Using Single Neuron Dynamics to Predict Synchronous Global Network Activities Robert Kim Neurosciences Graduate Program University of California, San Diego December 8, 2017 Neurodynamics Final Project December 8, 2017 1 / 16
Outline Background 1 Methods 2 Results 3 Summary 4 Neurodynamics Final Project December 8, 2017 2 / 16
Outline Background 1 Methods 2 Results 3 Summary 4 Neurodynamics Final Project December 8, 2017 3 / 16
Background Based on the previous findings from Neurodynamics Final Project December 8, 2017 4 / 16
Background Based on the previous findings from Rat cortical neurons artificially grown on a multi-electrode arrays (Figure from Tajima, S. et al. Locally embedded presages of global network bursts. PNAS , 114: 9517-9522, 2017) Neurodynamics Final Project December 8, 2017 4 / 16
Background 1 0.9 0.8 Mean Firing Activity 0.7 0.6 0.5 0.4 0.3 0.2 0.1 5 10 15 20 25 30 Time (sec) Neurodynamics Final Project December 8, 2017 5 / 16
Background 1 0.9 0.8 Mean Firing Activity 0.7 0.6 0.5 0.4 0.3 0.2 0.1 5 10 15 20 25 30 Time (sec) 1 0.8 0.6 x 2 (t) 0.4 0.2 1 0.8 0.6 0.9 0.8 (Figure from Tajima, S. et al. Locally embedded presages of 0.4 0.7 x 1 (t) 0.6 0.5 0.4 0.2 global network bursts. PNAS , 114: 9517-9522, 2017) 0.3 0.2 x(t) 0.1 Neurodynamics Final Project December 8, 2017 5 / 16
Outline Background 1 Methods 2 Results 3 Summary 4 Neurodynamics Final Project December 8, 2017 6 / 16
Methods Izhikevich neurons will be used to replicate some of the findings of Tajima et al. 0 . 04 v 2 + 5 v + 140 − u + I v ˙ = ˙ = a · ( bv − u ) u if v 35 mV, v = c and u = u + d ≥ Neurodynamics Final Project December 8, 2017 7 / 16
Methods Izhikevich neurons will be used to replicate some of the findings of Tajima et al. 0 . 04 v 2 + 5 v + 140 − u + I v ˙ = ˙ = a · ( bv − u ) u if v 35 mV, v = c and u = u + d ≥ 20 v (mV) 0 -20 -40 -60 -80 -100 -50 0 50 100 150 200 250 300 350 400 Time (ms) 20 0 v (mV) -20 -40 -60 -80 -100 -50 0 50 100 150 200 250 300 350 400 Time (ms) 20 v (mV) 0 -20 -40 -60 -80 -100 -50 0 50 100 150 200 250 300 350 400 Time (ms) 0 v (mV) -50 -100 -100 -50 0 50 100 150 200 250 300 350 400 Time (ms) Neurodynamics Final Project December 8, 2017 7 / 16
Methods RS Excitatory Neuron a = 0 . 02, b = 0 . 13 c = − 65 mV, d = 8 20 Voltage (mV) 0 -20 -40 -60 -80 200 400 600 800 1000 Time (ms) Neurodynamics Final Project December 8, 2017 8 / 16
Methods RS Excitatory Neuron FS Inhibitory Neuron a = 0 . 02, b = 0 . 13 a = 0 . 1, b = 0 . 13 c = − 65 mV, d = 8 c = − 65 mV, d = 2 20 20 Voltage (mV) Voltage (mV) 0 0 -20 -20 -40 -40 -60 -60 -80 200 400 600 800 1000 200 400 600 800 1000 Time (ms) Time (ms) Neurodynamics Final Project December 8, 2017 8 / 16
Methods Network Configuration 450 Izhikevich neurons 360 RS excitatory neurons 90 FS inhibitory neurons Neurodynamics Final Project December 8, 2017 9 / 16
Methods Network Configuration 450 Izhikevich neurons 360 RS excitatory neurons 90 FS inhibitory neurons Sparsely and randomly connected to one another (40% connections) Neurodynamics Final Project December 8, 2017 9 / 16
Methods Network Configuration 450 Izhikevich neurons 360 RS excitatory neurons 90 FS inhibitory neurons Sparsely and randomly connected to one another (40% connections) No external/inject current Neurodynamics Final Project December 8, 2017 9 / 16
Outline Background 1 Methods 2 Results 3 Summary 4 Neurodynamics Final Project December 8, 2017 10 / 16
Results Neurons 130 131 132 133 134 135 136 Time (sec) 1 Mean Firing Activity 0 130 131 132 133 134 135 136 Time (sec) Neurodynamics Final Project December 8, 2017 11 / 16
Results Dynamics of individual neurons were able to forecast/predict the spontaneous global burst. 1 1 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 b 1 (t) x 1 (t) 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0 0.2 0.4 0.6 0.8 1 b(t) x(t) Neurodynamics Final Project December 8, 2017 12 / 16
Results Dynamics of individual neurons were able to forecast/predict the spontaneous global burst. 1 1 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 b 1 (t) x 1 (t) 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0 0.2 0.4 0.6 0.8 1 b(t) x(t) Neurodynamics Final Project December 8, 2017 12 / 16
Results Dynamics of individual neurons were able to forecast/predict the spontaneous global burst. 1 1 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 b 1 (t) x 1 (t) 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0 0.2 0.4 0.6 0.8 1 b(t) x(t) Neurodynamics Final Project December 8, 2017 12 / 16
Results Dynamics of individual neurons were able to forecast/predict the spontaneous global burst. 1 1 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 b 1 (t) x 1 (t) 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0 0.2 0.4 0.6 0.8 1 b(t) x(t) Neurodynamics Final Project December 8, 2017 12 / 16
Results Dynamics of individual neurons were able to forecast/predict the spontaneous global burst. 1 1 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 b 1 (t) x 1 (t) 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0 0.2 0.4 0.6 0.8 1 b(t) x(t) Neurodynamics Final Project December 8, 2017 12 / 16
Results Dynamics of individual neurons were able to forecast/predict the spontaneous global burst. 1 1 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 b 1 (t) x 1 (t) 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0 0.2 0.4 0.6 0.8 1 b(t) x(t) Neurodynamics Final Project December 8, 2017 12 / 16
Results Dynamics of individual neurons were able to forecast/predict the spontaneous global burst. 1 1 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 b 1 (t) x 1 (t) 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0 0.2 0.4 0.6 0.8 1 b(t) x(t) Neurodynamics Final Project December 8, 2017 12 / 16
Results Single Neuron Dynamics Forecast Mean Population Dynamics Forecast 1 1 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 b 1 (t) b 1 (t) 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 b(t) b(t) Neurodynamics Final Project December 8, 2017 13 / 16
Outline Background 1 Methods 2 Results 3 Summary 4 Neurodynamics Final Project December 8, 2017 14 / 16
Summary Main findings of Tajima et al. were also observed in a network of Izhikevich neurons Future work: Investigate the synaptic connectivity and strength of “good predictor” neurons Investigate the effects of sparsity and E/I balance on predictability Investigate the effects of synaptic strength on predictability Neurodynamics Final Project December 8, 2017 15 / 16
Acknowledgement Gerald Pao, MD, PhD Neurodynamics Final Project December 8, 2017 16 / 16
Acknowledgement Gerald Pao, MD, PhD Any questions? Neurodynamics Final Project December 8, 2017 16 / 16
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