Neurobiology is a field of research devoted to research of the nervous system. This field of research bridges between diverse fields of research, beginning with biochemistry, molecular biology, physiology and genetics, through computer sciences and ending with psychology and philosophy. It can be said that the main goal of neurobiology is to explain behavior in terms of neural activity. How do the brain recruit billions upon billions of nerve cells in order to create behavior? How are nerve cells in the brain affected by behavior? The last and perhaps greatest challenge of the biological sciences is neurobiological research which tries to explain the basis for consciousness and the basic processes by which we sense, act, learn and remember. At the molecular level, the basic questions that are investigated include mechanisms of expression and use of cellular information carriers which in turn contribute to cellular activities such as gene expression and cell death. The strong connection between the shape of the various nerve cells and their physiological properties has also been extensively researched in recent years. At the cellular level, researchers use electrophysiological methods and advanced microscopes for investigating how a single cell processes the electric signals which enter it through the dendritic tree and leave it via the axon and its branches. At the cognitive level, questions are studied which connect between conditions of nerve cell network activity and behavior.