1. Topography of Visual Features in the Human Ventral Visual Pathway
Shijia FAN ; Xiaosha WANG ; Xiaoying WANG ; Tao WEI ; Yanchao BI ; Shijia FAN ; Xiaosha WANG ; Xiaoying WANG ; Tao WEI ; Yanchao BI ; Yanchao BI
Neuroscience Bulletin 2021;37(10):1454-1468
Visual object recognition in humans and nonhuman primates is achieved by the ventral visual pathway (ventral occipital-temporal cortex, VOTC), which shows a well-documented object domain structure. An on-going question is what type of information is processed in the higher-order VOTC that underlies such observations, with recent evidence suggesting effects of certain visual features. Combining computational vision models, fMRI experiment using a parametric-modulation approach, and natural image statistics of common objects, we depicted the neural distribution of a comprehensive set of visual features in the VOTC, identifying voxel sensitivities with specific feature sets across geometry/shape, Fourier power, and color. The visual feature combination pattern in the VOTC is significantly explained by their relationships to different types of response-action computation (fight-or-flight, navigation, and manipulation), as derived from behavioral ratings and natural image statistics. These results offer a comprehensive visual feature map in the VOTC and a plausible theoretical explanation as a mapping onto different types of downstream response-action systems.
2.Topography of Visual Features in the Human Ventral Visual Pathway.
Shijia FAN ; Xiaosha WANG ; Xiaoying WANG ; Tao WEI ; Yanchao BI
Neuroscience Bulletin 2021;37(10):1454-1468
Visual object recognition in humans and nonhuman primates is achieved by the ventral visual pathway (ventral occipital-temporal cortex, VOTC), which shows a well-documented object domain structure. An on-going question is what type of information is processed in the higher-order VOTC that underlies such observations, with recent evidence suggesting effects of certain visual features. Combining computational vision models, fMRI experiment using a parametric-modulation approach, and natural image statistics of common objects, we depicted the neural distribution of a comprehensive set of visual features in the VOTC, identifying voxel sensitivities with specific feature sets across geometry/shape, Fourier power, and color. The visual feature combination pattern in the VOTC is significantly explained by their relationships to different types of response-action computation (fight-or-flight, navigation, and manipulation), as derived from behavioral ratings and natural image statistics. These results offer a comprehensive visual feature map in the VOTC and a plausible theoretical explanation as a mapping onto different types of downstream response-action systems.
Animals
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Brain Mapping
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Humans
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Magnetic Resonance Imaging
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Occipital Lobe
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Pattern Recognition, Visual
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Photic Stimulation
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Temporal Lobe
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Visual Pathways/diagnostic imaging*
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Visual Perception
3.SIRT7 antagonizes human stem cell aging as a heterochromatin stabilizer.
Shijia BI ; Zunpeng LIU ; Zeming WU ; Zehua WANG ; Xiaoqian LIU ; Si WANG ; Jie REN ; Yan YAO ; Weiqi ZHANG ; Moshi SONG ; Guang-Hui LIU ; Jing QU
Protein & Cell 2020;11(7):483-504
SIRT7, a sirtuin family member implicated in aging and disease, is a regulator of metabolism and stress responses. It remains elusive how human somatic stem cell populations might be impacted by SIRT7. Here, we found that SIRT7 expression declines during human mesenchymal stem cell (hMSC) aging and that SIRT7 deficiency accelerates senescence. Mechanistically, SIRT7 forms a complex with nuclear lamina proteins and heterochromatin proteins, thus maintaining the repressive state of heterochromatin at nuclear periphery. Accordingly, deficiency of SIRT7 results in loss of heterochromatin, de-repression of the LINE1 retrotransposon (LINE1), and activation of innate immune signaling via the cGAS-STING pathway. These aging-associated cellular defects were reversed by overexpression of heterochromatin proteins or treatment with a LINE1 targeted reverse-transcriptase inhibitor. Together, these findings highlight how SIRT7 safeguards chromatin architecture to control innate immune regulation and ensure geroprotection during stem cell aging.