一般口演
視覚 2
Vision 2
座長：伊藤 南（東京医科歯科大学） |
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| 2022年7月2日 17:10～17:25 沖縄コンベンションセンター 会議場A2 第7会場
3O07e2-01
脳梁膨大後部皮質から一次視覚野へのフィードバック投射におけるシナプス可塑性
Timing-dependent LTP and LTD at feedback inputs from retrosplenial cortex to layer 2/3 pyramidal neurons in mice visual cortex
*石川 理子(1)、柚崎 通介(1)
1. 慶應義塾大学
*Ayako Wendy Ishikawa(1), Michisuke Yuzaki(1)
1. Keio University School of Medicine
Keyword: visual cortex, plasticity, feedback projection
The cortical visual system consists of many richly interconnected areas. Feedback inputs from higher to lower areas are thought to convey contextual information and attention-related signals. Learning can enhance feedback modulation, but its synaptic basis remains unknown. It has been well studied in primary visual cortex (V1) local circuits but remains largely uncharacterized in corticocortical pathways. Here, we studied synaptic plasticity in feedback input to V1. We focused on the retrosplenial cortex (RSC) to V1 inputs because previous studies have shown that layer 2/3 neurons in V1 are strongly influenced by RSC activities during learning. First, we examined neuronal connectivity in the mouse RSC-V1 projection using optogenetic stimulation, retrograde labeling, and electrophysiology in visual cortical slices from young adult mice at postnatal day (P) 26-32. Whole-cell recordings were conducted from V1 pyramidal neurons in layer 2/3 to record excitatory postsynaptic potentials (EPSPs) evoked by optogenetic stimulation of RSC terminals. We found that RSC axons formed monosynaptic excitatory connections onto layer 2/3 pyramidal neurons across all projection classes, including reciprocally and colossally projecting neurons. Next, we examined synaptic plasticity at RSC-V1 synapses. We characterized the dependence of synaptic modification on the interval between RSC terminal stimulation and postsynaptic spike activity using a pairing protocol. Each pairing consisted of optogenetic stimulation of RSC terminals and brief depolarization-induced postsynaptic action potentials. After pairing of 100 -150 presynaptic stimulation followed by postsynaptic action potentials at 0.5-1 Hz, long-term potentiation (LTP) was induced. By contrast, when postsynaptic action potentials preceded presynaptic ones, the same number of pairings resulted in long-term depression (LTD). These data indicate that feedback synapses undergo plasticity in a timing-dependent manner. Finally, we assessed age dependency of timing-dependent plasticity at RSC-V1 synapses using optogenetic stimulation. Consistent with previous studies, synaptic plasticity at V1 local circuits sharply decayed with age. By contrast, synaptic plasticity at RSC-V1 synapses could be induced in adulthood (P60-90) in a similar manner that was observed during the critical period. These data suggest that with aging, feedback input synapses retain their plasticity to a greater extent than local input synapses and may thus play a greater role in supporting learning during adulthood. | | 2022年7月2日 17:25～17:40 沖縄コンベンションセンター 会議場A2 第7会場
3O07e2-02
マウス一次視覚野における開眼後の情報表現変化
Functional reorganization of visual representation after eye opening in the mouse primary visual cortex.
*岸野 文昭(1,2,3)、吉田 盛史(1,2,3)、上村 允人(4)、大木 研一(1,2,3)
1. 東京大院医統合生理、2. ニューロインテリジェンス国際研究機構、3. Beyond AI 研究推進機構、4. 関西医科大院生理学
*Fumiaki Kishino(1,2,3), Takashi Yoshida(1,2,3), Masato Uemura(4), Kenichi Ohki(1,2,3)
1. Dept. Physiol., Univ. of Tokyo, Japan, 2. WPI-IRCN, 3. Institute for AI and Beyond, 4. Dept. Biology, Kansai Medical Univ., Japan
Keyword: INFORMATION REPRESENTATION, MOUSE PRIMARY VISUAL CORTEX, FUNCTIONAL DEVELOPMENT, CHRONIC TWO-PHOTON MICROSCOPY
It has been reported that information representation in the visual cortex changes after eye opening. However, few studies examined the process of changes in the representation after eye opening over time. In this study, we investigated the maturation process of the mouse primary visual cortex (V1) after eye opening at the single-cell level. Using two-photon chronic calcium imaging, we tracked the functional properties of the same neurons over time. At eye opening, most of the V1 neurons represented either vertical or horizontal orientation, and the visual selectivity of the neuronal population representing vertical or horizontal orientation was similar to each other and not diverse. Within a few days after eye opening, the number of neurons responding to oblique orientations increased, and the visual selectivity of the neuronal population representing vertical or horizontal orientation became more diverse. Next, we examined the changes at the single-cell level underlying these population-level changes. We found that half of the neurons visually responsive at eye opening changed their visual responsiveness, and a large-scale reorganization of visually responsive neurons occurred. Thus, the mouse primary visual cortex undergoes a large-scale reorganization of information representation after eye opening and this reorganization is accompanied by a diversification of information representation, which may be useful for efficient adaptation to the environment. | | 2022年7月2日 17:40～17:55 沖縄コンベンションセンター 会議場A2 第7会場
3O07e2-03
皮質電気刺激によって誘発されたキネトプシア：側頭葉てんかん症例における検討
Kinetopsia induced by electrocortical stimulation: a case of temporal lobe epilepsy
*柿沼 一雄(1)、大沢 伸一郎(1)、浮城 一司(1)、篠田 元気(1)、細川 大瑛(1)、親富祖 まりえ(1)、太田 祥子(1)、石田 誠(1)、神 一敬(1)、冨永 悌二(1)、中里 信和(1)、鈴木 匡子(1)
1. 東北大学大学院医学系研究科
*Kazuo Kakinuma(1), Shin-ichiro Osawa(1), Kazushi Ukishiro(1), Genki Shinoda(1), Hiroaki Hosokawa(1), Marie Oyafuso(1), Shoko Ota(1), Makoto Ishida(1), Kazutaka Jin(1), Teiji Tominaga(1), Nobukazu Nakasato(1), Kyoko Suzuki(1)
1. Grad Sch Med, Tohoku Univ, Sendai, Japan
Keyword: kinetopsia, visual motion, epilepsy, electrocortical stimulation
Background: Kinetopsia is a visual illusion in which a static object is perceived as moving. Visual motion perception is thought to be processed in the hMT+ (or V5) in the temporo-parieto-occipital region. Several studies on non-human primates have indicated the relationship between the neural activity in the V5 and visual motion stimulation. Some studies have reported impaired visual motion perception due to brain damage involving the hMT+. However, only a few direct observations have reported that electrical stimulation of the hMT+ generates kinetopsia. The illusionary visual movement experienced by the patients is reported to be diverse. Case description: A 20-year-old right-handed female with a history of viral encephalitis at 6 years of age was referred to our hospital. She had experienced epileptic seizures with the impairment of consciousness preceded by a fearful feeling since 11 years of age. Because pharmacological treatment failed to control her seizures, neurosurgical management was considered. Radiological and electroencephalography studies indicated the right temporal lobe and insular cortex as the possible epileptic foci. She underwent intracranial electrode implantation in the right hemisphere. Functional mapping with electrocortical stimulation (ECS) was performed around the right temporal lobe, where the seizure focus was expected. In the ECS mapping, the stimulation at the electrodes in the right temporo-parieto-occipital region caused kinetopsia in a particular visual field. She complained that the objects in the center to slightly lower left visual field rotated and moved to the lower-left during ECS, while the rest of the objects in the other visual field remained stationary. This visual symptom occurred regardless of whether she was staring at a picture, word, or meaningless symbol. She noticed no change in the shape or color of the objects and could easily recognize them during ECS. Discussion: We observed that ECS in the hMT+ area induced kinetopsia in the corresponding visual field, indicating the causative role of the hMT+ for motion perception. The kinetopsia occurrence without changes in object recognition supported different pathways for motion perception and object identification. A few reports of kinetopsia exist, and the reported movement patterns are not consistent. The specific description of kinetopsia caused by ECS varies with reports, and further exploration is needed. | | 2022年7月2日 17:55～18:10 沖縄コンベンションセンター 会議場A2 第7会場
3O07e2-04
マーモセット視覚野における運動残効と予測符号化の神経基盤に関する研究
Neural basis of motion aftereffect mediated by predictive coding in the marmoset motion-selective visual areas
*橋本 昂之(1,2)、松井 鉄平(1,3)、上村 允人(1)、村上 知成(1)、菊田 浩平(1)、加藤 利樹(1)、浮田 純平(1)、磯村 拓哉(4)、大木 研一(1,2,5)
1. 東京大学大学院医学系研究科統合生理学分野、2. Beyond AI 研究推進機構、3. さきがけ、4. 理化学研究所脳神経科学研究センター脳型知能理論研究ユニット、5. 東京大学国際高等研究所ニューロインテリジェンス国際研究機構
*Takayuki Hashimoto(1,2), Teppei Matsui(1,3), Masato Uemura(1), Tomonari Murakami(1), Kohei Kikuta(1), Toshiki Kato(1), Jumpei Ukita(1), Takuya Isomura(4), Kenichi Ohki(1,2,5)
1. Department of Physiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan, 2. Institute for AI and Beyond, The University of Tokyo, Tokyo, Japan, 3. JST-PRESTO, Japan Science and Technology Agency, Tokyo, Japan, 4. Brain Intelligence Theory Unit, RIKEN Center for Brain Science, Saitama, Japan, 5. International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo, Tokyo, Japan
Keyword: Perceptual illusion, Predictive coding, Calcium imaging, Visual cortex
The motion aftereffect, also known as the waterfall illusion, is a classical visual illusion first described by Aristotle: after watching a motion for tens of seconds, an illusory motion to the opposite direction is perceived. Although the visual cortex has been implicated as the origin of this illusion, the underlying circuit mechanisms remain unclear. We addressed this by studying the middle temporal and medial superior temporal visual areas (MT/MST) in marmoset monkeys using a newly developed genetic tool for high-fidelity calcium imaging in nonhuman primates, and found that neurons in the MST, but not MT, display transient activity after motion offset, which shared common characteristics with the motion aftereffect such as opposite direction tuning and motion duration-dependency. Furthermore, we found two additional motion-selective neuronal activities in the MST: motion-locked activity and gradually increasing activity over tens of seconds. Thus, the MST contains three types of neuronal activities: motion-locked, gradually increasing, and the MAE-like transient activities. Using computational simulations, we showed that the transient activity corresponds to prediction error signals and, together with the motion-locked and gradually increasing activities encoding sensory and prediction signals, respectively, constitutes the neuronal basis for predictive coding of visual motion processing. Notably, the prediction error signals were almost always multiplexed with sensory or prediction signals in single neurons. Our findings suggest that the illusory motion results from this multiplexed predictive coding in the MST. | |
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