Interested in the regulatory effects of emerging optogenetics and classical deep brain stimulation (DBS) on Parkinson's disease (PD), through analysis of thalamic fidelity, here we conduct systematic work with the help of biophysically-based basal ganglia-thalamic circuits model. Under the excitatory ChannelRhodopsin-2 (ChR2), results show that photostimulation targeting globus pallidus externa (GPe) can restore the thalamic relay ability, reduce the synchrony of neurons and alleviate the excessive beta band oscillation, while the effects of targeting globus pallidus interna (GPi) and subthalamic nucleus (STN) are poor. To our delight, these results match experimental reports that the symptoms of PD's movement disorder can be alleviated effectively when GPe are excited by optogenetic, but the situation for STN is not satisfactory. For DBS, we also get considerable simulation results after stimulating GPi, STN and GPe. And the control effect of targeting GPe is better than that of GPi as revealed in some experiments. Furthermore, to reduce side effects and electrical energy, six different dual target combination stimulation strategies are compared, among which the combination of GPe and GPi is the best. Most noteworthy, GPe is shown to be a potential target for both electrical and photostimulation. Although these results need further clinical and experimental verification, they are still expected to provide some enlightenment for the treatment of PD.

Parkinson's disease (PD) is mainly characterized by changes of firing and pathological oscillations in the basal ganglia (BG). In order to better understand the therapeutic effect of noninvasive magnetic stimulation, which has been used in the treatment of PD, we employ the Izhikevich neuron model as the basic node to study the electrical activity and the controllability of magnetic stimulation in a cortico-basal ganglia-thalamus (CBGT) network. Results show that the firing properties of the physiological and pathological state can be reproduced. Additionally, the electrical activity of pyramidal neurons and strong synapse connection in the hyperdirect pathway cause abnormal $\beta$-band oscillations and excessive synchrony in the subthalamic nucleus (STN). Furthermore, the pathological firing properties of STN can be efficiently suppressed by external magnetic stimulation. The statistical results give the fitted boundary curves between controllable and uncontrollable regions. This work helps to understand the dynamic response of abnormal oscillation in the PD-related nucleus and provides insights into the mechanisms behind the therapeutic effect of magnetic stimulation.

The hippocampus in the brain encodes memorized information as long-term memory through the plasticity of the CA3–CA1 synaptic network, thereby forming stable engrams. Based on the hippocampal CA3–CA1 synaptic network model, memory engrams are encoded as trajectories within a stable heteroclinic network, where saddle points signify different information blocks. This stable heteroclinic network is further refined into a knowledge network that illustrates the relationships between information blocks, defining the retrieval efficiency, capability, and integration quality of the network among these blocks. In this paper, we examined the impact of the local and global topological properties of the knowledge network on retrieval efficiency, capability, and integration quality. Numerical results indicated that the retrieval efficiency between any two information blocks in the knowledge network decreased with the out-degree of the cue's corresponding node, increased with the in-degree of the target's corresponding node, and was negatively correlated with the distance between node pairs. The retrieval capability of any information block was determined by the out-degree centrality and out-closeness of the corresponding node, while the integration quality of the knowledge network was influenced by the information blocks corresponding to nodes with higher degree centrality or betweenness centrality, and was negatively correlated with the average path length of the network.

Abnormal activity of the excitatory glutamatergic system is a common phenomenon in the brains of patients with Alzheimer’s disease (AD). This hyperactivity leads to an imbalance between excitation and inhibition mechanisms, which is considered to be a key factor in the occurrence of neuronal degeneration and cognitive impairment. Based on the classical Wendling model, we successfully reproduced the typical electroencephalogram (EEG) characteristics of clinical AD patients, including the slowing of α rhythm and the enhancement of δ+θ rhythm activity. With the deterioration of AD, its pathological changes will diffuse to the entire cortex gradually, which is closely related to the gradual decline of cognitive ability. So, we developed a two-compartment Wendling model to further explore the interaction between health and AD pathological states. As the intensity of excitatory postsynaptic membrane potential and inter-population coupling strength increase, the propagation of pathological rhythms in AD becomes easier. Interestingly, under the same coupling strength, the healthy physiological state is more susceptible to the pathological state of AD. In addition, we tested the unique advantage of fast inhibitory interneurons in transmitting rhythms, which is consistent with the results of previous theoretical studies. In order to effectively control the pathological spread of AD, we explored two control strategies of open-loop and closed-loop deep brain stimulation (DBS). The closed-loop control could not only normalize the abnormal EEG signal, but also significantly reduce the energy consumption compared with open-loop DBS. This study aims to provide new insights into the propagation and regulation mechanism of AD, and hopefully provide new diagnosis and treatment ideas for the clinical treatment of related neurological diseases.