Fireflies, heart cells, clocks, and power grids all do it—they can spontaneously sync up, sending signals out in unison. For centuries, scientists have been perplexed by this self-organizing behavior, coming up with theories ...

Newly-discovered genes that helped supersize human brains along with DNA retrieved from extinct humans, which can still be found in people living today, are expanding scientists' understanding of how our species evolved.

University of Alberta neuroscientists have identified the neural circuit that may underlie intelligence in birds, according to a new study. The discovery is an example of convergent evolution between the brains of birds and ...

Glioblastoma multiforme, a type of brain tumor, is one of the most difficult-to-treat cancers. Only a handful of drugs are approved to treat glioblastoma, and the median life expectancy for patients diagnosed with the disease ...

In all animals, including humans, smell—the oldest of the five senses—plays a predominant role in many behaviors essential for survival and reproduction. It has been known since ancient times that animals react to odours.

The evolution of larger brains in the last 3 million years played an important role in our ability as a species to think, problem-solve, and develop culture. But the genetic changes behind the expansion that made us human ...

If you encountered an elephant bird today, it would be hard to miss. Measuring in at over 10 feet tall, the extinct avian is the largest bird known to science. However, while you looked up in awe, it's likely that the big ...

MIT researchers have invented a way to fabricate nanoscale 3-D objects of nearly any shape. They can also pattern the objects with a variety of useful materials, including metals, quantum dots, and DNA.

Biologists at Lund University in Sweden have shown that the great tit, a common European songbird, has a tremendous capacity for self-control. Until now, such impulse control has been primarily associated with larger cognitively ...

Brain

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.