Tick neurobiology: recent advances and the post-genomic era

Increasing worldwide resistance to acaricides necessitates greater research on the identification of potential acaricide targets in ticks to aid in the control of these serious pests of medical and veterinary importance. Historically, and most likely in the future, acaricide targets are largely of neural origin, but our knowledge of tick neurobiology is surprisingly limited. The tick central nervous system is a fused nerve mass, termed the synganglion. Tick synganglion material is relatively easily accessible to most researchers and employing modern amplification methods of complementary-DNA construction is readily amenable for gene cloning investigations. The various tick neurotransmitter systems are described with emphasis on our current knowledge of both existing and potential acaricide targets at the molecular level. We describe the impact of mass gene sequencing (expressed sequence tag and genome projects), advances in bioinformatics and RNA-interference on target identification and validation.