Monitoring neuronal activity in vivo is critical to understanding the physiological or pathological functions of the brain.Two-photon Ca^(2+)imaging in vivo using a cranial window and specific neuronal labeling enable...Monitoring neuronal activity in vivo is critical to understanding the physiological or pathological functions of the brain.Two-photon Ca^(2+)imaging in vivo using a cranial window and specific neuronal labeling enables realtime,in situ,and long-term imaging of the living brain.Here,we constructed a recombinant rabies virus containing the Ca^(2+)indicator GCaMP6 s along with the fluorescent protein DsRed2 as a baseline reference to ensure GCaMP6 s signal reliability.This functional tracer was applied to retrogradely label specific V1-thalamus circuits and detect spontaneous Ca^(2+)activity in the dendrites of V1 corticothalamic neurons by in vivo two-photon Ca^(2+)imaging.Notably,we were able to record single-spine spontaneous Ca2+activity in specific circuits.Distinct spontaneous Ca^(2+)dynamics in dendrites of V1 corticothalamic neurons were found for different V1-thalamus circuits.Our method can be applied to monitor Ca^(2+)dynamics in specific input circuits in vivo,and contribute to functional studies of defined neural circuits and the dissection of functional circuit connections.展开更多
Consciousness is the unified, structured, subjective experience that we all share. The Default Space Theory has been proposed as a unified theory of consciousness that includes the brain and body in describing the inf...Consciousness is the unified, structured, subjective experience that we all share. The Default Space Theory has been proposed as a unified theory of consciousness that includes the brain and body in describing the infrastructure of consciousness. We have presented the theory in journals with a variety of academic specialties;however, the model is continually being developed. Due to the current state of science on the nature of conscious experience lacking hard data, the theory’s concepts must thoroughly explain and shoulder phenomenological observations including the phenomenology of deficits of consciousness. According to the theory, the thalamus serves as a central hub which networks the globally distributed, and continuous fast oscillations not only among the brain, but also the eyes, ears, skin, and other sensory organs. These oscillations form the virtual template of external space within the mind in which external sensory information is integrated into this pre-existing, dynamic space. In this article, we explore phenomenological support for our theory of conscious experience in which such experience resides entirely in such a virtual space, termed the default space. In order to provide such support, we discuss simple personal experiments and observations which anyone can partake along with phenomenal symptoms of clinical deficits. We encourage readers to perform the personal experiments we describe in order to gain an understanding of the various concepts of the theory. The neurological deficits we elucidate not only support the theory but clarify obscurities surrounding these conditions. We assert the support we give in our theory here will advance the uphill struggle many paramount theories face in gaining initial acceptance. Further research is needed in order to acquire empirical evidence for the veracity of our theory.展开更多
The focus of this study is to explore the mechanisms during seizure behavior using a physiologically motivated by corticothalamic circuity. The model is based on the assumption that, the inhibitory projects from thala...The focus of this study is to explore the mechanisms during seizure behavior using a physiologically motivated by corticothalamic circuity. The model is based on the assumption that, the inhibitory projects from thalamus reticular nucleus(TRN) to specific relay nuclei(SRN) are mediated by GABAA and GABAB receptors which react different time scales in synaptic transmission.Secondly, we include the effects of slow modulation on the threshold current of TRN population that were found to generate bursting behavior. Our model can reproduce healthy and pathological dynamics including wake, spindle, deep sleep, and also seizure states. In addition, contour maps are used to explore the transition of different activity states. It is worthy to point out seizure duration is significantly affected by a time-varying delay as illustrated in our numerical simulation. Finally, a reduced model ignoring the cerebral cortex mass can also capture the feature of spike wave discharge as generated in the full network.展开更多
70%-80% of our sensory input comes from vision. Light hit the retina at the back of our eyes and the visual information is relayed into the dorsal lateral geniculate nuclei （dLGN） and primary visual cortex （V1） th...70%-80% of our sensory input comes from vision. Light hit the retina at the back of our eyes and the visual information is relayed into the dorsal lateral geniculate nuclei （dLGN） and primary visual cortex （V1） thereafter, constituting the image-forming visual circuit. Molecular cues are one of the key factors to guide the wiring and refinement of the image-forming visual circuit during pre- and post-embryonic stages. Distinct molecular cues are involved in different developmental stages and nucleus, suggesting diverse guidance mechanisms. In this review, we summarize molecular guidance cues throughout the image-forming visual circuit, including chiasm determination, eye-specific segregation and refinement in the dLGN, and at last the reciprocal con- nections between the dLGN and VI.展开更多
基金supported by the National Natural Science Foundation of China(31700934 and 31371106)。
文摘Monitoring neuronal activity in vivo is critical to understanding the physiological or pathological functions of the brain.Two-photon Ca^(2+)imaging in vivo using a cranial window and specific neuronal labeling enables realtime,in situ,and long-term imaging of the living brain.Here,we constructed a recombinant rabies virus containing the Ca^(2+)indicator GCaMP6 s along with the fluorescent protein DsRed2 as a baseline reference to ensure GCaMP6 s signal reliability.This functional tracer was applied to retrogradely label specific V1-thalamus circuits and detect spontaneous Ca^(2+)activity in the dendrites of V1 corticothalamic neurons by in vivo two-photon Ca^(2+)imaging.Notably,we were able to record single-spine spontaneous Ca2+activity in specific circuits.Distinct spontaneous Ca^(2+)dynamics in dendrites of V1 corticothalamic neurons were found for different V1-thalamus circuits.Our method can be applied to monitor Ca^(2+)dynamics in specific input circuits in vivo,and contribute to functional studies of defined neural circuits and the dissection of functional circuit connections.
文摘Consciousness is the unified, structured, subjective experience that we all share. The Default Space Theory has been proposed as a unified theory of consciousness that includes the brain and body in describing the infrastructure of consciousness. We have presented the theory in journals with a variety of academic specialties;however, the model is continually being developed. Due to the current state of science on the nature of conscious experience lacking hard data, the theory’s concepts must thoroughly explain and shoulder phenomenological observations including the phenomenology of deficits of consciousness. According to the theory, the thalamus serves as a central hub which networks the globally distributed, and continuous fast oscillations not only among the brain, but also the eyes, ears, skin, and other sensory organs. These oscillations form the virtual template of external space within the mind in which external sensory information is integrated into this pre-existing, dynamic space. In this article, we explore phenomenological support for our theory of conscious experience in which such experience resides entirely in such a virtual space, termed the default space. In order to provide such support, we discuss simple personal experiments and observations which anyone can partake along with phenomenal symptoms of clinical deficits. We encourage readers to perform the personal experiments we describe in order to gain an understanding of the various concepts of the theory. The neurological deficits we elucidate not only support the theory but clarify obscurities surrounding these conditions. We assert the support we give in our theory here will advance the uphill struggle many paramount theories face in gaining initial acceptance. Further research is needed in order to acquire empirical evidence for the veracity of our theory.
基金supported by the Foundational Research Funds for the Central Universities(Grant Nos.G2016KY0301)the National Natural Science Foundation of China(Grant Nos.11602192&11672074)
文摘The focus of this study is to explore the mechanisms during seizure behavior using a physiologically motivated by corticothalamic circuity. The model is based on the assumption that, the inhibitory projects from thalamus reticular nucleus(TRN) to specific relay nuclei(SRN) are mediated by GABAA and GABAB receptors which react different time scales in synaptic transmission.Secondly, we include the effects of slow modulation on the threshold current of TRN population that were found to generate bursting behavior. Our model can reproduce healthy and pathological dynamics including wake, spindle, deep sleep, and also seizure states. In addition, contour maps are used to explore the transition of different activity states. It is worthy to point out seizure duration is significantly affected by a time-varying delay as illustrated in our numerical simulation. Finally, a reduced model ignoring the cerebral cortex mass can also capture the feature of spike wave discharge as generated in the full network.
文摘70%-80% of our sensory input comes from vision. Light hit the retina at the back of our eyes and the visual information is relayed into the dorsal lateral geniculate nuclei （dLGN） and primary visual cortex （V1） thereafter, constituting the image-forming visual circuit. Molecular cues are one of the key factors to guide the wiring and refinement of the image-forming visual circuit during pre- and post-embryonic stages. Distinct molecular cues are involved in different developmental stages and nucleus, suggesting diverse guidance mechanisms. In this review, we summarize molecular guidance cues throughout the image-forming visual circuit, including chiasm determination, eye-specific segregation and refinement in the dLGN, and at last the reciprocal con- nections between the dLGN and VI.
