Hippocampal neurogenesis continues throughout the lifespan of adult mammals, but the rates decline dramatically with increasing age. Among the factors that have been shown to affect neurogenesis, aging has been shown ...Hippocampal neurogenesis continues throughout the lifespan of adult mammals, but the rates decline dramatically with increasing age. Among the factors that have been shown to affect neurogenesis, aging has been shown to be one of its most potent regulators in mice. The mechanism for the decline in neurogenesis with age is thought to be related to age-dependent changes in local and systemic neuroendocrinology and neurochemistry, as well as internal changes to precursor cells that result in decreased reactivity to normal stimuli. Since most of the data about neurogenesis and age were established from rodent studies, we sought to study this relationship in nonhuman primates in five previously studied cohorts of bonnet monkeys (Macaca radiata). In the present study, we statistically analyze the relationship of age and hippocampal neurogenesis rates, as measured by the number of DCX expressing cells in the subgranular zone of the dentate gyrus in 71 subjects with ages ranging from 3.5 to 17 years. We observed a non-significant relationship between age and doublecortin for subjects less than nine years old (corresponding to young and full adulthood) but a linear significant decline for subjects 9 years or greater (middle age and senescence). In contrast to previous studies that show neurogenesis to decline linearly throughout the lifespan, this study shows that neurogenesis occurs steadily throughout adulthood and begins to decline in middle age in bonnet macaques.展开更多
高科技传感器和软件生产商Quanergy Systems Inc.只用了10个月就从股市上市走到了申请破产。3D打印公司FastRadiusInc.用了九个月。在线零售初创公司Enjoy TechnologyInc.在申请破产前坚持了八个半月。这些公司的共同之处是它们上市的...高科技传感器和软件生产商Quanergy Systems Inc.只用了10个月就从股市上市走到了申请破产。3D打印公司FastRadiusInc.用了九个月。在线零售初创公司Enjoy TechnologyInc.在申请破产前坚持了八个半月。这些公司的共同之处是它们上市的方式。它们都没有采取传统的首次公开募股(IPO)形式,而是与一家特殊目的收购公司(SPAC)合并而上市。SPAC是公开上市的壳公司,自身没有具体业务,只是寻求与另一家公司合并,后者随后继承壳公司的上市地位。展开更多
文摘Hippocampal neurogenesis continues throughout the lifespan of adult mammals, but the rates decline dramatically with increasing age. Among the factors that have been shown to affect neurogenesis, aging has been shown to be one of its most potent regulators in mice. The mechanism for the decline in neurogenesis with age is thought to be related to age-dependent changes in local and systemic neuroendocrinology and neurochemistry, as well as internal changes to precursor cells that result in decreased reactivity to normal stimuli. Since most of the data about neurogenesis and age were established from rodent studies, we sought to study this relationship in nonhuman primates in five previously studied cohorts of bonnet monkeys (Macaca radiata). In the present study, we statistically analyze the relationship of age and hippocampal neurogenesis rates, as measured by the number of DCX expressing cells in the subgranular zone of the dentate gyrus in 71 subjects with ages ranging from 3.5 to 17 years. We observed a non-significant relationship between age and doublecortin for subjects less than nine years old (corresponding to young and full adulthood) but a linear significant decline for subjects 9 years or greater (middle age and senescence). In contrast to previous studies that show neurogenesis to decline linearly throughout the lifespan, this study shows that neurogenesis occurs steadily throughout adulthood and begins to decline in middle age in bonnet macaques.
文摘高科技传感器和软件生产商Quanergy Systems Inc.只用了10个月就从股市上市走到了申请破产。3D打印公司FastRadiusInc.用了九个月。在线零售初创公司Enjoy TechnologyInc.在申请破产前坚持了八个半月。这些公司的共同之处是它们上市的方式。它们都没有采取传统的首次公开募股(IPO)形式,而是与一家特殊目的收购公司(SPAC)合并而上市。SPAC是公开上市的壳公司,自身没有具体业务,只是寻求与另一家公司合并,后者随后继承壳公司的上市地位。
