University of Pennsylvania scientists said they have provided a new model of behavior for the nicotinic acetylcholine receptor, a well studied protein involved in inflammation, Alzheimer's disease, Parkinson's disease, schizophrenia, epilepsy, the effect of general anesthetics and addiction to alcohol, nicotine and cocaine.

As a result of the study, scientists now theorize drugs binding to the receptor not only interact with amino acids, but also cholesterol located within the protein.

"The shift in thinking transforms the understanding of this receptor in many ways, from shape and structure to its interaction with its environment and its response to neurotransmitters," the scientists said. "The new model should spark a re-examination of several decades of research on the receptor's structure and function.

The study that included Grace Brannigan, Michael Klein and Jerome Henin of the university's Center for Molecular Modeling; Richard Law of the Lawrence Livermore National Laboratory and Roderic Eckenhoff of the Department of Anesthesiology and Critical Care at the Penn School of Medicine appears in the Proceedings of the National Academy of Sciences.