Control of firing activities in thermosensitive neuron by activating excitatory autapse*

In this study, a memristor-coupled heterogenous neural network consisting of two-dimensional (2D) FitzHugh–Nagumo (FHN) and Hindmarsh–Rose (HR) neurons with two time delays is established. Taking the time delays as the control parameters, the existence of Hopf bifurcation near the stable equilibrium point in four cases is derived theoretically, and the validity of the Hopf bifurcation condition is verified by numerical analysis. The results shows that the two time delays can make the stable equilibrium point unstable, thus leading to periodic oscillations induced by Hopf bifurcation. Furthermore, the time delays in FHN and HR neurons have different effects on the firing activity of neural network. Complex firing patterns, such as quiescent state, chaotic spiking and periodic spiking can be induced by the time delay in FHN neuron, while the neural network only exhibits quiescent state and periodic spiking with the change of the time delay in HR neuron. Especially, phase synchronization between the heterogeneous neurons is explored, and the results show that the time delay in HR neurons has a greater effect on blocking the synchronization than the time delay in FHN neuron. Finally, the theoretical analysis is verified by circuit simulations.

Section: Introductionmentioning

confidence: 73%

Hopf bifurcation and phase synchronization in memristor-coupled Hindmarsh–Rose and FitzHugh–Nagumo neurons with two time delays

Guo¹,

Li²,

Wang³

et al. 2023

“…[30,31] The experimental results also reveal that autapse promotes the accuracy of neuronal firing and regulates the activities of the nervous system. [29,[32][33][34][35][36] Nevertheless, the function of autapses and their contribution to the accuracy of neuronal firing are still unclear. Thus, understanding the effect of autaptic activities on accurate neuronal responses is still critical work.…”

Section: Introductionmentioning

confidence: 99%

Effect of autaptic delay signal on spike-timing precision of single neuron

Zhao

Wang

et al. 2023

Experimental and theoretical studies have reported that the precise firing of neurons is crucial for sensory representation. Autapse serves as a special synapse connecting neuron and itself, which has also been found to improve the accuracy of neuronal response. In current work, the effect of autaptic delay signal on the spike-timing precision is investigated on a single autaptic Hodgkin–Huxley neuron in the present of noise. The simulation results show that both excitatory and inhibitory autaptic signals can effectively adjust the precise spike time of neurons with noise by choosing the appropriate coupling strength g and time delay of autaptic signal τ. The g–τ parameter space is divided into two regions: one is the region where the spike-timing precision is effectively regulated; the other is the region where the neuronal firing is almost not regulated. For the excitatory and inhibitory autapse, the range of parameters causing the accuracy of neuronal firing is different. Moreover, it is also found that the mechanisms of the spike-timing precision regulation are different for the two kinds of autaptic signals.

“…Recently, the paradoxical role of the autapse (a special synapse connecting to the neuron itself widely observed in multiple types of neuron) has attracted much attention, [44][45][46][47][48][49][50][51][52][53][54][55][56][57][58] in addition to its common role in modulating electrical behaviors of single neurons and neuronal networks have been studied. [44][45][46][47][48][49][50][51][52][53] For example, inhibitory autapse has been observed in inhibitory interneurons.…”

Section: Introductionmentioning

confidence: 99%

Paradoxical roles of inhibitory autapse and excitatory synapse in formation of counterintuitive anticipated synchronization

Ding

et al. 2023

Different from the common delayed synchronization (DS) that response appears after stimulation, anticipated synchronization (AS) in unidirectionally coupled neurons denotes a counterintuitive phenomenon that response of the receiver neuron appears before stimulation of the sender neuron, showing an interesting function of brain to anticipate the future. The dynamical mechanism for the AS remains unclear due to complex dynamics of inhibitory and excitatory modulations. In the present paper, the paradoxical roles of excitatory synapse and inhibitory autapse in the formation of AS are acquired. Firstly, in addition to the common roles that inhibitory modulation delays and excitatory modulation advances spike, paradoxical roles of excitatory stimulation to delay spike via type II phase response and of inhibitory autapse to advance spike are obtained in suitable parameter regions, extending the dynamics and functions of the excitatory and inhibitory modulations. Secondly, AS is related to the paradoxical roles of the excitatory and inhibitory modulations, presenting deep understandings to the AS. Inhibitory autapse induces spike of the receiver neuron advanced to appear before that of the sender neuron at first, and then excitatory synapse plays a delay role to prevent the spike further advanced, resulting in the AS as the advance and delay effects realize a dynamic balance. Last, inhibitory autapse with strong advance, middle advance, and weak advance and delay effects induces phase drift (spike of the receiver neuron advances continuously), AS, and DS, respectively, presenting comprehensive relationships between AS and other behaviors. The results present potential measures to modulate AS related to brain function.