Psychobiology is a science in which biology principles are applied to genetic and physiological development of animals and humans. This field is also known as biopsychology, biological psychology and behavioral neuroscience. Some examples of the types of topics or ideas covered in psychobiology courses include how work stress, social isolation and socioeconomic status influence different biological functions in disease and health. How all the different science topics available this is a multidisciplinary field with links to psychophysiology, health psychology, cardiology, psychoneuroimmunology, nursing, sports science and molecular biology. Psychobiology degrees programs may not be available at all universities and colleges, though they are typically found within psychology departments or biology departments. Normally students interested in this field will begin with an undergraduate degree in biology or related courses and then move onto a specialized graduate program in the chosen area. Many times before being accepted into an undergraduate psychobiology program, students first must do well in first and second year science classes; these students are considered pre-psychobiology and must meet all the necessary requirements during the start of their studies to fully enter the program. Psychobiology classes that are required normally used as preparatory courses before admitting students into the full program include courses in life science, chemistry, mathematics, physics and psychology. Each university will have a list of the appropriate courses that can be applied toward this major. Many times students must be declared as pre-psychobiology in order to even enrol in the classes. Courses available to those that have entered the full program will consist of several different types of psychology topics, developmental biology, systems biology, neuroscience, molecular, cell & developmental biology, physiological science and advanced chemistry courses. The text books used in these courses will all vary and many times the psychobiology notes from classes will be the base of information for exams. However some text books that may be helpful include Biological Psychology by James Kalat, the Psychobiology of Human Motivation by Hugh Wagner, the Psychobiology of Gene Expression by Ernest Rossi, Introduction to Psychobiology and Born Gay: The psychobiology of sex orientation by Wilson and Rahman. There are several different fields of research that graduate student typically investigate. Research may investigate neural activity and what activities tend to enhance activity or change where the neural activity is occurring. Optical techniques are typically used as dyes and neurotransmitters will then move to the active parts of the brain. Once the brain is scanned the active areas can be discovered. Another topic is the influence of genes and manipulation of genetics. Different research will look into how the activation or deactivation of different genes affects individuals and how behavior may favor one gene over another, a very important part of evolution.