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Localization of histamine H2 receptor in the gerbil retina
Abstracts medial terminal nucleus (MTN) of the AOS, and then analyzed immunohistochemically the distribution of labeled retinal neurons. Double labeling with rabies virus and amacrine cell markers revealed that the MTN-projecting direction-selective GCs received major input from inhibitory amacrine cells except cholinergic (starburst) amacrine cells. doi:10.1016/j.neures.2009.09.1123
P3-b15 Localization of histamine H2 receptor in the gerbil retina Mahito Ohkuma, Hideki Imada, Ei-ichi Miyachi Dept of Physiol, Sch of Med, Fujita Health Univ, Aichi, Japan Histaminergic signal transduction system exists in the vertebrate retina. This system has been considered to participate in the efferent innervation. Although histamine H1 receptor and/or histamine H3 receptor were involved this visual function, the histamine H2 receptor (H2R) was excluded because it expressed glial cells. However, we found that H2R expressed on the retinal ganglion cells in the premature gerbil. Furthermore, some retinal ganglion cells were excited by dimaprit, an agonist of the H2R. While expression of H2R became maximum at about 14 to 21 postnatal days, decreased according to mature and disappeared at postmature gerbil. These results suggest functional H2R transduction system exists at the premature retina. Since the gerbil opens the eyes at 3 weeks old, it is considered that the H2R plays specific role at the formation of the early optical signal transduction system. doi:10.1016/j.neures.2009.09.1124
P3-b16 Inhibitory stabilization of the cortical network underlies visual surround suppression Hirofumi Ozeki 1,2 , Ian M. Finn 2 , Evan S. Schaffer 3 , Kenneth D. Miller 3 , David Ferster 2 1
RIKEN BSI, Wako, Saitama, Japan; 2 Northwestern Univ, Evanston, IL, USA; 3 Columbia Univ, New York, NY, USA
In what regime does the cortical circuit operate? Our intracellular studies of surround suppression in cat primary visual cortex (V1) provide strong evidence on this question. Although suppression has been thought to arise from an increase in lateral inhibition, we find that the inhibition that cells receive is reduced, not increased, by a surround stimulus. Instead, suppression is mediated by a withdrawal of excitation. Thalamic recordings and previous work show that these effects cannot be explained by a withdrawal of thalamic input. We find in theoretical work that this behavior can only arise if V1 operates as an inhibition-stabilized network (ISN), in which excitatory recurrence alone is strong enough to destabilize visual responses but feedback inhibition maintains stability. We confirm two strong tests of this scenario experimentally, and show through simulation that observed cell-to-cell variability in surround effects, from facilitation to suppression, can arise naturally from variability in the ISN. doi:10.1016/j.neures.2009.09.1125
P3-b17 Robust preservation of altered orientation maps in the visual cortex of kittens reared with discordant goggles Toshiki Tani, Shigeru Tanaka RIKEN Brain Science Institute, Japan The marked over-representation of an exposed orientation is induced by 1- or 2week single-orientation exposure in the two eyes with head-mounted goggles in early life. After prolonged goggle rearing, however, the over-representation of the exposed orientation gradually decreases towards a moderate level. In the present study, to examine interocular cortical inhibition working between the left- and righteye dominance patches on altered orientation maps, we performed optical imaging of intrinsic signals in the visual cortex of kittens reared with discordant goggles which exposed animals to orthogonal orientations in the respective eyes. In these kittens, the representations of the vertical and horizontal orientations separately occupied cortical patches of opposite ocular dominance. The overrepresentation of the exposed orientation for each eye tended to be robustly preserved even after prolonged discordant-goggle rearing. These findings suggest that interocular cortical inhibition enhanced by concordant-goggle rearing moderates the initially induced over-representation of the exposed orientation. doi:10.1016/j.neures.2009.09.1126
S205
P3-b18 Saccade-related signals in V1 change within the sequence of eye-movements during natural vision Junji Ito 1 , Pedro Maldonado 2 , Sonja Gruen 1 1
RIKEN Brain Science Inst, Wako-shi, Japan;
2
Univ de Chile, Santiage, Chile
In our previous studies of V1 activity of freely viewing monkeys, we found that visually induced spikes during fixations are phase-locked to LFP beta-oscillations evoked by preceding saccades. These signals may be instrumental during selfinitiated eye movements enabling precise temporal relationships within the neural network involved in visual processing. Studies in humans that freely view natural images have reported changes in the durations of the saccades and fixations as a function of the sequence order of sucessive eye movements (EM). Thus, here we reexamine our monkey neuronal activity to determine whether the order in EMsequences influences saccade-evoked LFP and phase locking of spikes. We found an EM-sequence dependent modulation of the amplitude of the saccade-evoked LFP oscillations, along with changes of the phase locking of visually induced early spikes. These results suggest that different types of visual processing are involved during early and late EMs in visual exploration. doi:10.1016/j.neures.2009.09.1127
P3-b19 A mathematical model of color map formation in macaque V1 and V2 Masanobu Miyashita 1,2 , Shigeru Tanaka 2 1
Numazu National College of Technology, Japan; RIKEN, Japan
2
Brain Science Institute,
In macaque V1 and V2, some portions of neurons are selective for color information. However, the spatial organizations of color representation are different between V1 and V2: in V1, color cells in response to red/green or blue/yellow are located in CO blobs and bridges linking nearest neighbor CO blobs; and in V2, color responsive cells, which are mainly confined in the CO thin stripes, are rather regularly arranged according to hue. Thus far, few models have not successfully explained such organization about color representation. In this study, we built a self-organization model to explain cortical color representation in V1 and V2 in a unified manner. Changing the values of coefficients of response biases, we reproduced basic structure of color blobs and bridges in V1 and alternating achromatic (thick and pale) stripes and chromatic (thin) stripes in which hue is regularly represented. doi:10.1016/j.neures.2009.09.1128
P3-b20 Organization of multisynaptic inputs from LGN to MT and V4 of macaques Taihei Ninomiya 1,2 , Hiromasa Sawamura 1,3 , Ken-ichi Inoue 1 , Masahiko Takada 1 1
System Neurosci, Tokyo Met Inst Neurosci, Tokyo, Japan; 2 Grad Sch Frontier Biosci, Osaka Univ, Osaka, Japan; 3 Dept Opthal, Tokyo Univ, Tokyo, Japan The primate visual system is composed of multisynaptic pathways connecting the lateral geniculate nucleus (LGN) and higher cortical areas via the primary visual cortex. To investigate the architecture of the dorsal and ventral visual pathways, we injected rabies virus into the middle temporal area (MT) and visual area 4 (V4) of macaque monkeys and compared the patterns of transneuronal labeling in the LGN. The neuronal labeling in the LGN occurred 3 days after the MT injection, whereas the labeling appeared 4 days after V4. In these cases, labeled neurons were observed in both magno- and parvocellular layers of the LGN. The present results suggest that the MT and V4 receive the second- or third-order multisynaptic inputs, respectively, from the LGN with convergent signals originating in magno- and parvocellular layers. doi:10.1016/j.neures.2009.09.1129
P3-b21 Face identity decoding by population activity in macaque inferotemporal cortex face-selective region Naohisa Miyakawa 1,2 , Manabu Tanifuji 1 1
Integrative Neural Systems, RIKEN BSI, Saitama, Japan; sity, Niigata, Japan
2
Niigata Univer-
Primates can recognize faces invariantly even when they view the faces from different viewing angles. Inferotemporal (IT) cortex is the latest stage of the ventral visual stream, and is widely accepted to be a crucial area for visual recognition. It has been shown that in IT cortex, there are multiple face-responsive regions, which have strong selectivity to face images. These face-selective regions are considered to contribute to face detection, however, it is still unclear how identification of view-invariant face identification is realized. We recorded population activities
P3-b15 Localization of histamine H2 receptor in the gerbil retina Mahito Ohkuma, Hideki Imada, Ei-ichi Miyachi Dept of Physiol, Sch of Med, Fujita Health Univ, Aichi, Japan Histaminergic signal transduction system exists in the vertebrate retina. This system has been considered to participate in the efferent innervation. Although histamine H1 receptor and/or histamine H3 receptor were involved this visual function, the histamine H2 receptor (H2R) was excluded because it expressed glial cells. However, we found that H2R expressed on the retinal ganglion cells in the premature gerbil. Furthermore, some retinal ganglion cells were excited by dimaprit, an agonist of the H2R. While expression of H2R became maximum at about 14 to 21 postnatal days, decreased according to mature and disappeared at postmature gerbil. These results suggest functional H2R transduction system exists at the premature retina. Since the gerbil opens the eyes at 3 weeks old, it is considered that the H2R plays specific role at the formation of the early optical signal transduction system. doi:10.1016/j.neures.2009.09.1124
P3-b16 Inhibitory stabilization of the cortical network underlies visual surround suppression Hirofumi Ozeki 1,2 , Ian M. Finn 2 , Evan S. Schaffer 3 , Kenneth D. Miller 3 , David Ferster 2 1
RIKEN BSI, Wako, Saitama, Japan; 2 Northwestern Univ, Evanston, IL, USA; 3 Columbia Univ, New York, NY, USA
In what regime does the cortical circuit operate? Our intracellular studies of surround suppression in cat primary visual cortex (V1) provide strong evidence on this question. Although suppression has been thought to arise from an increase in lateral inhibition, we find that the inhibition that cells receive is reduced, not increased, by a surround stimulus. Instead, suppression is mediated by a withdrawal of excitation. Thalamic recordings and previous work show that these effects cannot be explained by a withdrawal of thalamic input. We find in theoretical work that this behavior can only arise if V1 operates as an inhibition-stabilized network (ISN), in which excitatory recurrence alone is strong enough to destabilize visual responses but feedback inhibition maintains stability. We confirm two strong tests of this scenario experimentally, and show through simulation that observed cell-to-cell variability in surround effects, from facilitation to suppression, can arise naturally from variability in the ISN. doi:10.1016/j.neures.2009.09.1125
P3-b17 Robust preservation of altered orientation maps in the visual cortex of kittens reared with discordant goggles Toshiki Tani, Shigeru Tanaka RIKEN Brain Science Institute, Japan The marked over-representation of an exposed orientation is induced by 1- or 2week single-orientation exposure in the two eyes with head-mounted goggles in early life. After prolonged goggle rearing, however, the over-representation of the exposed orientation gradually decreases towards a moderate level. In the present study, to examine interocular cortical inhibition working between the left- and righteye dominance patches on altered orientation maps, we performed optical imaging of intrinsic signals in the visual cortex of kittens reared with discordant goggles which exposed animals to orthogonal orientations in the respective eyes. In these kittens, the representations of the vertical and horizontal orientations separately occupied cortical patches of opposite ocular dominance. The overrepresentation of the exposed orientation for each eye tended to be robustly preserved even after prolonged discordant-goggle rearing. These findings suggest that interocular cortical inhibition enhanced by concordant-goggle rearing moderates the initially induced over-representation of the exposed orientation. doi:10.1016/j.neures.2009.09.1126
S205
P3-b18 Saccade-related signals in V1 change within the sequence of eye-movements during natural vision Junji Ito 1 , Pedro Maldonado 2 , Sonja Gruen 1 1
RIKEN Brain Science Inst, Wako-shi, Japan;
2
Univ de Chile, Santiage, Chile
In our previous studies of V1 activity of freely viewing monkeys, we found that visually induced spikes during fixations are phase-locked to LFP beta-oscillations evoked by preceding saccades. These signals may be instrumental during selfinitiated eye movements enabling precise temporal relationships within the neural network involved in visual processing. Studies in humans that freely view natural images have reported changes in the durations of the saccades and fixations as a function of the sequence order of sucessive eye movements (EM). Thus, here we reexamine our monkey neuronal activity to determine whether the order in EMsequences influences saccade-evoked LFP and phase locking of spikes. We found an EM-sequence dependent modulation of the amplitude of the saccade-evoked LFP oscillations, along with changes of the phase locking of visually induced early spikes. These results suggest that different types of visual processing are involved during early and late EMs in visual exploration. doi:10.1016/j.neures.2009.09.1127
P3-b19 A mathematical model of color map formation in macaque V1 and V2 Masanobu Miyashita 1,2 , Shigeru Tanaka 2 1
Numazu National College of Technology, Japan; RIKEN, Japan
2
Brain Science Institute,
In macaque V1 and V2, some portions of neurons are selective for color information. However, the spatial organizations of color representation are different between V1 and V2: in V1, color cells in response to red/green or blue/yellow are located in CO blobs and bridges linking nearest neighbor CO blobs; and in V2, color responsive cells, which are mainly confined in the CO thin stripes, are rather regularly arranged according to hue. Thus far, few models have not successfully explained such organization about color representation. In this study, we built a self-organization model to explain cortical color representation in V1 and V2 in a unified manner. Changing the values of coefficients of response biases, we reproduced basic structure of color blobs and bridges in V1 and alternating achromatic (thick and pale) stripes and chromatic (thin) stripes in which hue is regularly represented. doi:10.1016/j.neures.2009.09.1128
P3-b20 Organization of multisynaptic inputs from LGN to MT and V4 of macaques Taihei Ninomiya 1,2 , Hiromasa Sawamura 1,3 , Ken-ichi Inoue 1 , Masahiko Takada 1 1
System Neurosci, Tokyo Met Inst Neurosci, Tokyo, Japan; 2 Grad Sch Frontier Biosci, Osaka Univ, Osaka, Japan; 3 Dept Opthal, Tokyo Univ, Tokyo, Japan The primate visual system is composed of multisynaptic pathways connecting the lateral geniculate nucleus (LGN) and higher cortical areas via the primary visual cortex. To investigate the architecture of the dorsal and ventral visual pathways, we injected rabies virus into the middle temporal area (MT) and visual area 4 (V4) of macaque monkeys and compared the patterns of transneuronal labeling in the LGN. The neuronal labeling in the LGN occurred 3 days after the MT injection, whereas the labeling appeared 4 days after V4. In these cases, labeled neurons were observed in both magno- and parvocellular layers of the LGN. The present results suggest that the MT and V4 receive the second- or third-order multisynaptic inputs, respectively, from the LGN with convergent signals originating in magno- and parvocellular layers. doi:10.1016/j.neures.2009.09.1129
P3-b21 Face identity decoding by population activity in macaque inferotemporal cortex face-selective region Naohisa Miyakawa 1,2 , Manabu Tanifuji 1 1
Integrative Neural Systems, RIKEN BSI, Saitama, Japan; sity, Niigata, Japan
2
Niigata Univer-
Primates can recognize faces invariantly even when they view the faces from different viewing angles. Inferotemporal (IT) cortex is the latest stage of the ventral visual stream, and is widely accepted to be a crucial area for visual recognition. It has been shown that in IT cortex, there are multiple face-responsive regions, which have strong selectivity to face images. These face-selective regions are considered to contribute to face detection, however, it is still unclear how identification of view-invariant face identification is realized. We recorded population activities