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Superior colliculus

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https://www.readbyqxmd.com/read/28925314/effect-of-methylphenidate-on-visual-responses-in-the-superior-colliculus-in-the-anaesthetised-rat-role-of-cortical-activation
#1
L Hetherington, E J Dommett, A C Turner, T B Riley, J X Haensel, P G Overton
The mechanism of action of psychostimulant drugs in the treatment of Attention Deficit Hyperactivity Disorder is still largely unknown, although recent evidence suggests one possibility is that the drugs affect the superior colliculus (SC). We have previously demonstrated that systemically administered d-amphetamine attenuates/abolishes visual responses to wholefield light flashes in the superficial layers of the SC in anaesthetised rats, and the present study sought to extend this work to methylphenidate (MPH)...
September 1, 2017: Journal of Psychopharmacology
https://www.readbyqxmd.com/read/28921678/ipsilateral-corticotectal-projections-from-the-primary-premotor-and-supplementary-motor-cortical-areas-in-adult-macaque-monkeys-a-quantitative-anterograde-tracing-study
#2
Michela Fregosi, Eric M Rouiller
The corticotectal projection from cortical motor areas is one of several descending pathways involved in the indirect control of spinal motoneurons. In non-human primates, previous studies reported that cortical projections to the superior colliculus originated from the premotor cortex and the primary motor cortex, whereas no projection originated from the supplementary motor area. The aim of the present study was to investigate and compare the properties of corticotectal projections originating from these three cortical motor areas in intact adult macaques (n=9)...
September 18, 2017: European Journal of Neuroscience
https://www.readbyqxmd.com/read/28912695/region-and-cell-specific-expression-of-transmembrane-collagens-in-mouse-brain
#3
Aboozar Monavarfeshani, Courtney N Knill, Ubadah Sabbagh, Jianmin Su, Michael A Fox
Unconventional collagens are nonfribrillar proteins that not only contribute to the structure of extracellular matrices but exhibit unique bio-activities. Although roles for unconventional collagens have been well-established in the development and function of non-neural tissues, only recently have studies identified roles for these proteins in brain development, and more specifically, in the formation and refinement of synaptic connections between neurons. Still, our understanding of the full cohort of unconventional collagens that are generated in the mammalian brain remains unclear...
2017: Frontiers in Integrative Neuroscience
https://www.readbyqxmd.com/read/28904104/the-superior-colliculus-and-the-steering-of-saccades-toward-a-moving-visual-target
#4
Laurent Goffart, Aaron Lee Cecala, Neeraj J Gandhi
Following the suggestion that a command encoding the current target location feeds the oculomotor system during interceptive saccades, we tested the involvement of the deep superior colliculus (dSC). Extracellular activity of 52 saccade-related neurons was recorded in three monkeys while they generated saccades to targets that were static or moving along the preferred axis, away from (outward) or toward a fixated target (inward) with a constant speed (20°/s). Vertical and horizontal motions were tested when possible...
September 13, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28891467/removal-of-inhibition-uncovers-latent-movement-potential-during-preparation
#5
Uday K Jagadisan, Neeraj J Gandhi
The motor system prepares for movements well in advance of their execution. In the gaze control system, the dynamics of preparatory neural activity have been well described by stochastic accumulation-to-threshold models. However, it is unclear whether this activity has features indicative of a hidden movement command. We explicitly tested whether preparatory neural activity in premotor neurons of the primate superior colliculus has "motor potential". We removed downstream inhibition on the saccadic system using the trigeminal blink reflex, triggering saccades at earlier-than-normal latencies...
September 11, 2017: ELife
https://www.readbyqxmd.com/read/28864246/pathways-for-smiling-disgust-and-fear-recognition-in-blindsight-patients
#6
Marzio Gerbella, Fausto Caruana, Giacomo Rizzolatti
The aim of the present review is to discuss the localization of circuits that allow recognition of emotional facial expressions in blindsight patients. Because recognition of facial expressions is function of different centers, and their localization is not always clear, we decided to discuss here three emotional facial expression - smiling, disgust, and fear - whose anatomical localization in the pregenual sector of the anterior cingulate cortex (pACC), anterior insula (AI), and amygdala, respectively, is well established...
August 29, 2017: Neuropsychologia
https://www.readbyqxmd.com/read/28856406/panicolytic-like-effects-caused-by-substantia-nigra-pars-reticulata-pretreatment-with-low-doses-of-endomorphin-1-and-high-doses-of-ctop-or-the-nop-receptors-antagonist-jtc-801-in-male-rattus-norvegicus
#7
Juliana Almeida da Silva, Audrey Franceschi Biagioni, Rafael Carvalho Almada, Renato Leonardo de Freitas, Norberto Cysne Coimbra
RATIONALE: Gamma-aminobutyric acid (GABA)ergic neurons of the substantia nigra pars reticulata (SNpr) are connected to the deep layers of the superior colliculus (dlSC). The dlSC, in turn, connect with the SNpr through opioid projections. Nociceptin/orphanin FQ peptide (N/OFQ) is a natural ligand of a Gi protein-coupled nociceptin receptor (ORL1; NOP) that is also found in the SNpr. Our hypothesis is that tectonigral opioid pathways and intranigral orphanin-mediated mechanisms modulate GABAergic nigrotectal connections...
August 30, 2017: Psychopharmacology
https://www.readbyqxmd.com/read/28852862/connections-between-the-zona-incerta-and-superior-colliculus-in-the-monkey-and-squirrel
#8
Paul J May, Michele A Basso
The zona incerta contains GABAergic neurons that project to the superior colliculus in the cat and rat, suggesting that it plays a role in gaze changes. However, whether this incertal connection represents a general mammalian pattern remains to be determined. We used neuronal tracers to examine the zona incerta connections with the midbrain tectum in the gray squirrel and macaque monkey. Collicular injections in both species revealed that most incertotectal neurons lay in the ventral layer, but anterogradely labeled tectoincertal terminals were found in both the dorsal and ventral layers...
August 29, 2017: Brain Structure & Function
https://www.readbyqxmd.com/read/28852092/change-in-sensitivity-to-visual-error-in-superior-colliculus-during-saccade-adaptation
#9
Yoshiko Kojima, Robijanto Soetedjo
Saccadic eye movements provide a valuable model to study the brain mechanisms underlying motor learning. If a target is displaced surreptitiously while a saccade is underway, the saccade appears to be in error. If the error persists gradual neuronal adjustments cause the eye movement again to land near the target. This saccade adaptation typically follows an exponential time course, i.e., adaptation speed slows as adaptation progresses, indicating that the sensitivity to error decreases during adaptation. Previous studies suggested that the superior colliculus (SC) sends error signals to drive saccade adaptation...
August 29, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28815321/fixational-eye-movements-in-tourette-syndrome
#10
Aasef G Shaikh, Shlomit Ritz Finkelstein, Ronald Schuchard, Glen Ross, Jorge L Juncos
Studies of saccadic eye movements in subjects with Tourette syndrome (TS) have provided additional evidence that there is a link between TS symptoms and deficits in fronto-striato-thalamic networks. These studies revealed impaired timing and inhibition of saccades. We compared fixational eye movements, such as microsaccades and ocular drifts, in subjects with TS and healthy controls.We measured horizontal and vertical eye positions with video-oculography in 14 subjects with Tourette syndrome. We found reduced microsaccade amplitude but increased time between adjacent microsaccades (intersaccadic interval)...
August 16, 2017: Neurological Sciences
https://www.readbyqxmd.com/read/28813307/the-innate-alarm-system-in-ptsd-conscious-and-subconscious-processing-of-threat
#11
REVIEW
Ruth A Lanius, Daniela Rabellino, Jenna E Boyd, Sherain Harricharan, Paul A Frewen, Margaret C McKinnon
The innate alarm system (IAS), comprised of functionally connected brain regions including the brainstem, amygdala, pulvinar, and frontotemporal cortex, is a fast subcortical brain network facilitating rapid responses to threat. Post-traumatic stress disorder (PTSD) features subconscious and conscious threat detection, together contributing to hyperarousal symptoms. Emerging literature identifies aberrant threat-related neurocircuitry involved in subconscious and conscious threat processing in PTSD. We review this literature, focusing on subconscious threat processing and its relation to the IAS...
April 2017: Current Opinion in Psychology
https://www.readbyqxmd.com/read/28808026/superior-colliculus-encodes-visual-saliency-before-the-primary-visual-cortex
#12
Brian J White, Janis Y Kan, Ron Levy, Laurent Itti, Douglas P Munoz
Models of visual attention postulate the existence of a bottom-up saliency map that is formed early in the visual processing stream. Although studies have reported evidence of a saliency map in various cortical brain areas, determining the contribution of phylogenetically older pathways is crucial to understanding its origin. Here, we compared saliency coding from neurons in two early gateways into the visual system: the primary visual cortex (V1) and the evolutionarily older superior colliculus (SC). We found that, while the response latency to visual stimulus onset was earlier for V1 neurons than superior colliculus superficial visual-layer neurons (SCs), the saliency representation emerged earlier in SCs than in V1...
August 29, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28794192/neural-correlates-for-task-switching-in-the-macaque-superior-colliculus
#13
Jason Lloyd Chan, Michael J Koval, Kevin Johnston, Stefan Everling
Successful task switching requires a network of brain areas to select, maintain, implement, and execute the appropriate task. Although frontoparietal brain areas are thought to play a critical role in task switching by selecting and encoding task rules and exerting top-down control, how brain areas closer to the execution of tasks participate in task switching is unclear. The superior colliculus (SC) integrates information from various brain areas to generate saccades and is likely influenced by task switching...
August 9, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28789960/multisensory-integration-in-orienting-behavior-pupil-size-microsaccades-and-saccades
#14
Chin-An Wang, Gunnar Blohm, Jeff Huang, Susan E Boehnke, Douglas P Munoz
Signals from different sensory modalities are integrated in the brain to optimize behavior. Although multisensory integration has been demonstrated in saccadic eye movements, its influence on other orienting responses, including pupil size and microsaccades, is still poorly understood. We examined human gaze orienting responses following presentation of visual, auditory, or combined audiovisual stimuli. Transient pupil dilation and microsaccade inhibition were evoked shortly after the appearance of a salient stimulus...
August 5, 2017: Biological Psychology
https://www.readbyqxmd.com/read/28774646/subcortical-and-cortical-correlates-of-pitch-discrimination-evidence-for-two-levels-of-neuroplasticity-in-musicians
#15
Federica Bianchi, Jens Hjortkjær, Sébastien Santurette, Robert J Zatorre, Hartwig R Siebner, Torsten Dau
Musicians are highly trained to discriminate fine pitch changes but the neural bases of this ability are poorly understood. It is unclear whether such training-dependent differences in pitch processing arise already in the subcortical auditory system or are linked to more central stages. To address this question, we combined psychoacoustic testing with functional MRI to measure cortical and subcortical responses in musicians and non-musicians during a pitch-discrimination task. First, we estimated behavioral pitch-discrimination thresholds for complex tones with harmonic components that were either resolved or unresolved in the auditory system...
July 31, 2017: NeuroImage
https://www.readbyqxmd.com/read/28774322/tau-accumulation-in-the-retina-promotes-early-neuronal-dysfunction-and-precedes-brain-pathology-in-a-mouse-model-of-alzheimer-s-disease
#16
Marius Chiasseu, Luis Alarcon-Martinez, Nicolas Belforte, Heberto Quintero, Florence Dotigny, Laurie Destroismaisons, Christine Vande Velde, Fany Panayi, Caroline Louis, Adriana Di Polo
BACKGROUND: Tau is an axon-enriched protein that binds to and stabilizes microtubules, and hence plays a crucial role in neuronal function. In Alzheimer's disease (AD), pathological tau accumulation correlates with cognitive decline. Substantial visual deficits are found in individuals affected by AD including a preferential loss of retinal ganglion cells (RGCs), the neurons that convey visual information from the retina to the brain. At present, however, the mechanisms that underlie vision changes in these patients are poorly understood...
August 3, 2017: Molecular Neurodegeneration
https://www.readbyqxmd.com/read/28760858/segregation-of-visual-response-properties-in-the-mouse-superior-colliculus-and-their-modulation-during-locomotion
#17
Shinya Ito, David A Feldheim, Alan M Litke
The superior colliculus (SC) receives direct input from the retina and integrates it with information about sound, touch, and state of the animal that is relayed from other parts of the brain to initiate specific behavioral outcomes. The superficial SC layers (sSC) contain cells that respond to visual stimuli, whereas the deep SC layers (dSC) contain cells that also respond to auditory and somatosensory stimuli. Here, we used a large-scale silicon probe recording system to examine the visual response properties of SC cells of head-fixed and alert male mice...
August 30, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28760697/vision-in-laboratory-rodents-tools-to-measure-it-and-implications-for-behavioral-research
#18
REVIEW
Henri Leinonen, Heikki Tanila
Mice and rats are nocturnal mammals and their vision is specialized for detection of motion and contrast in dim light conditions. These species possess a large proportion of UV-sensitive cones in their retinas and the majority of their optic nerve axons target superior colliculus rather than visual cortex. Therefore, it was a widely held belief that laboratory rodents hardly utilize vision during day-time behavior. This dogma is being questioned as accumulating evidence suggests that laboratory rodents are able to perform complex visual functions, such as perceiving subjective contours, and that declined vision may affect their performance in many behavioral tasks...
July 28, 2017: Behavioural Brain Research
https://www.readbyqxmd.com/read/28747592/investigation-of-spinal-nerve-ligation-mediated-functional-activation-of-the-rat-brain-using-manganese-enhanced-mri
#19
Keun-Yeong Jeong, Ji-Hyuk Kang
To provide clear information on the cerebral regions according to peripheral neuropathy, the functional activation was investigated using manganese-enhanced magnetic resonance imaging (MEMRI). L5-spinal nerve ligation (SNL) was applied to the rats to induce neuropathic pain. Mechanical allodynia and thermal hyperalgesia were measured to confirm neuropathic pain induction following before and after gabapentin (GBP) treatment. The cerebral regions were investigated using a 4.7T MRI system in the sham, SNL, and GBP-treated SNL rats...
July 26, 2017: Experimental Animals
https://www.readbyqxmd.com/read/28743454/convergence-of-primary-sensory-cortex-and-cerebellar-nuclei-pathways-in-the-whisker-system
#20
REVIEW
Carmen B Schäfer, Freek E Hoebeek
To safely maneuver through the environment the brain needs to compare active sensory information with ongoing motor programs. This process occurs at various levels in the brain: at the lower level, i.e., in the spinal cord, reflexes are generated for the most primitive motor responses; at the intermediate level, i.e., in the brainstem, various nuclei co-process sensory- and motor-related inputs; and, at the higher level cerebellum and thalamo-cortical networks individually compute suitable commands for fine-tuned motor output...
July 22, 2017: Neuroscience
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