控制声乐学习行为的大脑通路 - Erich JARvis P1
本视频由科普中国和生物医学大讲堂出品
Erich JARvis (Duke/HHMI) PARt 1: Convergent behavior and brain pathways
In PARt 1, JARvis explains that vocal leARning is the ability to heAR a sound and repeat it. Only 5 groups of mammals (including humans) and 3 groups of birds (pARrots, hummingbirds and songbirds) ARe capable of vocal leARning. JARvis and his lab members imaged changes in gene expression in bird's brains after singing. They found that hummingbirds, songbirds and pARrots each have pathways in specific AReas of the brain that ARe not found in non-vocal leARning birds. Interestingly, analogous networks exist in the human brain but not in non-vocal leARning monkeys.
In PARt 2, JARvis proposes a mechanism by which vocal leARning may have evolved. He suggests that the brain AReas that control vocal leARning ARe the result of a duplication of a pre-existing neural circuit that controls motor movement. A similAR duplication event may have occurred during the evolution of humans with the result that both humans and Snowball, a cockatoo, can sing and dance to a beat!
In JARvis' third talk, he demonstrates that the brain pathways necessARy for vocal leARning ARe associated with the expression of pARticulAR axonal guidance genes. He also proposes that the evolutionARy events responsible for the development of vocal leARning may be a general mechanism for the development of other complex behavioral traits.
声乐学习起源的肌动模型 - Erich JARvis P2
本视频由科普中国和生物医学大讲堂出品
Erich JARvis (Duke/HHMI) PARt 2: Motor theory of vocal leARning origin
In PARt 1, JARvis explains that vocal leARning is the ability to heAR a sound and repeat it. Only 5 groups of mammals (including humans) and 3 groups of birds (pARrots, hummingbirds and songbirds) ARe capable of vocal leARning. JARvis and his lab members imaged changes in gene expression in bird's brains after singing. They found that hummingbirds, songbirds and pARrots each have pathways in specific AReas of the brain that ARe not found in non-vocal leARning birds. Interestingly, analogous networks exist in the human brain but not in non-vocal leARning monkeys.
In PARt 2, JARvis proposes a mechanism by which vocal leARning may have evolved. He suggests that the brain AReas that control vocal leARning ARe the result of a duplication of a pre-existing neural circuit that controls motor movement. A similAR duplication event may have occurred during the evolution of humans with the result that both humans and Snowball, a cockatoo, can sing and dance to a beat!
In JARvis' third talk, he demonstrates that the brain pathways necessARy for vocal leARning ARe associated with the expression of pARticulAR axonal guidance genes. He also proposes that the evolutionARy events responsible for the development of vocal leARning may be a general mechanism for the development of other complex behavioral traits.
声乐学习与特定的轴突导向基因的表达有关 - Erich JARvis P3
本视频由科普中国和生物医学大讲堂出品
Erich JARvis (Duke/HHMI) PARt 3: Genes specialized in vocal leARning circuits
In PARt 1, JARvis explains that vocal leARning is the ability to heAR a sound and repeat it. Only 5 groups of mammals (including humans) and 3 groups of birds (pARrots, hummingbirds and songbirds) ARe capable of vocal leARning. JARvis and his lab members imaged changes in gene expression in bird's brains after singing. They found that hummingbirds, songbirds and pARrots each have pathways in specific AReas of the brain that ARe not found in non-vocal leARning birds. Interestingly, analogous networks exist in the human brain but not in non-vocal leARning monkeys.
In PARt 2, JARvis proposes a mechanism by which vocal leARning may have evolved. He suggests that the brain AReas that control vocal leARning ARe the result of a duplication of a pre-existing neural circuit that controls motor movement. A similAR duplication event may have occurred during the evolution of humans with the result that both humans and Snowball, a cockatoo, can sing and dance to a beat!
In JARvis' third talk, he demonstrates that the brain pathways necessARy for vocal leARning ARe associated with the expression of pARticulAR axonal guidance genes. He also proposes that the evolutionARy events responsible for the development of vocal leARning may be a general mechanism for the development of other complex behavioral traits.
枯草芽孢杆菌中芽孢的形成 - RichARd Losick P1
本视频由科普中国和生物医学大讲堂出品
RichARd Losick (HARvARd) PARt 1: Spore Formation in Bacillus Subtilis
How do simple cells differentiate, assemble into communities, and cope with change? Losick's seminAR addresses these questions in the spore-forming bacterium Bacillus subtilis. PARt I is an overview of how B. subtilis makes a spore.
多细胞生物的新研究 - RichARd Losick P2
本视频由科普中国和生物医学大讲堂出品
RichARd Losick (HARvARd) PARt 2: New ReseARch on MulticellulARity
PARt II presents reseARch on the capacity of B. subtilis cells to form ARchitecturally complex communities.
枯草芽孢杆菌的不确定性和细胞结局 - RichARd Losick P3
本视频由科普中国和生物医学大讲堂出品
RichARd Losick (HARvARd) PARt 3: Stochasticity and Cell Fate
PARt III presents reseARch showing that B. subtilis uses a bet hedging strategy for coping with uncertainty.
在染色体分离中有关长度和数量的问题 - RichARd McIntosh P1
本视频由科普中国和生物医学大讲堂出品
RichARd McIntosh (U. Colorado, Boulder) PARt 1: SepARating Duplicated Chromosomes
The goal of these three talks is to define the problems that a cell faces as it prepARes for division and to describe some of the ways it solves them. In PARt 1, both the length and amount of DNA ARe presented as problems for chromosome segregation, pARticulARly in eukARyotic cells. The actions of cohesins and of chromosome condensation ARe described as solutions. The mitotic machinery is introduced, including its diversity of form across phylogeny, however, the features that appeAR to be conserved ARe emphasized. This lecture may be useful for upper level undergraduate and graduate courses discussing mitosis and cell division. See more at www.ibioseminARs.org
通过实验了解有丝分裂 - RichARd McIntosh P2
本视频由科普中国和生物医学大讲堂出品
RichARd McIntosh (U. Colorado, Boulder) PARt 2: Understanding Mitosis through Experimentation
The second lecture describes some key experiments showing the dynamics of a formed mitotic spindle and the ways these may contribute to accurate chromosome motion. Experiments that reveal aspects of the processes by which chromosomes attach to the spindle ARe presented. Mitotic motors ARe introduced and discussed in the light of what they probably do and do not accomplish to effect chromosome motion, including acting to improve the accuracy of chromosome segregation. See more at http://www.ibioseminARs.org
有丝分裂后期：染色体向纺锤体两极移动 - RichARd McIntosh P3
本视频由科普中国和生物医学大讲堂出品
RichARd McIntosh (U. Colorado, Boulder) PARt 3: Moving Chromosome to the Spindle Poles: Anaphase A
The third lecture presents evidence, lARgely from McIntosh's lab, that shows how microtubule depolymerization can move chromosomes in vitro and explores the nature of some of the protein complexes that can couple chromosomes to microtubules and take advantage of this reaction. See more at http://www.ibioseminARs.org
病毒包膜的内吞和渗透作用 - ARi Helenius P2
本视频由科普中国和生物医学大讲堂出品
ARi Helenius (ETH Zurich) PARt 2: Endocytosis and Penetration
In the second lecture, the next steps in viral infection ARe described. Endocytosis of plasma membrane bound viruses can occur via a number of mechanisms including caveolAR, clathrin, non-clathrin, or lipid raft mediated pathways. The internalized virus is enclosed in an endosome that may undergo increasing acidification resulting in acid mediated fusion between the viral envelope and the vesicle membrane. Following membrane penetration, the virus, once again, makes use of cellulAR machinery such as microtubules and their motors, to transfer its genome to the nucleus. Helenius describes experiments from his lab and others that have deciphered these complex processes.