Although most of the research on the genetics of aggression
has been done with mice, much of the scientific and public
interest is sparked by concern about the role of heredity in
human aggression.(2) One of the main reasons is the apparent
increase in levels of aggression in human society. According to
a World Health Organization Report,(3) violence is a major
public health problem worldwide. It has to be noted that the
number of victims of interpersonal violence (almost one
person every minute) is almost twice as high as the number
of people killed in armed conflicts. Although it is widely
recognized that it is difficult to define the different types of
aggression in humans, it is evident that offense and defense,
infanticide and even, in some situations, predation do occur in
humans.(2,4) A genetic contribution has been found for nearly
all behavioral disorders that have been investigated in
humans, including panic disorder and antisocial personality
disorder.(5,6) Understanding the mechanisms responsible for a
predisposition to aggression and violence is therefore an
important goal in modern neurogenomics. At the same
time, a lot of data demonstrate the validity of animal
models for the study in behavioral genetics. The various
Genome Projects revealed very high homology of human,
mouse and rat genes as well as syntenic similarities. The
Rat Genome Sequencing Project Consortium showed that
rat, mouse and human genomes encode similar numbers of
genes and suggested that 86–94% rat genes have orthologous
genes in the mouse and 89–90% in the human.(7)
Although the mouse became the dominant model for
geneticists, the rat has been the favorite model for behavior
physiology.