Future investigation into the neural mechanisms governing innate fear, viewed through an oscillatory lens, could prove beneficial.
The online version's supplemental materials are located at 101007/s11571-022-09839-6; these materials are available online.
Reference 101007/s11571-022-09839-6 directs you to additional material contained in the online version.
The encoding of social experience information and the support of social memory are functions of the hippocampal CA2 area. Our earlier research indicated that CA2 place cells displayed a particular reaction to social triggers, consistent with the findings of Alexander et al. (2016) in Nature Communications. A prior investigation, detailed in Elife (Alexander, 2018), showed that hippocampal CA2 activation resulted in slow gamma rhythms, featuring frequencies from 25 to 55 Hz. These outcomes in conjunction raise a pivotal question regarding the relationship between slow gamma rhythms and CA2 activity during social information processing. The transmission of social memories from the CA2 to CA1 hippocampus could potentially be correlated with slow gamma oscillations, potentially serving to combine information across brain areas or to boost social memory retrieval. Four rats, engaging in a social exploration task, had local field potentials recorded from their hippocampal subregions CA1, CA2, and CA3. We examined the presence of theta, slow gamma, and fast gamma rhythms, plus sharp wave-ripples (SWRs), in each of the subfields. During social exploration sessions and presumed social memory retrieval in subsequent post-exploration sessions, we analyzed interactions between subfields. While social interactions resulted in elevated CA2 slow gamma rhythms, non-social exploration did not produce any such increase. Social exploration contributed to the intensification of the CA2-CA1 theta-show gamma coupling. Furthermore, CA1's slow gamma rhythms and sharp wave ripples were associated with the presumed process of recalling social memories. The overall implications of these findings suggest that CA2-CA1 interactions mediated by slow gamma activity are crucial for establishing social memories, and that CA1 slow gamma activity is instrumental in the retrieval of stored social experiences.
Supplementary material for the online version is accessible at 101007/s11571-022-09829-8.
The online publication's supplementary materials are linked from the URL 101007/s11571-022-09829-8.
The external globus pallidus (GPe), a subcortical nucleus situated within the basal ganglia's indirect pathway, is frequently linked to the aberrant beta oscillations (13-30 Hz) prevalent in Parkinson's disease (PD). Despite the many proposed mechanisms for the emergence of these beta oscillations, the functional significance of the GPe, especially whether it is capable of generating beta oscillations, continues to be elusive. A thoroughly described firing rate model of the GPe neural population is utilized in order to investigate the involvement of the GPe in producing beta oscillations. Based on our simulations, the transmission delay in the GPe-GPe pathway is a major factor in the generation of beta oscillations, and the impact of the time constant and connection strength of the GPe-GPe pathway on generating beta oscillations is important. Beyond this, the firing characteristics of GPe cells are greatly dependent on the time constant of the GPe-GPe pathway's connections, its connection strength, and the transmission delay along this same circuit. Interestingly, the manipulation of transmission delay, whether amplified or diminished, can influence the GPe's firing pattern, shifting it from beta oscillations to alternative patterns, including both oscillatory and non-oscillatory firing. These results propose a scenario wherein transmission delays of at least 98 milliseconds in the GPe might be the trigger for the primary creation of beta oscillations within the GPe neuronal community. This possible origin of PD-related beta oscillations establishes the GPe as a noteworthy treatment target for Parkinson's Disease.
The communication between neurons, fostered by synaptic plasticity and synchronization, is vital for learning and memory. STDP, a form of synaptic plasticity, modulates synaptic strengths in neural circuits based on the precise temporal relationship between pre- and postsynaptic action potentials. In this iterative fashion, STDP concurrently molds neuronal activity and synaptic connectivity within a feedback loop. Despite the proximity of neurons, the physical distance still causes transmission delays, impacting neuronal synchronization and the symmetry of synaptic coupling. We examined the combined effect of transmission delays and spike-timing-dependent plasticity (STDP) on the emergence of pairwise activity-connectivity patterns, focusing on the phase synchronization properties and coupling symmetry of two bidirectionally connected neurons using both phase oscillator and conductance-based neuron models. The two-neuron motif's activity synchronizes in either in-phase or anti-phase patterns, which are influenced by transmission delay range, and in parallel, its connectivity adopts either symmetric or asymmetric coupling. Stable motifs in neuronal systems, co-evolving with synaptic weights regulated by STDP, are achieved via transitions between in-phase/anti-phase synchronization and symmetric/asymmetric coupling regimes at specific transmission delays. These transitions, governed by the phase response curves (PRCs) of neurons, are remarkably resistant to the heterogeneous nature of transmission delays and the STDP profile's imbalance of potentiation and depression.
Examining the effects of acute high-frequency repetitive transcranial magnetic stimulation (hf-rTMS) on granule cell excitability in the hippocampal dentate gyrus and the underlying mediating mechanisms through which rTMS regulates neuronal excitability is the objective of this study. Initially, high-frequency single transcranial magnetic stimulation (TMS) was utilized to assess the motor threshold (MT) in mice. Acute brain slices from mice were exposed to rTMS at three different intensity levels: a control group of 0 mT, followed by stimulation at 8 mT and 12 mT. A patch-clamp recording procedure was employed to assess the resting membrane potential and induced nerve impulses of granule cells, and also the voltage-gated sodium current (I Na) of voltage-gated sodium channels (VGSCs), the transient outward potassium current (I A), and the delayed rectifier potassium current (I K) of voltage-gated potassium channels (Kv). Acute hf-rTMS treatment, applied to both the 08 MT and 12 MT groups, resulted in substantial activation of I Na and inhibition of both I A and I K channels, noticeably deviating from the control group. These alterations can be explained by the modified dynamic characteristics of voltage-gated sodium and potassium channels. Acute hf-rTMS demonstrably enhanced membrane potential and nerve discharge frequency across both the 08 MT and 12 MT cohorts. In granular cells, a likely intrinsic mechanism for rTMS-induced neuronal excitability enhancement involves changes to the dynamic characteristics of voltage-gated sodium channels (VGSCs) and potassium channels (Kv), activation of the sodium current (I Na), and inhibition of the A-type and delayed rectifier potassium currents (I A and I K). This regulation becomes more pronounced as the stimulus intensity increases.
H-state estimation in quaternion-valued inertial neural networks (QVINNs) with non-identical time-varying delay is the subject of this paper. The addressed QVINNs are investigated using a non-reduced order method, an approach contrasting with the majority of extant literature that typically involves decomposing the original second-order system into two first-order systems. Arabidopsis immunity By introducing a new Lyapunov functional, incorporating adjustable parameters, easily verifiable algebraic criteria are established for the asymptotic stability of the error-state system with the required H performance level. Beside that, an effective approach using algorithms is provided to determine the estimator parameters. For the purpose of illustrating the feasibility of the state estimator, a numerical example is presented.
New findings from this study suggest a strong relationship between graph-theoretic measures of global brain connectivity and healthy adults' skill in managing and regulating negative emotional states. Resting-state EEG recordings taken with eyes open and closed were used to ascertain functional brain connectivity patterns in four groups of individuals categorized by their diverse emotion regulation strategies (ERS). Group one contained 20 individuals who often employed opposing strategies, like rumination and cognitive distraction. Conversely, group two involved 20 participants who did not employ these cognitive strategies. Across the third and fourth groups, a pattern emerges: individuals in one group routinely employ both Expressive Suppression and Cognitive Reappraisal, whereas individuals in the other group never use either technique. naïve and primed embryonic stem cells EEG measurements and psychometric scores were downloaded from the public LEMON dataset for individual participants. The Directed Transfer Function, not sensitive to volume conduction, was applied to 62-channel recordings to extract estimations of cortical connectivity over the complete cortical expanse. PF-04418948 concentration Connectivity estimations, when adhering to a precisely established threshold, are rendered into binary format for application within the Brain Connectivity Toolbox. Statistical logistic regression models and deep learning models, driven by frequency band-specific network measures of segregation, integration, and modularity, are used to compare the groups to one another. Analyzing full-band (0.5-45 Hz) EEG yields high classification accuracies of 96.05% (1st vs 2nd) and 89.66% (3rd vs 4th), as evidenced by overall results. Finally, strategies that are detrimental in nature can upset the balance of division and unification. Specifically, visual results reveal that often ruminating reduces network resilience, as observed through a decrease in assortativity.