It is a relatively new field of science, only emerging as a distinct subject in its own right during the 20th century. However, it has grown rapidly and now covers multiple areas including novel technologies, and research into many brain functions and disorders, as well as applications as diverse as education, artificial intelligence and the law.
Weighing about 1.3 kg, the human brain consists of millions of individual nerve cells or neurons (as shown in the image) plus millions of additional cells known as glia*. These are all connected via microscopic points of contact into a vast network of interlinking circuits and sub-circuits.
The brain is responsible for our thoughts, mood, emotions and intelligence, as well as our physical movement, breathing, heart rate and sleep. In short, it makes us who we are and facilitates almost every aspect of what it means to be alive.
Neuroscientists have the daunting task of trying to understand how all these billions of neurons in the brain and nervous system work.
https://www.bna.org.uk/about-neuroscience/