Chemically distinct rat olivocochlear neurons.

We have produced a neurochemical map of the cell bodies of origin of the cochlear efferent terminals in rat by combining glutamic acid decarboxylase (GAD), choline acetyltransferase (ChAT), or calcitonin gene-related peptide (CGRP) immunocytochemistry with retrograde transport of horseradish peroxidase. The locations of cochlear efferent cell bodies are in general agreement with the medial and lateral systems described by White and Warr (J. Comp. Neurol. 219:203-214, 1983) with some minor modifications. The lateral system consists of at least two pools of chemically distinct neurons located within the lateral superior olive (LSO) ipsilateral to the injected cochlea. One pool immunostains with an antibody to GAD while the other immunostains with antibodies to ChAT and to CGRP. The medial efferent system consists of periolivary neurons that are almost exclusively large and ChAT-positive but CGRP-negative. They are located both ipsilateral and contralateral to the cochlea they project to. There are a few GAD-positive small neurons in the medioventral and rostral periolivary regions that project ipsilaterally, but these may prove tobe ectopic neurons. The ipsilateral lateroventral periolivary region (LVPO) contains some efferent neurons, all of which are ChAT-positive but CGRP-negative. Additional cochlear efferent neurons, some of which are ChAT-positive and others GAD-positive, are present within and immediately dorsal to the fiber capsule surrounding the medial limb, and to a lesser extent the lateral limb, of the ipsilateral LSO. Not all GAD-positive or ChAT-positive olivary cells project to the cochlea. We have complemented the results in the brainstem by demonstrating two immunocytochemically distinct populations of efferent terminals in the cochlea simultaneously, one CGRP-positive and the other GAD-positive. Approximately equal numbers of boutons immunoreactive for both markers are present beneath inner hair cells throughout the entire length of the cochlea. Surprisingly high numbers of GAD-positive and CGRP-positive boutons are also present on outer hair cells, with each class having its spatially and morphologically distinct features. The lack of CGRP-positive periolivary cells that are retrogradely labeled by cochlear injections of HRP suggests that the lateral olivocochlear system sends projections to outer hair cells. Our results raise questions about species differences in the organization of targets of the lateral and medial olivocochlear systems.     

自身免疫性感音神经性聋豚鼠的子代内耳生理功能研究

目的 :观察自身免疫性感音神经性聋 (ASHL)母豚鼠所产子代内耳生理功能的变化 ,探讨针对内耳的自身免疫因素对子代内耳生理功能的影响及其改变特点。方法 :同种内耳抗原 (CIEAg)持续免疫孕豚鼠 ,采用耳蜗电图 (记录cAP、CM )和眼震电图仪 (记录自发性眼震和冷热空气试验 )测试母鼠和子鼠的听觉和前庭功能 ,并检测血清特异性体液免疫反应。结果 :ASHL模型母豚鼠所产子鼠血清中发现有特异性抗体水平升高 ,部分 (3 /9)出现听觉损伤。非ASHL母鼠和对照组母鼠所产子代未见明显异常。结论 :ASHL雌鼠所产子代可出现感音神经性聋 ,其内耳损伤和功能障碍极可能与针对内耳组织的自身免疫反应 (尤其是体液免疫 )有关 ,从而提示内耳自身免疫因素可能为部分先天性非遗传性感音神经性聋的病因之一。     

豚鼠内耳前庭感觉毛细胞的分离

用机械分离法从豚鼠前庭感觉上皮中分离出不同种类的前庭感觉毛细胞（ＶＨＣ）。ＶＨＣ主要可分为Ⅰ型和Ⅱ型细胞。两种细胞形态虽有所差异，但一般均有四形或瓶形胞体，胞核位于细胞基部，胞颈和纤毛变化较大。细胞的活性可通过１％中性红染色鉴定，发现在室温下，１ｈ内大约９０％以上的分离ＶＨＣ可维持其正常形态和活性。并参照对外毛细胞形态的研究提出活性ＶＨＣ的鉴别标准。此项工作为进一步研究ＶＨＣ的感觉机制和某些疾病的发生机理打下了基础。     

Cellular degeneration and synaptogenesis in the developing retina of the rat

We have investigated the time course and magnitude of cellular degeneration in the ganglion cell layer and the presumptive amacrine and bipolar regions of the inner nuclear layer during the development of the retina in the rat. Pyknotic profiles are present in the ganglion cell layer during the first 2 postnatal weeks, reaching peak numbers during the first 4 postnatal days (corresponding to the time of greatest loss of ganglion cells and their axons: Potts et al., '82; Lam et al., '82; Perry et al., '83). Two observations suggest that the majority of pyknotic profiles present in the ganglion cell layer during the second postnatal week are not ganglion cells. First, following injection of kainic acid into one superior colliculus, degenerating ganglion cells in the contralateral retina are cleared within 24-48 hours. Therefore, since most ganglion cell and axon loss occurs within the first postnatal week, few of the pyknotic profiles present in the second week are likely to be ganglion cells. Second, the time course of cellular degeneration in the ganglion cell layer during the second postnatal week follows a very similar pattern to that seen in the presumptive amacrine sublayer of the inner nuclear layer. Such a correspondence suggests that two phases of cell death occur in the ganglion cell layer: during the first postnatal week the majority of dying cells are ganglion cells, and in the second, most cell death is due to a loss of displaced amacrine cells. In the inner nuclear layer pyknotic profiles are most numerous in the presumptive amacrine region on postnatal days 6 and 7, and in the presumptive bipolar region on day 10. Synaptogenesis in the inner plexiform layer occurs later but reflects the order of cell death. Thus, conventional (presumed amacrine) synapses were first observed on day 11 and synaptic ribbons (indicative of bipolar synapses) on day 13. These observations suggest that amacrine and bipolar cells initiate synapses only after their numbers have stabilized.     

A critical period for functional vestibular development in zebrafish.

We have determined a critical period for vestibular development in zebrafish by using a bioreactor designed by NASA to simulate microgravity for cells in culture. A critical period is defined as the briefest period of time during development when stimulus deprivation results in long lasting or permanent sensory deficits. Zebrafish eggs were collected within 3 hours of being laid and fertilized. In experiment 1, eggs were placed in the bioreactor at 3, 24, 30, 36, 48, or 72 hours postfertilization (hPF) and maintained in the bioreactor until 96 hPF. In experiment 2, eggs were placed in the bioreactor immediately after they were collected and maintained in the bioreactor until 24, 36, 48, 60, 66, 72, or 96 hPF. Beginning at 96 hPF, all larvae had their vestibulo-ocular reflexes (VOR) evaluated once each day for 5 days. Only larvae that hatched from eggs that were placed in the bioreactor before 30 hPF in experiment 1 or removed from the bioreactor later than 66 hPF in experiment 2 had VOR deficits that persisted for at least 5 days. These data suggest a critical period for vestibular development in the zebrafish that begins before 30 hPF and ends after 66 hPF. To confirm this, zebrafish eggs were placed in the bioreactor at 24 hPF and removed at 72 hPF. VORs were evaluated in these larvae once each day for 5 days beginning at 96 hPF. These larvae had VOR deficits that persisted for at least 5 days. In addition, larvae that had been maintained in the bioreactor from 24 to 66 hPF or from 30 to 72 hPF, had only temporary VOR deficits. In a final experiment, zebrafish eggs were placed in the bioreactor at 3 hPF and removed at 96 hPF but the bioreactor was turned off from 24 hPF to 72 hPF. These larvae had normal VORs when they were removed from the bioreactor at 96 hPF. Taken as a whole, these data support the idea that there is a critical period for functional maturation of the zebrafish vestibular system. The developmental period identified includes the timeframe during which the vestibular primary afferent neurons are born, innervate their central and peripheral targets, and remodel their central projections.     

Fertilization and early embrology: Monozygotic twinning in the human is associated with the zona pellucida architecture

Six cases of identical twin pregnancies which occurred in 2163cycles of in-vitro fertilization during a 3 year period arereported. Monozygosity was confirmed when the number of fetusesexceeded the number of embryos replaced (n = 4) or when twoconcepti were observed in a single amniotic sac (n = 2). Eachof the reported pregnancies resulted from replacement of embryoseither with naturally thin zonae pellucida or embryos whosezonae had been breached during micromanipulation for assistedfertilization (subzonal sperminsertion) or assisted hatching.That such cases exclusively gave rise to monozygosity suggestsa link between the physical state of the zona pellucida, hatching,and generation of identical twins.     

保留部分皮肤皱襞的内眦开大术

目的在应用“横切法”内眦开大的基础上，探寻一种充分开大内眦，切口瘢痕隐蔽，术后内眦赘皮不易复发，效果持久的手术方法。方法水平切开皮肤赘皮及部分错位的眼轮匝肌纤维，将内眦点向内侧移位，并与鼻侧腱膜固定，保留内眦点上方赘皮皱褶，剪除少许眼轮匝肌及退缩于该处的眼轮匝肌纤维束，将皮肤皱褶下充分松解并使该处形成自然凹陷后，与重睑线顺延缝合。结果本组260例中，190例得到1个月至2年的随访，内眦赘皮矫正充分，形态满意者156例，内眦赘皮部分矫正，形态改善者19例，术后赘皮复发者8例，严重瘢痕增生，影响内眦形态者7例。结论本方法内眦开大充分，切口瘢痕隐蔽，无需切除皮肤，赘皮不易复发，是矫正内眦赘皮简单而有效的方法。     

鼻内镜下上颌窦（扩大）内壁切除术在鼻内翻性乳头状瘤手术中的应用

目的探讨鼻内镜下上颌窦（扩大）内壁切除术在鼻内翻性乳头状瘤手术中的应用价值。方法回顾分析2002年1月～2006年12月采用鼻内镜下上颌窦（扩大）内壁切除术治疗鼻内翻性乳头状瘤10例的临床资料。结果10例均在鼻内镜下完全切除。10例随访12～72个月,平均30个月;术后仅1例术后1年后复发;10例均无溢泪发生。结论鼻内镜下上颌窦（扩大）内壁切除术在鼻内翻性乳头状瘤手术中的应用是可行的,基本接近鼻侧切开的手术范围;最大优点是可避免面部瘢痕、创伤小、手术视野清晰、能够准确完整地切除肿瘤、术后复发率低。