This paper proposes a model of neural networks consisting of populations of perceptive neurons, inter-neurons, and motor neurons according to the theory of stochastic phase resetting dynamics. According to this model,...This paper proposes a model of neural networks consisting of populations of perceptive neurons, inter-neurons, and motor neurons according to the theory of stochastic phase resetting dynamics. According to this model, the dynamical characteristics of neural networks are studied in three coupling cases, namely, series and parallel coupling, series coupling, and unilateral coupling. The results show that the indentified structure of neural networks enables the basic characteristics of neural information processing to be described in terms of the actions of both the optional motor and the reflected motor. The excitation of local neural networks is caused by the action of the optional motor. In particular, the excitation of the neural population caused by the action of the optional motor in the motor cortex is larger than that caused by the action of the reflected motor. This phenomenon indicates that there are more neurons participating in the neural information processing and the excited synchronization motion under the action of the optional motor.展开更多
Background:Depression affects approximately 5% of elderly people and its etiology might be related to chronic stress exposure during neurodevelopmental periods.In this study,we examined the effects of adolescent chron...Background:Depression affects approximately 5% of elderly people and its etiology might be related to chronic stress exposure during neurodevelopmental periods.In this study,we examined the effects of adolescent chronic social stress in aged mice on depressive behaviors and the excitatory-inhibitory (E/I) balance in stress-sensitive regions of the brain.Methods:Sixty-four adolescent,male C57BL/6 mice were randomly assigned to either the 7-week (from post-natal days 29 to 77) social instability stress (stress group,n =32) or normal housing conditions (control group,n =32).At 15 months of age,16 mice were randomly selected from each group for a series of behavioral tests,including two depression-related tasks (the sucrose preference test and the tail suspension test).Three days following the last behavioral test,eight mice were randomly selected from each group for immunohistochemical analyses to measure the cell density of parvalbumin (PV+)-and calretinin (CR+)-positive gamma-aminobutyric-acid (GABA)ergic inhibitory inter-neurons,and the expression levels of vesicular transporters of glutamate-1 (VGIuT1) and vesicular GABA transporter (VGAT) in three stress-sensitive regions of the brain (the medial pre-frontal cortex [mPFC],hippocampus,and amygdala).Results:Behaviorally,compared with the control group,adolescent chronic stress increased depression-like behaviors as shown in decreased sucrose preference (54.96 ± 1.97% vs.43.11 ± 2.85%,t(22)=3.417,P =0.003) and reduced latency to immobility in the tail suspension test (92.77 ± 25.08 s vs.33.14 ± 5.95 s,t(25)=2.394,P =0.025),but did not affect anxiety-like behaviors and pre-pulse inhibition.At the neurobiologic level,adolescent stress down-regulated PV+,not CR+,inter-neuron density in the mPFC (F(1,39)=19.30,P < 0.001),and hippocampus (F(1,42)=5.823,P =0.020) and altered the CR+,not PV+,inter-neuron density in the amygdala (F(1,28)=23.16,P < 0.001).The VGluT1/VGAT ratio was decreased in all three regions (all F > 10.09,all P < 0.004),which suggests stress-induce展开更多
基金supported by the National Natural Science Foundation of China (Nos.10872068,10672057)
文摘This paper proposes a model of neural networks consisting of populations of perceptive neurons, inter-neurons, and motor neurons according to the theory of stochastic phase resetting dynamics. According to this model, the dynamical characteristics of neural networks are studied in three coupling cases, namely, series and parallel coupling, series coupling, and unilateral coupling. The results show that the indentified structure of neural networks enables the basic characteristics of neural information processing to be described in terms of the actions of both the optional motor and the reflected motor. The excitation of local neural networks is caused by the action of the optional motor. In particular, the excitation of the neural population caused by the action of the optional motor in the motor cortex is larger than that caused by the action of the reflected motor. This phenomenon indicates that there are more neurons participating in the neural information processing and the excited synchronization motion under the action of the optional motor.
基金grants from the National Natural Science Foundation of China (Nos. 81630031, 81401129, 81571321, and 81571312)the Beijing Brain Project (No.Z171100000117016), the National Key Basic Research Program of China (973 program+1 种基金No. 2015CB856401)the Peking University Medicine Seed Fund for Interdisciplinary Research (No. BMU2017MX021).
文摘Background:Depression affects approximately 5% of elderly people and its etiology might be related to chronic stress exposure during neurodevelopmental periods.In this study,we examined the effects of adolescent chronic social stress in aged mice on depressive behaviors and the excitatory-inhibitory (E/I) balance in stress-sensitive regions of the brain.Methods:Sixty-four adolescent,male C57BL/6 mice were randomly assigned to either the 7-week (from post-natal days 29 to 77) social instability stress (stress group,n =32) or normal housing conditions (control group,n =32).At 15 months of age,16 mice were randomly selected from each group for a series of behavioral tests,including two depression-related tasks (the sucrose preference test and the tail suspension test).Three days following the last behavioral test,eight mice were randomly selected from each group for immunohistochemical analyses to measure the cell density of parvalbumin (PV+)-and calretinin (CR+)-positive gamma-aminobutyric-acid (GABA)ergic inhibitory inter-neurons,and the expression levels of vesicular transporters of glutamate-1 (VGIuT1) and vesicular GABA transporter (VGAT) in three stress-sensitive regions of the brain (the medial pre-frontal cortex [mPFC],hippocampus,and amygdala).Results:Behaviorally,compared with the control group,adolescent chronic stress increased depression-like behaviors as shown in decreased sucrose preference (54.96 ± 1.97% vs.43.11 ± 2.85%,t(22)=3.417,P =0.003) and reduced latency to immobility in the tail suspension test (92.77 ± 25.08 s vs.33.14 ± 5.95 s,t(25)=2.394,P =0.025),but did not affect anxiety-like behaviors and pre-pulse inhibition.At the neurobiologic level,adolescent stress down-regulated PV+,not CR+,inter-neuron density in the mPFC (F(1,39)=19.30,P < 0.001),and hippocampus (F(1,42)=5.823,P =0.020) and altered the CR+,not PV+,inter-neuron density in the amygdala (F(1,28)=23.16,P < 0.001).The VGluT1/VGAT ratio was decreased in all three regions (all F > 10.09,all P < 0.004),which suggests stress-induce
