Ritasakano - Outubros

Molecular body guards for neurons

In the brain, patterns of neural activity are perfectly balanced. The interplay between activating and inhibitory neurotransmitters ensures that the level of activity stays within the physiological range. During an epileptic attack excitation gains the upper hand resulting in the death of neurons. Researchers of the Bonn University Medical School have now discovered a key player in a signal transduction cascade, which protects neurons from hyperexcitation-induced cell death. These results open a new direction for the development of novel therapy options. The results are now published in “The Journal of Neuroscience“.

Pathophysiological activity often triggers neuronal cell death. This can for example be observed after an epileptic insult. The cause for this hyperexcitation is excessive release of the signaling molecule glutamate. “This neurotransmitter can switch on signaling cascades that act neurotoxic”, says Prof. Dr. Schoch McGovern of the Institute of Neuropathology and the Department of Epileptology at the University Clinic Bonn. However, neurons try to protect themselves and prevent the damaging hyperexcitation.

The molecular nature of these “body guards” is so far unresolved. Accumulating evidence shows transcription factors to play an essential role in the processes by which neurons protect themselves. These factors switch on certain genes, which then via signal transduction cascades result in the production of neuroprotective substances. These in turn counteract the damaging glutamate-induced hyperexcitability.

Increased neuronal cell death in the absence of Syt10

The team of Prof. Dr. Schoch McGovern could now show that the protein Synaptotagmin 10 (Syt10) is an integral part of this protective shield. If rats for example experience an epileptic seizure, the amount of Syt10 in the hippocampal formation of the brain strongly increases. The researchers used neurons from mice, in which the Syt10 gene had been ablated, and stimulated them with a glutamate like substance. This treatment resulted in substantial neuronal death.

NPAS4 modulates the production of protective factors

The research team discovered, which transcription factor activates the gene for Syt10 in response to pathophysiological neuronal activity. This essential member of the neuronal body guard is called NPAS4. The researchers cultured rodent neurons and added several transcription factors. NPAS4 activated the Syt10 gene and required Syt10 to exert its neuroprotective function. “NPAS4 triggers a signaling cascade that results in the production of neuroprotective factors”, says Prof. Dr. Schoch McGovern.

Search for novel therapy approaches

The molecular identity of the neuroprotective substances is still unknown. “A potential candidate, the insulin-like growth factor IGF-1, was not able to reverse the increased neuronal cell death in the absence of Syt10”, reports the neurobiologist. The next step therefore is to test other substances. Once the identity of the neuroprotective body guards is revealed, novel avenues for therapy development open up, for example for stroke and epilepsy patients. “The goal would be to administer these protective substances from the outside in order to prevent neuronal cell death in the brain”, says Prof. Dr. Albert Becker, a medical doctor, who was part of the study. However, there is still a long road ahead.

BAYAH: O GENOCÍDIO ESQUECIDO – A REVOLTA DOS HEREROS E NAMA NA NAMÍBIA

Solar System: Things to Know This Week

Discoveries in planetary science are often both weird and wonderful, and these newest announcements are no exception. This week we present a few of the most interesting recent scientific findings from our missions and NASA-funded planetary science. Take a look:

1. Seeing Spots

Scientists from our Dawn mission unveiled new images from the spacecraft’s lowest orbit at the dwarf planet Ceres, including highly anticipated views of the famous “bright spots” of Occator Crater. Take a look HERE.

2. Pluto’s Secrets Brought to Light

A year ago, Pluto was just a bright speck in the cameras of our approaching New Horizons spacecraft, not much different than its appearances in telescopes since Clyde Tombaugh discovered the dwarf planet in 1930. Now, New Horizons scientists have authored the first comprehensive set of papers describing results from last summer’s Pluto system flyby. Find out more HERE.

3. Rising Above the Rest

In a nod to extraterrestrial mountaineers of the future, scientists working on our Cassini mission have identified the highest point on Saturn’s largest moon, Titan. The tallest peak is 10,948 feet (3,337 meters) high and is found within a trio of mountainous ridges called the Mithrim Montes, named for the mountains in Tolkien’s Middle-Earth.

4. Does the “Man in the Moon” Have a New Face?

New NASA-funded research provides evidence that the spin axis of Earth’s moon shifted by about five degrees roughly three billion years ago. The evidence of this motion is recorded in the distribution of ancient lunar ice, evidence of delivery of water to the early solar system.

5. X-Ray Vision

Solar storms are triggering X-ray auroras on Jupiter that are about eight times brighter than normal over a large area of the planet and hundreds of times more energetic than Earth’s “northern lights,” according to a new study using data from our Chandra X-ray Observatory.

Want to learn more? Read our full list of things to know this week about the solar system HERE.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

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“The Stella Pinafore Toilette.”

Enquire Within, Ladies Home Journal

5th February 1916.

Mohommah G. Baquaqua

“’Que aqueles ‘indivíduos humanitários’ que são a favor da escravidão se coloquem no lugar do escravo no porão barulhento de um navio negreiro, apenas por uma viagem da África à América, sem sequer experimentar mais que isso dos horrores da escravidão: se não saírem abolicionistas convictos, então não tenho mais nada a dizer a favor da abolição.’ As palavras são de Mahommah Gardo Baquaqua, ex-escravo nascido no Norte da África no início do século XIX e que trabalhou no Brasil antes de fugir das amarras da servidão em Nova York, em 1847. O trecho consta do livro “An interesting narrative. Biography of Mahommah G. Baquaqua” (“Uma interessante narrativa: biografia de Mahommah G. Baquaqua”, em tradução livre), lançado assim mesmo, em inglês, pelo próprio ex-escravo, em Detroit, no ano de 1854, em plena campanha abolicionista nos EUA. A obra jamais foi traduzida para o português, permanecendo desconhecida do público brasileiro.

Fonte: http://www.bocadaforte.com.br/reportagens/baquaqua-a-auto-biografia-de-um-escravo.html