Connectivity of a Praying Mantis Movement Detecting Neuron

Insects are not only important in research for pest control but also give us the opportunity to investigate the underlying neuronal principles of biological systems. They are rewarding to study as their neurons are often easy identifiable and accessible, in contrast to neurons of more complex organisms. The project Connectivity of a movement detecting neuron in the praying mantis aims to investigate the visual system of the praying mantis as the visual system is a good model for questions about the contribution of neurons in a neuronal circuit to the computation of information. The praying mantis uses stereopsis to estimate the distance to potential prey which distinguishes it from most of the other insects. With its unique stereo vison the praying mantis is a promising animal for neuronal studies of its visual system. Our main objective is to investigate neurons which contribute to the detection of potential predators. For an animal it is vital to recognise them early enough to start defence actions or to flee. Such a special neuron was described in locusts in the third optical ganglion, the lobula complex. Physiological experiments suggest that a similar neuron is present in the praying mantis. To verify this, we will use a new electron microscopic technique which is called ATUMtome SEM and allows us to produce several thousand of ultra-thin sections (with a thickness below 70 nm) through the lobula complex and collect them on a special tape for further investigations. In a scanning electron microscope the sections are scanned and neurons of interest can be tracked over consecutive sections. By that single neurons of whole neuron populations in the recorded volume can be traced and reconstructed. This allows us not only to reveal the morphology and ultra-structure but also the interactions between the neurons. The synapses, the structure were information is passed on from one neuron to another, can be easily identified in the electron micrographs. The knowledge about the wiring between the neurons is vital for our understanding of how the sensory stimuli are processed in the neuronal system. The collected image data in this project will be public accessible in an online database. Through this database other research groups all around the world can browse the data and use them for their research questions. This is necessary due to the amount of image data that will be produced during this project.