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Developmental change of activity-dependent regulation of mGluR1( in the lateral geniculate nucleus
Abstracts / Neuroscience Research 58S (2007) S1–S244
P1-e33 Express visual search Rikako Kato 1,2 , Tadashi Isa 1,2,3 1 Department of Developmental Physiology, National Institute for Physiological Science, Japan; 2 CREST, JST, Japan; 3 School of Life Sciences, The Graduate University for Advanced Studies, Japan The neural mechanisms underlying oddball visual search have been studied in the frontal and parietal cortices and in the superior colliculus. The initial visual responses to the target and the distractor were indiscriminable in most neurons in these areas but then responses became distinguishable about 120 ms after the stimulus. However, it was also reported that V1 cells distinguished oddball stimulus from homogeneous background stimuli around the peak of initial visual responses (about 60 ms after stimulus onset; Knierim and VanEssen, 1992). We expected that monkeys might be able to use such initial discrimination signal under appropriate conditions. We introduced a temporal gap between the fixation spot offset and the stimulus onset. Then, in the color and shape visual search with a gap of 200 ms, the monkey made express saccades (reaction time between 65 and 90 ms) to the target, respectively, in 50.2% and 47.2% of the trials. These results suggest that the animal can utilize the difference in the initial visual response for visual search under the gap condition.
S97
P1-e36 Neural mechanism of biological motion processing: An MEG study Masahiro Hirai 1,2 , Yoshiki Kaneoke 1 , Hiroki Nakata 1 , Ryusuke Kakigi 1 1 Department of Integrative Physiology, National Institute for Pysiological Sciences, Japan; 2 Japan Society for the Promotion of Science, Japan Many neuroimaging studies have identified the brain region that was activated by biological motion (BM) perception, however, its neural dynamics still remains unclear. Unlike previous studies, we adopted ‘double stimulus presentation ‘method to extract magnetoencephalographic (MEG) response relating to processing of BM perception. We presented scrambled point-light walker (PLW) as a first stimulus (S1) and then presented upright PLW or inverted PLW as a second stimulus (S2) sequentially. The MEG response was observed for S1 at around 280 ms, and the peak latency of S2 was at around 380 ms from each stimulus onset. Additionally, in S2, the peak amplitude of PLW stimulus was significantly larger than that of scrambled PLW and the dipole was estimated more anterior to that in S1. These findings suggest that MEG response to human figure and action was enhanced in occipitotemporal region and PLW stimulus would be processed after general motion processing.
Research funds: CREST, JST
Research fund: Grant-in-Aid for JSPS Fellows No. 18-11826
P1-e34 A physiological role of gap junctions in firing properties
P1-e38 Laminar specificity of callosal connections in the rat striate cortex
of retinal AII amacrine cells Fuminobu Tamalu, Shu-Ichi Watanabe Department of Physiology, Saitama Medical University, Saitama, Japan Retinal AII amacrine cells (AII cells) generate TTX-sensitive repetitive spikes that are dependent on glutamatergic synaptic input and are reciprocally connected via gap junctions. To examine physiological roles of the gap junctions, we performed whole-cell patch clamping of AII cells in the mouse retinal slice. In current-clamp mode, we observed large fluctuations of membrane potential in AII cells. Adding gap junction blockers to the external solution diminished the voltage fluctuations, suggesting that the fluctuations are originated from the activities of neighboring AII cells. In addition, under these conditions, AII cells fired spikes at the highest frequency even when a small amount of current injection (about 10 pA) was applied at a membrane potential of about -65 mV. This is possibly because the gap junction blockers made the input resistance higher by closing the shunt via gap junctions. Our data suggested that gap junctional connections of AII cells might have a crucial role to respond wide range of input, probably by controlling shunt current.
P1-e35 Developmental change of activity-dependent regulation
Takemasa Satoh 1 , Yosio Hata 2 Division of Neurobiology, Tottori University Faculty of Medicine, Yonago, Japan; 2 Division of Integrative BioScience, Tottori University Graduate School of Medical Science, Yonago, Japan 1
In lateral part of rat striate cortex, which represents central visual space, reciprocal callosal linkages are organized in a topographic manner. Callosal projecting cells of this region distribute in the supra- and infragranular layers. Although previous investigations revealed overall distribution of callosal cells and their axon terminations, laminar specificity of the callosal projections has not been characterized. Therefore, we made small injections of antero- or retrograde tracers into the supraor infragranular layers in the lateral striate cortex of one hemisphere. In supragranular injections, retrogradely labeled cells distributed mainly in layer II/III and IV of contralateral striate cortex. Antrogradely labeled axons densely branched in layer II/III. In contrast, in infragranular injections, labeled cells distributed mainly in layer IV, V and VI. Afferent axons terminated mainly in the infragranular layers. These results suggest the laminar specific segregation of callosal connectivity in the lateral striate cortex.
P1-e39 Inconsistency and uncertainty in the locations of
of mGluR1( in the lateral geniculate nucleus
human visual areas in Talairach space
Miho Yoshida 1 , Takemasa Satoh 2 , Kouichi Nakamura 3 , Takeshi Kaneko 3 , Yoshio Hata 1 1 Division of Integrative Bioscience, Tottori University Graduate School of Medicine Science, Yonago, Japan; 2 Division of Neurobiology, School of Life Science, Faculty of Medicine, Tottori University, Yonago, Japan; 3 Department of Morphology and Brain Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
Hiroki Yamamoto 1 , Masaki Fukunaga 2 , Chuzo Tanaka 3 , Masahiro Umeda 2 , Yoshimichi Ejima 4 1 Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan; 2 Department of Medical Informatics, Meiji University of Oriental Medicine, Kyoto, Japan; 3 Department of Neurosurgery, Meiji University of Oriental Medicine, Kyoto, Japan; 4 Kyoto Institute of Technology, Kyoto, Japan
The neural connections from the lateral geniculate nucleus (LGN) to the primary visual cortex (V1) shows significant plasticity responding to visual experience in early life. To determine whether similar plasticity operates in other connections in the visual system, we explored the plasticity of feedback projection from V1 to the LGN in rat. We examined effects of cortical inactivation on the density of type 1 metabotropic glutamate receptor ␣ (mGluR1␣) and vesicular glutamate transporter 1 (vGluT1) in the LGN which locate postsynaptically and presynaptically at synapses of the feedback projection, respectively. The immunohistochemical signal for mGluR1␣, but not vGluT1 in the LGN significantly decreased following pharmacological inactivation of V1. This effect was observed in both young and adult rats. These results suggest that mGluR1( in the LGN is maintained by cortical activity at any age. Research fund: KAKENHI (17023033)
By combining brain imaging and information theory, we measured the amount of alignment inconsistency for each visual area in Talairach space and the amount of uncertainty about which area resides there. The inconsistency and uncertainty were quantified as the occurrence probabilities of 13 visual areas and the entropy of the probabilities, respectively. The overall average probability and entropy were found to be ∼0.2 and ∼1.0 bits, respectively, indicating substantial inconsistency and uncertainty. There was some inhomogeneity between areas. The probability and entropy maps generated here can be readily beneficial to any application in which it is desirable to predict the areas that are most probably present at an anatomical point and to know the uncertainty associated with this prediction. Research fund: The 21st Century COE Program (D-2 to Kyoto University), MEXT, Japan
P1-e33 Express visual search Rikako Kato 1,2 , Tadashi Isa 1,2,3 1 Department of Developmental Physiology, National Institute for Physiological Science, Japan; 2 CREST, JST, Japan; 3 School of Life Sciences, The Graduate University for Advanced Studies, Japan The neural mechanisms underlying oddball visual search have been studied in the frontal and parietal cortices and in the superior colliculus. The initial visual responses to the target and the distractor were indiscriminable in most neurons in these areas but then responses became distinguishable about 120 ms after the stimulus. However, it was also reported that V1 cells distinguished oddball stimulus from homogeneous background stimuli around the peak of initial visual responses (about 60 ms after stimulus onset; Knierim and VanEssen, 1992). We expected that monkeys might be able to use such initial discrimination signal under appropriate conditions. We introduced a temporal gap between the fixation spot offset and the stimulus onset. Then, in the color and shape visual search with a gap of 200 ms, the monkey made express saccades (reaction time between 65 and 90 ms) to the target, respectively, in 50.2% and 47.2% of the trials. These results suggest that the animal can utilize the difference in the initial visual response for visual search under the gap condition.
S97
P1-e36 Neural mechanism of biological motion processing: An MEG study Masahiro Hirai 1,2 , Yoshiki Kaneoke 1 , Hiroki Nakata 1 , Ryusuke Kakigi 1 1 Department of Integrative Physiology, National Institute for Pysiological Sciences, Japan; 2 Japan Society for the Promotion of Science, Japan Many neuroimaging studies have identified the brain region that was activated by biological motion (BM) perception, however, its neural dynamics still remains unclear. Unlike previous studies, we adopted ‘double stimulus presentation ‘method to extract magnetoencephalographic (MEG) response relating to processing of BM perception. We presented scrambled point-light walker (PLW) as a first stimulus (S1) and then presented upright PLW or inverted PLW as a second stimulus (S2) sequentially. The MEG response was observed for S1 at around 280 ms, and the peak latency of S2 was at around 380 ms from each stimulus onset. Additionally, in S2, the peak amplitude of PLW stimulus was significantly larger than that of scrambled PLW and the dipole was estimated more anterior to that in S1. These findings suggest that MEG response to human figure and action was enhanced in occipitotemporal region and PLW stimulus would be processed after general motion processing.
Research funds: CREST, JST
Research fund: Grant-in-Aid for JSPS Fellows No. 18-11826
P1-e34 A physiological role of gap junctions in firing properties
P1-e38 Laminar specificity of callosal connections in the rat striate cortex
of retinal AII amacrine cells Fuminobu Tamalu, Shu-Ichi Watanabe Department of Physiology, Saitama Medical University, Saitama, Japan Retinal AII amacrine cells (AII cells) generate TTX-sensitive repetitive spikes that are dependent on glutamatergic synaptic input and are reciprocally connected via gap junctions. To examine physiological roles of the gap junctions, we performed whole-cell patch clamping of AII cells in the mouse retinal slice. In current-clamp mode, we observed large fluctuations of membrane potential in AII cells. Adding gap junction blockers to the external solution diminished the voltage fluctuations, suggesting that the fluctuations are originated from the activities of neighboring AII cells. In addition, under these conditions, AII cells fired spikes at the highest frequency even when a small amount of current injection (about 10 pA) was applied at a membrane potential of about -65 mV. This is possibly because the gap junction blockers made the input resistance higher by closing the shunt via gap junctions. Our data suggested that gap junctional connections of AII cells might have a crucial role to respond wide range of input, probably by controlling shunt current.
P1-e35 Developmental change of activity-dependent regulation
Takemasa Satoh 1 , Yosio Hata 2 Division of Neurobiology, Tottori University Faculty of Medicine, Yonago, Japan; 2 Division of Integrative BioScience, Tottori University Graduate School of Medical Science, Yonago, Japan 1
In lateral part of rat striate cortex, which represents central visual space, reciprocal callosal linkages are organized in a topographic manner. Callosal projecting cells of this region distribute in the supra- and infragranular layers. Although previous investigations revealed overall distribution of callosal cells and their axon terminations, laminar specificity of the callosal projections has not been characterized. Therefore, we made small injections of antero- or retrograde tracers into the supraor infragranular layers in the lateral striate cortex of one hemisphere. In supragranular injections, retrogradely labeled cells distributed mainly in layer II/III and IV of contralateral striate cortex. Antrogradely labeled axons densely branched in layer II/III. In contrast, in infragranular injections, labeled cells distributed mainly in layer IV, V and VI. Afferent axons terminated mainly in the infragranular layers. These results suggest the laminar specific segregation of callosal connectivity in the lateral striate cortex.
P1-e39 Inconsistency and uncertainty in the locations of
of mGluR1( in the lateral geniculate nucleus
human visual areas in Talairach space
Miho Yoshida 1 , Takemasa Satoh 2 , Kouichi Nakamura 3 , Takeshi Kaneko 3 , Yoshio Hata 1 1 Division of Integrative Bioscience, Tottori University Graduate School of Medicine Science, Yonago, Japan; 2 Division of Neurobiology, School of Life Science, Faculty of Medicine, Tottori University, Yonago, Japan; 3 Department of Morphology and Brain Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
Hiroki Yamamoto 1 , Masaki Fukunaga 2 , Chuzo Tanaka 3 , Masahiro Umeda 2 , Yoshimichi Ejima 4 1 Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan; 2 Department of Medical Informatics, Meiji University of Oriental Medicine, Kyoto, Japan; 3 Department of Neurosurgery, Meiji University of Oriental Medicine, Kyoto, Japan; 4 Kyoto Institute of Technology, Kyoto, Japan
The neural connections from the lateral geniculate nucleus (LGN) to the primary visual cortex (V1) shows significant plasticity responding to visual experience in early life. To determine whether similar plasticity operates in other connections in the visual system, we explored the plasticity of feedback projection from V1 to the LGN in rat. We examined effects of cortical inactivation on the density of type 1 metabotropic glutamate receptor ␣ (mGluR1␣) and vesicular glutamate transporter 1 (vGluT1) in the LGN which locate postsynaptically and presynaptically at synapses of the feedback projection, respectively. The immunohistochemical signal for mGluR1␣, but not vGluT1 in the LGN significantly decreased following pharmacological inactivation of V1. This effect was observed in both young and adult rats. These results suggest that mGluR1( in the LGN is maintained by cortical activity at any age. Research fund: KAKENHI (17023033)
By combining brain imaging and information theory, we measured the amount of alignment inconsistency for each visual area in Talairach space and the amount of uncertainty about which area resides there. The inconsistency and uncertainty were quantified as the occurrence probabilities of 13 visual areas and the entropy of the probabilities, respectively. The overall average probability and entropy were found to be ∼0.2 and ∼1.0 bits, respectively, indicating substantial inconsistency and uncertainty. There was some inhomogeneity between areas. The probability and entropy maps generated here can be readily beneficial to any application in which it is desirable to predict the areas that are most probably present at an anatomical point and to know the uncertainty associated with this prediction. Research fund: The 21st Century COE Program (D-2 to Kyoto University), MEXT, Japan