The Wake Promoting Role of the Mediodorsal Thalamic Nuclei in Rat

2021 ◽  
Author(s):  
Sriji Somanath ◽  
Binney Sharma ◽  
Preeti Puskar ◽  
Avishek Roy ◽  
Nasreen Akhtar ◽  
...  
Keyword(s):  
Thalamic Nuclei

scholarly journals Subcortical circuits mediate communication between primary sensory cortical areas in mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michael Lohse ◽  
Johannes C. Dahmen ◽  
Victoria M. Bajo ◽  
Andrew J. King
Keyword(s):  
Cortical Neurons ◽  
Common Property ◽  
Primary Auditory Cortex ◽  
Facilitatory Effect ◽  
Thalamic Nuclei ◽  
Auditory Midbrain ◽  
Cortical Areas ◽  
Auditory Responses ◽  
Evoked Activity

AbstractIntegration of information across the senses is critical for perception and is a common property of neurons in the cerebral cortex, where it is thought to arise primarily from corticocortical connections. Much less is known about the role of subcortical circuits in shaping the multisensory properties of cortical neurons. We show that stimulation of the whiskers causes widespread suppression of sound-evoked activity in mouse primary auditory cortex (A1). This suppression depends on the primary somatosensory cortex (S1), and is implemented through a descending circuit that links S1, via the auditory midbrain, with thalamic neurons that project to A1. Furthermore, a direct pathway from S1 has a facilitatory effect on auditory responses in higher-order thalamic nuclei that project to other brain areas. Crossmodal corticofugal projections to the auditory midbrain and thalamus therefore play a pivotal role in integrating multisensory signals and in enabling communication between different sensory cortical areas.

scholarly journals Role of Thalamus in Recovery of Traumatic Brain Injury

2016 ◽  
Vol 07 (S 01) ◽  
pp. S076-S079 ◽  
Author(s):  
Ashok Munivenkatappa ◽  
Amit Agrawal
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Brain Structures ◽  
Thalamic Nuclei ◽  
Posttraumatic Symptoms ◽  
Injured Brain ◽  
Recovery Mechanisms ◽  
The Brain ◽  
Degree Of Recovery

ABSTRACTDegree of recovery after traumatic brain injury is highly variable that lasts for many weeks to months. The evidence of brain structures involved in recovery mechanisms is limited. This review highlights evidence of the brain structure particularly thalamus in neuroplasticity mechanism. Thalamus with its complex global networking has potential role in refining the cortical and other brain structures. Thalamic nuclei activation both naturally or by neurorehabilitation in injured brain can enhance and facilitate the improvement of posttraumatic symptoms. This review provides evidence from literature that thalamus plays a key role in recovery mechanism after injury. The study also emphasize that thalamus should be specifically targeted in neurorehabilitation following brain injury.

Mamillary Body Lesions in Monkeys Impair Object-in-Place Memory: Functional Unity of the Fornix-Mamillary System

1997 ◽  
Vol 9 (4) ◽  
pp. 512-521 ◽  
Author(s):  
Amanda Parker ◽  
David Gaffan
Keyword(s):  
Episodic Memory ◽  
Memory Task ◽  
Control Group ◽  
Thalamic Nuclei ◽  
Mamillary Body ◽  
Control Operation ◽  
Place Memory ◽  
Severe Impairment ◽  
Anterior Thalamic Nuclei

Six monkeys were trained preoperatively in an automated object-in-place memory task in which they learned 20 new scenes in each daily session. Three of the six monkeys then received stereotaxically guided bilateral mamillary body lesions, leaving the fornix intact, while the other three received a control operation. Postoperatively the control animals' rate of learning new scenes was unchanged, but the animals with mamillary body lesions showed a severe impairment, equal to that seen in previous experiments after fornix transection. All six animals were then given fornix transection, in addition to the existing mamillary or control operation. The control group now showed, after fornix transection, an impairment equal to that of the animals with mamillary body lesions alone. But the animals with mamillary body lesions did not show any additional impairment following fornix transection. We conclude that (1) the role of the mamillary bodies in a model of human episodic memory is as important as the role of the fornix, (2) the fornix and mamillary bodies form a single functional memory system, since the effect of lesions in both parts is no more severe than the effects of a lesion in one of the parts alone, and (3) the idea that the functional effects of fornix transection result from cholmergic deafferentation of the hippocampus receives no support from the present results; rather, they support the idea that in primates the fornix and mamillary bodies, together with connected structures, including the subiculum, mamillo-thalamic tract, anterior thalamic nuclei, and cingulate bundle, form a cortico-cortical association pathway for episodic memory.

Dendritic integration theory: A thalamo-cortical theory of state and content of consciousness

2020 ◽  
Vol 1 (II) ◽  
Author(s):  
Talis Bachmann ◽  
Mototaka Suzuki ◽  
Jaan Aru
Keyword(s):  
Pyramidal Neurons ◽  
Conscious Experience ◽  
Pyramidal Cells ◽  
Neural Mechanisms ◽  
Integration Theory ◽  
Thalamic Nuclei ◽  
Cortical Pyramidal Neurons ◽  
Cortical System ◽  
Work Done

The idea that the thalamo-cortical system is the crucial constituent of the neurobiological mechanisms of consciousness has a long history. For the last few decades, however, consciousness research has to a large extent overlooked the interplay between the cortex and thalamus. Here we revive an integrated view of the neurobiology of consciousness by presenting and discussing several recent major findings about the role of the thalamocortical interactions in consciousness. Based on these findings we propose a specific cellular mechanism how thalamic nuclei modulate the integration of different processing streams within single cortical pyramidal neurons. This theory is inspired by recent work done in rodents, but it integrates decades of work conducted on various species. We illustrate how this new view readily explains various properties and experimental phenomena associated with conscious experience. We discuss the implications of this idea and some of the experiments that need to be done in order to test it. Our view bridges two long-standing perspectives on the neural mechanisms of consciousness and proposes that cortical and thalamo-cortical processing interact at the level of single pyramidal cells.

scholarly journals Characterization of pruriceptive trigeminothalamic tract neurons in rats

2014 ◽  
Vol 111 (8) ◽  
pp. 1574-1589 ◽  
Author(s):  
Hannah R. Moser ◽  
Glenn J. Giesler
Keyword(s):  
Discharge Rate ◽  
Response Duration ◽  
Spike Timing ◽  
Thalamic Nuclei ◽  
Medial Nucleus ◽  
The Face ◽  
Deep Layers ◽  
Noxious Stimuli

Rodent models of facial itch and pain provide a valuable tool for distinguishing between behaviors related to each sensation. In rats, pruritogens applied to the face elicit scratching using the hindlimb while algogens elicit wiping using the forelimb. We wished to determine the role of trigeminothalamic tract (VTT) neurons in carrying information regarding facial itch and pain to the forebrain. We have characterized responses to facially applied pruritogens (serotonin, BAM8–22, chloroquine, histamine, capsaicin, and cowhage) and noxious stimuli in 104 VTT neurons recorded from anesthetized rats. Each VTT neuron had a mechanically sensitive cutaneous receptive field on the ipsilateral face. All pruriceptive VTT neurons also responded to noxious mechanical and/or thermal stimulation. Over half of VTT neurons responsive to noxious stimuli also responded to at least one pruritogen. Each tested pruritogen, with the exception of cowhage, produced an increase in discharge rate in a subset of VTT neurons. The response to each pruritogen was characterized, including maximum discharge rate, response duration, and spike timing dynamics. Pruriceptive VTT neurons were recorded from throughout superficial and deep layers of the spinal trigeminal nucleus and were shown to project via antidromic mapping to the ventroposterior medial nucleus or posterior thalamic nuclei. These results indicate that pruriceptive VTT neurons are a subset of polymodal nociceptive VTT neurons and characterize a system conducive to future experiments regarding the similarities and differences between facial itch and pain.

The role of the thalamic nuclei in recognition memory accompanied by recall during encoding and retrieval: An fMRI study

NeuroImage ◽  
2013 ◽  
Vol 74 ◽  
pp. 195-208 ◽  
Author(s):  
Giulio Pergola ◽  
Alexander Ranft ◽  
Klaus Mathias ◽  
Boris Suchan
Keyword(s):  
Recognition Memory ◽  
Thalamic Nuclei ◽  
Fmri Study ◽  
Encoding And Retrieval

scholarly journals Blink Synchronized Brain Activation: Association With Ascending Arousal Network

2020 ◽  
Author(s):  
Şükrü Barış Demiral ◽  
Christopher Liu ◽  
Helene Benveniste ◽  
Dardo Tomasi ◽  
Nora Volkow
Keyword(s):  
Ventral Tegmental Area ◽  
Strong Evidence ◽  
Resting State ◽  
Temporal Relationship ◽  
Thalamic Nuclei ◽  
Eye Blinks ◽  
Cognitive States ◽  
Thalamic Projections ◽  
Eyes Open

Abstract Eye-blinking has been implicated in arousal and attention. Here we test the hypothesis that, blinking-moments represent arousal transitions associated with activation of the ascending arousal network (AAN) and its thalamic projections. For this purpose, we explored the temporal relationship between eye-blinks and fMRI BOLD activity in the AAN and thalamus during a choice-reward task and an eyes-open resting state. We show that during the task, blinks were associated with activation of AAN and thalamic nuclei at the blink moment. During rest, peaks of AAN and thalamic nuclei were not synchronized and appeared weaker except for the ventral tegmental area (VTA). Our findings of an association between eye blinks and activation of the AAN and thalamus provides strong evidence in support of the role of eye blinking in arousal transitions that are influenced by cognitive states. It also corroborates the involvement of the dopaminergic VTA nucleus in eye blinking.

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