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Lateral geniculate nucleus

Sean J Farley, Heba Albazboz, Benjamin J De Corte, Jason J Radley, John H Freeman
Previous studies found that reversible inactivation of the central amygdala (CeA) severely impairs acquisition and retention of cerebellum-dependent eye-blink conditioning (EBC) with an auditory conditioned stimulus (CS). A monosynaptic pathway between the CeA and basilar pontine nuclei (BPN) may be capable of facilitating cerebellar learning. However, given that the CeA projects to the medial auditory thalamus, a critical part of the auditory CS pathway in EBC, the CeA influence on cerebellar learning could be specific to auditory stimuli...
March 10, 2018: Neurobiology of Learning and Memory
Henry J Alitto, Daniel L Rathbun, Tucker G Fisher, Prescott C Alexander, W Martin Usrey
Visual information processed in the retina is transmitted to primary visual cortex via relay cells in the lateral geniculate nucleus (LGN) of the dorsal thalamus. Although retinal ganglion cells are the primary source of driving input to LGN neurons, not all retinal spikes are transmitted to the cortex. Here, we investigate the relationship between stimulus contrast and retinogeniculate communication and test the hypothesis that both the time course and strength of retinogeniculate interactions are dynamic and dependent on stimulus contrast...
March 8, 2018: European Journal of Neuroscience
Hongjian Li, Qi Fang, Yijun Ge, Zhong Li, Jianjun Meng, Jianbing Zhu, Hongbo Yu
Simple cells in the cat primary visual cortex usually have elongated receptive fields (RFs), and their orientation selectivity can be largely predicted by their RFs. As to the relay cells in cats' lateral geniculate nucleus (LGN), they also have weak but significant orientation bias. It is thus of interest to investigate the fine spatiotemporal receptive field (STRF) properties in LGN, compare them with the dynamics of orientation tuning, and examine the dynamic relationship between STRF and orientation sensitivity in LGN...
February 23, 2018: Neuroscience
Kacie Dougherty, Michael C Schmid, Alexander Maier
The dorsal lateral geniculate nucleus of the thalamus (LGN) receives the main outputs of both eyes and relays those signals to the visual cortex. Each retina projects to separate layers of the LGN so that each LGN neuron is innervated by a single eye. In line with this anatomical separation, visual responses of almost all of LGN neurons are driven by one eye only. Nonetheless, many LGN neurons are sensitive to what is shown to the other eye as their visual responses differ when both eyes are stimulated compared to when the driving eye is stimulated in isolation...
February 23, 2018: Journal of Comparative Neurology
Cristiano Bombardi, Marcello Venzi, Vincenzo Crunelli, Giuseppe Di Giovanni
Absence seizures (ASs) are associated with abnormalities in gamma-aminobutyric acid (GABA) neurotransmission in the thalamus and the cortex. In the present study, we used light microscopy GABA immunocytochemistry to quantify the GABA-immunoreactive (GABA-IR) neurons and neuropil in the thalamic ventral basal (VB) nucleus, the nucleus reticularis thalami (NRT), the dorsal lateral geniculate (dLGN), the primary motor cortex (M1) and perioral region of the somatosensory cortex (S1po) of genetic absence epilepsy rats from Strasbourg (GAERS)...
February 19, 2018: Neuropharmacology
João Jorge, Patrícia Figueiredo, Rolf Gruetter, Wietske van der Zwaag
External stimuli and tasks often elicit negative BOLD responses in various brain regions, and growing experimental evidence supports that these phenomena are functionally meaningful. In this work, the high sensitivity available at 7T was explored to map and characterize both positive (PBRs) and negative BOLD responses (NBRs) to visual checkerboard stimulation, occurring in various brain regions within and beyond the visual cortex. Recently-proposed accelerated fMRI techniques were employed for data acquisition, and procedures for exclusion of large draining vein contributions, together with ICA-assisted denoising, were included in the analysis to improve response estimation...
February 20, 2018: Human Brain Mapping
Z F Xu, J S Sun, X H Zhang, Y Y Feng, A Z Pan, M Y Gao, H Zhao
AIM: To evaluate microstructural visual pathway damage in patients with primary glaucoma (PG) by using 3 T diffusion kurtosis imaging (DKI). MATERIALS AND METHODS: The study was approved by the ethics committee, and all participants provided written informed consent. Ten patients with PG were examined. Twenty healthy individuals served as control subjects. DKI was performed with a GE Silent 3 T magnetic resonance imaging (MRI) unit. Mean diffusivity (MD), fractional anisotropy (FA), and mean kurtosis (MK) maps were automatically created...
February 16, 2018: Clinical Radiology
Brian Allen, Melanie A Schmitt, Burton J Kushner, Bas Rokers
Purpose: Amblyopia is associated with a broad array of perceptual and neural abnormalities in the visual system, particularly in untreated or unsuccessfully treated populations. Traditionally, it has been believed that the neural abnormalities are confined to the visual cortex and subcortex (e.g., lateral geniculate nucleus). Here, we investigate the presence of neuroanatomical abnormalities earlier in the visual stream, in the optic nerves and tracts, of participants with two predominant forms of amblyopia...
February 1, 2018: Investigative Ophthalmology & Visual Science
Heywood M Petry, Martha E Bickford
This review provides a historical account of the discovery of secondary visual pathways (from retina to the superior colliculus to the dorsal thalamus and extrastriate cortex), and Vivien Casagrande's pioneering studies of this system using the tree shrew as a model. Subsequent studies of visual pathways in the tree shrew are also reviewed, beginning with a description of the organization and central projections of the tree shrew retina. The organization and connectivity of 2nd visual system components, that include the retino-recipient superior colliculus, tecto-recipient pulvinar nucleus and its projections, and the tecto-recipient dorsal lateral geniculate nucleus and its projections are detailed...
February 15, 2018: Journal of Comparative Neurology
Maria Emanuela Martins Dos Reis, Lucimário Thiago Félix de Araújo, Wylqui Mikael Gomes de Andrade, Nayra da Silva Resende, Ruthnaldo Rodrigues Melo de Lima, Expedito Silva do Nascimento, Miriam Stela Maris de Oliveira Costa, Judney Cley Cavalcante
Nitric oxide (NO) is a highly soluble and membrane-permeable neurotransmitter, so it does not need to be packed in vesicles or have a membrane receptor. In the nervous system, NO is synthesized by the neuronal form of the nitric oxide synthase (NOS) enzyme and has been considered as a local neurotransmitter. NOS distribution is widespread in the nervous system of various vertebrate species, which may explain its participation in many functions such as memory, blood pressure regulation and sexual behavior. Here we used immunohistochemistry against NOS and NADPH diaphorase histochemistry to map the distribution of NO in the diencephalon of the rock cavy (Kerodon rupestris), a rodent endemic to the Brazilian Northeast...
February 10, 2018: Brain Research
Keith P Johnson, Lei Zhao, Daniel Kerschensteiner
The spike trains of retinal ganglion cells (RGCs) are the only source of visual information to the brain. Here, we genetically identify an RGC type in mice that functions as a pixel encoder and increases firing to light increments (PixON-RGC). PixON-RGCs have medium-sized dendritic arbors and non-canonical center-surround receptive fields. From their receptive field center, PixON-RGCs receive only excitatory input, which encodes contrast and spatial information linearly. From their receptive field surround, PixON-RGCs receive only inhibitory input, which is temporally matched to the excitatory center input...
February 6, 2018: Cell Reports
Mónica Giraldo-Chica, Keith A Schneider
Human brain asymmetry reflects normal specialization of functional roles and may derive from evolutionary, hereditary, developmental, experiential, and pathological factors (Toga & Thompson, 2003). Geschwind and Galaburda (1985) suggested that processing difficulties in dyslexia are due to structural differences between hemispheres. Because of its potential significance to the controversial magnocellular theory of dyslexia, we investigated hemispheric differences in the human lateral geniculate nucleus (LGN), the primary visual relay and control nucleus in the thalamus, in subjects with dyslexia compared to normal readers...
January 29, 2018: Dyslexia: the Journal of the British Dyslexia Association
Pablo Martínez-Cañada, Milad Hobbi Mobarhan, Geir Halnes, Marianne Fyhn, Christian Morillas, Francisco Pelayo, Gaute T Einevoll
Despite half-a-century of research since the seminal work of Hubel and Wiesel, the role of the dorsal lateral geniculate nucleus (dLGN) in shaping the visual signals is not properly understood. Placed on route from retina to primary visual cortex in the early visual pathway, a striking feature of the dLGN circuit is that both the relay cells (RCs) and interneurons (INs) not only receive feedforward input from retinal ganglion cells, but also a prominent feedback from cells in layer 6 of visual cortex. This feedback has been proposed to affect synchronicity and other temporal properties of the RC firing...
January 29, 2018: PLoS Computational Biology
Timothy K MacLachlan, Mark N Milton, Oliver Turner, Francis Tukov, Vivian W Choi, Jan Penraat, Marie-Hélène Delmotte, Lydia Michaut, Bruce D Jaffee, Chad E Bigelow
Retinitis pigmentosa is a form of retinal degeneration usually caused by genetic mutations affecting key functional proteins. We have previously demonstrated efficacy in a mouse model of RLBP1 deficiency with a self-complementary AAV8 vector carrying the gene for human RLBP1 under control of a short RLBP1 promoter (CPK850).1 In this article, we describe the nonclinical safety profile of this construct as well as updated efficacy data in the intended clinical formulation. In Rlbp1-/- mice dosed at a range of CPK850 levels, a minimum efficacious dose of 3 × 107 vg in a volume of 1 μL was observed...
March 16, 2018: Molecular Therapy. Methods & Clinical Development
Xufeng Chen, Muhammad Aslam, Tim Gollisch, Kevin Allen, Jakob von Engelhardt
Relay neurons in the dorsal lateral geniculate nucleus (dLGN) receive excitatory inputs from retinal ganglion cells (RGCs). Retinogeniculate synapses are characterized by a prominent short-term depression of AMPA receptor (AMPAR)-mediated currents, but the underlying mechanisms and its function for visual integration are not known. Here we identify CKAMP44 as a crucial auxiliary subunit of AMPARs in dLGN relay neurons, where it increases AMPAR-mediated current amplitudes and modulates gating of AMPARs. Importantly, CKAMP44 is responsible for the distinctive short-term depression in retinogeniculate synapses by reducing the rate of recovery from desensitization of AMPARs...
January 17, 2018: Nature Communications
Brian T Kalish, Lucas Cheadle, Sinisa Hrvatin, M Aurel Nagy, Samuel Rivera, Megan Crow, Jesse Gillis, Rory Kirchner, Michael E Greenberg
Coordinated changes in gene expression underlie the early patterning and cell-type specification of the central nervous system. However, much less is known about how such changes contribute to later stages of circuit assembly and refinement. In this study, we employ single-cell RNA sequencing to develop a detailed, whole-transcriptome resource of gene expression across four time points in the developing dorsal lateral geniculate nucleus (LGN), a visual structure in the brain that undergoes a well-characterized program of postnatal circuit development...
January 17, 2018: Proceedings of the National Academy of Sciences of the United States of America
Austen A Sitko, Takaaki Kuwajima, Carol Mason
Prior to forming and refining synaptic connections, axons of projection neurons navigate long distances to their targets. While much is known about guidance cues for axon navigation through intermediate choice points, whether and how axons are organized within tracts is less clear. Here we analyze the organization of retinal ganglion cell (RGC) axons in the developing mouse retinogeniculate pathway. RGC axons are organized by both eye-specificity and topography in the optic nerve and tract: ipsilateral RGC axons are segregated from contralateral axons and are offset laterally in the tract relative to contralateral axon topographic position...
January 11, 2018: Journal of Comparative Neurology
Sara Ajina, Holly Bridge
Residual vision, or blindsight, following damage to the primary visual cortex (V1) has been investigated for almost half a century. While there have been many studies of patients with unilateral damage to V1, far fewer have examined bilateral damage, mainly due to the rarity of such patients. Here we re-examine the residual visual function and underlying pathways of previously studied patient SBR who, as a young adult, suffered bilateral damage restricted to V1 which rendered him cortically blind. While earlier work compared his visual cortex to healthy, sighted participants, here we consider how his visual responses and connections compare to patients with unilateral damage to V1 in addition to sighted participants...
January 7, 2018: Neuropsychologia
Natalie Zeater, Péter Buzás, Bogdan Dreher, Ulrike Grünert, Paul R Martin
The dorsal lateral geniculate nucleus receives projections from visuotopically organised subcortical nuclei, in addition to inputs from the retina, visual cortices, and the thalamic reticular nucleus. Here, we study subcortical projections to the geniculate from the superior colliculus (SC) and parabigeminal nucleus (PBG) in the midbrain, and the nucleus of the optic tract (NOT) in the pretectum of marmosets. Marmosets are New World diurnal foveate monkeys, and are an increasingly popular model for studying the primate visual system...
January 9, 2018: Journal of Comparative Neurology
Julien Fournier, Christian M Müller, Ingmar Schneider, Gilles Laurent
Turtle dorsal cortex (dCx), a three-layered cortical area of the reptilian telencephalon, receives inputs from the retina via the thalamic lateral geniculate nucleus and constitutes the first cortical stage of visual processing. The receptive fields of dCx neurons usually occupy the entire contralateral visual field. Electrophysiological recordings in awake and anesthetized animals reveal that dCx is sensitive to the spatial structure of natural images, that dCx receptive fields are not entirely uniform across space, and that adaptation to repeated stimulation is position specific...
December 8, 2017: Neuron
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