COVID has had an impact on academics' well-being

The COVID pandemic has had a considerable impact on academics' work and well-being. They have had much less time to spend on their research. The Young Academy and the Dutch Network of Women Professors have conducted research ...

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The intricate functions of cellular processes have mystified scientists for decades. But with the help of tools like cryogenic electron microscopy (Cryo-EM), researchers at Penn State College of Medicine are starting to see ...

How to read a jellyfish's mind

The human brain has 100 billion neurons, making 100 trillion connections. Understanding the precise circuits of brain cells that orchestrate all of our day-to-day behaviors—such as moving our limbs, responding to fear and ...

Sun compass on demand

Monarch butterflies are famous for their annual long-distance migration, which takes them over several thousand kilometers from the north of the USA to their overwintering habitat in central Mexico. On their migration, the ...

How smart is an octopus?

The unique brainpower of octopuses—known for their intelligence and Houdini-like escapes—has been revealed by University of Queensland researchers.

It's official: Science says grannies are good for you

Scientists say they have proven what many people fortunate enough to grow up with theirs have known all along: Grandmothers have strong nurturing instincts and are hard-wired to care deeply about their grandchildren.

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The brain is the center of the nervous system in all vertebrate, and most invertebrate, animals. Some primitive animals such as jellyfish and starfish have a decentralized nervous system without a brain, while sponges lack any nervous system at all. In vertebrates, the brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing, balance, taste, and smell.

Brains can be extremely complex. The cerebral cortex of the human brain contains roughly 15-33 billion neurons depending on gender and age, linked with up to 10,000 synaptic connections each. Each cubic millimeter of cerebral cortex contains roughly one billion synapses. These neurons communicate with one another by means of long protoplasmic fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body and target them to specific recipient cells.

The most important biological function of the brain is to generate behaviors that promote the welfare of an animal. Brains control behavior either by activating muscles, or by causing secretion of chemicals such as hormones. Even single-celled organisms may be capable of extracting information from the environment and acting in response to it. Sponges, which lack a central nervous system, are capable of coordinated body contractions and even locomotion. In vertebrates, the spinal cord by itself contains neural circuitry capable of generating reflex responses as well as simple motor patterns such as swimming or walking. However, sophisticated control of behavior on the basis of complex sensory input requires the information-integrating capabilities of a centralized brain.

Despite rapid scientific progress, much about how brains work remains a mystery. The operations of individual neurons and synapses are now understood in considerable detail, but the way they cooperate in ensembles of thousands or millions has been very difficult to decipher. Methods of observation such as EEG recording and functional brain imaging tell us that brain operations are highly organized, but these methods do not have the resolution to reveal the activity of individual neurons.

This text uses material from Wikipedia, licensed under CC BY-SA