Azusa Kamikouchi

We established a comprehensive projection map of the auditory receptor cells (Johnston's organ neurons: JONs) from the antennae to the primary auditory center of the Drosophila brain. We found 477 +/- 24 cell bodies of JONs, which are arranged like a "bottomless bowl" within the auditory organ. The target of the JONs in the brain comprises five spatially segregated zones, each of which is contributed by bundles of JON axons that gradually branch out from the antennal nerve. Four zones are confin

We have previously used the differential display method to identify a gene that is expressed preferentially in the mushroom bodies of worker honeybees and to show that it encodes a putative inositol 1,4,5-trisphosphate receptor (IP3R) homologue (Kamikouchi et al. [1998] Biochem. Biophys. Res. Commun. 242:181-186). In the present study, we examined whether the expression of some of the genes for proteins involved in the intracellular Ca2+ signal transduction is also concentrated in the mushroom b

Acoustic communication between insects serves as an excellent model system for analyzing the neuronal mechanisms underlying auditory information processing. The detailed organization of auditory neural circuits in the brain has not yet been described. To understand the central auditory pathways, we used the brain of the fruit fly Drosophila melanogaster as a model and performed a large-scale analysis of the interneurons associated with the primary auditory center. By screening expression driver

The fruit fly Drosophila melanogaster responds behaviorally to sound, gravity, and wind. Johnston's organ (JO) at the antennal base serves as a sensory organ in the fruit fly to detect these mechanosensory stimuli. Among the five anatomically defined subgroups of sensory neurons in JO, subgroups A and B detect sound vibrations and subgroups C and E respond to static deflections, such as gravity and wind. The functions of subgroup-D JO neurons, however, remain unknown. In this study, we used mole

We identified three candidate proteins/genes involved in caste and/or sex-specific olfactory processing in the honeybee Apis mellifera L., that are differentially expressed between the antennae of the worker, queen, and drone honeybees using SDS-polyacrylamide gel electrophoresis or the differential display method. A protein was identified, termed D-AP1, that was expressed preferentially in drone antennae when compared to those of workers. cDNA cloning revealed that D-AP1 is homologous to carbox

The antennal ear of the fruit fly detects acoustic signals in intraspecific communication, such as the courtship song and agonistic sounds. Among the five subgroups of mechanosensory neurons in the fly ear, subgroup-A neurons respond maximally to vibrations over a wide frequency range between 100 and 1,200 Hz. The functional organization of the neural circuit comprised of subgroup-A neurons, however, remains largely unknown. In the present study, we used 11 <i>GAL4</i> strains that selectively l

During courtship, many animals, including insects, birds, fish, and mammals, utilize acoustic signals to transmit information about species identity. Although auditory communication is crucial across phyla, the neuronal and physiologic processes are poorly understood. Sound-evoked chaining behavior, a display of homosexual courtship behavior in Drosophila males, has long been used as an excellent model for analyzing auditory behavior responses, outcomes of acoustic perception and higher-order br

Vertebrate inner-ear hair cells use mechanical feedback to amplify sound-induced vibrations. The gain of this 'cochlear amplifier' is centrally controlled via efferent fibres that, making synaptic contacts with the hair cells, modulate the feedback gain. The sensory neurons of the Drosophila ear likewise employ mechanical feedback to assist sound-evoked vibrations, yet whether this neuron-based feedback is also subject to efferent control has remained uncertain. We show here that the function of

Many animals rely on acoustic cues to decide what action to take next. Unraveling the wiring patterns of the auditory neural pathways is prerequisite for understanding such information processing. Here, we reconstructed the first step of the auditory neural pathway in the fruit fly brain, from primary to secondary auditory neurons, at the resolution of transmission electron microscopy. By tracing axons of two major subgroups of auditory sensory neurons in fruit flies, low-frequency tuned Johnsto

Acoustic communication signals diversify even on short evolutionary time scales. To understand how the auditory system underlying acoustic communication could evolve, we conducted a systematic comparison of the early stages of the auditory neural circuit involved in song information processing between closely-related fruit-fly species. Male Drosophila melanogaster and D. simulans produce different sound signals during mating rituals, known as courtship songs. Female flies from these species sele