As early as the sixth century B.C., a Greek physician performing a dissection noticed the connection between the optic nerve and the brain. Anatomical research through the Renaissance gradually mapped the connections between the brain. The spinal column, and the nerves that carry neural signals throughout the body. Religious and philosophical worldviews tended to separate the mind and body. The advancement in technology suggests the two were intimately connected. In the late 18th century, Italian professor Luigi Galvani applied static electric charges to the muscles of dead frogs. And made them twitch a feat that provided evidence for the idea that intention and perhaps even the lifeforce itself had a physical basis. For decades after, the study and clinical use of electricity in the body were called galvanism in his honor.
These efforts to understand how the brain sends its signals evolved into today’s neuroscience. The field has begun to provide anatomical and biochemical explanations. And treatments for problems once thought to be purely psychological involving emotions and attitudes. Not organic processes In the late 19th and early 20th centuries, Spanish physician and anatomist Santiago Ramón y Cajal made painstaking descriptions of the nervous system, distinguishing the basic nerve cell, or neuron, through the use of a silver nitrate stain.
Numbering in the billions, neurons in the human body carry messages via neurotransmitter chemicals, released from cell to cell across a vast network. Depending on the chemical mix and the origin of the message.
Different Researches over time:
Early research linked different parts of the brain to different activities higher-level functions to the cerebral cortex. The language in the left hemisphere, memory in the right. Advances in electromagnetic imaging refined the study even further. Researchers at the University of Pennsylvania in 2005. Used functional magnetic resonance imaging to document increased blood flow to the prefrontal cortex of people subjected to stress. Research into the role of neurotransmitters has linked chemicals such as dopamine and serotonin to different diseases and disorders the basis for antidepressants.