Development of insect mechanosensory neurons

Nerve cells that detect mechanical signals are important for a wide range of senses, such as touch, hearing, balance and pain. They also monitor the position of the body. Mechanosensitive ion channels in the specialized nerve endings open in response to sensory stimuli and ion flux thorough these channels causes a change in membrane potential. This leads to propagation of nerve impulses along the sensory axon, release of neurotransmitter from the axon terminal and transfer of the sensory information to the cental nervous system. Propagation of nerve impulses can be modulated by synaptic inputs from other neurons. Our research program aims to learn how the mechanosensory neurons develop and the detailed processes involved in mechanosensation. The experimental animal we use is a large moth, Manduca sexta, that undergoes a full metamorphosis from an egg to a caterpillar to a pupa, finally emerging as an adult moth. The adult neural development occurs during the two-week pupal period, during which the nervous system is relatively easily accessible for experimental research, making it possible to perform experiments at each developmental stage. The mechanosensory neurons that we study are located in long appendices, the antennae, and can be easily isolated and used in experiments that would not be possible in mammals. Our research program aims to learn the specific molecular interactions that occur between the sensory neurons and other cells to guide the developing nerve axons to their final destinations in the brain. We also want to learn the molecular structures of the mechanosensitive components and the mechanisms involved in placing them to the sensory endings of these neurons. The knowledge that we gain from this research will offer insight in the cellular and developmental processes in an experimentally accessible insect mechanosensory system. However, many of the structures and processes are similar in vertebrate mechanosensory organs that are significantly less accessible for experimental research.