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Signal propagation properties in the visual cortex evoked by flush photolysis of a caged glutamate
S96
Abstracts / Neuroscience Research 58S (2007) S1–S244
P1-e27 Discrete color-related subregions in the monkey inferior temporal cortex Takuya Harada 1,2 , Naokazu Goda 1,2 , Tadashi Ogawa 1,2 , Minami Ito 1,2 , Hiroshi Toyoda 1 , Norihiro Sadato 1,2 , Hidehiko Komatsu 1,2 1 National Institute for Physiological Sciences, Okazaki, Japan; 2 Sokendai, Okazaki, Japan Single neuron recordings have shown that there are many color-sensitive neurons in the inferior temporal (IT) cortex, but it is still unclear how they distribute in this area. We examined color-related responses in broad brain area, including the IT cortex, by using fMRI in the alert macaque monkey. We measured the BOLD responses to chromatic stimuli (colored gratings and Mondrian-like patterns) and achromatic stimluli (same patterns without color) while the monkey was performing a fixation task. Color-biased responses were observed in LGN, V1, V2, V3 and V4. In addition, some color-biased patches were distributed in the IT cortex; around the posterior middle temporal sulcus, in the posterior bank of the superior temporal sulcus and in the anterior middle temporal sulcus. Their positions were partly overlapped with shape-biased patches detected in a separate experiment. Our results support the hypothesis that color-sensitive neurons are concentrated in multiple sub-regions in the IT cortex.
P1-e30 Signal propagation properties in the visual cortex evoked by flush photolysis of a caged glutamate Makoto Osanai, Hidesato Uegaki, Tetsuya Yagi Graduate School of Engineering, Osaka University, Suita, Japan Spatio-temporal properties of signal propagation in the visual cortical circuit have not fully understood. Previously, we studied the signal propagation pattern induced by externally applied electrical stimulation to the visual cortex. In this study, we used a UV laser photolysis of the caged glutamate for stimulation, since it mimics the excitation induced by the synaptic transmission. The induced exciation was measured by Ca2+ imaging system. When the photostimulation was applied to layer 4, which receives inputs from LGN, the transient intracellular Ca2+ ([Ca2+ ]i ) elevation was observed. The high [Ca2+ ]i region spread horizontally from the stimulus site in layer 4. The high [Ca2+ ]i region also spread vertically to layer 2/3 and layer 5 and then spread horizontally in these layers. The horizontal spread of high [Ca2+ ]i region in layer 2/3 was more restricted than those in layer 4 or 5, and sometimes a hotspot was observed in layer 2/3. When the photostimulation was applied to layer 2/3 or layer 5, the transient [Ca2+ ]i elevation was observed only within the same layer of the stimulus site.
Research fund: KAKENHI (17022040)
P1-e28 Influence of visual saliency in monkey visual cortex Naokazu Goda 1,2 , Takuya Harada 1,2 , Tadashi Ogawa 1,2 , Minami Ito 1,2 , Hiroshi Toyoda 1 , Norihiro Sadato 1,2 , Hidehiko Komatsu 1,2 1 National Institute of Physiological Science, Okazaki, Japan; 2 SOKENDAI, Okazaki, Japan
P1-e31 Characteristics of neuronal responses in cortical
Recent studies suggest that a detection of a visually salient object in a cluttered scene involves processing in multiple areas in occipital, parietal and frontal cortices. To clarify the whole picture of this network, we measured the influence of the saliency on the activities in the monkey brain by using fMRI. We presented an array stimulus containing eight disks during a fixation task; in some arrays one of the disks was unique in color (singleton), in others all were identical. We found that the presence of the singleton in the array enhanced the responses in V2/V3/V4, LIP and FEF. The enhancement was stronger in the contralateral hemisphere in V2/V3/V4 and part of LIP, but not in the other areas, suggesting these areas have different functions. Interestingly, we also found a strong response enhancement with the contralateral bias on the posterior bank of the superior temporal sulcus, which was anterior to the motion-sensitive region identified by a separate experiment. This sheds new light on the neural system involved in the detection of the salient object.
To study neuronal mechanisms of our ability to perceive visual motion in space independent of pursuit eye movements, we studied responses of neurons in the cortical areas MT/MST of monkeys to textured images, either random-dot pattern or check pattern, which were presented briefly and moved at various speeds during smooth pursuit and stationary fixation. During pursuit, most MST neurons were more sensitive to the actual motion of the textured image than to the motion of its retinal image, whereas most MT neurons showed the reverse tendency. When a check pattern was used and its temporal frequency exceeded 20Hz on the retina, neuronal responses in both areas decreased irrespective of fixation or pursuit eye movement. The decreased neuronal responses at higher temporal frequencies on the retina support the idea that the MST neurons code visual motion in space while compensating for the eye movements by utilizing the retina-based information obtained from the area MT and the information encoding eye movements.
P1-e29 Functional effects of 5-HT1B and 5-HT2A receptors
Research fund: KAKENHI (17022019)
areas MT/MST of monkey during pursuit eye movements Naoko Inaba, Kenji Kawano Department of Integrative Brain Science, Kyoto University, Kyoto, Japan
in macaque V1
P1-e32
Match to heading tasks influence MST neuronal responses to optic flow
Osamu Sadakane 1 , Akiya Watakabe 1 , Yusuke Komatsu 1 , Satoshi Shimegi 2 , Tomoyuki Naito 2 , Hironobu Osaki 2 , Hiromichi Sato 2 , Tetsuo Yamamori 1 1 Division of Brain Biology, National Institute of Basic Biology, Okazaki, Japan; 2 Graduate School of Medicine, Osaka University, Toyonaka, Japan
1
We recently reported that mRNAs of serotonin receptor subtypes, 5-HT1B and 5-HT2A, are specifically expressed in the primary visual cortex (V1) of macaque monkey. To elucidate functional roles of these receptors in vivo, we performed single-unit recordings of visual responses from 101 V1 neurons with microiontophoretic administration of specific drugs for each receptor subtypes in anesthetized and paralyzed monkeys. The effects of activating these receptors seemed to be bi-directional depending on the activity levels of each neuron. The effect of agonist for 5-HT1B receptor, CP93129, was more facilitatory when the firing rate was high, but more suppressive when the firing rate was low. The effect of DOI, agonist for 5-HT2A receptor, was opposite in direction. We also found that activation of these receptors affects the relative timing of firings to visual stimulation. We concluded that these receptor subtypes control the gain and the timing of visual responses complementarily.
When moving through our environment we monitor our heading to match our established path. We studied the influence of a match to heading task on optic flow responses in MST neurons. Two monkeys distinguished between sustained or reversed headings. We first presented large-field optic flow simulating one of eight headings. After a blank-screen delay, a second optic flow stimulus presented either the matching or the opposite heading. Two-thirds of the neurons (65%, 67/103) showed significant heading selectivity; half of which (31%, 32/103) also showed stimulus condition effects. These were equally divided between neurons with decreased responses amplitudes to either the match or the opposite test stimulus. An additional 7% (7/103) of the neurons showed significant heading by condition interaction effects, suggesting a change in heading selectivity, typically as a loss of selectivity in response to either the match or opposite stimuli. These findings suggest top-down directional influences on optic flow responses in MST that might contribute to recognizing heading deviations.
Nobuya Sato 1,2,3 , Charles J. Duffy 3 CREST, JST, Japan; 2 Nihon University, Tokyo, Japan; of Rochester, Rochester, NY, USA
Research funds: JSPS 2004, NEI R01EY10287
3
University
Abstracts / Neuroscience Research 58S (2007) S1–S244
P1-e27 Discrete color-related subregions in the monkey inferior temporal cortex Takuya Harada 1,2 , Naokazu Goda 1,2 , Tadashi Ogawa 1,2 , Minami Ito 1,2 , Hiroshi Toyoda 1 , Norihiro Sadato 1,2 , Hidehiko Komatsu 1,2 1 National Institute for Physiological Sciences, Okazaki, Japan; 2 Sokendai, Okazaki, Japan Single neuron recordings have shown that there are many color-sensitive neurons in the inferior temporal (IT) cortex, but it is still unclear how they distribute in this area. We examined color-related responses in broad brain area, including the IT cortex, by using fMRI in the alert macaque monkey. We measured the BOLD responses to chromatic stimuli (colored gratings and Mondrian-like patterns) and achromatic stimluli (same patterns without color) while the monkey was performing a fixation task. Color-biased responses were observed in LGN, V1, V2, V3 and V4. In addition, some color-biased patches were distributed in the IT cortex; around the posterior middle temporal sulcus, in the posterior bank of the superior temporal sulcus and in the anterior middle temporal sulcus. Their positions were partly overlapped with shape-biased patches detected in a separate experiment. Our results support the hypothesis that color-sensitive neurons are concentrated in multiple sub-regions in the IT cortex.
P1-e30 Signal propagation properties in the visual cortex evoked by flush photolysis of a caged glutamate Makoto Osanai, Hidesato Uegaki, Tetsuya Yagi Graduate School of Engineering, Osaka University, Suita, Japan Spatio-temporal properties of signal propagation in the visual cortical circuit have not fully understood. Previously, we studied the signal propagation pattern induced by externally applied electrical stimulation to the visual cortex. In this study, we used a UV laser photolysis of the caged glutamate for stimulation, since it mimics the excitation induced by the synaptic transmission. The induced exciation was measured by Ca2+ imaging system. When the photostimulation was applied to layer 4, which receives inputs from LGN, the transient intracellular Ca2+ ([Ca2+ ]i ) elevation was observed. The high [Ca2+ ]i region spread horizontally from the stimulus site in layer 4. The high [Ca2+ ]i region also spread vertically to layer 2/3 and layer 5 and then spread horizontally in these layers. The horizontal spread of high [Ca2+ ]i region in layer 2/3 was more restricted than those in layer 4 or 5, and sometimes a hotspot was observed in layer 2/3. When the photostimulation was applied to layer 2/3 or layer 5, the transient [Ca2+ ]i elevation was observed only within the same layer of the stimulus site.
Research fund: KAKENHI (17022040)
P1-e28 Influence of visual saliency in monkey visual cortex Naokazu Goda 1,2 , Takuya Harada 1,2 , Tadashi Ogawa 1,2 , Minami Ito 1,2 , Hiroshi Toyoda 1 , Norihiro Sadato 1,2 , Hidehiko Komatsu 1,2 1 National Institute of Physiological Science, Okazaki, Japan; 2 SOKENDAI, Okazaki, Japan
P1-e31 Characteristics of neuronal responses in cortical
Recent studies suggest that a detection of a visually salient object in a cluttered scene involves processing in multiple areas in occipital, parietal and frontal cortices. To clarify the whole picture of this network, we measured the influence of the saliency on the activities in the monkey brain by using fMRI. We presented an array stimulus containing eight disks during a fixation task; in some arrays one of the disks was unique in color (singleton), in others all were identical. We found that the presence of the singleton in the array enhanced the responses in V2/V3/V4, LIP and FEF. The enhancement was stronger in the contralateral hemisphere in V2/V3/V4 and part of LIP, but not in the other areas, suggesting these areas have different functions. Interestingly, we also found a strong response enhancement with the contralateral bias on the posterior bank of the superior temporal sulcus, which was anterior to the motion-sensitive region identified by a separate experiment. This sheds new light on the neural system involved in the detection of the salient object.
To study neuronal mechanisms of our ability to perceive visual motion in space independent of pursuit eye movements, we studied responses of neurons in the cortical areas MT/MST of monkeys to textured images, either random-dot pattern or check pattern, which were presented briefly and moved at various speeds during smooth pursuit and stationary fixation. During pursuit, most MST neurons were more sensitive to the actual motion of the textured image than to the motion of its retinal image, whereas most MT neurons showed the reverse tendency. When a check pattern was used and its temporal frequency exceeded 20Hz on the retina, neuronal responses in both areas decreased irrespective of fixation or pursuit eye movement. The decreased neuronal responses at higher temporal frequencies on the retina support the idea that the MST neurons code visual motion in space while compensating for the eye movements by utilizing the retina-based information obtained from the area MT and the information encoding eye movements.
P1-e29 Functional effects of 5-HT1B and 5-HT2A receptors
Research fund: KAKENHI (17022019)
areas MT/MST of monkey during pursuit eye movements Naoko Inaba, Kenji Kawano Department of Integrative Brain Science, Kyoto University, Kyoto, Japan
in macaque V1
P1-e32
Match to heading tasks influence MST neuronal responses to optic flow
Osamu Sadakane 1 , Akiya Watakabe 1 , Yusuke Komatsu 1 , Satoshi Shimegi 2 , Tomoyuki Naito 2 , Hironobu Osaki 2 , Hiromichi Sato 2 , Tetsuo Yamamori 1 1 Division of Brain Biology, National Institute of Basic Biology, Okazaki, Japan; 2 Graduate School of Medicine, Osaka University, Toyonaka, Japan
1
We recently reported that mRNAs of serotonin receptor subtypes, 5-HT1B and 5-HT2A, are specifically expressed in the primary visual cortex (V1) of macaque monkey. To elucidate functional roles of these receptors in vivo, we performed single-unit recordings of visual responses from 101 V1 neurons with microiontophoretic administration of specific drugs for each receptor subtypes in anesthetized and paralyzed monkeys. The effects of activating these receptors seemed to be bi-directional depending on the activity levels of each neuron. The effect of agonist for 5-HT1B receptor, CP93129, was more facilitatory when the firing rate was high, but more suppressive when the firing rate was low. The effect of DOI, agonist for 5-HT2A receptor, was opposite in direction. We also found that activation of these receptors affects the relative timing of firings to visual stimulation. We concluded that these receptor subtypes control the gain and the timing of visual responses complementarily.
When moving through our environment we monitor our heading to match our established path. We studied the influence of a match to heading task on optic flow responses in MST neurons. Two monkeys distinguished between sustained or reversed headings. We first presented large-field optic flow simulating one of eight headings. After a blank-screen delay, a second optic flow stimulus presented either the matching or the opposite heading. Two-thirds of the neurons (65%, 67/103) showed significant heading selectivity; half of which (31%, 32/103) also showed stimulus condition effects. These were equally divided between neurons with decreased responses amplitudes to either the match or the opposite test stimulus. An additional 7% (7/103) of the neurons showed significant heading by condition interaction effects, suggesting a change in heading selectivity, typically as a loss of selectivity in response to either the match or opposite stimuli. These findings suggest top-down directional influences on optic flow responses in MST that might contribute to recognizing heading deviations.
Nobuya Sato 1,2,3 , Charles J. Duffy 3 CREST, JST, Japan; 2 Nihon University, Tokyo, Japan; of Rochester, Rochester, NY, USA
Research funds: JSPS 2004, NEI R01EY10287
3
University