Loss of deep cerebellar nuclei neurons in the 3xTg-AD mice and protection by an anti-amyloid β antibody fragment

The therapeutic potential of scFv-h3D6 has recently been shown in the 3xTg-AD mice. A clear effect on amyloid β (Aβ) oligomers and certain apolipoproteins in the brain was found, but no effect was seen in the cerebellum. Here, cellular vulnerability of the 3xTg-AD cerebellum is described for the first time, together with its protection by scFv-h3D6. Neuron depletion in the DCN was regionally variable and followed a mediolateral axis of involvement that was greatest in the fastigial nucleus, lesser in the interpositus and negligible in the dentate nucleus. A sole and low intraperitoneal dose of scFv-h3D6 protected 3xTg-AD DCN neurons from death. Further studies might provide interesting information about both the potential of scFv-h3D6 as a therapeutic agent and the role of the cerebellum in AD.     

Muc2和DCN基因敲除小鼠食子现象的初步研究

目的探讨Muc2和DCN基因敲除小鼠繁殖能力和食子现象的异同。方法分别将Muc2和DCN基因敲除纯合子雌雄小鼠按1∶1或1∶2的合笼,观察1～3胎产仔量、胎次间隔时间、出生存活率和食子现象。结果Muc2基因敲除小鼠平均产子量5.80±0.95只,平均胎次间隔时间（42.29±2.28）d;DCN基因敲除小鼠平均产子量3.85±0.76只,平均胎次间隔时间（24.86±10.42）d。Muc2和DCN基因敲除小鼠在产仔量、胎次间隔时间、出生存活率和食子率差异均存在显著性。结论两组基因敲除小鼠繁殖性能有差异,揭示可能与Muc2和DCN基因有关。     

Precision of Discrete and Rhythmic Forelimb Movements Requires a Distinct Neuronal Subpopulation in the Interposed Anterior Nucleus

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Cerebellar stem cells do not produce neurons and astrocytes in adult mouse

Although previous studies implied that cerebellar stem cells exist in some adult mammals, little is known about whether these stem cells can produce new neurons and astrocytes. In this study by bromodeoxyuridine (BrdU) intraperitoneal (i.p.) injection, we found that there are abundant BrdU⁺ cells in adult mouse cerebellum, and their quantity and density decreases significantly over time. We also found cell proliferation rate is diversified in different cerebellar regions. Among these BrdU⁺ cells, very few are mash1⁺ or nestin⁺ stem cells, and the vast majority of cerebellar stem cells are quiescent. Data obtained by in vivo retrovirus injection indicate that stem cells do not produce neurons and astrocytes in adult mouse cerebellum. Instead, some cells labeled by retrovirus are Iba1⁺ microglia. These results indicate that very few stem cells exist in adult mouse cerebellum, and none of these stem cells contribute to neurogenesis and astrogenesis under physiological condition.