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Thalamic neuron theory

George M Ibrahim, Simeon Wong, Benjamin R Morgan, Nir Lipsman, Aria Fallah, Alexander G Weil, Vibhor Krishna, Richard A Wennberg, Andres A Lozano
Cross-frequency phase-amplitude coupling (cfPAC) subserves an integral role in the hierarchical organization of inter-regional neuronal communication, and is also expressed by epileptogenic cortex during seizures. Here, we sought to characterize patterns of cfPAC expression in the anterior thalamic nuclei during seizures by studying extra-operative recordings in patients implanted with deep brain stimulation electrodes for intractable epilepsy. Nine seizures from 2 patients were analyzed in the peri-ictal period...
December 27, 2017: Journal of Neurophysiology
Diellor Basha, Jonathan O Dostrovsky, Suneil K Kalia, Mojgan Hodaie, Andres M Lozano, William D Hutchison
The amputation of an extremity is commonly followed by phantom sensations that are perceived to originate from the missing limb. The mechanism underlying the generation of these sensations is still not clear although the development of abnormal oscillatory bursting in thalamic neurons may be involved. The theory of thalamocortical dysrhythmia implicates gamma oscillations in phantom pathophysiology although this rhythm has not been previously observed in the phantom limb thalamus. In this study, the authors report the novel observation of widespread 38-Hz gamma oscillatory activity in spike and local field potential recordings obtained from the ventral caudal somatosensory nucleus of the thalamus (Vc) of a phantom limb patient undergoing deep brain stimulation (DBS) surgery...
November 10, 2017: Journal of Neurosurgery
Xin-Xiu Xu, Yu-Ying Zhai, Xiao-Kai Kou, Xiongjie Yu
The capacity to identify unanticipated abnormal cues in a natural scene is vital for animal survival. Stimulus-specific adaptation (SSA) has been considered the neuronal correlate for deviance detection. There have been comprehensive assessments of SSA in the frequency domain along the ascending auditory pathway, but only little attention given to deviance detection in the spatial domain. We found that thalamic reticular nucleus (TRN) neurons exhibited stronger responses to a tone when it was presented rarely as opposed to frequently at a certain spatial location...
December 4, 2017: Neuroscience
Tilo Schwalger, Moritz Deger, Wulfram Gerstner
Neural population equations such as neural mass or field models are widely used to study brain activity on a large scale. However, the relation of these models to the properties of single neurons is unclear. Here we derive an equation for several interacting populations at the mesoscopic scale starting from a microscopic model of randomly connected generalized integrate-and-fire neuron models. Each population consists of 50-2000 neurons of the same type but different populations account for different neuron types...
April 2017: PLoS Computational Biology
Adan-Ulises Dominguez-Vargas, Lukas Schneider, Melanie Wilke, Igor Kagan
The pulvinar complex is interconnected extensively with brain regions involved in spatial processing and eye movement control. Recent inactivation studies have shown that the dorsal pulvinar (dPul) plays a role in saccade target selection; however, it remains unknown whether it exerts effects on visual processing or at planning/execution stages. We used electrical microstimulation of the dPul while monkeys performed saccade tasks toward instructed and freely chosen targets. Timing of stimulation was varied, starting before, at, or after onset of target(s)...
February 22, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Erwin B Montgomery
Theories impact the movement disorders clinic, not only affecting the development of new therapies but determining how current therapies are used. Models are theories that are procedural rather than declarative. Theories and models are important because, as argued by Kant, one cannot know the thing-in-itself (das Ding an sich) and only a model is knowable. Further, biological variability forces higher level abstraction relevant for all variants. It is that abstraction that is raison d'être of theories and models...
2016: Frontiers in Human Neuroscience
Lu Li, Ford F Ebner
Cortex actively modulates the responses of thalamic relay neurons through corticothalamic (CT) projections. Here we investigated the temporal precision of CT modulation on sensory responses of relay neurons in rat ventral posterior medial thalamus (VPM) to direction-specific whisker stimuli. CT feedback levels were either augmented by cortical electrical microstimulation or depressed by cortical application of muscimol, a potent agonist of γ-aminobutyric acid A-type (GABAA) receptors. To evaluate the temporal specificity of CT influence, we compared the early (3-10 ms after stimulus onset) and late (10-100 ms) response components of VPM single units to whisker deflections in preferred or nonpreferred directions before and after altering CT feedback levels under urethane anesthesia...
November 1, 2016: Journal of Neurophysiology
Donald M Caspary, Daniel A Llano
Tinnitus is defined as a phantom sound (ringing in the ears), and can significantly reduce the quality of life for those who suffer its effects. Ten to fifteen percent of the general adult population report symptoms of tinnitus with 1-2% reporting that tinnitus negatively impacts their quality of life. Noise exposure is the most common cause of tinnitus and the military environment presents many challenging high-noise situations. Military noise levels can be so intense that standard hearing protection is not adequate...
June 2017: Hearing Research
Erwin B Montgomery, Huang He
The efficacy of Deep Brain Stimulation (DBS) for an expanding array of neurological and psychiatric disorders demonstrates directly that DBS affects the basic electroneurophysiological mechanisms of the brain. The increasing array of active electrode configurations, stimulation currents, pulse widths, frequencies, and pulse patterns provides valuable tools to probe electroneurophysiological mechanisms. The extension of basic electroneurophysiological and anatomical concepts using sophisticated computational modeling and simulation has provided relatively straightforward explanations of all the DBS parameters except frequency...
August 17, 2016: Brain Sciences
Duncan J Hodkinson, Sophie L Wilcox, Rosanna Veggeberg, Rodrigo Noseda, Rami Burstein, David Borsook, Lino Becerra
UNLABELLED: For many years, neurobiological theories have emphasized the importance of neuronal oscillations in the emergence of brain function. At the same time, clinical studies have shown that disturbances or irregularities in brain rhythms may relate to various common neurological conditions, including migraine. Increasing evidence suggests that the CNS plays a fundamental role in the predisposition to develop different forms of headache. Here, we present human imaging data that strongly support the presence of abnormal low-frequency oscillations (LFOs) in thalamocortical networks of patients in the interictal phase of migraine...
July 27, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Fady Girgis, Jonathan P Miller
Electrical stimulation in the treatment of epilepsy has been tried in numerous forms and with a variety of targets. Some of these, such as anterior thalamic stimulation, responsive cortical stimulation, and vagal nerve stimulation, have shown promise. A relatively novel concept, that of white matter stimulation, offers a different mechanism in that a small population of stimulated axons can transmit current to a large population of epileptogenic neurons. In theory, this allows for the modulation of seizure circuits and neural networks using lower stimulation volumes...
April 2016: Seizure: the Journal of the British Epilepsy Association
Haram R Kim, Su Z Hong, Christopher D Fiorillo
Although neurons within intact nervous systems can be classified as 'sensory' or 'motor,' it is not known whether there is any general distinction between sensory and motor neurons at the cellular or molecular levels. Here, we extend and test a theory according to which activation of certain subtypes of voltage-gated ion channel (VGC) generate patterns of spikes in neurons of motor systems, whereas VGC are proposed to counteract patterns in sensory neurons. We previously reported experimental evidence for the theory from visual thalamus, where we found that T-type calcium channels (TtCCs) did not cause bursts of spikes but instead served the function of 'predictive homeostasis' to maximize the causal and informational link between retinogeniculate excitation and spike output...
2015: Frontiers in Cellular Neuroscience
Daniel H Elijah, Inés Samengo, Marcelo A Montemurro
Thalamic neurons have been long assumed to fire in tonic mode during perceptive states, and in burst mode during sleep and unconsciousness. However, recent evidence suggests that bursts may also be relevant in the encoding of sensory information. Here, we explore the neural code of such thalamic bursts. In order to assess whether the burst code is generic or whether it depends on the detailed properties of each bursting neuron, we analyzed two neuron models incorporating different levels of biological detail...
2015: Frontiers in Computational Neuroscience
Katharine N Thakkar, Jeffrey D Schall, Stephan Heckers, Sohee Park
UNLABELLED: Disruptions in corollary discharge (CD), motor signals that send information to sensory areas and allow for prediction of sensory states, are argued to underlie the perceived loss of agency in schizophrenia. Behavioral and neurophysiological evidence for CD in primates comes largely from the saccadic double-step task, which requires participants to make two visually triggered saccadic eye movements in brief succession. Healthy individuals use CD to anticipate the change in eye position resulting from the first saccade when preparing the second saccade...
July 8, 2015: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Judith A Hirsch, Xin Wang, Friedrich T Sommer, Luis M Martinez
Inhibitory neurons dominate the intrinsic circuits in the visual thalamus. Interneurons in the lateral geniculate nucleus innervate relay cells and each other densely to provide powerful inhibition. The visual sector of the overlying thalamic reticular nucleus receives input from relay cells and supplies feedback inhibition to them in return. Together, these two inhibitory circuits influence all information transmitted from the retina to the primary visual cortex. By contrast, relay cells make few local connections...
July 8, 2015: Annual Review of Neuroscience
E M Aldana, J L Valverde, N Fábregas
A detailed analysis of the literature on consciousness and cognition mechanisms based on the neural networks theory is presented. The immune and inflammatory response to the anesthetic-surgical procedure induces modulation of neuronal plasticity by influencing higher cognitive functions. Anesthetic drugs can cause unconsciousness, producing a functional disruption of cortical and thalamic cortical integration complex. The external and internal perceptions are processed through an intricate network of neural connections, involving the higher nervous activity centers, especially the cerebral cortex...
October 2016: Revista Española de Anestesiología y Reanimación
Marian Tsanov, Shane M O'Mara
A major tool in understanding how information is processed in the brain is the analysis of neuronal output at each hierarchical level through which neurophysiological signals are propagated. Since the experimental brain operation performed on Henry Gustav Molaison (known as patient H.M.) in 1953, the hippocampal formation has gained special attention, resulting in a very large number of studies investigating signals processed by the hippocampal formation. One of the main information streams to the hippocampal formation, vital for episodic memory formation, arises from thalamo-hippocampal projections, as there is extensive connectivity between these structures...
September 24, 2015: Brain Research
Lleuvelyn A Cacha, Roman R Poznanski
A theoretical framework is developed based on the premise that brains evolved into sufficiently complex adaptive systems capable of instantiating genomic consciousness through self-awareness and complex interactions that recognize qualitatively the controlling factors of biological processes. Furthermore, our hypothesis assumes that the collective interactions in neurons yield macroergic effects, which can produce sufficiently strong electric energy fields for electronic excitations to take place on the surface of endogenous structures via alpha-helical integral proteins as electro-solitons...
June 2014: Journal of Integrative Neuroscience
Y Wu, D Liu, Z Song
Epilepsy can be defined as the abnormal activities of neurons. The occurrence, propagation and termination of epileptic seizures rely on the networks of neuronal cells that are connected through both synaptic- and non-synaptic interactions. These complicated interactions contain the modified functions of normal neurons and glias as well as the mediation of excitatory and inhibitory mechanisms with feedback homeostasis. Numerous spread patterns are detected in disparate networks of ictal activities. The cortical-thalamic-cortical loop is present during a general spike wave seizure...
February 26, 2015: Neuroscience
Tsun-Nin Lee
The clinical practice of acupuncture and study of the traditional Chinese medicine literature has led to the observation that if the diaphragm is used as an axis of symmetry, there are many symmetrical points on the upper and lower halves of the body. The symmetrical points share several common properties, including physiological functions, mechanisms of pathogenesis and therapeutic effects. Employing these corresponding points on the upper and lower parts of the body simultaneously can frequently enhance the therapeutic outcome rather substantially...
2013: American Journal of Chinese Medicine
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