- Email: [email protected]
The sulfated polysaccharides regulate neuronal plasticity in visual cortex
e256
Abstracts / Neuroscience Research 71S (2011) e108–e415
P3-j15 Functional roles of TRPM1 channels in the synaptic transmission between rod bipolar and AII amacrine cells in the mouse retina Fuminobu Tamalu , Shu-Ichi Watanabe Dept. of Physiol., Fac. of Med., Saitama Med. Univ., Saitama, Japan In the mammalian retina, synaptic transmission from rods to rod bipolar cells is mediated by a metabotropic glutamate receptor 6. In the dark, rods release glutamate by which rod bipolar cells hyperpolarize; conversely, in response to light, reduced release of glutamate from rods opens a nonselective cation channel and depolarizes the rod bipolar cells, from which glutamate is released to post-synaptic AII amacrine cells. We found that an inter-event interval and an amplitude of EPSCs observed in AII cells dramatically increased with the temperature and that the current-time integral of the EPSCs at 35 ◦ C was about 3-fold greater than that at 20 ◦ C. The temperature dependent EPSCs should reflect glutamatergic input from rod bipolar cells because the EPSCs in AII cells were blocked by CNQX or L-AP4 regardless of the temperature, but not strychnine and bicuculline, and the reversal potential was near 0 mV. Recent studies have demonstrated that the non-selective cation channel expressed in rod bipolar cells was a transient receptor potential (TRP) subfamily, TRPM1 channel. These data raise the possibility that body temperature may expand the dynamic range of the membrane potential in rod bipolar cells by increasing the open probability of the TRPM1 channels. doi:10.1016/j.neures.2011.07.1115
nance shift, whereas in adults after the critical period there is no such shift. However, it has been reported that the digestion of CS with chondroitinaseABC (ChABC) promotes ocular dominance plasticity in adult rat primary visual cortex (V1) (1). Because there are many KSPG in the central nervous system, we tested weather keratanaseII (KSII) treatment of adult rats facilitates functional recovery and found that when KS in adult V1 were digested with KSII, OD shift occurred. We further investigated the significance of KS on neuronal network activity in the visual cortex. Low-frequency stimulation (2 Hz, 15 min) of presynaptic fibers with bipolar electrodes placed in layer 4 induces long-term potentiation (LTP) of extracellular field potentials recorded from layer 2/3 in visual cortical slices prepared from rats during the critical period but not in adulthood. We used visual cortical slices prepared from adult rats 7–8 days after the start of the enzyme injection, and examined LTP. LTP occurred in slices prepared from normal rats during the critical period but not in adulthood. LTP occurred in visual cortical slices treated with ChABC or KSII, whereas it did not occur in those treated with PBS. The magnitude of LTP in slices treated with ChABC or KSII was significantly larger than that in slices without any treatment or with PBS treatment, and was almost the same as LTP magnitude during critical period. Our data suggest that CSPG and KSPG are involved in the regulation of neuronal plasticity. Reference (1) Pizzorusso, et al., 2002. Science 298, 1248–1251.
doi:10.1016/j.neures.2011.07.1117
P3-j16 Visual search model considering spatial modification of visual attributes Katsuya Yano 1 , Takeshi Kohama 2
1 Dep. of Elec. Sys. and Info. Eng., Grad. Sch. of Bio.-Ori. Sci. and Tec, Kinki Univ., Wakayama, Japan 2 Dep. of Com. Sys. Bio., Fac. of Bio.-Ori. Sci. and Tec, Kinki Univ., Wakayama, Japan
To understand the macroscopic dynamics of the eye movement control system, we developed a saliency-based visual search model that reproduces realistic scan-path patterns and trajectories of gaze position. The saliency map model is a mathematical expression of the characteristics of early visual information processing systems, which calculates the distribution of the saliency of a visual scene, and such models can predict the distribution of gaze positions. However, the simulated scan-path patterns show iterating and deterministic profiles for long-range simulations. In order to avoid these unrealistic gaze patterns and search the outside environment effectively, the abstraction of inhibition of return (IOR) is important; IOR refers to the suppression of processing of objects that have recently been gazed at with a high degree of attention. In peripheral vision, there is a phenomenon called facilitation of return (FOR), which refers as an enhancement of the visibility of particular visual attributes to make a search more efficient. Furthermore, because of the heterogeneous distribution of cone cells on the retina, which are extremely concentrated in the fovea, the perception of the outside environment by the visual system would suddenly change; this might affect the target search process. In this study, we modified the IOR operation using a Gaussian function proportion decrement with random peak value and the FOR operation by performing weighing DoG type spatial modulation during the early-stage processing of saliency map calculation. Moreover, input images were remapped to represent the cortical magnification in visual area 1. We tested the proposed model by measuring the target detection rate in a visual search task simulation. Results indicate that the target detection rate of the present model was higher than that of the previous model, and the simulated scan paths show profiles similar to that of the scan path obtained by visual search under a certain strategy. doi:10.1016/j.neures.2011.07.1116
P3-j17 The sulfated polysaccharides regulate neuronal plasticity in visual cortex Takamitsu Natori 1,2,3,4 , Yukio Komatsu 3 , Kaoru Nagai 4 , Kenji Kadomatsu 2 1
Dept. Health and Nutrition, Yamanashi Gakuin Univ., Kofu, Japan 2 Dept. Biochem., Grad. Sch. Med. Univ. Nagoya 3 Dept. Neurosci., Res. Inst. Enviro. Med., Univ. Nagoya 4 Dept. Epigenetic. Med., Grad. Sch. Med. Eng., Univ. Yamanashi The major components of the extracellular matrix (ECM) of CNS are proteoglycans (PG), hyarulonan and tenascins. Especially, ECM around neurons is called perineuronal nets (PNN), and PNN begin to increase after critical period. In young animals, monocular deprivation leads to an ocular domi-
P3-j18 Category decoding from macaque anterior inferotemporal cortex with simultaneous electrocorticogram and multi-channel unit recording Naohisa Miyakawa 1 , Kei Majima 2,3,4 , Hirohito Sawahata 1 , Keisuke Kawasaki 1 , Takeshi Matsuo 1,5 , Naoki Kotake 6 , Takafumi Suzuki 6 , Yukiyasu Kamitani 2,3 , Isao Hasegawa 1 1
Dept Physiol, Grad Sch of Med, Niigata Univ, Niigata 2 Grad Sch Info Sci, NAIST, Nara 3 DNI, BIC, ATR, Kyoto 4 JSPS 5 Dept Neurosurg, Grad Sch Med, Univ Tokyo, Tokyo 6 Grad Sch Info Sci and Tech, Univ Tokyo, Tokyo
The macaque inferotemporal (IT) cortex is suggested to have functional domain structures selective to certain categories, and population vector derived from visually evoked single unit recording in this region has been shown to form category clusters. We aimed to find whether visually evoked electrocorticogram (ECoG) recorded at this site also could be used to extract category information. We implanted a surface electrode array with 1.2 mmspaced grid configuration for ECoG recording and a needle electrode array with the same spatial configuration for multi-site unit recording simultaneously in the macaque anterior IT gyrus. The ECoG array had a mesh-like structure and the needle electrodes penetrated through the window of the mesh, giving approximately same coverage area for both types of electrode array. Two implanted monkeys performed fixation tasks and the stimulusevoked ECoG activities at different frequency band and latency were used as the response features for the decoding analysis. The face stimuli could be decoded from the non-face stimuli with high accuracy using the ECoG response. Response vectors from multi-site unit activity also gave a good decoding performance. We further attempted classifying face into other lower-level categories. The viewing angle and specie (macaque or human) of the face stimuli were decoded with high accuracy by the ECoG response vector, whereas classification accuracy of the face familiarity was significantly above chance, but lower than that of the view and specie categorization. For all the low-level categories, decoding performance was slightly better when multi-site unit response vectors were used. These results suggest that the ECoG signal from IT cortex is a useful source for reading out category information of the visual input. Research fund: KAKENHI 21700442, SRPBS from MEXT, Nissan Science Foundation. doi:10.1016/j.neures.2011.07.1118
Abstracts / Neuroscience Research 71S (2011) e108–e415
P3-j15 Functional roles of TRPM1 channels in the synaptic transmission between rod bipolar and AII amacrine cells in the mouse retina Fuminobu Tamalu , Shu-Ichi Watanabe Dept. of Physiol., Fac. of Med., Saitama Med. Univ., Saitama, Japan In the mammalian retina, synaptic transmission from rods to rod bipolar cells is mediated by a metabotropic glutamate receptor 6. In the dark, rods release glutamate by which rod bipolar cells hyperpolarize; conversely, in response to light, reduced release of glutamate from rods opens a nonselective cation channel and depolarizes the rod bipolar cells, from which glutamate is released to post-synaptic AII amacrine cells. We found that an inter-event interval and an amplitude of EPSCs observed in AII cells dramatically increased with the temperature and that the current-time integral of the EPSCs at 35 ◦ C was about 3-fold greater than that at 20 ◦ C. The temperature dependent EPSCs should reflect glutamatergic input from rod bipolar cells because the EPSCs in AII cells were blocked by CNQX or L-AP4 regardless of the temperature, but not strychnine and bicuculline, and the reversal potential was near 0 mV. Recent studies have demonstrated that the non-selective cation channel expressed in rod bipolar cells was a transient receptor potential (TRP) subfamily, TRPM1 channel. These data raise the possibility that body temperature may expand the dynamic range of the membrane potential in rod bipolar cells by increasing the open probability of the TRPM1 channels. doi:10.1016/j.neures.2011.07.1115
nance shift, whereas in adults after the critical period there is no such shift. However, it has been reported that the digestion of CS with chondroitinaseABC (ChABC) promotes ocular dominance plasticity in adult rat primary visual cortex (V1) (1). Because there are many KSPG in the central nervous system, we tested weather keratanaseII (KSII) treatment of adult rats facilitates functional recovery and found that when KS in adult V1 were digested with KSII, OD shift occurred. We further investigated the significance of KS on neuronal network activity in the visual cortex. Low-frequency stimulation (2 Hz, 15 min) of presynaptic fibers with bipolar electrodes placed in layer 4 induces long-term potentiation (LTP) of extracellular field potentials recorded from layer 2/3 in visual cortical slices prepared from rats during the critical period but not in adulthood. We used visual cortical slices prepared from adult rats 7–8 days after the start of the enzyme injection, and examined LTP. LTP occurred in slices prepared from normal rats during the critical period but not in adulthood. LTP occurred in visual cortical slices treated with ChABC or KSII, whereas it did not occur in those treated with PBS. The magnitude of LTP in slices treated with ChABC or KSII was significantly larger than that in slices without any treatment or with PBS treatment, and was almost the same as LTP magnitude during critical period. Our data suggest that CSPG and KSPG are involved in the regulation of neuronal plasticity. Reference (1) Pizzorusso, et al., 2002. Science 298, 1248–1251.
doi:10.1016/j.neures.2011.07.1117
P3-j16 Visual search model considering spatial modification of visual attributes Katsuya Yano 1 , Takeshi Kohama 2
1 Dep. of Elec. Sys. and Info. Eng., Grad. Sch. of Bio.-Ori. Sci. and Tec, Kinki Univ., Wakayama, Japan 2 Dep. of Com. Sys. Bio., Fac. of Bio.-Ori. Sci. and Tec, Kinki Univ., Wakayama, Japan
To understand the macroscopic dynamics of the eye movement control system, we developed a saliency-based visual search model that reproduces realistic scan-path patterns and trajectories of gaze position. The saliency map model is a mathematical expression of the characteristics of early visual information processing systems, which calculates the distribution of the saliency of a visual scene, and such models can predict the distribution of gaze positions. However, the simulated scan-path patterns show iterating and deterministic profiles for long-range simulations. In order to avoid these unrealistic gaze patterns and search the outside environment effectively, the abstraction of inhibition of return (IOR) is important; IOR refers to the suppression of processing of objects that have recently been gazed at with a high degree of attention. In peripheral vision, there is a phenomenon called facilitation of return (FOR), which refers as an enhancement of the visibility of particular visual attributes to make a search more efficient. Furthermore, because of the heterogeneous distribution of cone cells on the retina, which are extremely concentrated in the fovea, the perception of the outside environment by the visual system would suddenly change; this might affect the target search process. In this study, we modified the IOR operation using a Gaussian function proportion decrement with random peak value and the FOR operation by performing weighing DoG type spatial modulation during the early-stage processing of saliency map calculation. Moreover, input images were remapped to represent the cortical magnification in visual area 1. We tested the proposed model by measuring the target detection rate in a visual search task simulation. Results indicate that the target detection rate of the present model was higher than that of the previous model, and the simulated scan paths show profiles similar to that of the scan path obtained by visual search under a certain strategy. doi:10.1016/j.neures.2011.07.1116
P3-j17 The sulfated polysaccharides regulate neuronal plasticity in visual cortex Takamitsu Natori 1,2,3,4 , Yukio Komatsu 3 , Kaoru Nagai 4 , Kenji Kadomatsu 2 1
Dept. Health and Nutrition, Yamanashi Gakuin Univ., Kofu, Japan 2 Dept. Biochem., Grad. Sch. Med. Univ. Nagoya 3 Dept. Neurosci., Res. Inst. Enviro. Med., Univ. Nagoya 4 Dept. Epigenetic. Med., Grad. Sch. Med. Eng., Univ. Yamanashi The major components of the extracellular matrix (ECM) of CNS are proteoglycans (PG), hyarulonan and tenascins. Especially, ECM around neurons is called perineuronal nets (PNN), and PNN begin to increase after critical period. In young animals, monocular deprivation leads to an ocular domi-
P3-j18 Category decoding from macaque anterior inferotemporal cortex with simultaneous electrocorticogram and multi-channel unit recording Naohisa Miyakawa 1 , Kei Majima 2,3,4 , Hirohito Sawahata 1 , Keisuke Kawasaki 1 , Takeshi Matsuo 1,5 , Naoki Kotake 6 , Takafumi Suzuki 6 , Yukiyasu Kamitani 2,3 , Isao Hasegawa 1 1
Dept Physiol, Grad Sch of Med, Niigata Univ, Niigata 2 Grad Sch Info Sci, NAIST, Nara 3 DNI, BIC, ATR, Kyoto 4 JSPS 5 Dept Neurosurg, Grad Sch Med, Univ Tokyo, Tokyo 6 Grad Sch Info Sci and Tech, Univ Tokyo, Tokyo
The macaque inferotemporal (IT) cortex is suggested to have functional domain structures selective to certain categories, and population vector derived from visually evoked single unit recording in this region has been shown to form category clusters. We aimed to find whether visually evoked electrocorticogram (ECoG) recorded at this site also could be used to extract category information. We implanted a surface electrode array with 1.2 mmspaced grid configuration for ECoG recording and a needle electrode array with the same spatial configuration for multi-site unit recording simultaneously in the macaque anterior IT gyrus. The ECoG array had a mesh-like structure and the needle electrodes penetrated through the window of the mesh, giving approximately same coverage area for both types of electrode array. Two implanted monkeys performed fixation tasks and the stimulusevoked ECoG activities at different frequency band and latency were used as the response features for the decoding analysis. The face stimuli could be decoded from the non-face stimuli with high accuracy using the ECoG response. Response vectors from multi-site unit activity also gave a good decoding performance. We further attempted classifying face into other lower-level categories. The viewing angle and specie (macaque or human) of the face stimuli were decoded with high accuracy by the ECoG response vector, whereas classification accuracy of the face familiarity was significantly above chance, but lower than that of the view and specie categorization. For all the low-level categories, decoding performance was slightly better when multi-site unit response vectors were used. These results suggest that the ECoG signal from IT cortex is a useful source for reading out category information of the visual input. Research fund: KAKENHI 21700442, SRPBS from MEXT, Nissan Science Foundation. doi:10.1016/j.neures.2011.07.1118