Question: What kind of cells do Eric Kandel and Paul Greengard share a Nobel Prize for their research of?
Context: The Nobel Prize in Physiology or Medicine (Swedish: "Nobelpriset i fysiologi eller medicin" ) is awarded annually by the Swedish Karolinska Institute to scientists and doctors in the various fields of physiology or medicine.  It is one of the five Nobel Prizes established by the 1895 will of Alfred Nobel (who died in 1896), awarded for outstanding contributions in chemistry, physics, literature, peace, and physiology or medicine.  As dictated by Nobel's will, the award is administered by the Nobel Foundation and awarded by a committee that consists of five members and an executive secretary elected by the Karolinska Institute.  While commonly referred to as the Nobel Prize in Medicine, Nobel specifically stated that the prize be awarded for "physiology or medicine" in his will.  Because of this, the prize can be awarded in a broader range of fields.  The first Nobel Prize in Physiology or Medicine was awarded in 1901 to Emil Adolf von Behring, of Germany.  Each recipient receives a medal, a diploma and a monetary award that has varied throughout the years.  In 1901, von Behring received 150,782 SEK, which is equal to 7,731,004 SEK in December 2008.  In 2013, the prize was awarded to James E. Rothman, Randy W. Schekman and Thomas C. Südhof; they were recognised "after discovering how cells precisely transport material".  The award is presented in Stockholm at an annual ceremony on December 10, the anniversary of Nobel's death. Paul Greengard (born December 11, 1925) is an American neuroscientist best known for his work on the molecular and cellular function of neurons.  In 2000, Greengard, Arvid Carlsson and Eric Kandel were awarded the Nobel Prize for Physiology or Medicine for their discoveries concerning signal transduction in the nervous system.  He is currently Vincent Astor Professor at Rockefeller University, and serves on the Scientific Advisory Board of the Cure Alzheimer's Fund, as well as the Scientific Council of the Brain & Behavior Research Foundation.  He is married to artist Ursula von Rydingsvard. Since 1901, the Nobel Prize in Literature (Swedish: "Nobelpriset i litteratur" ) has been awarded annually to an author from any country who has, in the words of the will of Alfred Nobel, produced "in the field of literature the most outstanding work in an ideal direction" (original Swedish: "den som inom litteraturen har producerat det mest framstående verket i en idealisk riktning").  Though individual works are sometimes cited as being particularly noteworthy, here "work" refers to an author's work as a whole.  The Swedish Academy decides who, if anyone, will receive the prize in any given year.  The academy announces the name of the chosen laureate in early October.  It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895; the others are the Nobel Prize in Chemistry, Nobel Prize in Physics, Nobel Peace Prize, and Nobel Prize in Physiology or Medicine. Eric Richard Kandel (] ; born November 7, 1929) is an Austrian-American neuroscientist and a University Professor of biochemistry and biophysics at the College of Physicians and Surgeons at Columbia University.  He was a recipient of the 2000 Nobel Prize in Physiology or Medicine for his research on the physiological basis of memory storage in neurons.  He shared the prize with Arvid Carlsson and Paul Greengard. Arvid Carlsson (born 25 January 1923) is a Swedish neuropharmacologist who is best known for his work with the neurotransmitter dopamine and its effects in Parkinson's disease.  For his work on dopamine, Carlsson was awarded the Nobel Prize in Physiology or Medicine in 2000, along with co-recipients Eric Kandel and Paul Greengard. First published in 1981 by Elsevier, Principles of Neural Science is an influential neuroscience textbook edited by Eric R. Kandel, James H. Schwartz, and Thomas M. Jessell.  The original edition was 468 pages; now on the fifth edition, the book has grown to 1747 pages.  The second edition was published in 1985, third in 1991, fourth in 2000.  The fifth and latest edition was published on October 26th, 2012 and includes Steven A. Siegelbaum and A.J. Hudspeth as editors.  It has been hailed as the "Bible of Neuroscience" having been co-written by the "Father of Neuroscience", Eric Kandel. Chris Chase (born Irene Greengard; January 12, 1924 – October 31, 2013), also known by the stage name Irene Kane, was an American model, film actress, writer, and journalist.  Her best-known role was in "Killer's Kiss".  She later wrote advice books and co-authored several celebrity autobiographies.  Her younger brother is Nobel Prize winner Paul Greengard. Michael Nehls (born October 20, 1962) is a German doctor of medicine, author and former cyclist.  From 1983 until 1989 he studied medicine at the universities of Freiburg and Heidelberg.  In 1997, he achieved his postdoctoral lecture qualification in molecular genetics.  Nehls authored over 50 scientific publications, two of which were published with the Nobel Prize winners Paul Greengard and Martin Evans.  In 2015, his work was honored by the American American Association of Immunologists as a "pillar of immunologic research" for leading investigators in the discovery of a key molecular switch required for the development of the adaptive immune system. Daniele Piomelli is an Italian-born American scientist.  He studied neuroscience in New York City, with James H. Schwartz and Eric R. Kandel at Columbia University College of Physicians and Surgeons (PhD, 1983-1988) and later with Paul Greengard at the Rockefeller University (Post-doc, 1988-1990).  Two of his mentors (ERK and PG) received in 2000 the Nobel Prize for their contributions to medicine.  After working at the INSERM in Paris (1990-1995) and at the Neurosciences Institute in La Jolla (1995-1998) with Nobel Prize winner Gerald Edelman, he joined the University of California Irvine School of Medicine, where he is now Louise Turner Arnold Chair in Neurosciences and Professor of Anatomy and Neurobiology, Pharmacology and Biological Chemistry.  He is also founding director of the department of Drug Discovery and Development (D3) at the Istituto Italiano di Tecnologia in Genova, Italy. The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science is a book on neuroplasticity by psychiatrist and psychoanalyst Norman Doidge, M.D.  It features numerous case studies of patients suffering from neurological disorders and details how in each case the brain adapts to compensate for the disabilities of the individual patients, often in unusual and unexpected ways.  Interviews with the patients, clinicians, and research scientists involved in these studies make up a large portion of the contents.  Doidge uses examples of previous work carried out by neuroscientists such as Paul Broca, Sigmund Freud, Alexander Luria, Donald O. Hebb, Paul Bach-y-Rita, and Eric Kandel to show that the brain is adaptive, and thus plastic.  Through the case studies, Doidge demonstrates both the beneficial and detrimental effects that neuroplasticity can have on a patient, saying, "... neuroplasticity contributes to both the constrained and unconstrained aspects of our nature."  However, according to Doige, neuroplasticity "... renders our brains not only more resourceful, but also more vulnerable to outside influences."
Answer: neurons