How Brain Works

The human brain weighs only three pounds and is estimated to have about 100 billion cells. There are two types of cells- the neurons and the glial cells. Neurons are the cells which carry information to and from brain. Communication between the neurons is both electrical and chemical. Neurons transmit and analyze communication within the brain and other parts of nervous system. Dendrites are structures that extend from cell body and they receive impulses from one neuron and send it to other neuron. Axon is a fiber extending from the cell body that carries impulses from the cell body to other dendrites of other neurons.

The process of brain is very complicated. An electrical impulse travels down the cell body and through it reaches the end of the axon. The end of the axon contains tiny sacs that hold chemical messengers and when the electrical impulse stimulates the sacs, the chemical messengers are released into the synapse. The impulse in this way passes through the synapse. After it moves from the synapse, the neurotransmitters attach a receptor on the dendrites of the cell body. This sparks an electrical impulse in the receiving cell body. In this way, a message within the brain is converted.

There are several theories regarding storage of memory in the brain:

Biochemical theory- It states that memory storage occurs in biochemical changes at the synapse. A depletion of bio-chemical messengers in synapse like Acetylcholine and Glutamate results in memory loss.

Neural Circuit Theory- It suggests that there may be specific circuits in the brain for specific memories. There can also be some dendritic growth.

The unit of memory is Engram.