nepuinthesky Posted May 25, 2012 Report Share Posted May 25, 2012 i was watching a TV show about sensory illusions. there were shown a lot of illusions, visual and auditory. the thalamus plays the main part in these illusions. maybe our occipital lobe is only the sufferer of a wrong working thalamus. here is something intersseting. The thalamus (from Greek θάλαμος = inner chamber) is a midline symmetrical structure within the brains of vertebrates including humans, situated between the cerebral cortex and midbrain. Its function includes relaying sensory and motor signals to the cerebral cortex,  along with the regulation of consciousness, sleep, and alertness. maybe this would also explain some of the comorbid deseasses a few of us have. e.g. regulation of sleep. The thalamus has multiple functions. It may be thought of as a kind of switchboard of information. It is generally believed to act as a relay between a variety of subcortical areas and the cerebral cortex. In particular, every sensory system (with the exception of the olfactory system) includes a thalamic nucleus that receives sensory signals and sends them to the associated primary cortical area. For the visual system, for example, inputs from the retina are sent to the lateral geniculate nucleus of the thalamus, which in turn projects to the primary visual cortex (area V1) in the occipital lobe. The thalamus is believed to both process sensory information as well as relay it—each of the primary sensory relay areas receives strong "back projections" from the cerebral cortex. Similarly the medial geniculate nucleus acts as a key auditory relay between the inferior colliculus of the midbrain and the primary auditory cortex, and the ventral posterior nucleus is a key somatosensory relay, which sends touch and proprioceptive information to the primary somatosensory cortex. The thalamus also plays an important role in regulating states of sleep and wakefulness. Thalamic nuclei have strong reciprocal connections with the cerebral cortex, forming thalamo-cortico-thalamic circuits that are believed to be involved with consciousness. The thalamus plays a major role in regulating arousal, the level of awareness, and activity. Damage to the thalamus can lead to permanent coma. The role of the thalamus in the more anterior pallidal and nigral territories in the basal ganglia system disturbances is recognized but still poorly understood. The contribution of the thalamus to vestibular or to tectal functions is almost ignored. The thalamus has been thought of as a "relay" that simply forwards signals to the cerebral cortex. Newer research suggests that thalamic function is more selective.Many different functions are linked to various regions of the thalamus. This is the case for many of the sensory systems (except for the olfactory system), such as the auditory, somatic, visceral, gustatory and visual systems where localized lesions provoke specific sensory deficits. A major role of the thalamus is devoted to "motor" systems. The thalamus is functionally connected to the hippocampus as part of the extended hippocampal system at the thalamic anterior nuclei with respect to spatial memory and spatial sensory datum they are crucial for human episodic memory and rodent event memory. There is support for the hypothesis that thalamic regions connection to particular parts of the mesio-temporal lobe provide differentiation of the functioning of recollective and familiarity memory. The neuronal information processes necessary for motor control were proposed as a network involving the thalamus as a subcortical motor centre. Through investigations of the anatomy of the brains of primates the nature of the interconnected tissues of the cerebellum to the multiple motor cortices suggested that the thalamus fulfills a key function in providing the specific channels from the basal ganglia and cerebellum to the cortical motor areas. In an investigation of the saccade and antisaccade motor response in three monkeys, the thalamic regions were found to be involved in the generation of antisaccade eye-movement. seems everything could be explained by a not propper working thalamus. also tinnitus seems to be connected to the thalamus in some way: Region-of-Interest Analysis Within the auditory system, we encountered significant structural differences between tinnitus sufferers and normal controls only at the thalamic level (Fig. 2), although auditory brain stem structures and the auditory cortex were equally included in our analysis. The right posterior thalamus including the MGN showed an increase in gray-matter concentration (Fig. 1A,B; thresholded at P < 0.05, corrected at both voxel and cluster level; Z value of peak voxel, 3.7; P value corrected at the voxel level using FDR, 0.04; P value corrected at the cluster level, 0.02). After relaxing the significance threshold to P < 0.05 uncorrected (extent threshold: 30 voxels), concentration increases surfaced also in the left posterior thalamus but not in any other structures of the auditory system (Fig. 2C). also dopamine plays a part in the thalamus maybe this would explain why drugs like sinemet coul help some of us: The thalamus relays information to the cerebral cortex from subcortical centers or other cortices; in addition, it projects to the striatum and amygdala. The thalamic relay function is subject to modulation, so the flow of information to the target regions may change depending on behavioral demands. Modulation of thalamic relay by dopamine is not currently acknowledged, perhaps because dopamine innervation is reportedly scant in the rodent thalamus. We show that dopaminergic axons profusely target the human and macaque monkey thalamus using immunolabeling with three markers of the dopaminergic phenotype (tyrosine hydroxylase, dopamine, and the dopamine transporter). The dopamine innervation is especially prominent in specific association, limbic, and motor thalamic nuclei, where the densities of dopaminergic axons are as high as or higher than in the cortical area with the densest dopamine innervation. We also identified the dopaminergic neurons projecting to the macaque thalamus using retrograde tract-tracing combined with immunohistochemistry. The origin of thalamic dopamine is multiple, and thus more complex, than in any other dopaminergic system defined to date: dopaminergic neurons of the hypothalamus, periaqueductal gray matter, ventral mesencephalon, and the lateral parabrachial nucleus project bilaterally to the monkey thalamus. We propose a novel dopaminergic system that targets the primate thalamus and is independent from the previously defined nigrostriatal, mesocortical, and mesolimbic dopaminergic systems. Investigating this "thalamic dopaminergic system" should further our understanding of higher brain functions and conditions such as Parkinson's disease, schizophrenia, and drug addiction i think it woul also explain why there is such a big bunch in symptoms and not all of us has the same. i am in a hurry right now i will elaborate this theory a bit more soon. Link to comment Share on other sites More sharing options...
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