Objective: To clarify the firing characteristics of the hippocampal pyramidal cells and in-terneurons in the auditory discrimination cognition. Methods: Thirteen guinea pigs were studied by the paired (active cognitio...Objective: To clarify the firing characteristics of the hippocampal pyramidal cells and in-terneurons in the auditory discrimination cognition. Methods: Thirteen guinea pigs were studied by the paired (active cognition group. n=10) or unpaired (passive cognition group. n = 3) training with 1 kHz (CS+)and 500 Hz tones (CS- ) and the air puff (US) applied 250 ms after the CS+ onset. Results: In active group. 32 pyramidal cells showed exciting response to the CS+ tone. 16 cells inhibited response and 4 cells revealed no response to the high frequency tone and 18 interneurons almost unchanged. In passive group, the pyramidal cells responded to the tone casually and 10 out of the 13 interneurons remained invariably. Conclusion: The result suggests that the pyramidal cells play a major role in coding auditory information by the networks, and the interneuons may modulate it via forward and feedback.展开更多
Lepidoptera evolved tympanic ears in response to echolocating bats. Comparative studies have shown that moth ears evolved many times independently from chordotonal organs. With only 1 to 4 receptor cells, they are one...Lepidoptera evolved tympanic ears in response to echolocating bats. Comparative studies have shown that moth ears evolved many times independently from chordotonal organs. With only 1 to 4 receptor cells, they are one of the simplest hearing organs. The small number of receptors does not imply simplicity, neither in behavior nor in the neural circuit. Behaviorally, the response to ultrasound is far from being a simple reflex. Moths' escape behavior is modulated by a variety of cues, especially pheromones, which can alter the auditory response. Neurally the receptor cell(s) diverges onto many interneurons, enabling pa- rallel processing and feature extraction. Ascending interneurons and sound-sensitive brain neurons innervate a neuropil in the ventrolateral protocerebrum. Further, recent electrophysiological data provides the first glimpses into how the acoustic response is modulated as well as how ultrasound influences the other senses. So far, the auditory pathway has been studied in noctuids. The findings agree well with common computational principles found in other insects. However, moth ears also show unique mechanical and neural adaptation. Here, we first describe the variety of moths' auditory behavior, especially the co-option of ul- trasonic signals for intraspecific communication. Second, we describe the current knowledge of the neural pathway gained from noctuid moths. Finally, we argue that Galleriinae which show negative and positive phonotaxis, are an interesting model species for future electrophysiological studies of the auditory pathway and multimodal sensory integration, and so are ideally suited for the study of the evolution of behavioral mechanisms given a few receptors.展开更多
文摘Objective: To clarify the firing characteristics of the hippocampal pyramidal cells and in-terneurons in the auditory discrimination cognition. Methods: Thirteen guinea pigs were studied by the paired (active cognition group. n=10) or unpaired (passive cognition group. n = 3) training with 1 kHz (CS+)and 500 Hz tones (CS- ) and the air puff (US) applied 250 ms after the CS+ onset. Results: In active group. 32 pyramidal cells showed exciting response to the CS+ tone. 16 cells inhibited response and 4 cells revealed no response to the high frequency tone and 18 interneurons almost unchanged. In passive group, the pyramidal cells responded to the tone casually and 10 out of the 13 interneurons remained invariably. Conclusion: The result suggests that the pyramidal cells play a major role in coding auditory information by the networks, and the interneuons may modulate it via forward and feedback.
文摘Lepidoptera evolved tympanic ears in response to echolocating bats. Comparative studies have shown that moth ears evolved many times independently from chordotonal organs. With only 1 to 4 receptor cells, they are one of the simplest hearing organs. The small number of receptors does not imply simplicity, neither in behavior nor in the neural circuit. Behaviorally, the response to ultrasound is far from being a simple reflex. Moths' escape behavior is modulated by a variety of cues, especially pheromones, which can alter the auditory response. Neurally the receptor cell(s) diverges onto many interneurons, enabling pa- rallel processing and feature extraction. Ascending interneurons and sound-sensitive brain neurons innervate a neuropil in the ventrolateral protocerebrum. Further, recent electrophysiological data provides the first glimpses into how the acoustic response is modulated as well as how ultrasound influences the other senses. So far, the auditory pathway has been studied in noctuids. The findings agree well with common computational principles found in other insects. However, moth ears also show unique mechanical and neural adaptation. Here, we first describe the variety of moths' auditory behavior, especially the co-option of ul- trasonic signals for intraspecific communication. Second, we describe the current knowledge of the neural pathway gained from noctuid moths. Finally, we argue that Galleriinae which show negative and positive phonotaxis, are an interesting model species for future electrophysiological studies of the auditory pathway and multimodal sensory integration, and so are ideally suited for the study of the evolution of behavioral mechanisms given a few receptors.