Brain neurotransmitters as key players in
behavior regulations: brain 5-HT and
aggressive behavior
It has long been clear that there are no genes controlling
behavior directly, but that there are behavior regulators in
the brain. Numerous neurophysiological, neurochemical and
neuropharmacological studies demonstrated a pivotal role of
brain neurotransmitters in the regulation of emotionality and
behavior while current knowledge indicates that behavioraffecting
genes might act via brain neurotransmitters.
The problem of searching for the genetic and neurochemical
determinants of aggressive behavior is complicated by
their apparent heterogeneity. In fact, aggressive behavior is
complex trait, regulated by multiple genetic factors as well as
by a set of neurotransmitters. At least 16 genes have been
reported to affect some aspects of offense.(2) At the same
time, it is evident that, for effective regulation, the number of
genes and neurotransmitters must be limited and, therefore,
the contribution of different candidate genes must be different;
some genes and neurotransmitters must predominate for
most kinds of behavior. This idea is in accordance with the
numerous neurophysiological and neurochemical data, aswell
as with the data of QTLs. Brodkin et al.(13) identified QTLs that
contribute to individual mouse strain differences in intermale
aggression and mapped two loci on distal chromosome 10 and
proximal chromosome X.