Neurons and Near-Death Spikes
141
Fig. 2 Raster plots depicting firing times of PCNN at G syn = 10, cn = 131. With increase in G syn
the synchronization in the network decreases. When more and more neurons are turned chaotic,
their firing stops abruptly at around 56–600 ms
2.4 Bursting Synchronization (B)
B is a measure of degree of interspike distance synchrony. To find B, all the spike
times of the network are arranged in the order of spike generation and then using the
following equation bursting synchronization is calculated.
B =
1
√
N
τ 2
v − −τ v 2
τ v
− 1
(5)
where τ v is the network interspike interval (ISI) between (τ v + 1)th and (τ v )th spikes
of the network, i.e., τ v = τ v+1 − τ v . When B = 1, the network is in highly synchronous
bursting state and low values of B indicates asynchronous behaviour.
As the number of the chaotic neurons and Gsyn increases, there is a tendency for
the bursting synchronization of the network to become high. However, the increase
is not uniform. For specific values of synaptic strength, when chaotic neurons in the
network are above 120, the network moves toward complete synchronization (Fig. 3).
2.5 Influence of Inhibitory Neurons
Since all the interneurons of the network are not necessarily inhibitory, the above
studies are repeated by making 32 randomly selected neurons in the network as
inhibitory neurons. Then, the dynamics of both inhibitory and excitatory neuron can
141
Fig. 2 Raster plots depicting firing times of PCNN at G syn = 10, cn = 131. With increase in G syn
the synchronization in the network decreases. When more and more neurons are turned chaotic,
their firing stops abruptly at around 56–600 ms
2.4 Bursting Synchronization (B)
B is a measure of degree of interspike distance synchrony. To find B, all the spike
times of the network are arranged in the order of spike generation and then using the
following equation bursting synchronization is calculated.
B =
1
√
N
τ 2
v − −τ v 2
τ v
− 1
(5)
where τ v is the network interspike interval (ISI) between (τ v + 1)th and (τ v )th spikes
of the network, i.e., τ v = τ v+1 − τ v . When B = 1, the network is in highly synchronous
bursting state and low values of B indicates asynchronous behaviour.
As the number of the chaotic neurons and Gsyn increases, there is a tendency for
the bursting synchronization of the network to become high. However, the increase
is not uniform. For specific values of synaptic strength, when chaotic neurons in the
network are above 120, the network moves toward complete synchronization (Fig. 3).
2.5 Influence of Inhibitory Neurons
Since all the interneurons of the network are not necessarily inhibitory, the above
studies are repeated by making 32 randomly selected neurons in the network as
inhibitory neurons. Then, the dynamics of both inhibitory and excitatory neuron can