The scientific study of the nervous system has increased significantly during the second half of the twentieth century, primarily due to advances in molecular biology and computational neuroscience.

In 1952, Hodgkin and Huxley presented the Hodgkin-Huxley model, a mathematical model that describes how action potentials in neurons are initiated and propagated. The model is a set of equations that approximates the electrical characteristics of excitable cells. In 1962, Katz modeled neurotransmission across synapses, the gaps across which nerve cells signal to each other and to other types of cells (Bear, Connors, and Paradiso, 2001).

Between 1962 and 1963, the brain anatomy of rodents was found to be altered by experience; this was the first evidence for the role of protein synthesis in the formation of memories. Starting in 1966, American neuropsychiatrist Eric Kandel studied the biochemical changes in neurons associated with learning and memory storage, winning him the Nobel Prize in 2000 (Kandel, Schwartz, and Jessel, 2000).

The existence of opioid receptors was conclusively demonstrated in 1973 by Candace Pert and Solomon Snyder. In 1974, John Hughes and Hans Kosterlitz discovered enkephalin, an opioid peptide; a year later they published their work on the pain pathway regulator.  At the University of California, San Francisco, Chinese-born biochemist Choh Hao Li and David Chung published their work on beta-endorphins in 1976. These discoveries led to further improvements in pain management (Marshall and Magoun, 1998).

In 1986, the clinical case of the patient R.B. establishes the importance of the hippocampus for human memory. After suffering an ischemic episode during a cardiac bypass operation, the patient R.B. woke up with severe amnesia. An autopsy revealed lesions along the hippocampus. The image below (from Gray’s Anatomy, 1918) depicts a lateral view of the human brain, featuring the hippocampus as well as other neuroanatomical features (Kandel, 2000).

In 1991, Linda Buck and Richard Axel discovered that the family that olfactory receptors belong to consists of over 1000 different genes. This research allowed for the genetic and molecular analysis of the sense of smell. They would win the Nobel Prize for their work in 2004 (Sebastian, 2000).


Gray, Henry. (1918). Anatomy of the Human Body. Philadelphia: Lea & Febiger; Bartleby.com, 2000. www.bartleby.com/107/

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