哺乳动物嗅觉与母性识别

Olfaction-Based Maternal Recognition in Mammals

嗅觉通讯在陆生哺乳动物母性识别中具有重要作用。通过嗅觉信息,早熟性动物(有蹄类)产后早期能够迅速建立专一性的母性识别和母子联系,并具有母性识别的敏感期。在敏感期内,分娩经验、催产素及一氧化氮等神经递质的释放有助于这种识别和联系的形成。多项研究表明,晚熟性动物(如啮齿类)母性识别的形成主要基于断乳前母兽与幼仔共处获得的熟悉性,产后早期不能迅速形成专一性的母性识别和母子联系,母兽对亲生幼仔和非亲生幼仔的选择性哺育不完全取决于识别。实验方法及识别的判定标准对研究啮齿类的母性识别尤其重要。包括人类在内的灵长类母亲产后只通过嗅觉信息即可以对婴儿进行识别。在哺乳动物的母性识别中,妊娠和分娩过程会诱导嗅觉系统的高度可塑性,有利于促进母亲对幼体气味的学习,但硬连接(hard-wired)路径也可能参与母性识别。

Olfaction communication plays a significant role in maternal recognition of terrestrial mammals.Precocial species（ungulates） rapidly and selectively recognize and form bonds with their offspring by olfactory cues during the immediate postpartum period,which may be a sensitive period for establishing maternal recognition.Parturition experience,release of oxytocin and nitric oxide contribute to underlying the selective recognition of offspring within sensitive period.Contrast with precocial species,many studies have confirmed that establishment of maternal recognition is based on the familiarity from cohabitation with pups before weaning in altricial species（e.g.rodents）.They can not rapidly develop a specialized maternal recognition and bonding with pups after parturition.Recognition between own and alien pups does not necessarily ensure discriminative maternal care.Experimental technique and standard of assessing recognition are critical for studying maternal recognition in rodents.Shortly after birth,mothers of primates,including humans,are capable of forming an early maternal recognition by the scent of their newborn infants.Processes of pregnancy and parturition induce a high state of plasticity of the olfactory system,which may facilitate maternal olfactory learning in mammals.It is also possible that hard-wired perceptual processes are involved in maternal recognition.