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Superior colliculus

Swarupa Kancherla, William J Kohler, Yolandi van der Merwe, Kevin C Chan
Visual function has been shown to deteriorate prior to the onset of retinopathy in some diabetic patients and experimental animal models. This suggests the involvement of the brain's visual system in the early stages of diabetes. In this study, we tested this hypothesis by examining the integrity of the visual pathway in a diabetic rat model using in vivo multi-modal magnetic resonance imaging (MRI). Ten-week-old Sprague-Dawley rats were divided into an experimental diabetic group by intraperitoneal injection of 65 mg/kg streptozotocin in 0...
2016: PloS One
Siyu Zhang, Min Xu, Wei-Cheng Chang, Chenyan Ma, Johnny Phong Hoang Do, Daniel Jeong, Tiffany Lei, Jiang Lan Fan, Yang Dan
Long-range projections from the frontal cortex are known to modulate sensory processing in multiple modalities. Although the mouse has become an increasingly important animal model for studying the circuit basis of behavior, the functional organization of its frontal cortical long-range connectivity remains poorly characterized. Here we used virus-assisted circuit mapping to identify the brain networks for top-down modulation of visual, somatosensory and auditory processing. The visual cortex is reciprocally connected to the anterior cingulate area, whereas the somatosensory and auditory cortices are connected to the primary and secondary motor cortices...
October 17, 2016: Nature Neuroscience
Takako Kita, Naoki Shigematsu, Hitoshi Kita
Projections from the posterior intralaminar thalamic nuclei and the superior colliculus (SC) to the subthalamic nucleus (STN) and the zona incerta (ZI) have been described in the primate and rodent. The aims of this study was to investigate several questions on these projections, using modern neurotracing techniques in rats, to advance our understanding of the role of STN and ZI. We examined whether projection patterns to the subthlamus can be used to identify homologues of the primate centromedian (CM) and the parafascicular nucleus (Pf) in the rodent, the topography of the projection including what percent of intralaminar neurons participate in the projections, and electron microscopic examination of intralaminar synaptic boutons in STN...
September 26, 2016: European Journal of Neuroscience
Mo Chen, Bing Li, Jing Guang, Linyu Wei, Si Wu, Yu Liu, Mingsha Zhang
Although the cerebral cortex is thought to be composed of functionally distinct areas, the actual parcellation of area and assignment of function are still highly controversial. An example is the much-studied lateral intraparietal cortex (LIP). Despite the general agreement that LIP plays an important role in visual-oculomotor transformation, it remains unclear whether the area is primary sensory- or motor-related (the attention-intention debate). Although LIP has been considered as a functionally unitary area, its dorsal (LIPd) and ventral (LIPv) parts differ in local morphology and long-distance connectivity...
October 11, 2016: Proceedings of the National Academy of Sciences of the United States of America
Se-Jin Jeong, Chang-Jin Jeon
The purpose of this study was to determine whether the superior colliculus (SC) of the microbat has the same neurochemical makeup as that of other mammals. We examined the organization of choline acetyltransferase (ChAT)- and tyrosine hydroxylase-immunoreactive (TH-IR) fibers/cells using standard immunohistochemistry with antibodies against ChAT and TH. ChAT-IR fibers observed in the superficial layers were denser than those in the deeper layers, and these fibers were classified into two types: small varicose fibers and large varicose fibers...
September 29, 2016: Histology and Histopathology
Joana R Loureiro, Gisela E Hagberg, Thomas Ethofer, Michael Erb, Jonas Bause, Philipp Ehses, Klaus Scheffler, Marc Himmelbach
The superior colliculus (SC) is a layered structure located in the midbrain. We exploited the improved spatial resolution and BOLD signal strength available at 9.4 T to investigate the depth profile of visual BOLD responses in the human SC based on distortion-corrected EPI data with a 1 mm isotropic resolution. We used high resolution (350 µm in-plane) anatomical images to determine regions-of-interest of the SC and applied a semi-automated method to segment it into superficial, intermediate, and deep zones...
September 23, 2016: Human Brain Mapping
Andreas A Kardamakis, Juan Pérez-Fernández, Sten Grillner
Animals integrate the different senses to facilitate event-detection for navigation in their environment. In vertebrates, the optic tectum (superior colliculus) commands gaze shifts by synaptic integration of different sensory modalities. Recent works suggest that tectum can elaborate gaze reorientation commands on its own, rather than merely acting as a relay from upstream/forebrain circuits to downstream premotor centers. We show that tectal circuits can perform multisensory computations independently and, hence, configure final motor commands...
2016: ELife
Daniela Rabellino, Maria Densmore, Paul A Frewen, Jean Théberge, Margaret C McKinnon, Ruth A Lanius
Post-traumatic stress disorder (PTSD) is characterized by altered functional connectivity of the amygdala complexes at rest. However, amygdala complex connectivity during conscious and subconscious threat processing remains to be elucidated. Here, we investigate specific connectivity of the centromedial amygdala (CMA) and basolateral amygdala (BLA) during conscious and subconscious processing of trauma-related words among individuals with PTSD (n = 26) as compared to non-trauma-exposed controls (n = 20). Psycho-physiological interaction analyses were performed using the right and left amygdala complexes as regions of interest during conscious and subconscious trauma word processing...
2016: PloS One
Wei-Ling Wang, Hui Xu, Ying Li, Zhi-Zhong Ma, Xiao-Dong Sun, Yun-Tao Hu
Axonal tracing is useful for detecting optic nerve injury and regeneration, but many commonly used methods cannot be used to observe axoplasmic flow and synaptic transmission in vivo. Manganese (Mn(2+))-enhanced magnetic resonance imaging (MEMRI) can be used for in vivo longitudinal tracing of the visual pathway. Here, we explored the dose response and time course of an intravitreal injection of MnCl2 for tracing the visual pathway in rabbits in vivo using MEMRI. We found that 2 mM MnCl2 enhanced images of the optic nerve but not the lateral geniculate body or superior colliculus, whereas at all other doses tested (5-40 mM), images of the visual pathway from the retina to the contralateral superior colliculus were significantly enhanced...
July 2016: Neural Regeneration Research
Alexander A Nevue, Richard A Felix, Christine V Portfors
Neuromodulators can alter the response properties of sensory neurons, including those in the auditory system. Dopamine, which plays a major role in reward and movement, has been shown to alter neural responses in the auditory brainstem and midbrain. Recently we identified the subparafascicular thalamic nucleus (SPF), part of the A11 dopaminergic cell group, as the source of dopamine to the inferior colliculus (IC). The superior olivary complex (SOC) is also a likely target of dopaminergic projections from the SPF because it receives projections from the SPF and contains fibers and terminals immunoreactive for tyrosine hydroxylase, the rate limiting enzyme in dopamine synthesis...
September 10, 2016: Hearing Research
Ricardo de Oliveira, Rithiele Cristina de Oliveira, Luiz Luciano Falconi-Sobrinho, Raimundo da Silva Soares, Norberto Cysne Coimbra
The electrical stimulation of the dorsolateral columns of the periaquedutal grey matter (dlPAG) or deep layers of the superior colliculus (dlSC) evokes defensive behaviours followed by an antinociceptive response. Monoaminergic brainstem reticular nuclei are suggested to comprise the endogenous pain modulatory system. The aim of the present work was to investigate the role played by 5-HT2 subfamily of serotonergic receptors of the nucleus raphe magnus (NRM) and the gigantocellularis/paragigantocellularis pars α reticular nuclei (Gi/PGiα) in the elaboration of instinctive fear-induced antinociception elicited by electrical stimulation of dlPAG or of dlSC...
January 1, 2017: Behavioural Brain Research
John R Economides, Daniel L Adams, Jonathan C Horton
The superior colliculus is a major brainstem structure for the production of saccadic eye movements. Electrical stimulation at any given point in the motor map generates saccades of defined amplitude and direction. It is unknown how this saccade map is affected by strabismus. Three macaques were raised with exotropia, an outwards ocular deviation, by detaching the medial rectus tendon in each eye at age one month. The animals were able to make saccades to targets with either eye and appeared to alternate fixation freely...
September 7, 2016: Journal of Neurophysiology
Susanne Hoffmann, Tomas Vega-Zuniga, Wolfgang Greiter, Quirin Krabichler, Alexandra Bley, Mariana Matthes, Christiane Zimmer, Uwe Firzlaff, Harald Luksch
The midbrain superior colliculus (SC) commonly features a retinotopic representation of visual space in its superficial layers, which is congruent with maps formed by multisensory neurons and motor neurons in its deep layers. Information flow between layers is suggested to enable the SC to mediate goal-directed orienting movements. While most mammals strongly rely on vision for orienting, some species such as echolocating bats have developed alternative strategies, which raises the question how sensory maps are organized in these animals...
September 7, 2016: European Journal of Neuroscience
Samuel D Gale, Gabe J Murphy
UNLABELLED: Neurons respond to specific features of sensory stimuli. In the visual system, for example, some neurons respond to motion of small but not large objects, whereas other neurons prefer motion of the entire visual field. Separate neurons respond equally to local and global motion but selectively to additional features of visual stimuli. How and where does response selectivity emerge? Here, we show that wide-field (WF) cells in retino-recipient layers of the mouse superior colliculus (SC) respond selectively to small moving objects...
August 31, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Alexander Dee, Kairong Li, Xin Heng, Qiuxia Guo, James Y H Li
During embryogenesis, the tectum (dorsal midbrain) displays gradients in both gene expression and cytogenesis along the anteroposterior axis, and eventually produces the superior colliculus anteriorly and inferior colliculus posteriorly. Although it is known that different strengths and durations of FGF signaling control the developmental gradient and cell fate decision in the developing tectum, the underlying mechanism and signaling cascade downstream of FGF remains unclear. Here, we showed that deleting Shp2, which links FGF with the ERK pathway, prevented inferior colliculus formation by depleting a previously uncharacterized stem cell zone, designated as tectal stem zone, in the posterior part of the developing tectum...
August 30, 2016: Development
Kevin E Houston, A M Barrett
PURPOSE: Patching for double vision is a common palliative treatment for head-trauma patients with acquired strabismus when prisms are not feasible. METHODS: We review literature on spatial neglect and discuss possible effects of monocular occlusion on spatial attention. RESULTS: Patching the left eye has been shown to worsen spatial judgments in some brain-injured patients with left neglect by inhibiting the right superior colliculus further impairing contralateral leftward orienting (the Sprague Effect)...
August 30, 2016: Optometry and Vision Science: Official Publication of the American Academy of Optometry
Lorenza Capantini, Arndt von Twickel, Brita Robertson, Sten Grillner
In vertebrates, the pretectum and optic tectum (superior colliculus in mammals) are visuomotor areas that process sensory information and shape motor responses. Whereas the tectum has been investigated in great detail, the pretectum has received far less attention. The present study provides a detailed analysis of the connectivity and neuronal properties of lamprey pretectal cells. The pretectum can be subdivided roughly into three areas based on cellular location and projection pattern: superficial, central, and periventricular...
August 25, 2016: Journal of Comparative Neurology
Qun-Yong Zhou, Katherine J Burton, Matthew L Neal, Yu Qiao, Anumantha G Kanthasamy, Yanjun Sun, Xiangmin Xu, Yuanye Ma, Xiaohan Li
The temporal organization of activity/rest or sleep/wake rhythms for mammals is regulated by the interaction of light/dark cycle and circadian clocks. The neural and molecular mechanisms that confine the active phase to either day or night period for the diurnal and the nocturnal mammals are unclear. Here we report that prokineticin 2, previously shown as a circadian clock output molecule, is expressed in the intrinsically photosensitive retinal ganglion cells, and the expression of prokineticin 2 in the intrinsically photosensitive retinal ganglion cells is oscillatory in a clock-dependent manner...
2016: Molecular Brain
Masatoshi Kasai, Tadashi Isa
The superior colliculus (SC) plays a key role in controlling spatial attention. It is hypothesized that some forms of spatial attention, such as the detection of a single salient object arise from lateral competitive interactions between different locations within the spatial map in the SC. This hypothesis is supported by a recent in vitro study showing that a 'Mexican hat'-like pattern of synaptic connectivity is implemented in the intrinsic circuit of the superficial layer of the SC (sSC). However, the neuronal population mechanisms responsible for this pattern still remain unclear...
October 2016: European Journal of Neuroscience
Ben Mead, Stanislav Tomarev
Retinal ganglion cells (RGC) bear the sole responsibility of propagating visual stimuli to the brain. Their axons, which make up the optic nerve, project from the retina to the brain through the lamina cribrosa and in rodents, decussate almost entirely at the optic chiasm before synapsing at the superior colliculus. For many traumatic and degenerative ocular conditions, the dysfunction and/or loss of RGC is the primary determinant of visual loss and are the measurable endpoints in current research into experimental therapies...
October 2016: Experimental Eye Research
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