After a two-day stay in the chamber without light previously rejected males of Drosophila is again showing interest in mating, reported in the Journal of Neuroscience. Because of the failed copulation is stressful for the male, the authors concluded that prolonged darkness allows flies to forget about negative influences. The scientists also suggested a possible molecular mechanism of this forgetting.
One of the processes, required for the formation of long term memory, — synthesis of specific proteins in neurons. If they block it, memorization is likely not going to happen. This fact formed the basis of many studies which try to limit the formation of a memorial trace (engram) from traumatic events or their retrieval from memory (recollection).
Within this same concept, researchers from the Tokyo Metropolitan University led by Professor Takaomi Sakai (Takaomi Sakai) tested the effect of darkness on protein synthesis in memory in fruit flies. It is known that the amount of light affects the mood and learning, and in Drosophila there are neurons that are activated by light and produce the peptide Pdf (pigment-dispersing factor). This molecule controls morning activity of the insect.
Therefore, scientists tried to block the secretion of this peptide by placing a group of males flies for two days in complete darkness during the “learning courting” (courtship conditioning). These males before the experiment had sex and during he first was taken off already covered females who are already receptive to the courtship. After this experience (and it is considered to Drosophila stress) males normally do not show motivation to mate, even if there is a suitable uncovered females.