The Genetics of Brain Wiring: From Molecule to Mind    • Kevin J
Mitchell   • Published: April 17, 2007   • DOI:
10.1371/journal.pbio.0050113   • Published in PLOS Biology
There is compelling evidence that many psychiatric disorders
have their origins in disturbed neurodevelopment, resulting in
altered connectivity [1,2]. Similarly, many behavioural or
cognitive traits are both heritable, at least moderately [3],
and correlated with functional connectivity differences in
various circuits [2]. The study of the genetics of behavioural
or psychiatric traits may thus be directly informed by an
understanding of the genetic architecture of the developmental
processes underlying brain wiring. This essay presents a
systems-level overview of these processes, highlighting several
important properties that can have large effects on how genotype
is mapped to phenotype: epistasis (meaning non-additive
gene–gene interactions in this context), compensation, and
stochastic developmental variation.  Wiring the Brain   No G