The GABAergic neurons in the parafacial zone（PZ） play an important role in sleep-wake regulation and have been identified as part of a sleep-promoting center in the brainstem, but the long-range connections mediatin...The GABAergic neurons in the parafacial zone（PZ） play an important role in sleep-wake regulation and have been identified as part of a sleep-promoting center in the brainstem, but the long-range connections mediating this function remain poorly characterized. Here, we performed whole-brain mapping of both the inputs and outputs of the GABAergic neurons in the PZ of the mouse brain. We used the modified rabies virus Env A-DG-Ds Red combined with a Cre/lox P gene-expression strategy to map the direct monosynaptic inputs to the GABAergic neurons in the PZ, and found that they receive inputs mainly from the hypothalamic area, zona incerta, and parasubthalamic nucleus in the hypothalamus; the substantia nigra, pars reticulata and deep mesencephalic nucleus in the midbrain;and the intermediate reticular nucleus and medial vestibular nucleus（parvocellular part） in the pons and medulla.We also mapped the axonal projections of the PZ GABAergic neurons with adeno-associated virus, and defined the reciprocal connections of the PZ GABAergic neurons with their input and output nuclei. The newlyfound inputs and outputs of the PZ were also listed compared with the literature. This cell-type-specific neuronal whole-brain mapping of the PZ GABAergic neurons may reveal the circuits underlying various functions such as sleep-wake regulation.展开更多
Although extensively studied, the exact role of sleep in learning and memory is still not very clear. Sleep deprivation has been most frequently used to explore the effects of sleep on learning and memory, but the res...Although extensively studied, the exact role of sleep in learning and memory is still not very clear. Sleep deprivation has been most frequently used to explore the effects of sleep on learning and memory, but the results from such studies are inevitably complicated by concurrent stress and distress. Furthermore, it is not clear whether there is a strict time-window between sleep and memory consolidation. In the present study we were able to induce time-locked slow-wave sleep(SWS) in mice by optogenetically stimulating GABAergic neurons in the parafacial zone(PZ), providing a direct approach to analyze the influences of SWS on learning and memory with precise time-windows. We found that SWS induced by light for 30 min immediately or 15 min after the training phase of the object-in-place task significantly prolonged the memory from 30 min to 6 h. However, induction of SWS 30 min after the training phase did not improve memory, suggesting a critical time-window between the induction of a brief episode of SWS and learning for memory consolidation.Application of a gentle touch to the mice during light stimulation to prevent SWS induction also failed to improve memory, indicating the specific role of SWS,but not the activation of PZ GABAergic neurons itself, in memory consolidation. Similar influences of light-induced SWS on memory consolidation also occurred for Y-maze spatial memory and contextual fear memory, but not for cued fear memory. SWS induction immediately before the test phase had no effect on memory performance, indicating that SWS does not affect memory retrieval. Thus, by induction of a brief-episode SWS we have revealed a critical time window for the consolidation of hippocampusdependent memory.展开更多
Breathing is an integrated motor behavior that is driven and controlled by a network of brainstem neurons.Zfhx4 is a zinc finger transcription factor and our results showed that it was specifically expressed in severa...Breathing is an integrated motor behavior that is driven and controlled by a network of brainstem neurons.Zfhx4 is a zinc finger transcription factor and our results showed that it was specifically expressed in several regions of the mouse brainstem.Mice lacking Zfhx4 died shortly after birth from an apparent inability to initiate respiration.We also found that the electrical rhythm of brainstem‒spinal cord preparations was significantly depressed in Zfhx4-null mice compared to wild-type mice.Immunofluorescence staining revealed that Zfhx4 was coexpressed with Phox2b and Math1 in the brainstem and that Zfhx4 ablation greatly decreased the expression of these proteins,especially in the retrotrapezoid nucleus.Combined ChIP‒seq and mRNA expression microarray analysis identified Phox2b as the direct downstream target gene of Zfhx4,and this finding was validated by ChIP‒qPCR.Previous studies have reported that both Phox2b and Math1 play key roles in the development of the respiratory center,and Phox2b and Math1 knockout mice are neonatal lethal due to severe central apnea.On top of this,our study revealed that Zfhx4 is a critical regulator of Phox2b expression and essential for perinatal breathing.展开更多
基金supported by the National Natural Science Foundation of China (31571090 and 31771167)the National Key Research and Development Program (2016YFC1306700)+1 种基金the National High Technology Research and Development Program (863 Program) of China (2015AA020512)the Fundamental Research Funds for the Central Universities of China (2017FZA7003)
文摘The GABAergic neurons in the parafacial zone（PZ） play an important role in sleep-wake regulation and have been identified as part of a sleep-promoting center in the brainstem, but the long-range connections mediating this function remain poorly characterized. Here, we performed whole-brain mapping of both the inputs and outputs of the GABAergic neurons in the PZ of the mouse brain. We used the modified rabies virus Env A-DG-Ds Red combined with a Cre/lox P gene-expression strategy to map the direct monosynaptic inputs to the GABAergic neurons in the PZ, and found that they receive inputs mainly from the hypothalamic area, zona incerta, and parasubthalamic nucleus in the hypothalamus; the substantia nigra, pars reticulata and deep mesencephalic nucleus in the midbrain;and the intermediate reticular nucleus and medial vestibular nucleus（parvocellular part） in the pons and medulla.We also mapped the axonal projections of the PZ GABAergic neurons with adeno-associated virus, and defined the reciprocal connections of the PZ GABAergic neurons with their input and output nuclei. The newlyfound inputs and outputs of the PZ were also listed compared with the literature. This cell-type-specific neuronal whole-brain mapping of the PZ GABAergic neurons may reveal the circuits underlying various functions such as sleep-wake regulation.
基金supported by grants from the National Natural Science Foundation of China (31771167 and 31571090)the National Basic Research Development Program of China (2016YFC1306700)+1 种基金the Non-profit Central Research Institute Fund of the Chinese Academy of Medical Sciences (2018PT31041)the Fundamental Research Funds for the Central Universities of China (2017FZA7003)
文摘Although extensively studied, the exact role of sleep in learning and memory is still not very clear. Sleep deprivation has been most frequently used to explore the effects of sleep on learning and memory, but the results from such studies are inevitably complicated by concurrent stress and distress. Furthermore, it is not clear whether there is a strict time-window between sleep and memory consolidation. In the present study we were able to induce time-locked slow-wave sleep(SWS) in mice by optogenetically stimulating GABAergic neurons in the parafacial zone(PZ), providing a direct approach to analyze the influences of SWS on learning and memory with precise time-windows. We found that SWS induced by light for 30 min immediately or 15 min after the training phase of the object-in-place task significantly prolonged the memory from 30 min to 6 h. However, induction of SWS 30 min after the training phase did not improve memory, suggesting a critical time-window between the induction of a brief episode of SWS and learning for memory consolidation.Application of a gentle touch to the mice during light stimulation to prevent SWS induction also failed to improve memory, indicating the specific role of SWS,but not the activation of PZ GABAergic neurons itself, in memory consolidation. Similar influences of light-induced SWS on memory consolidation also occurred for Y-maze spatial memory and contextual fear memory, but not for cued fear memory. SWS induction immediately before the test phase had no effect on memory performance, indicating that SWS does not affect memory retrieval. Thus, by induction of a brief-episode SWS we have revealed a critical time window for the consolidation of hippocampusdependent memory.
基金supported by grants from the National Key Research and Development Program of China(2016YFC1000503)the National Natural Science Foundation of China(81571472,81741085,and 81971197).
文摘Breathing is an integrated motor behavior that is driven and controlled by a network of brainstem neurons.Zfhx4 is a zinc finger transcription factor and our results showed that it was specifically expressed in several regions of the mouse brainstem.Mice lacking Zfhx4 died shortly after birth from an apparent inability to initiate respiration.We also found that the electrical rhythm of brainstem‒spinal cord preparations was significantly depressed in Zfhx4-null mice compared to wild-type mice.Immunofluorescence staining revealed that Zfhx4 was coexpressed with Phox2b and Math1 in the brainstem and that Zfhx4 ablation greatly decreased the expression of these proteins,especially in the retrotrapezoid nucleus.Combined ChIP‒seq and mRNA expression microarray analysis identified Phox2b as the direct downstream target gene of Zfhx4,and this finding was validated by ChIP‒qPCR.Previous studies have reported that both Phox2b and Math1 play key roles in the development of the respiratory center,and Phox2b and Math1 knockout mice are neonatal lethal due to severe central apnea.On top of this,our study revealed that Zfhx4 is a critical regulator of Phox2b expression and essential for perinatal breathing.
