mV0 mVExcitatory reversal potential
Ein–65 mV–65 mVInhibitory reversal potential
Ie1 pA12 pAConstant input current
Cm60 pF40 pFMembrane capacitance
gL1 nS1 nSLeak conductance
tref2ms2msDuration of the refractory period
Appendix 2—table 6
Synaptic conductance weight and delay parameters in LIF model.
SynapseValue (nS)DelayValue (ms)
JD2D2-0.35ΔD2D21.7
JD2FSN-2.6 nSΔD2FSN1.7
JD2Arky-0.04 nSΔD2Arky7
JFSNFSN-0.4 nSΔFSNFSN1.7
JFSNArky-0.25 nSΔFSNArky7
JFSNProto-1 nSΔFSNProto7
JProtoProto-1.3 nSΔProtoProto1
JProtoD2-1.08 nSΔProtoD27
JProtoSTN0.175 nSΔProtoSTN2
JArkyArky-0.11 nSΔArkyArky1
JArkyProto-0.35 nSΔArkyProto1
JArkySTN0.24 nSΔArkySTN2
JSTNProto-0.3 nSΔSTNProto1
Appendix 2—table 7
Number of connections on each neuron and constant input current for Figure 5c (LIF model).
PopulationsD2ArkyProtoSTNConstant input current (pA)
D2504100000
Arky05503050
Proto5000253050
STN003001/–49/–99
  1. Note: To simulate the increasing inhibition to STN, the constant input current to STN was changed from 1 pA to –49 pA and then to –99 pA.

Appendix 2—table 8
Number of connections on each neuron and constant input current for Figure 5d (LIF model).
PopulationsD2ArkyProtoSTNConstant input current (pA)
D250410000
Arky0525301
Proto500025150–10
STN00150030/–10/–80
  1. Note: To simulate the increasing inhibition to STN, the constant input current to STN was changed from 30 pA to –10 pA and then to –50 pA.

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  1. Jie Zang
  2. Shenquan Liu
  3. Pascal Helson
  4. Arvind Kumar
(2024)
Structural constraints on the emergence of oscillations in multi-population neural networks
eLife 12:RP88777.
https://doi.org/10.7554/eLife.88777.3