For normal function, i.e. the communication between nerve cells, there is a need for a stable environment. This was a requirement of evolutionary old organisms and a basis for development of more advanced and complex species like man. Under extreme evolutionary pressure a brain barrier was developed fulfilling the task to regulate the nerve cell environment. The barrier was equipped with a number of functions that selected what should pass and what should be excluded. This is a sophisticated system like our virus programs enabling a proper function of our computers.
Thus insects and vertebrates both need to have a highly advanced BBB functions that retain a functional brain with communicating nerve cells. A number of studies have shown that invertebrates react to CNS active compounds and recent studies have shown that insects contain efflux proteins.
EntomoPharm PoC publication:
Nielsen PA, Andersson O, Hansen SH, Simonsen KB, Andersson G (2011). Models for predicting blood-brain barrier permeation. Drug Discovery Today, June;16
(11-12):472-5.