Feed aggregator

Fast near-whole–brain imaging in adult Drosophila during responses to stimuli and behavior

PLOS Biology (new articles) - Sat, 2019-02-16 00:00

by Sophie Aimon, Takeo Katsuki, Tongqiu Jia, Logan Grosenick, Michael Broxton, Karl Deisseroth, Terrence J. Sejnowski, Ralph J. Greenspan

Whole-brain recordings give us a global perspective of the brain in action. In this study, we describe a method using light field microscopy to record near-whole brain calcium and voltage activity at high speed in behaving adult flies. We first obtained global activity maps for various stimuli and behaviors. Notably, we found that brain activity increased on a global scale when the fly walked but not when it groomed. This global increase with walking was particularly strong in dopamine neurons, which showed little activity otherwise. Second, we extracted maps of spatially distinct sources of activity as well as their time series using principal component analysis and independent component analysis. The characteristic shapes in the maps matched the anatomy of subneuropil regions and, in some cases, a specific neuron type. Brain structures that responded to light and odor were consistent with previous reports, confirming the new technique’s validity. We also observed previously uncharacterized behavior-related activity as well as patterns of spontaneous voltage activity.
Categories: Biology, Journals

Fears of OpenAI’s super-trolling artificial intelligence are overblown

Genetically modified organisms (GMO) - Fri, 2019-02-15 17:55
Elon Musk-backed firm OpenAI has built a text-generating AI that it says is too dangerous to release because of potential misuse
Categories: Science and society

Fears of OpenAI’s super-trolling artificial intelligence are overblown

Genetics - Fri, 2019-02-15 17:55
Elon Musk-backed firm OpenAI has built a text-generating AI that it says is too dangerous to release because of potential misuse
Categories: Biology

Fears of OpenAI’s super-trolling artificial intelligence are overblown

HIV and AIDS - Fri, 2019-02-15 17:55
Elon Musk-backed firm OpenAI has built a text-generating AI that it says is too dangerous to release because of potential misuse

A dialect quiz shows we still cling to our regional identities

Genetically modified organisms (GMO) - Fri, 2019-02-15 17:52
The New York Times' online quiz can pinpoint where in the UK or Ireland you grew up by the words you use and how you say them. We asked a linguist to explain why dialects persist
Categories: Science and society

A dialect quiz shows we still cling to our regional identities

Genetics - Fri, 2019-02-15 17:52
The New York Times' online quiz can pinpoint where in the UK or Ireland you grew up by the words you use and how you say them. We asked a linguist to explain why dialects persist
Categories: Biology

A dialect quiz shows we still cling to our regional identities

HIV and AIDS - Fri, 2019-02-15 17:52
The New York Times' online quiz can pinpoint where in the UK or Ireland you grew up by the words you use and how you say them. We asked a linguist to explain why dialects persist

The children striking over climate change speak to New Scientist

Genetically modified organisms (GMO) - Fri, 2019-02-15 16:30
New Scientist went to meet the UK schoolchildren who have left their classrooms to join a global protest that calls for the government to declare a climate emergency
Categories: Science and society

The children striking over climate change speak to New Scientist

Genetics - Fri, 2019-02-15 16:30
New Scientist went to meet the UK schoolchildren who have left their classrooms to join a global protest that calls for the government to declare a climate emergency
Categories: Biology

The children striking over climate change speak to New Scientist

HIV and AIDS - Fri, 2019-02-15 16:30
New Scientist went to meet the UK schoolchildren who have left their classrooms to join a global protest that calls for the government to declare a climate emergency

Meet the man who made CRISPR monkey clones to study depression

Genetically modified organisms (GMO) - Fri, 2019-02-15 14:05
Hung-Chun Chang told New Scientist about his team’s controversial project to find drugs for depression and schizophrenia using clones of gene-edited monkeys
Categories: Science and society

Meet the man who made CRISPR monkey clones to study depression

Genetics - Fri, 2019-02-15 14:05
Hung-Chun Chang told New Scientist about his team’s controversial project to find drugs for depression and schizophrenia using clones of gene-edited monkeys
Categories: Biology

Meet the man who made CRISPR monkey clones to study depression

HIV and AIDS - Fri, 2019-02-15 14:05
Hung-Chun Chang told New Scientist about his team’s controversial project to find drugs for depression and schizophrenia using clones of gene-edited monkeys

Russia’s plan to unplug from the internet shows cyberwar is escalating

Genetically modified organisms (GMO) - Fri, 2019-02-15 14:03
Media reports suggest Russia is contemplating disconnecting from the global internet. The move is not about isolationism but security, says James Ball
Categories: Science and society

Russia’s plan to unplug from the internet shows cyberwar is escalating

Genetics - Fri, 2019-02-15 14:03
Media reports suggest Russia is contemplating disconnecting from the global internet. The move is not about isolationism but security, says James Ball
Categories: Biology

Russia’s plan to unplug from the internet shows cyberwar is escalating

HIV and AIDS - Fri, 2019-02-15 14:03
Media reports suggest Russia is contemplating disconnecting from the global internet. The move is not about isolationism but security, says James Ball

Interstellar ‘Oumuamua might be a fractal snowflake not an alien probe

Genetically modified organisms (GMO) - Fri, 2019-02-15 13:13
The interstellar asteroid ‘Oumuamua might be an alien spaceship, at least according to one prominent researcher, but now there is a much more reasonable explanation
Categories: Science and society

Interstellar ‘Oumuamua might be a fractal snowflake not an alien probe

Genetics - Fri, 2019-02-15 13:13
The interstellar asteroid ‘Oumuamua might be an alien spaceship, at least according to one prominent researcher, but now there is a much more reasonable explanation
Categories: Biology

Interstellar ‘Oumuamua might be a fractal snowflake not an alien probe

HIV and AIDS - Fri, 2019-02-15 13:13
The interstellar asteroid ‘Oumuamua might be an alien spaceship, at least according to one prominent researcher, but now there is a much more reasonable explanation

Alternative (backdoor) androgen production and masculinization in the human fetus

PLOS Biology (new articles) - Fri, 2019-02-15 00:00

by Peter J. O’Shaughnessy, Jean Philippe Antignac, Bruno Le Bizec, Marie-Line Morvan, Konstantin Svechnikov, Olle Söder, Iuliia Savchuk, Ana Monteiro, Ugo Soffientini, Zoe C. Johnston, Michelle Bellingham, Denise Hough, Natasha Walker, Panagiotis Filis, Paul A. Fowler

Masculinization of the external genitalia in humans is dependent on formation of 5α-dihydrotestosterone (DHT) through both the canonical androgenic pathway and an alternative (backdoor) pathway. The fetal testes are essential for canonical androgen production, but little is known about the synthesis of backdoor androgens, despite their known critical role in masculinization. In this study, we have measured plasma and tissue levels of endogenous steroids in second trimester human fetuses using multidimensional and high-resolution mass spectrometry. Results show that androsterone is the principal backdoor androgen in the male fetal circulation and that DHT is undetectable (<1 ng/mL), while in female fetuses, there are significantly lower levels of androsterone and testosterone. In the male, intermediates in the backdoor pathway are found primarily in the placenta and fetal liver, with significant androsterone levels also in the fetal adrenal. Backdoor intermediates, including androsterone, are only present at very low levels in the fetal testes. This is consistent with transcript levels of enzymes involved in the alternate pathway (steroid 5α-reductase type 1 [SRD5A1], aldo-keto reductase type 1C2 [AKR1C2], aldo-keto reductase type 1C4 [AKR1C4], cytochrome P450 17A1 [CYP17A1]), as measured by quantitative PCR (qPCR). These data identify androsterone as the predominant backdoor androgen in the human fetus and show that circulating levels are sex dependent, but also that there is little de novo synthesis in the testis. Instead, the data indicate that placental progesterone acts as substrate for synthesis of backdoor androgens, which occurs across several tissues. Masculinization of the human fetus depends, therefore, on testosterone and androsterone synthesis by both the fetal testes and nongonadal tissues, leading to DHT formation at the genital tubercle. Our findings also provide a solid basis to explain why placental insufficiency is associated with disorders of sex development in humans.
Categories: Biology, Journals