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mouse visual cortex

María Sáez, Maya Ketzef, Javier Alegre-Cortés, Ramón Reig, Gilad Silberberg
Focal administration of pharmacological agents during in vivo recordings is a useful technique to study the functional properties of neural microcircuits. However, the lack of visual control makes this task difficult and inaccurate, especially when targeting small and deep regions where spillover to neighboring regions is likely to occur. An additional problem with recording stability arises when combining focal drug administration with in vivo intracellular recordings, which are highly sensitive to mechanical vibrations...
April 18, 2018: Neuroscience
Luis O Jimenez, Elaine Tring, Joshua T Trachtenberg, Dario L Ringach
Neurons in primary visual cortex are selective to the orientation and spatial frequency of sinusoidal gratings. In the classic model of cortical organization, a population of neurons responding to the same region of the visual field, but tuned to all possible feature combinations, provides a detailed representation of the local image. Such a functional module is assumed to be replicated across primary visual cortex to provide a uniform representation of the image across the entire the visual field. In contrast, it has been hypothesized that the tiling properties of ON and OFF-center receptive fields in the retina, largely mirrored in the geniculate, may constrain cortical tuning at each location in the visual field...
April 18, 2018: Journal of Neurophysiology
Tiago Marques, Julia Nguyen, Gabriela Fioreze, Leopoldo Petreanu
Cortical feedback is thought to mediate cognitive processes like attention, prediction, and awareness. Understanding its function requires identifying the organizational logic of feedback axons relaying different signals. We measured retinotopic specificity in inputs from the lateromedial visual area in mouse primary visual cortex (V1) by mapping receptive fields in feedback boutons and relating them to those of neurons in their vicinity. Lateromedial visual area inputs in layer 1 targeted, on average, retinotopically matched locations in V1, but many of them relayed distal visual information...
April 16, 2018: Nature Neuroscience
Mario Dipoppa, Adam Ranson, Michael Krumin, Marius Pachitariu, Matteo Carandini, Kenneth D Harris
Cortical computation arises from the interaction of multiple neuronal types, including pyramidal (Pyr) cells and interneurons expressing Sst, Vip, or Pvalb. To study the circuit underlying such interactions, we imaged these four types of cells in mouse primary visual cortex (V1). Our recordings in darkness were consistent with a "disinhibitory" model in which locomotion activates Vip cells, thus inhibiting Sst cells and disinhibiting Pyr cells. However, the disinhibitory model failed when visual stimuli were present: locomotion increased Sst cell responses to large stimuli and Vip cell responses to small stimuli...
April 11, 2018: Neuron
Jun Zhuang, Quanxin Wang, Marc Takeno, Jack Waters
This protocol describes a method for registration of in vivo cortical retinotopic map with cytochrome c oxidase (CO) labeled architectonic maps of the same mouse brain through the alignment of vascular fiducials. By recording surface blood vessel pattern and sequential alignment at each step, this method overcomes the challenge imposed by tissue distortion during perfusion, mounting, sectioning and histology procedures. This method can also be generalized to register and align other types of in vivo functional maps like ocular dominance map and spatial/temporal frequency tuning map with various anatomical maps of mouse cortex...
February 20, 2018: Bio-protocol
Kalina Makowiecki, Andrew Garrett, Alan R Harvey, Jennifer Rodger
Repetitive transcranial stimulation (rTMS) is an increasingly popular method to non-invasively modulate cortical excitability in research and clinical settings. During rTMS, low-intensity magnetic fields reach areas perifocal to the target brain region, however, effects of these low-intensity (LI-) fields and how they interact with ongoing neural activity remains poorly defined. We evaluated whether coordinated neural activity during electromagnetic stimulation alters LI-rTMS effects on cortical excitability by comparing visually evoked potentials (VEP) and densities of parvalbumin-expressing (PV+) GABAergic interneurons in adult mouse visual cortex after LI-rTMS under different conditions: LI-rTMS applied during visually evoked (strong, coordinated) activity or in darkness (weak, spontaneous activity)...
April 11, 2018: Scientific Reports
Simon Schwab, Ruth Harbord, Valerio Zerbi, Lloyd Elliott, Soroosh Afyouni, Jim Q Smith, Mark W Woolrich, Stephen M Smith, Thomas E Nichols
There are a growing number of neuroimaging methods that model spatio-temporal patterns of brain activity to allow more meaningful characterizations of brain networks. This paper proposes dynamic graphical models (DGMs) for dynamic, directed functional connectivity. DGMs are a multivariate graphical model with time-varying coefficients that describe instantaneous directed relationships between nodes. A further benefit of DGMs is that networks may contain loops and that large networks can be estimated. We use network simulations, human resting-state fMRI (N = 500) to investigate the validity and reliability of the estimated networks...
April 3, 2018: NeuroImage
Michael G White, Brian N Mathur
The claustrum is a telencephalic gray matter nucleus that is richly interconnected with the neocortex. This structure subserves top-down executive functions that require frontal cortical control of posterior cortical regions. However, functional anatomical support for the claustrum allowing for long-range intercortical communication is lacking. To test this, we performed a channelrhodopsin-assisted long-circuit mapping strategy in mouse brain slices. We find that anterior cingulate cortex input to the claustrum is transiently amplified by claustrum neurons that, in turn, project to parietal association cortex or to primary and secondary visual cortices...
April 6, 2018: Brain Structure & Function
Fengling Li, Weiqian Jiang, Tian-Yi Wang, Taorong Xie, Haishan Yao
In the primary visual cortex (V1), neuronal responses to stimuli within the receptive field (RF) are modulated by stimuli in the RF surround. A common effect of surround modulation is surround suppression, which is dependent on the feature difference between stimuli within and surround the RF and is suggested to be involved in the perceptual phenomenon of figure-ground segregation. In this study, we examined the relationship between feature-specific surround suppression of V1 neurons and figure detection behavior based on figure-ground feature difference...
March 30, 2018: Neuroscience
Yosuke Hirakawa, Kiichi Mizukami, Toshitada Yoshihara, Ippei Takahashi, Purevsuren Khulan, Tomoko Honda, Imari Mimura, Tetsuhiro Tanaka, Seiji Tobita, Masaomi Nangaku
Renal tubulointerstitial hypoxia is recognized as a final common pathway of chronic kidney disease and is considered a promising drug target. However, hypoxia in the tubules is not well examined because of limited detection methods. Here, we devised a method to visualize renal tubular oxygen tension with spatial resolution at a cellular level using the cell-penetrating phosphorescent probe, BTPDM1 (an iridium-based cationic lipophilic dye), and confocal phosphorescence lifetime imaging microscopy to precisely assess renal hypoxia...
March 30, 2018: Kidney International
Yunyun Han, Justus M Kebschull, Robert A A Campbell, Devon Cowan, Fabia Imhof, Anthony M Zador, Thomas D Mrsic-Flogel
Neocortical areas communicate through extensive axonal projections, but the logic of information transfer remains poorly understood, because the projections of individual neurons have not been systematically characterized. It is not known whether individual neurons send projections only to single cortical areas or distribute signals across multiple targets. Here we determine the projection patterns of 591 individual neurons in the mouse primary visual cortex using whole-brain fluorescence-based axonal tracing and high-throughput DNA sequencing of genetically barcoded neurons (MAPseq)...
March 28, 2018: Nature
Sofie C Sundberg, Björn Granseth
Genetically modified mouse strains that express Cre-recombinase in specific neuronal sub-populations have become widely used tools for investigating neuronal function. The Ntsr1-Cre GN220 mouse expresses this enzyme in corticothalamic neurons in layer 6 of cerebral cortex. We observed that about 7% of Cre-expressing cells in the primary visual cortex are found within the white matter bordering layer 6. By using the immunohistochemical marker for layer 6 neurons, Forkhead box protein 2 (FoxP2), and fluorescently conjugated latex beads injected into the dorsal lateral geniculate nucleus, we show that about half of these cells are similar to and could belong to the layer 6 corticothalamic neuron population...
March 23, 2018: Neuroscience Letters
D Himmelhan, O Rawashdeh, H H A Oelschläger
This study characterizes the early postnatal development of the visual neocortex in C3H/HeNRj mice. These mice are homozygous for the Pde6brd1 mutation, which causes retinal degeneration starting from postnatal day 7 (P7). To monitor the development of the visual cortex between P3 and P28 we used eight antigens known to be expressed at different developmental stages (Nestin, tau3, β3- Tubulin, Calbindin, Doublecortin, MAP2, Parvalbumin and NeuN). Using semiquantitative analysis we traced the expression and localization of different developmental markers throughout the layers of the visual cortex...
March 18, 2018: Mechanisms of Development
Daisuke Shimaoka, Kenneth D Harris, Matteo Carandini
Changes in arousal modulate the activity of mouse sensory cortex, but studies in different mice and different sensory areas disagree on whether this modulation enhances or suppresses activity. We measured this modulation simultaneously in multiple cortical areas by imaging mice expressing voltage-sensitive fluorescent proteins (VSFP). VSFP imaging estimates local membrane potential across large portions of cortex. We used temporal filters to predict local potential from running speed or from pupil dilation, two measures of arousal...
March 20, 2018: Cell Reports
Mateo Vélez-Fort, Edward F Bracey, Sepiedeh Keshavarzi, Charly V Rousseau, Lee Cossell, Stephen C Lenzi, Molly Strom, Troy W Margrie
To interpret visual-motion events, the underlying computation must involve internal reference to the motion status of the observer's head. We show here that layer 6 (L6) principal neurons in mouse primary visual cortex (V1) receive a diffuse, vestibular-mediated synaptic input that signals the angular velocity of horizontal rotation. Behavioral and theoretical experiments indicate that these inputs, distributed over a network of 100 L6 neurons, provide both a reliable estimate and, therefore, physiological separation of head-velocity signals...
March 8, 2018: Neuron
Magdalena Kolasa, Joanna Solich, Agata Faron-Górecka, Dariusz Żurawek, Paulina Pabian, Sylwia Łukasiewicz, Maciej Kuśmider, Kinga Szafran-Pilch, Marta Szlachta, Marta Dziedzicka-Wasylewska
Recently, it has been shown that serotonin 5-HT1A receptor interacts with dopamine D2 receptor in vitro. However, the existence of 5-HT1A -D2 heteromers in native tissue remains unexplored. In the present study, we investigated 5-HT1A -D2 receptor heteromerization in mice treated acutely or chronically with paroxetine (10 mg/kg) or risperidone (0.05 mg/kg). Receptor heteromerization was visualized and quantified in the mouse brain by in situ proximity ligation assay (PLA). Additionally, we aimed to determine the cellular localization of 5-HT1A -D2 receptor heteromers in mouse adult primary neuronal cells by immunofluorescent staining with markers for astrocytes (GFAP) and neurons (NeuN and MAP2)...
March 12, 2018: Neuroscience
Marco Pisanello, Filippo Pisano, Leonardo Sileo, Emanuela Maglie, Elisa Bellistri, Barbara Spagnolo, Gil Mandelbaum, Bernardo L Sabatini, Massimo De Vittorio, Ferruccio Pisanello
Optogenetic control of neural activity in deep brain regions ideally requires precise and flexible light delivery with non-invasive devices. To this end, Tapered Optical Fibers (TFs) represent a versatile tool that can deliver light over either large brain volumes or spatially confined sub-regions, while being sensibly smaller than flat-cleaved optical fibers. In this work, we report on the possibility of further extending light emission length along the taper in the range 0.4 mm-3.0 mm by increasing the numerical aperture of the TFs to NA = 0...
March 13, 2018: Scientific Reports
Marta Szlachta, Maciej Kuśmider, Paulina Pabian, Joanna Solich, Magdalena Kolasa, Dariusz Żurawek, Marta Dziedzicka-Wasylewska, Agata Faron-Górecka
G-protein-coupled receptor (GPCR) heterodimers are new targets for the treatment of schizophrenia. Dopamine D2 receptors and serotonin 5-HT1A and 5-HT2A receptors play an important role in neurotransmission and have been implicated in many human psychiatric disorders, including schizophrenia. Therefore, in this study, we investigated whether antipsychotic drugs (clozapine (CLZ) and haloperidol (HAL)) affected the formation of heterodimers of D2 -5-HT1A receptors as well as 5-HT1A -5-HT2A receptors. Proximity ligation assay (PLA) was used to accurately visualize, for the first time, GPCR heterodimers both at in vitro and ex vivo levels...
2018: Frontiers in Molecular Neuroscience
Naoki Shigematsu, Akinori Nishi, Takaichi Fukuda
Parvalbumin (PV)-positive interneurons form dendritic gap junctions with one another, but the connectivity among gap junction-coupled dendrites remains uninvestigated in most neocortical areas. We visualized gap junctions in layer 4 of the mouse barrel cortex and examined their structural details. PV neurons were divided into 4 types based on the location of soma and dendrites within or outside barrels. Type 1 neurons that had soma and all dendrites inside a barrel, considered most specific to single vibrissa-derived signals, unexpectedly formed gap junctions only with other types but never with each other...
February 27, 2018: Cerebral Cortex
Mansi P Saraf, Pooja Balaram, Fabien Pifferi, Răzvan Gămănuț, Henry Kennedy, Jon H Kaas
Mouse lemurs are the smallest of the living primates, and are members of the understudied radiation of strepsirrhine lemurs of Madagascar. They are thought to closely resemble the ancestral primates that gave rise to present day primates. Here we have used multiple histological and immunochemical methods to identify and characterize sensory areas of neocortex in four brains of adult lemurs obtained from a licensed breeding colony. We describe the laminar features for the primary visual area (V1), the secondary visual area (V2), the middle temporal visual area (MT) and area prostriata, somatosensory areas S1(3b), 3a, and area 1, the primary motor cortex (M1), and the primary auditory cortex (A1)...
February 26, 2018: Journal of Comparative Neurology
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