抑郁障碍患者五种脑诱发电位指标的临床随访研究

目的探讨抑郁障碍患者5种脑诱发电位指标及其治疗前后的特点。方法应用美国脑诱发电位仪，记录38例抑郁障碍患者（患者组）和33名正常对照者（对照组）的听觉诱发电位（AEP）、视觉诱发电位（VEP）、事件相关电位P300（ERP-P300）、失匹性负波（MMN）和关联性负变（CNV）。对其中18例患者随访至缓解期（治疗第9周末）。结果（1）与对照组相比，患者组出现AEP-N1潜伏期长[对照组（88±18）ms，患者组（104±25）ms]，N1-P2波幅低[对照组（5．3±1．9）μV，患者组（3．7±1．6）μV]；VEP-N1潜伏期长[对照组（125±19）ms，患者组（141±21）ms]，N1-P2波幅低[对照组（8．4±2．9）μV，患者组（6．9±2．6）μV]；P300-P3b潜伏期长[对照组（316±26）ms，患者组（330±21）ms]，P3．和P弘的波幅均低；CNV中的M1和M2波幅低，反应时间（RT）长[对照组（213±81）ms，患者组（306±126）ms]，均P〈0．01和P〈0．05。（2）随访部分患者，AEP中的N1-P2波幅、VEP中的N1潜伏期、P300中的P3b潜伏期，MMN波幅及CNV的波幅和RT等，与治疗前比较，差异有统计学意义（P〈0．05和P〈0．01）。结论抑郁障碍患者的AEP、VEP、P300和CNV，较正常对照组有改变。治疗后随抑郁症状的改善，与认知功能有关的指标也有相应的改善。     

难治性精神分裂症患者治疗前后感觉门控P50的变化

目的探讨难治性精神分裂症患者治疗前后感觉门控P50的变化特点。方法采用配对听觉条件（s1）、测试（S2）刺激范式,对36例难治性精神分裂症患者进行听觉诱发电位P50检测,测量P50的潜伏期、波幅,并与32例健康被试（对照组）进行比较。结果（1）与对照组比较,患者组S1潜伏期显著延迟,波幅显著降低（P〈0．05）;S2潜伏期和波幅差异无统计学意义（P〉0．05）;s2／s1显著升高（P〈0．05）。（2）与治疗前（8Z．21±8．59）比较,患者组治疗6周后PANSS得分（37．00±6．86）显著降低（t=16．81,P〈0．05）。（3）与治疗前比较,治疗后S1潜伏期显著缩短,波幅显著升高（P〈0．05）,S2潜伏期、波幅差异均无统计学意义（P〉0．05）,S2／S1显著降低（P〈0．05）;与对照组比较,$2／S1仍显著偏高（P〈0．05）。结论难治性精神分裂症患者感觉门控抑制能力有缺陷,提示P50比率可能是难治性精神分裂患者的一个潜在的素质性生物学标记。     

氯氮平与氯丙嗪对精神分裂症患者听觉感觉门控的比较：前瞻性病例对照研究

背景精神分裂症患者听觉感觉门控（以下简称感觉门控）P50受损,各种抗精神病药物对该P50的作用仍有争议。假设第二代抗精神病药物氯氮平治疗的精神分裂症患者比氯丙嗪治疗患者的感觉门控P50的改善明显。方法前瞻性对照研究纳入刚住院的精神分裂症患者,由治疗医师决定氯氮平治疗者26例（研究组）,氯丙嗪治疗者30例（对照组）。氯氮平组有23例完成8周研究纳入分析,氯丙嗪组为20例。检测P50的方法为双短声刺激[听觉条件（S1）-测试刺激（S2）范式],检测时点为基线、治疗第4周和第8周。临床症状用阳性与阴性综合征量表（Positive and Negative Syndrome Scale,PANSS）评定。结果两组年龄、性别、教育程度、病程和基线PANSS总分差异均无统计学意义。氯丙嗪组平均（标准差）治疗剂量为389（96）mg/d,氯氮平组为345（117）mg/d。重复测量的方差分析显示,氯氮平组颅顶中央脑区（central zone,Cz）P50比值（S2/S1）的下降比氯丙嗪组明显[基线为108%比106%,第4周94%比102%,第8周84%比95%,F=4.91,P=0.029],而S1和S2波幅差异无统计学意义。两组间S1和S2的波幅无明显差异。氯氮平组治疗后P50比值较治疗前下降（F=4.39,P=0.014）,氯丙嗪组治疗前后P50比值没有明显变化。结论氯氮平治疗可以减轻精神分裂症患者感觉门控的受损程度;与氯丙嗪治疗相比,氯氮平治疗者的改善程度较明显。     

青少年首次发病精神分裂症患者前额叶和海马磁共振质子波谱成像的研究

目的探讨青少年首次发病（以下简称首发）精神分裂症患者前额叶、海马的磁共振质子波谱（^1H—MRS）变化特点。方法对21例青少年（13—17岁）首发精神分裂症患者（患者组）和20名（14～17岁）年龄、性别、受教育时间均匹配的正常对照者（对照组），应用^1H—MRS成像技术检测两组前额叶、海乌N-乙酰天门冬氨酸（NAA）、肌碱（Cho）、肌酸（Cr）3种代谢物，计算NAA／Cr和Cho／Cr比值。采用t检验进行分析。结果（1）患者组左侧前额叶NAA／Cr（1．56±0．81）低于对照组（2．09±0．81），右侧前额叶NAA／Cr（1．84±0．42）低于对照组（2．58±0．83），右侧前额叶Cho／Cr（1．25±0．17）也低于对照组（1．51±0．38），差异有统计学意义（P〈0．05和P〈0．01）。（2）患者组左侧海马NAA／Cr（1．33±0．34）低于对照组（1．64±0．56），差异有统计学意义（P〈0．05）。结论青少年首发精神分裂症患者存在双侧前额叶、左侧海弓神经元完整性和功能障碍，同时可能提示右侧前额叶神经厄能黾需要降低及神经胶质细胞的密度或功能完整性受损。     

利培酮与舒必利对精神分裂症男性老年患者血清催乳素水平影响的对照研究

目的 探讨利培酮和舒必利对精神分裂症男性老年患者血清催乳素（PRL）水平的影响。方法 将51例精神分裂症男性老年患者随机分为利培酮组[（3．7±0、9）mg／d，24例]和舒必利组[（800±156）mg／d，27例]，采用酶联免疫方法测定两组治疗前后的PRL水平，并与25名正常男性老年人（对照组）进行对照。结果 （1）治疗前，患者组PRL水平[（26±11）彬L]与对照组[（24±14）μg／L]的差异无统计学意义，利培酮组[（26±11）μg/L]与舒必利组[（28±12）μg/L]的差异亦无统计学意义（均P〉0．05）。（2）治疗后，患者组PRL水平[（149±59）μg/L]高于治疗前（t=14．53，P〈0．01）；利培酮组[（118±47）μg/L]和舒必利组[（196±73）μg/L]亦均高于治疗前，其中舒必利组高于利培酮组（均P〈0．01）。结论 利培酮和舒必利均能升高精神分裂症男性老年患者的PRL水平，其中以舒必利更为显著。     

儿童精神分裂症患者微小躯体异常与脑室扩大关系的研究

目的探讨儿童精神分裂症患者微小躯体异常（MPAs）与脑室扩大的关系。方法对168例儿童精神分裂症患者（患者组）进行躯体异常量表（WS）评定，并将患者分为MPAs明显组（WS总分≥4分，85例）和MPAs不明显组（WS总分≤3分，83例）。用阳性和阴性症状量表（PANSS）评定患者组的精神症状；用CT测量患者的脑室（脑室值用哈氏值、三脑室宽度、脑室指数、侧脑室体部指数、侧脑室宽度指数、前角指数表示），并与40名健康儿童（对照组）进行对照。结果（1）患者组哈氏值[（5．37±0．53）cm]和三脑室宽度[（3．83±1．21cm）]均大于对照组[分别为（4．94±0．34）cm和（3．16±0．41）cm]，腩室指数（1．55±0．18）和前角指数（3．52±0．31）小于对照组（分别为1．65±0．22和3．77±0．34），均P〈0．01。（2）MPAs明显组哈氏值[（5．50±0．54）cm]和三脑室宽度[（4．10±1．32）cm]大于MPAs不明显组[分别为（5．24±0．49）cm和（3．55±1．01）cm]和对照组，前角指数（3．47±0．30）小于MPAs不明显组（3．57±0．31）和对照组，脑室指数（1．55±0．18）小于对照组。（3）MPAs不明显组哈氏值大于对照组，脑室指数和前角指数小于对照组，均P〈0．01和P〈0．05。（4）患者组WS总分与哈氏值（r=0．263）及三脑室宽度（r=0．287）存在正相关，与前角指数存在负相关（r=-0．178）；患者组的WS总分与阴性症状分呈正相关（r=0．247）；患者组的阴性症状分与哈氏值（r=0．375）和三脑室宽度（r=0．161）呈正相关，与脑室指数（r=-0．159）和前角指数（r=-0．191）呈负相关（均P〈0．01和P〈0．05）。结论儿童精神分裂症患者存在显著的MPAs和脑室扩大，MPAs与脑室扩大之间有明显的相关。     

精神分裂症患者致炎性细胞因子和酪氨酸羟化酶mRNA表达水平的研究

目的探讨精神分裂症的外周神经免疫机制及其与临床症状的关系。方法检测精神分裂症患者致炎性细胞因子白介素-1β（IL-1β）、肿瘤坏死因子-α（TNF—α）以及酪氨酸羟化酶（TH）的mRNA表达水平，采用逆转录-聚合酶链反应及半定量检测技术，分别检测39例精神分裂症患者（患者组）、25例同胞（同胞组）及30名正常对照（对照组）外周血单个核细胞（PBMC）IL-1β、TNF-α及TH基因表达水平，同时应用阳性和阴性症状量表（PANSS）评定精神分裂症患者临床症状。结果患者组、同胞组及对照组IL-1β的mRNA表达水平分别为1．52±1．01、1．52±1．09和0．74±0．38；TNF—α的mRNA表达水平分别为1．18±0．99、1．01±0．87和0．70±0．29；TH的mRNA表达水平分别为0．55±0．33、0．61±0．32和0．28±0．20。患者组和同胞组的IL-1β、TNF—α、TH的mRNA表达水平均明显高于对照组（P〈0．05或P〈0．01）。患者组IL-1β（r=0．420）、TNF—α（r=0．430）的mRNA表达水平与PANSS的-般病理症状分呈正相关（P〈0．01）。同胞组与对照组合并统计，IL-1β与TNF-α的mRNA表达水平呈正相关（r=0．847，P〈0．01）；IL-1β与TH的mRNA表达水平呈正相关（r=0．666，P〈0．01）。患者组仅IL-1β与TNF—α的mRNA表达水平呈正相关（r=0．942，P〈0．01）。结论精神分裂症患者PBMC细胞TH、IL-1β和TNF—α的mRNA表达水平高于正常，且与精神分裂症的-般病理症状显著相关。     

精神分裂症患者治疗后多项诱发电位的变化

目的 了解精神分裂症患者P300、听觉诱发电位（AEP）和脑干听觉反应（ABR）的特征以及治疗前后诱发电位的变化。方法 应用美国Nicolet Spirit脑诱发电位仪．记录34例精神分裂症患者和31名正常成人的P300、AEP和ABR．于治疗6个月时进行P300、AEP和ABR随访。结果 1．与NC组比较，精神分裂症组三项诱发电位主成份（P300-P3靶潜伏期、AEP-P2潜伏期和ABR-波V波幅）延迟，波幅降低（P〈0．05～0．01）。2．随访提示：P300中的P3靶潜伏期和波幅，AEP中的P2潜伏期和波幅以及ABR中的波Ⅲ潜伏期和波V波幅改变可能是属于该疾病的状态标志。结论 本组精神分裂症患者的诱发电位变化为状态标志，多项诱发电位指标联合应用可作为精神分裂症治疗监测的有用指标。     

首次发病的精神分裂症患者感觉门控P50特征及其相关因素

目的:探讨首次发病的精神分裂症患者感觉门控P50特征及其相关临床因素。方法:给予87例首发未服药的精神分裂症住院患者(患者组)单一利培酮(4~6 mg/d)治疗,疗程10周;治疗前后分别进行阳性和阴性综合征量表(PANSS)评定及P50检测;以PANSS减分率50%分割点将患者分为有效组和无效组;P50检测结果与86名健康志愿者(对照组)比较;分析患者组P50指标与临床因素的关系。结果:患者组治疗前P50听觉条件(S1)、测试刺激(S2)潜伏期显著长于对照组,S1波幅及S1-S2波幅差值显著低于对照组,S2/S1显著高于对照组(P均0.01);治疗后S1、S2波幅较治疗前显著下降(P均0.01);有效组与无效组间P50各项指标差异无统计学意义;治疗前S2波幅与PANSS阳性症状分呈正相关;S1-S2波幅差值与病程、PANSS中一般精神病理分呈负相关;S2波幅/S1波幅与病程、PANSS总分及一般精神病理分正相关(P均0.05)。结论:首发精神分裂症患者P50抑制缺陷;其与患者的病程、精神病理症状相关;利培酮治疗对P50 S1、S2波幅有影响,但可能未改善其抑制缺陷。     

氟西汀对慢性应激大鼠海马S100B和糖基化代谢终产物受体表达的影响

目的 探讨氟西汀对慢性应激大鼠海马S100B和晚期糖基化代谢终产物受体（RAGE）含量的影响。方法 将雄性sD大鼠4J0只随机分为正常对照组（以下简称对照组）、抑郁组、氟西汀（10mg·kg^-1，腹腔注射）＋抑郁组（F＋抑郁组）、氟西汀（10mg·kg^-1，腹腔注射）＋对照组（F＋对照组），每组各10只。采用21d不可预见性中等强度应激造成大鼠抑郁模型，于应激前及应激第22天观察大鼠行为（体质量、24h饮用1％蔗糖溶液量、旷场实验）；以Western blotting和激光共聚焦显微镜测定药物对各组大鼠海马S100B及RAGE表达水平的影响。结果 （1）在应激第22天，抑郁组大鼠体质量、蔗糖溶液消耗量、直立次数均低于对照组（P〈0．05），水平运动格子数低于对照组（P〈0．01），粪便颗粒数多于对照组（P〈0．05）；F＋抑郁组体质量、蔗糖溶液消耗量、水平运动格子数、直立次数均高于抑郁组（P〈0．05）。（2）抑郁组大鼠海马S100B[荧光强度18±5，吸光度（A）值3．24土0．45]、RAGE（荧光强度16±5，A值2．89±0．24）水平较对照组S100B（荧光强度25±7，A值5．28±0．48）、RAGE（荧光强度24±6，A值5．68±0．29）明显降低（P〈0．05），F＋对照组S100B（荧光强度31±5，A值7．34±0．29）、RAGE（荧光强度30±4，A值7．43±0．32）表达水平高于对照组（P〈0．05），而F＋抑郁组S100B（荧光强度23±3，A值5．00±0．34）、RAGE（荧光强度22±4，A值4．93±0．54）表达水平明显高于抑郁组（P〈0．05）。结论 慢性应激下调大鼠S100B，RAGE蛋白表达水平，而氟西汀上调S100B，RAGE的表达水平。     

听觉信号加工的双通路模型

神经电生理学研究发现,处理视觉信息的人大脑皮层的双通路模型概念也适用于非人灵长类动物大脑皮层听觉信息的加工,即存在一条识别物体特征的腹侧通路和一条加工空间信息的背侧通路。本文系统地总结了近年来有关人类听觉加工的脑成像研究,并根据这些实验结果对人听觉双通路的加工理论模型进行了讨论。     

The cognitive neuropsychology of auditory hallucinations: a parallel auditory pathways framework

Auditory hallucinations are generally defined as false perceptions. Recent developments in auditory neuroscience have rapidly increased our understanding of normal auditory perception revealing (partially) separate pathways for the identification ("what") and localization ("where") of auditory objects. The current review offers a reexamination of the nature of auditory hallucinations in schizophrenia using this object-based framework. First, the structural and functional organization of auditory what and where pathways is briefly described. Then, using recent functional neuroimaging data from healthy subjects and patients with schizophrenia, key phenomenological features of hallucinations are linked to abnormal processing both within and between these pathways. Finally, current cognitive explanations of hallucinations, based on intrusive cognitions and impaired source memory, are briefly outlined and set within this framework to provide an integrated cognitive neuropsychological model of auditory hallucinations.     

Depth evoked potential and single unit correlates of vertex midlatency auditory evoked responses

The rostral brainstem and thalamus of awake cats were studied for depth correlates of a surface-recorded midlatency auditory evoked potential, wave "A', with a latency range of 17-25 ms. In response to clicks or pure tones, midlatency potentials were recorded from the level of the cuneiform nucleus (14-15 ms latencies) forward through the medial tegmentum to the level of the intralaminar thalamic nuclei centralis lateralis (CL) and center median (CM) (17-19 ms latencies). While this medial projection system to the thalamus involved primarily CL and CM, slightly longer latency responses were also found in nucleus ventralis anterior (VA) and ventralis lateralis (VL). A ventral diencephalic response was characterized by latencies averaging 0.5-1.2 ms less than those from the dorsal thalamic regions. Both surface and depth midlatency potentials showed comparable sensitivity to rate of stimulation. At click rates above 1/s, peak amplitudes diminished, and for rates greater than 10/s, both surface and depth midlatency responses were abolished. This rate sensitivity differs from that of the auditory brainstem responses (ABRs), which are essentially unchanged at rates of 20/s. Whereas ABRs are unaffected by surgical levels of sodium pentobarbital, the surface and depth midlatency potentials are replaced by a deep negativity within minutes following administration of anesthesia. Extracellular recordings of acoustically responsive single units in CL and CM demonstrated latencies comparable to the CL and CM field potential latencies. Both the units and field potentials were similarly rate sensitive. Each auditory unit showed a best frequency response, but none demonstrated somatosensory convergence. Bilateral aspiration of the inferior colliculus did not abolish the midlatency depth or surface responses. Rather, recordings in CL and CM suggested response enhancement over a two week postoperative period. Taken together these data suggest that the midlatency vertex potential, wave "A', reflects a generator system which projects from cuneiform nucleus, through the medial tegmentum to the medial thalamus, particularly to CL and CM. The functional significance of this medial auditory projection system remains to be determined. It could mediate physiological correlates of "state', modulate sensory input or motor output, or it could provide an integrative mechanism for the focusing of auditory attention.     

Projections from the anteroventral cochlear nucleus to the lateral and medial superior olivary nuclei

The projections from the cochlear nucleus to the lateral and medial superior olivary nuclei were studied in the cat by use of retrograde transport of horseradish peroxidase to demonstrate the connections. The medial superior olivary nucleus receives input only from the anterior and posterodorsal subdivisions of the anterior division of the anteroventral cochlear nucleus (AA and APD, respectively; Brawer, Morest, and Kane: J. Comp. Neurol. 155: 251-300, 1974). These two subdivisions are populated almost exclusively by spherical bushy cells. Like the medial superior olivary nucleus, the lateral superior olivary nucleus receives inputs from AA and APD. In addition, the lateral superior olivary nucleus receives projections from the posterior subdivision (AP) of the anterior division and also from the posterior division of the anteroventral cochlear nucleus. The projections to the medial superior olivary nucleus are bilateral, whereas the projections to the lateral superior olivary nucleus are almost entirely ipsilateral. One implication of the results is that the medial superior olivary nucleus receives inputs from only one cell type--the spherical bushy cell--but that, at the least, two cell types project to the lateral superior olivary nucleus. Both the olivary nuclei receive input from most, if not all, of the dorsoventral extent of the anteroventral cochlear nucleus, implying that both receive input from neurons arrayed across the entire frequency representation of the anteroventral cochlear nucleus. All of the projections appear to be organized topographically such that frequency representation is preserved.     

Inferior colliculus responses to dual-site intralamina stimulation in the ventral cochlear nucleus

A major limitation of the present auditory brainstem implant (ABI) is its inability to access the tonotopic organization of the ventral cochlear nucleus (VCN). A previous study by our group indicated that stimulation of single sites within a given VCN frequency region did not always elicit frequency-specific responses within the central nucleus of the inferior colliculus (CIC) and in some cases did not elicit a response at all. For this study, we hypothesized that sequential stimulation (with a short interpulse delay of 320 μsec) of two VCN sites in similar frequency regions would enhance responsiveness in CIC neurons. Multiunit neural recordings in response to pure tones were obtained at 58 VCN and 164 CIC sites in anesthetized rats. Among the 58 VCN sites, 39 pairs of sites with similar characteristic frequencies were chosen for electrical stimulation. Each member of a VCN pair was electrically stimulated individually, followed by sequential stimulation of the pair, while recording CIC responses. On average, CIC sites were found to respond to dual-site VCN stimulation with significantly lower thresholds, wider dynamic ranges, a greater extent of activation with increasing current levels, and a higher degree of frequency specificity compared with single-site stimulation. Although these effects were positive for the most part, in some cases dual-site stimulation resulted in increased CIC thresholds and decreased dynamic ranges, extent of activation, and frequency specificity. The results suggest that multisite stimulation within VCN isofrequency laminae using penetrating electrodes could significantly improve ABI stimulation strategies and implant performance.     

Musicians show general enhancement of complex sound encoding and better inhibition of irrelevant auditory change in music: an ERP study

Using electrophysiology, we have examined two questions in relation to musical training – namely, whether it enhances sensory encoding of the human voice and whether it improves the ability to ignore irrelevant auditory change. Participants performed an auditory distraction task, in which they identified each sound as either short (350 ms) or long (550 ms) and ignored a change in timbre of the sounds. Sounds consisted of a male and a female voice saying a neutral sound [a], and of a cello and a French Horn playing an F3 note. In some blocks, musical sounds occurred on 80% of trials, while voice sounds on 20% of trials. In other blocks, the reverse was true. Participants heard naturally recorded sounds in half of experimental blocks and their spectrally‐rotated versions in the other half. Regarding voice perception, we found that musicians had a larger N1 event‐related potential component not only to vocal sounds but also to their never before heard spectrally‐rotated versions. We therefore conclude that musical training is associated with a general improvement in the early neural encoding of complex sounds. Regarding the ability to ignore irrelevant auditory change, musicians' accuracy tended to suffer less from the change in timbre of the sounds, especially when deviants were musical notes. This behavioral finding was accompanied by a marginally larger re‐orienting negativity in musicians, suggesting that their advantage may lie in a more efficient disengagement of attention from the distracting auditory dimension.     

Selective neurophysiologic responses to music in instrumentalists with different listening biographies

To appropriately adapt to constant sensory stimulation, neurons in the auditory system are tuned to various acoustic characteristics, such as center frequencies, frequency modulations, and their combinations, particularly those combinations that carry species-specific communicative functions. The present study asks whether such tunings extend beyond acoustic and communicative functions to auditory self-relevance and expertise. More specifically, we examined the role of the listening biography--an individual's long term experience with a particular type of auditory input--on perceptual-neural plasticity. Two groups of expert instrumentalists (violinists and flutists) listened to matched musical excerpts played on the two instruments (J.S. Bach Partitas for solo violin and flute) while their cerebral hemodynamic responses were measured using fMRI. Our experimental design allowed for a comprehensive investigation of the neurophysiology (cerebral hemodynamic responses as measured by fMRI) of auditory expertise (i.e., when violinists listened to violin music and when flutists listened to flute music) and nonexpertise (i.e., when subjects listened to music played on the other instrument). We found an extensive cerebral network of expertise, which implicates increased sensitivity to musical syntax (BA 44), timbre (auditory association cortex), and sound-motor interactions (precentral gyrus) when listening to music played on the instrument of expertise (the instrument for which subjects had a unique listening biography). These findings highlight auditory self-relevance and expertise as a mechanism of perceptual-neural plasticity, and implicate neural tuning that includes and extends beyond acoustic and communication-relevant structures.     

Patterns of reciprocity in auditory thalamocortical and corticothalamic connections: study with horseradish peroxidase and autoradiographic methods in the rat medial geniculate body

The patterns of reciprocity between retrogradely labeled thalamocortical cells of origin and anterogradely projecting corticothalamic axon terminals were studied in the subdivisions of the adult rat medial geniculate body following auditory cortical injections of mixtures of horseradish peroxidase and [3H]leucine. The labeling produced by each method was examined independently, both qualitatively and quantitatively, in adjacent series of tetramethylbenzidine-processed sections and in autoradiographs after 24-96 hour survivals. The distribution and number of labeled cells and axon terminals were assessed separately for each method and compared systematically throughout the rostro-caudal extent of the medial geniculate complex. The principal finding was that zones containing many retrogradely labeled neuronal somata are not completely coextensive with areas of heavy terminal labeling within the medial geniculate body, although there is a gross congruence of thalamocortical-corticothalamic projections. Conversely, we found many zones of autoradiographic silver grains without retrogradely labeled somata in the adjacent sections; in general, the autoradiographic zones of non-reciprocity were more extensive and marked than were retrograde zones of non-reciprocity. The rat medial geniculate complex could be subdivided on the basis of its neuronal organization, cytoarchitecture, fiber architecture, and thalamocortical and corticothalamic connections into three major parts: the ventral, dorsal, and medial divisions. This pattern of organization was comparable, though not identical, to that of the corresponding subdivisions in the cat medial geniculate body (Winer: Adv. Anat. Embryol. Cell Biol. 86:1-98, '85). While the retrograde labeling appeared to mark many of the different types of neurons in each of the three divisions, there were distinct local and quantitative and qualitative differences in the distribution of autoradiographic terminal labeling. The ventral division received the heaviest cortical input, the medial division the least labeling, while the dorsal division was intermediate. Thus, corticogeniculate projections to the ventral division often produced values 20-100 times above background (absolute values: 2,001-10,000 silver grains/14,400 micron2; background: less than 100 silver grains/14,400 micron2); the same projection to the dorsal division usually resulted in grain counts no more than 5-20 times above background (501-2,000/14,400 micron2), while in the medial division the number of silver grains rarely exceeded two to five times the background (201-500/14,400 micron2).(ABSTRACT TRUNCATED AT 400 WORDS)     

Parvalbumin,calbindin D-28k,and calretinin immunoreactivity in the ascending auditory pathway of horseshoe bats

In the subcortical auditory system of Rhinolophus rouxi, antibodies directed against the calcium-binding proteins parvalbumin, calbindin D-28k, and calretinin yield partly overlapping and partly complementary labeling patterns which are described in detail for each nucleus. The most general features of the labeling patterns are that: (1) Parvalbumin is a potent marker for large and heterogenous populations of cells and puncta (presumed axon terminals) throughout the auditory pathway. (2) Immunostaining with the monoclonal calbindin-antiserum was typically absent or sparse in most auditory brainstem centers, but prominent in auditory nerve fibers and in cells of the medial geniculate body (MGB). (3) Calretinin label is abundant but more restricted to subsets of auditory nuclei or subpopulations of cells than parvalbumin. (4) Calcium-binding proteins are useful markers to define particular subregions or cell types in auditory nuclei: for example, (i) different labeling patterns are obtained within the nuclei of the lateral lemniscus and adjacent tegmental zones; (ii) in the inferior colliculus both calbindin- and calretinin-antisera yield similar regional specific staining patterns, but label different cell types; (iii) subregions of the medial geniculate body have characteristic profiles of calcium-binding proteins; and (iv) analyses of different nuclei showed that there is no simple common denominator for cells characterized by the expression of particular calcium-binding proteins, nor does labeling correspond in a straightforward way with specific functional systems. (5) there are profound differences between the calbindin labeling patterns seen in Rhinolophus and those in other mammals.