Circadian photoreceptors are required for light-dependent maintenance of long-term memory in Drosophila.

In the fruit fly Drosophila melanogaster, environmental light is required for maintaining long-term memory (LTM). Furthermore, the Pigment dispersing factor (Pdf), which is a circadian neuropeptide, and the neuronal activity of Pdf neurons are essential for light-dependent maintenance of courtship LTM. Since Pdf neurons can sense light directly via circadian photoreceptors [Rhodopsin 7 (Rh7) and Cryptochrome (Cry)], it is possible that Rh7 and Cry in Pdf neurons are involved in the maintenance of LTM.

Circadian Neuropeptide-Expressing Clock Neurons as Regulators of Long-Term Memory: Molecular and Cellular Perspectives.

The neuropeptide pigment-dispersing factor (Pdf) is critically involved in the regulation of circadian rhythms in various insects. The function of Pdf in circadian rhythms has been best studied in the fruitfly, i.e.

Consolidation and maintenance of long-term memory involve dual functions of the developmental regulator Apterous in clock neurons and mushroom bodies in the Drosophila brain.

Memory is initially labile but can be consolidated into stable long-term memory (LTM) that is stored in the brain for extended periods. Despite recent progress, the molecular and cellular mechanisms underlying the intriguing neurobiological processes of LTM remain incompletely understood. Using the Drosophila courtship conditioning assay as a memory paradigm, here, we show that the LIM homeodomain (LIM-HD) transcription factor Apterous (Ap), which is known to regulate various developmental events, is required for both the consolidation and maintenance of LTM.

Environmental Light Is Required for Maintenance of Long-Term Memory in .

Long-term memory (LTM) is stored as functional modifications of relevant neural circuits in the brain. A large body of evidence indicates that the initial establishment of such modifications through the process known as memory consolidation requires learning-dependent transcriptional activation and protein synthesis. However, it remains poorly understood how the consolidated memory is maintained for a long period in the brain, despite constant turnover of molecular substrates.

Light is required for proper female mate choice between winged and wingless males in Drosophila.

In many animal species, females choose potential mating partners according to their own preferences. Thus, female preference-based mate choice affects intraspecific mating success and prevents interspecific mating. To clarify the neuronal basis of female mate choice, it is essential to identify the important relevant sensory cues.

Modulation of light-driven arousal by LIM-homeodomain transcription factor Apterous in large PDF-positive lateral neurons of the Drosophila brain.

Apterous (Ap), the best studied LIM-homeodomain transcription factor in Drosophila, cooperates with the cofactor Chip (Chi) to regulate transcription of specific target genes. Although Ap regulates various developmental processes, its function in the adult brain remains unclear. Here, we report that Ap and Chi in the neurons expressing PDF, a neuropeptide, play important roles in proper sleep/wake regulation in adult flies.

Mushroom body signaling is required for locomotor activity rhythms in Drosophila.

In the fruitfly Drosophila melanogaster, circadian rhythms of locomotor activity under constant darkness are controlled by pacemaker neurons. To understand how behavioral rhythmicity is generated by the nervous system, it is essential to identify the output circuits from the pacemaker neurons. A recent study of Drosophila has suggested that pacemaker neurons project to mushroom body (MB) neurons, which are considered the memory center in Drosophila.

Insulin-producing cells regulate the sexual receptivity through the painless TRP channel in Drosophila virgin females.

In a variety of animal species, females hold a leading position in evaluating potential mating partners. The decision of virgin females to accept or reject a courting male is one of the most critical steps for mating success. In the fruitfly Drosophila melanogaster, however, the molecular and neuronal mechanisms underlying female receptivity are still poorly understood, particularly for virgin females.

Fan-shaped body neurons are involved in period-dependent regulation of long-term courtship memory in Drosophila.

In addition to its established function in the regulation of circadian rhythms, the Drosophila gene period (per) also plays an important role in processing long-term memory (LTM). Here, we used courtship conditioning as a learning paradigm and revealed that (1) overexpression and knocking down of per in subsets of brain neurons enhance and suppress LTM, respectively, and (2) suppression of synaptic transmission during memory retrieval in the same neuronal subsets leads to defective LTM. Further analysis strongly suggests that the brain region critical for per-dependent LTM regulation is the fan-shaped body, which is involved in sleep-induced enhancement of courtship LTM.