In labs, brains are chemically preserved with a chemical called formaldehyde which “fixes” the tissue and minimizes degradation of the sample. Scientists can then slice parts of the brain and add antibodies, which are other proteins that specifically bind to the proteins of interest in the brain. They can then quantify where and in what quantities specific proteins are expressed in different regions of the brain. Recently some efforts have been made to preserve the brain at very low temperatures in liquid nitrogen. This is called cryonics. Some people hope that we will be able to “revive” brains from these frozen samples, but this is highly debated.
Learn more about the cryonics debate here and here.
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Glutamate (or glutamic acid) is an amino acid found in meat, tomatoes, and other foods. It is responsible for the “umami” taste. It is also found in a slightly different form as a neurotransmitter in the brain. The food additive monosodium glutamate (MSG), first used in Japan, is derived from fermented vegetables, and is indistinguishable from glutamate found in naturally-occurring proteins.
The brain maintains a low concentration of glutamate in the fluid surrounding its cells; the level in our bloodstream and in the rest of the body is much higher. This is possible because the brain is separated from the rest of the body by the blood-brain-barrier. For the most part, glutamate cannot cross this barrier unless it is actively transported by cells. So even if you ingest a lot of MSG with your food, it would be difficult for it to find its way into your brain! After some reports of people suffering from neurological symptoms after eating in certain restaurants, there has been a lot of research on the effects of MSG. When studies of MSG consumption are blind, meaning the researchers are unaware of which group ingested MSG while doing their analysis, there seems to be little difference between the two groups. The FDA has therefore classified it “generally considered as safe”. Historically, men have dominated math, and some studies even showed males outperforming females on tasks of spatial abilities, including mental rotation, navigating spaces, etc. However, recent research suggests that the differences observed between boys and girls seem to be due to environmental factors. Gender stereotypes influence the likelihood of teachers and parents to encourage and train girls in math. Another factor is stereotype threat: women who think about their gender during a math task perform poorly, because “activating” their identity as a woman also activates the associated stereotype (“women are bad at math”). In one study, women performed better on a math test in a room full of other women, rather than in a room with more men than women. This evidence indicates boys and girls aren’t wired differently when it comes to math, and are affected by the social norms and stereotypes about their performance rather than their inherent ability.
See a scientific review of gender and intellectual abilities here. Anthropologist Robin Dunbar said that a person has a limit of about 150 social relationships. More specifically, it could range from 100 to 200 interactions depending on how social the person is. Our network of acquaintances may be three times as large as that of true friends.
Fun fact - there is a neurological condition called hyperthymesia in which someone will remember the name of every person he/she has ever met. In this case the number would be infinite! But for the rest of us, the number of people we can remember will be around 150. The Zika virus was first discovered in the Zika forest of Uganda in 1947. The virus is spread primarily through mosquitos but can be transmitted sexually, through blood, and during childbirth. People infected with the virus will show mild symptoms, including fever and muscle and joint pain, lasting 2-7 days. Unfortunately, there are currently no vaccines against the virus.
The Zika virus gained worldwide attention a couple of years ago due to its association with microcephaly, a disorder causing smaller than normal brain and head size in babies born to infected mothers in Brazil in 2015. Microcephaly is thought to be caused by mutations in developmental genes, and it’s possible that the Zika virus may lead to similar mutations. Microcephaly is a lifelong condition and occurs when the baby’s brain does not develop properly in the womb or stops growing after birth. The problems associated with microcephaly range from mild to severe, including intellectual disability, seizures, and developmental delay. Learn more about Zika risk and prevention from the WHO & CDC, and microcephaly here. |
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