Vestibular Interactions in the Thalamus (original) (raw)
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The thalamocortical vestibular system in animals and humans
Brain Research Reviews, 2011
The vestibular system provides the brain with sensory signals about three-dimensional head rotations and translations. These signals are important for postural and oculomotor control, as well as for spatial and bodily perception and cognition, and they are subtended by pathways running from the vestibular nuclei to the thalamus, cerebellum and the "vestibular cortex."
The Journal of neuroscience : the official journal of the Society for Neuroscience, 1997
Vestibular information influences spatial orientation and navigation in laboratory animals and humans. Neurons within the rat anterior thalamus encode the directional heading of the animal in absolute space. These neurons, referred to as head direction (HD) cells, fire selectively when the rat points its head in a specific direction in the horizontal plane with respect to the external laboratory reference frame. HD cells are thought to represent an essential component of a neural network that processes allocentric spatial information. The functional properties of HD cells may be dependent on vestibular input. Here, anterior thalamic HD cells were recorded before and after sodium arsanilate-induced vestibular system lesion. Vestibular lesions abolished the directional firing properties of HD cells. The time course of disruption in the directional firing properties paralleled the loss of vestibular function. Arsanilate-treated rats exhibited only minor changes in locomotor behavior, w...
Vestibulo-thalamic projection to the anterior suprasylvian cortex of the cat
Experimental Brain Research, 1981
Suggestive evidence as to the site of a major thalamic relay of the vestibular projection to the anterior suprasylvian (ASS) cortex in the cat has 9 been obtained using the retrograde axonal transport of horseradish peroxidase. The thalamo-cortical neurons are located in several patches surrounding the posterior margins of the ventro-basal complex (VB). This area also was found to receive vestibulothalamic projections. It comprises different nuclear groups known to carry somatic, accoustic, visual or combined information, which possibly have certain functions related to kinaesthesia and body orientation in common.
Brain Research Bulletin, 1984
RAMfREZ-CAMACHO, R., C. AVENDANO AND F. REINOSO-SUAREZ. Thalamic projections to the anterior suprasylvian and posterior sigmoid coretx: An HRP study of the "vestibular areas" of the cerebral cortex in the cat. BRAIN RES BULL 12(3) 245-252, 1!%4.-We have confirmed electrophysiologically the existence of an oligosynaptic vestibufar projection to the cortex surrounding the rostral end of the anterior suprasylvian sulcus (ASsS). However, we failed to confii a similar projection to area 3a in the posterior sigmoid gyrus. We studied the thrdamic projections to each of these cortical regions by injecting small amounts of HRP in the cortex and looking for neurons retrogradely labeled throughout the thalamus. The exact location of the cortical injections was assessed cytoarchitectonically. The heaviest neuronal labeling after injections in the banks of ASsS was obtained in PO (including in this complex GMmc). A moderate number of projections was found from VPi, VPm and VP1 (the labeling in the latter being particularly prominent in a case injected in the lower bank of ASsS), and also from VL. Occasional labeled neurons were found in the rostro-ventral part of LP. After injections in area 3a in the posterior sigmoid gyrus, which affected to a minor degree either area 3b or 4, many labeled cells appeared in the rostral and dorsal part of VPl, and in the central and lateral parts of VL. Fewer labeled cells were found in VPi, PO and LP. In most cases some occasional labeled cell was observed also in the intralaminar nuclei and in Vm. Vestibular cortex Thalamus Vestibular projections HRP Cat
Topographic representation of vestibular and somatosensory signals in the anuran thalamus
Neuroscience, 2004
In the isolated brain of the fire-bellied toad, Bombina orientalis, the spatial distribution of vestibular and somatosensory responses in thalamic nuclei was studied following electrical activation of the Vth nerve, the ramus anterior of the VIIIth nerve and of the dorsal roots of spinal nerves 3 and 8. Responses were systematically mapped in frontal planes through the diencephalon at four rostro-caudal levels. The calculated activity maps were superimposed on the outlines of diencephalic nuclei, and those nuclei that received particularly large inputs from the stimulated sensory nerve roots were indicated. Maximal response amplitudes coincided with ventral, central, and posterior thalamic areas and exhibited a topography that differed for each sensory nerve root. Maximal responses evoked from the Vth nerve were largely separated from those from spinal dorsal roots 3 and 8, whereas maximal vestibular responses partly overlapped with those from the other somatosensory nerve roots. Our findings indicate that within the amphibian thalamus sensory signals originating from different nerve roots are largely represented in separate areas as is the case in the thalamus of amniotes. However, the anterior dorsal thalamus which is the only origin of ascending pathways to the medial and dorsal pallium (assumed homologues of the mammalian hippocampus and neocortex, respectively) receives only minor vestibular and somatosensory input. This corroborates the view that amphibians lack a direct sensory thalamo-cortical, or "lemnothalamic," pathway typical of mammals and birds.
Widespread vestibular activation of the rodent cortex
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2015
Much of our understanding of the neuronal mechanisms of spatial navigation is derived from chronic recordings in rodents in which head-direction, place, and grid cells have all been described. However, despite the proposed importance of self-reference information to these internal representations of space, their congruence with vestibular signaling remains unclear. Here we have undertaken brain-wide functional mapping using both fMRI and electrophysiological methods to directly determine the spatial extent, strength, and time course of vestibular signaling across the rat forebrain. We find distributed activity throughout thalamic, limbic, and particularly primary sensory cortical areas in addition to known head-direction pathways. We also observe activation of frontal regions, including infralimbic and cingulate cortices, indicating integration of vestibular information throughout functionally diverse cortical regions. These whole-brain activity maps therefore suggest a widespread c...
Cerebral Cortex, 2009
Multisensory and sensorimotor integrations are usually considered to occur in superior colliculus and cerebral cortex, but few studies proposed the thalamus as being involved in these integrative processes. We investigated whether the organization of the thalamocortical (TC) systems for different modalities partly overlap, representing an anatomical support for multisensory and sensorimotor interplay in thalamus. In 2 macaque monkeys, 6 neuroanatomical tracers were injected in the rostral and caudal auditory cortex, posterior parietal cortex (PE/PEa in area 5), and dorsal and ventral premotor cortical areas (PMd, PMv), demonstrating the existence of overlapping territories of thalamic projections to areas of different modalities (sensory and motor). TC projections, distinct from the ones arising from specific unimodal sensory nuclei, were observed from motor thalamus to PE/PEa or auditory cortex and from sensory thalamus to PMd/PMv. The central lateral nucleus and the mediodorsal nucleus project to all injected areas, but the most significant overlap across modalities was found in the medial pulvinar nucleus. The present results demonstrate the presence of thalamic territories integrating different sensory modalities with motor attributes. Based on the divergent/convergent pattern of TC and corticothalamic projections, 4 distinct mechanisms of multisensory and sensorimotor interplay are proposed.
INTEGRATIVE NEUROSCIENCE Vestibular pathways involved in cognition
Recent discoveries have emphasized the role of the vestibular system in cognitive processes such as memory, spatial navigation and bodily self-consciousness. A precise understanding of the vestibular pathways involved is essential to understand the consequences of vestibular diseases for cognition, as well as develop therapeutic strategies to facilitate recovery. The knowledge of the "vestibular cortical projection areas" , defined as the cortical areas activated by vestibular stimulation, has dramatically increased over the last several years from both anatomical and functional points of view. Four major pathways have been hypothesized to transmit vestibular information to the vestibular cortex: (1) the vestibulo-thalamo-cortical pathway, which probably transmits spatial information about the environment via the parietal, entorhinal and perirhinal cortices to the hippocampus and is associated with spatial representation and self-versus object motion distinctions; (2) the pathway from the dorsal tegmental nucleus via the lateral mammillary nucleus, the anterodorsal nucleus of the thalamus to the entorhinal cortex, which transmits information for estimations of head direction; (3) the pathway via the nucleus reticularis pontis oralis, the supramammillary nucleus and the medial septum to the hippocampus, which transmits information supporting hippocampal theta rhythm and memory; and (4) a possible pathway via the cerebellum, and the ventral lateral nucleus of the thalamus (perhaps to the parietal cortex), which transmits information for spatial learning. Finally a new pathway is hypothesized via the basal ganglia, potentially involved in spatial learning and spatial memory. From these pathways, progressively emerges the anatomical network of vestibular cognition.
Head direction cell activity in the anterodorsal thalamus requires intact supragenual nuclei
Journal of Neurophysiology, 2012
Neural activity in several limbic areas varies as a function of the animal's head direction (HD) in the horizontal plane. Lesions of the vestibular periphery abolish this HD cell signal, suggesting an essential role for vestibular afference in HD signal generation. The organization of brain stem pathways conveying vestibular information to the HD circuit is poorly understood; however, recent anatomical work has identified the supragenual nucleus (SGN) as a putative relay. To test this hypothesis, we made lesions of the SGN in rats and screened for HD cells in the anterodorsal thalamus. In animals with complete bilateral lesions, the overall number of HD cells was significantly reduced relative to control animals. In animals with unilateral lesions of the SGN, directional activity was present, but the preferred firing directions of these cells were unstable and less influenced by the rotation of an environmental landmark. In addition, we found that preferred directions displayed large directional shifts when animals foraged for food in a darkened environment and when they were navigating from a familiar environment to a novel one, suggesting that the SGN plays a critical role in projecting essential self-motion (idiothetic) information to the HD cell circuit.