I am interested in the molecular mechanisms of axon guidance and synaptic target recognition – the proper wiring of all nervous systems depends on these mechanisms.
A mammal’s brain is very complex, so we studied this problem using identified neurons in the cockroach, Periplaneta americana. The cercal sensory – to - giant interneuron escape system of the cockroach has enabled it to survive for millions of years. We have cloned a transcription factor, Engrailed that is expressed in a subset of the sensory neurons that detect air movements. We showed that knockout of Engrailed using RNA interference alters the way the sensory axons grow, and more interestingly, alters the pattern of inputs onto their synaptic targets, the giant interneurons. Recently, we showed that this alteration in sensory input alters the animal’s perception of posterior wind, making it choose escape trajectories more appropriate for wind from the front.
Engrailed is found in the brain of all animals, including humans, and may have links to Parkinson’s disease and autism spectrum disorder. Recently I have started using Drosophila to characterize Engrailed-expressing sensory circuits. Eventually this will enable us to take advantage of its advanced genetics to screen for molecules that interact with Engrailed in controlling synaptic specificity.
Marie, B., Cruz-Orengo, L., and Blagburn, J.M. (2002) Persistent engrailed expression is required to determine sensory axon trajectory, branching, and target choice. J. Neurosci., 22, 832-841.
Marie B. and Blagburn J.M. (2003). Differential roles of Engrailed paralogs in determining sensory axon guidance and synaptic target recognition. J. Neurosci. 23: 7854-7862.
Blagburn, J.M. and Bacon, J.P. (2004). Control of central synaptic specificity in insects. Ann. Rev. Neurosci. 27: 29-51.
Blagburn J.M. (2007) Co-factors and co-repressors of Engrailed: expression in the central nervous system and cerci of the cockroach, Periplaneta americana. Cell Tissue Res. 327: 177-187.
Blagburn JM. (2008) Engrailed expression in subsets of adult Drosophila sensory neurons: an enhancer-trap study. Invert Neurosci.8:133-146.
Domenici P., Booth D., Blagburn J.M., Bacon J.P. (2008). Cockroaches keep predators guessing by using preferred escape trajectories.Current Biol. 18:1792-1796.
Booth D., Marie, B., Domenici P., Blagburn J.M., Bacon J.P. (2009). Transcriptional control of behavior: Engrailed knockout changes cockroach escape trajectories. J. Neurosci. 29: 7181-7190.
Domenici P., Booth D., Blagburn J.M., Bacon J.P. (2009). Escaping away from and towards a threat. Communicative and Integrative Biol. 2: 497-500.
Domenici P., Blagburn J.M., Bacon J.P. (2011). Review: Animal escapology I: Theoretical issues and emerging trends in escape trajectories. J Exp Biol. 214: 2463-73.
Domenici P., Blagburn J.M., Bacon J.P. (2011). Review: Animal escapology II: Review of escape trajectory case studies. J Exp Biol. 214: 2474-94.
Pézier A, Blagburn JM (2013) Auditory Responses of Engrailed and Invected-Expressing Johnston’s Organ Neurons in Drosophila melanogaster. PLoS ONE 8(8): e71419. doi:10.1371/journal.pone.0071419.