Response characteristics of an ascending auditory neuron AN3 and its projections in the brain of the bushcricket Gampsocleis grationsa

The phonotaxis of bushcrickets demonstrates that they have goodcapability of recognizing conspecific songs and locating the sound source,which bases on complicated auditory mechanisms of the central nervoussystem(CNS).This article describes the response characteristics of AN3,an auditory ascending neuron in the prothoracic ganglion,and its projec-tions within the brain.The AN3,with a quasi-tonic discharge pattern,has high sensitivity,directionality and ability to encode sound intensity.Therefore,it plays an important role in auditory information processingof CNS.Its projections in the brain are mainly concentrated in the lateralzone of the deutencephalon,where synaptically connecting local auditoryinterneurons in the brain.

THE EFFECTS OF ACOUSTIC TRACHEA SYSTEM ON DIRECTIONAL HEARING IN BUSHCRICKET Gampsocleis gratiosa

Directional hearing plays a particularly important role in acoustic communication of animals. For a signal-receiving animal, there are three tasks to be performed: to ascertain whether a singing animal is conspecific or a 'natural enemy'; to recognize the songs’ meaning; to detect the location of a singing animal in the space and then to determine which appropriate responses should be taken, either to approach the song source or to escape.

DIRECTIONAL SENSITIVITY OF AUDITORY Ω NEURON IN BUSHCRICKET Gampsocleis gratiosa

Sound plays an important role in animal communication. For a signal-receiving animal, there are three main tasks in acoustic communication: to ascertain whether the songproducing animal is conspecific or not, to recognize the behavioral meaning of the songs,

Temporal coding of auditory tonic neurons in bushcricketand effects of GABA

Acoustic communication plays an important role in the behavior of insects, such asmating, aggression or alarm, and preying. A typical example is that female bushcrickets(Orthoptera) can approach phonotactically towards singing conspecific males. For it fe-males should perform the following tasks: song recognition, understanding of songs, anddetection of sound source. To study physiological properties of the auditory nervous

DIRECTIONAL SENSITIVITY OF PRIMARY AUDITORY NEURONS IN THE BUSHCRICKET G. gratiosa

Directional hearing plays a particular role in acoustic communication of animals. A signal-receiving animal should not only ascertain whether a sound-producing animal is conspecific or 'natural enemy' and recognize the significance of the received sound signals, but also detect the location of the sound-producing animal in the space. It could then

MORPHOLOGICAL STRUCTURE AND FUNCTION OF AUDITORY NEURON IN BUSHCRICKET——Gampsocleis gratiosa

Acoustic communication is an important way for information exchange both in animals and human species. Orthopterans can produce species-specific songs and their behavioral activities, such as mate attraction, aggression or alarm, are mediated by the songs. There-fore, the study on acoustic reception, feature extraction and processing and recognition and understanding of different songs is an advanced and important problem in the auditory neurosciences. The authors have made quantitative analyses on the acoustic behavior of

Structure and Functions of a T-shaped Auditory Neuron in the Bushcricket Gampsocleis gratiosa

The phonotactic movement for mating and the escape on hearing are two typical activities by animals with the ability of intra-and interspecific acoustic communications.To study neural mechanisms of the acoustic behavior is the key problem in neuroethology. As the auditory systems in lower animals are relatively simple, lower animals are usually used as the prototype to study structures and functions of the auditory and motor neurons involved in the above-mentioned acoustic behavior at single cell level.

STRUCTURE AND FUNCTIONS OF AUDITORY ASCENDING NEURON IN BUSHCRICKET Gampsocleis gratiosa

Acoustic communication is one of the effective ways for the information exchange used by animals and human race. To explore the mystery of animal acoustic communication at the cellular level is not only conducive to expound the fundamental principles of auditory information processing, but also of great significance for the studies on neural network and artificial intelligence as well as the designs of auditory devices for new generations of computers.

QUANTITATIVE INVESTIGATION ON STRUCTURAL CHANGES OF PHOTORECEPTOR IN THE BUSHCRICKET Gamp socleis gratiosa

The bushcricket, one species of diurnal orthopterans, has compound eyes with the fused rhabdoms. Up to now, there are no reports on the photoreceptors and visual system of the bushcricket. In this study, using optical and electromicroscopic techniques, we have first investigated and compared the ultrastructural changes of the photoreceptors of compound eyes in the bushcricket under the conditions of light and dark adaptations at the two moments of midday and midnight. Then, through the computer micrograph analysing sys-

FREQUENCY SELECTIVITY OF PRIMARY AUDITORY NEURONS IN THE BUSHCRICKET GAMPSOCIEIS GRATIOSA

Sound is one of the information carriers often used in animal communication. Sound produced by animals is useful not only in intraspecific communication,but also in alarm or aggression.Three basic problems in hearing should be resolved i. e. frequency selectivity, pattern recognition and sound direction. With intracellular recording and single cell staining techniques, frequency selectivity of primary auditory neurons in the bushcricket has been studied. Each neuron has its characteristic best frequency (BF) and tuning curve in response to sound. The central projections of their axons in the prothoracic ganglion are unikteral, non - transsegmental and of some corresponding relation to their BFs. Neural mechanisms for frequency analysis in species - specific song recognition of the bushcricket are discussed.

Directional sensitivity of auditory ascending neuron in the bushcricket Gampsocleis gratiosa

Quantitative analyses on phonotactic behavior of the bushcricket have demonstrated that the bushcricket possesses good capability to determine direction of sound source. The morphological structure, laterality and directional sensitivity of the auditory ascending neuron in the prothoracic ganglion of the bushcricket have been studied. At its best frequency of 15 kHz, the laterality threshold difference of the neuron is great up to about 16 dB. Its directional sensitivity depends closely on stimulus frequency. The higher the stimulus frequency, the greater the directional threshold differences. Spike count and latency shift of the ascending neuron in response to each stimulus depend on the angle of incidence of sound. Therefore, the two parameters can be used as directional cues of sound source by the ascending neuron.

A study of song characteristics and hearing in the bushcricket Gampsocleis gratiosa

The structure, power spectrum and temporal parameters of the calling song of the bushcricket Gampsocleis gratiosa were studied with acoustic analysis techniques. The bushcricket uses an elytro-elytral mechanism in sound production: the denticulated vein ( file ) on the under-surface of the left elytron is rubbed by the insider edge of the right elytron ( plectrum ). The file-train of pulses is composed of one elytra-opening pulse and 6 - 7 elytra-closing tooth pulses. The power spectrum of the song covers a wide frequency band. The acoustic energy is mainly distributed over the frequency range between 3 and 35 kHz. The predominant peak lies near 7.5 kHz and the next one around 4.0kHz. The song intensity is measured of about 105 dB SPL at a distance of 10 cm from the animal. The temporal parameters of the song are dependent on the ambient temperature. Three-dimensional digital spectrograms of the song show its dynamic changes of the energy peaks. The bushcricket is very sensitive to acoustic stimuli and its thresholds are less than 30 dB SPL in the frequency range from 7 to 18 kHz, which corresponds to dominant energy zone. The auditory neurons of the bushcricket can code the temporal parameters of the calling songs.