Discovery
Following the isolation of neuropeptide-y (NPY) from the porcine hypothalamus in 1982, researchers began to speculate about the involvement of NPY in hypothalamic-mediated functions. In a 1983 study, NPY-ergic axon terminals were located in the paraventricular nucleus (PVN) of the hypothalamus, and the highest levels of NPY immunoreactivity was found within the PVN of the hypothalamus.
Six years later, in 1989, Morris et al. homed in on the location of NPYergic nuclei in the brain. Furthermore, in situ hybridization results from the study showed the highest cellular levels of NPY mRNA in the arcuate nucleus (ARC) of the hypothalamus.
In 1989, Haas & George reported that local injection of NPY into the PVN resulted in an acute release of corticotropin-releasing hormone (CRH) in the rat brain, proving that NPYergic activity directly stimulates the release and synthesis of CRH.
The latter became a hallmark paper in NPY studies. A significant amount of work had already been done in the 1970s on CRH and its involvement in stress and eating disorders such as obesity. These studies, collectively, marked the beginning of the role of NPY in orexigenesis or food intake.
Read more about this topic: Neuropeptide Y
Famous quotes containing the word discovery:
“I have known no experience more distressing than the discovery that Negroes didn’t love me. Unutterable loneliness claimed me. I felt without roots, like a man without a country ...”
—Sarah Patton Boyle, U.S. civil rights activist and author. The Desegregated Heart, part 1, ch. 10 (1962)
“He is not a true man of science who does not bring some sympathy to his studies, and expect to learn something by behavior as well as by application. It is childish to rest in the discovery of mere coincidences, or of partial and extraneous laws. The study of geometry is a petty and idle exercise of the mind, if it is applied to no larger system than the starry one.”
—Henry David Thoreau (1817–1862)
“We are all humiliated by the sudden discovery of a fact which has existed very comfortably and perhaps been staring at us in private while we have been making up our world entirely without it.”
—George Eliot [Mary Ann (or Marian)