Bidisha Roy, Ajeet P Singh, Chetak Shetty, Varun Chaudhary, Annemarie North, Matthias Landgraf, K VijayRaghavan, and Veronica Rodrigues
Neural Develop. 2007; 2: 20.
Description of a “contralaterally projecting serotonin-immunoreactive deutocerebral (CSD) interneuron.” There is one on each hemisphere. It is suggested that these neurons respond to some a stimulation like air currents and release serotonin to set detection thresholds in the antennal lobe. This would be especially useful for mate-finding in moths although I don’t know how developed this is in Drosophila. CSD is born in the embryo and has a simple form until metamorphosis. It has the basic shape of an insect neuron with one long neurite coming out of one side of the soma. There are two of them, one on each side of the brain. The neurite makes a shape like a staple as it bends around to the other side of the brain. At four places, near the soma where is interacts with the antenna lobe on that side, at the corners where it interacts with higher order neuropile and at the end where it interacts with the antenna lobe on the other side, there are extensive dendrite and/or axon arbors in the adult cell. The arbor near the soma is dendritic while the arbor on the other side in the other antenna lobe is an axon. The other two arbors in the higher order neuropile are mainly axon but there is some suggestion of dendrites. The confirmed dendrites of the larvae cell are more complex than the adult cell while the axon arbors are the opposite. This this is an interesting cell with a relatively simple dendrite topology and a very complex axonal. In some individuals, a neurite crosses back into the region above the soma to connect with the antenna lobe on that side. This also happens with Manduca Sexta. What this means is unclear although the structure of the neuron is very labile to stress and temperature and the arbors nearest the soma are the only ones that are reduced after metamorphosis.
- Initiating and Growing an Axon
F. Polleux and William Snider
Cold Spring Harb Perspect Biol 2: a001925 2010