Physiological studies on the physiological and behavioral changes after mating in the moth, Bombyx mori

蛾类交配后信息素产生的抑制似乎是由一种神经信号诱导的，这种信号来自腹部，并沿着腹神经索向上移动，以抑制信息素神经肽的释放。本研究表明，释放神经肽的神经分泌细胞对机械刺激最为敏感，其放电活动在交配开始时即被完全抑制。因此，交配过程中物理刺激产生的机械信号可以触发神经分泌细胞的失活机制。因为与不育的雄性交配未能引起细胞的永久性抑制。如果它们不能接收到可能由从可生育男性转移来的精子和/或睾丸因素诱导的另一信号，则由机械刺激引起的时间抑制可能被释放。从交配的雌性交配法氏囊获得的精液被人工注射到已经接受Tacti…的雌性体内不育雄蛾产生更多的LE刺激，信息素的产生被永久性地抑制，从而表明交配雌蛾的性信息素产生的两步失活机制是真实的。从交配的吉普赛蛾的观察中推断出类似的两步失活机制。家蚕中可能的信息素抑制雄性因子的鉴定和作用方式有待确定。交配的雌蛾在交配后固定在平台上时，交配的雌蛾往往会再次恢复信息素的产生。雌虫在95%CO_2中麻醉15分钟或乙醚麻醉1-2分钟，信息素的产生也有类似的恢复。突变株(XU20)未交配产卵的雌性处女性信息素含量很低，但在脑-食道下神经节提取液中有大量的PBAN活性，提示即使是处女，释放信息素神经肽的神经分泌细胞也可能失活。较少

Suppression of pheromone production after mating in moths seems to be induced by a neural signal that originates from the abdomen and runs up the ventral nerve cord to inhibit the release of pheromonotropic neuropeptides. The present study demonstrated that the neurosecretory cells releasing the neuropeptides were most sensitive to mechanical stimulation and their firing activities were completely suppressed as soon as mating began. Thus, a mechanical signal induced by physical stimulation during copulation can trigger an inactivation mechanism of the neurosecretory cells. Because mating with a sterile male failed to induce permanent suppression of the cells. a temporal inhibition caused by mechanical stimuli may be released if they cannot receive another signal that may be induced by the sperm and /or testicular factors transferred from a fertile male. When semen obtained from the bursa copulatorix of a mated female were artificially injected into a female which already received tacti … More le stimulation from a sterile male, permanent suppression of pheromone production occurred, thereby indicating that the two-step inactivation mechanism of sex pheromone production is true in a mated female.A similar two-step inactivation mechanism has been inferred from observations of mated gypsy moth.Identification and mode of action of the putative-pheromonostatic male factor in Bombyx mori remain to be determined.Pheromone production often resumed again in mated moths when the females were fixed to a platform after mating. Similar resumption of pheromone production were observed in the females which were anesthetized for 15 min in 95% CO_2 or for 1-2 min in etylether. The results suggest that the permanent suppressioncan be released under some stressful condition, such as restraint or anesthesia.Virgin females of a mutant strain (XU20), which lay eggs without mating, had very low amount of sex pheromone but had large amonunt of PBAN activity in the extract of the brain-suboesophageal ganglion, thereby suggesting that the neurosecretory cells releasing pheromonotropic neuropeptides may be inactivated even in a virgin female. Less