A lectin horseradish peroxidase study of the origin of ascending fibers in the medial forebrain bundle of the rat. The lower brainstem

The origins of projections within the medial forebrain bundle from the lower brainstem were examined with the horseradish peroxidase technique. Labeled cells were found in at least 15 lower brainstem nuclei following injections of a conjugate or horseradish peroxidase and wheat germ agglutinin at various levels of the medial forebrain bundle. Dense labeling was observed in the following cell groups (from caudal to rostral): A1 (above the lateral reticular nucleus); A2 (mainly within the nucleus of the solitary tract); a distinct group of cell trailing ventrolaterally from the medial longitudinal fasciculus at the level of the rostral pole of the inferior olive; raphe magnus; nucleus incertus; dorsolateral tegmental nucleus (of Castaldi); locus coeruleus; nucleus subcoeruleus; caudal part of the dorsal (lateral) parabrachial nucleus; and raphe pontis. Distinct but light labeling was seen in raphe pallidus and obscurus, nucleus prepositus hypoglossi, nucleus gigantocellularis pars ventralis, and the ventral (medial) parabrachial nucleus. Sparse labeling was observed throughout the medullary and caudal pontine reticular formation. Several lower brainstem nuclei were found to send strong projections along the medial forebrain bundle to very anterior levels of the forebrain. They were: A1, A2, raphe magnus (rostral part), nucleus incertus, dorsolateral tegmental nucleus, raphe pontis and locus coeruleus. With the exception of the locus coeruleus, attention has only recently been directed to the ascending projections of most of the nuclei mentioned above. Evidence was reviewed indicating that fibers from lower brainstem nuclei with ascending medial forebrain bundle projections distribute to widespread regions of the forebrain.It is concluded from the present findings that several medullary cell groups are capable of exerting a direct effect on the forebrain and that the medial forebrain bundle is the major ascending link between the lower brainstem and the forebrain.     

Callosal connections of suprasylvian visual areas in the cat

After horseradish peroxidase injections in cat's lateral suprasylvian visual area and in areas 17 and 18, labeled callosal neurons are found within the various subdivisions of the lateral suprasylvian area, mostly in regions where the area centralis and vertical meridian are represented. The homotopic callosal projections from lateral suprasylvian area to lateral suprasylvian area originate almost exclusively from layer III. The heterotopic callosal projections from the lateral suprasylvian area to areas 17 and 18 originate mainly from layer VI but also from layer III. Callosal neurons in the lateral suprasylvian area are pyramidal cells (layers III and VI), fusiform and triangular cells (layer VI).The distribution of callosal neurons in the lateral suprasylvian area is similar to that previously found in areas 17 and 18 in the sense that in all these areas callosal neurons are preferentially located near the vertical meridian representation within two radially separated laminae. However, the preponderance of layer VI neurons in the projection from the lateral suprasylvian area to contralateral areas 17 and 18 is different from what was observed in other callosal connections. Since layer VI usually gives rise to corticothalamic projections it is possible that similar feed-back mechanisms may modulate the information sent to the lateral suprasylvian area from the thalamus and the primary visual areas.     

Receptive field characteristics of neurones in striate cortex of newborn lambs and adult sheep

The properties of cells of the striate visual cortex (V1) have been studied in the normal adult sheep and in new-born lambs without visual experience, the majority of cells in the lamb are orientation specific, but 20% are non-oriented compared to only 3% cells in the adult. In the lamb there was little or no facilitation of binocularly-driven cells by simultaneous stimulation of both receptive fields. Cells which responded only to binocular stimulation of particular disparities ('obligate binocular' cells) were rarely encountered. In the adult, 15% of the sample were obligate binocular cells and a further 28% showed binocular facilitation. Simple and complex receptive fields were found in similar proportions in both new-born lambs and adult sheep. End-stopped cells comprised 17% of the sample in adults but only 2% in the lambs. Direction sensitive cells were found more frequently in the sheep (21% of cells) than in the lamb (4% of cells). It is concluded that facilitatory processes in binocular cells and inhibitory mechanisms generally, seem much less developed in the lamb.     

Another Look at the Relationship of Electrodermal Activity to Electrode Contact Area

The present study was undertaken lo reexamine the hypothesis that the relationship between skin conductance and electrode size is monotonic and linear. Skin conductance activity was recorded from 48 right-handed male subjects using 6 different sixes of electrode collars ranging in exposed surface area from .131 cm² to .786 cm². The dependent measures were skin conductance level (SCL); skin conductance response (SCR) amplitude to a series of 8 loud tones; latency, rise time, and recovery half-time of the first tone elicited response; (he largest self-generated SCR; and the number of nonspecific responses. The results indicated a significant linear relationship between contact area and SCL, stimulus and self-generated SCR amplitude, and the number of nonspecific responses. Latency was not affected by electrode size although the other time-based measures were. Differences in skin conductance activity were found among different palmar recording sites. The observed linear relationship between electrode size and electrodermal measures has implications for current models of electrodermal activity and for the comparison of results across studies in which different electrode contact areas are used.     

Interaction between the septal area and the subfornical organ in the control of water intake induced by thirst-eliciting procedures

Rats bearing lesions in the septal area followed by lesions in the subfornical organ were submitted to various thirst-eliciting procedures. The rats with hyperdipsia induced by lesions of the septal area drank more water than either during the control period or after lesion of the subfornical organ under the same thirst-eliciting or angiotensin-liberating stimuli (polyethyleneglycol, isoproterenol, water deprivation and ligation of the inferior vena cava). The overdrinking elicited by lesions in the septal area was blocked after lesion of the subfornical organ. Neither hypovolemia, nor hypotension or water deprivation could elicit increased water intake in animals whose subfornical organ had been destroyed. Animals with lesions in the subfornical organ showed decreased water intake after cellular dehydration. The results obtained suggest that the subfornical organ acts as a more important structure than the septal area in the regulation of water intake elicited by angiotensin, with two opposite effects: a direct one facilitating water intake, and an indirect one inhibiting the septal area. The septal area has an inhibitory effect on the subfornical organ and on water intake.     

Damage of purkinje cell axons following chronic phenytoin administration: An animal model of distal axonopathy

Summary An animal model of central distal axonopathy following chronic administration of phenytoin is described. Male C57/BL6J mice received diphenylhydantoin (DPH) in the daily diet (liquid diet Stardit, supplemented with vitamins) over a period of 8 weeks. Control and experimental animals were pair-fed.Twelve mice of both groups were perfused via the left ventricle with glutaraldehyde. Representative samples of the cerebral cortex (area 3), cerebellum (vermis and deep cerebellar nuclei), thalamus, hypothalamus, and liver were embedded in araldite. Semithin sections and electron microscopy of the cerebellar vermis revealed marked dystrophic changes in the Purkinje cell axons. The presynaptic segments of Purkinje cell axons in the deep cerebellar nuclei showed massive enlargement and swelling due to accumulation of spherical particles and tubular structures in the axoplasm. These structures represent a proliferation of the smooth endoplasmic reticulum.Identical changes were found in hepatocytes of treated animals. Because phenytoin induces hepatic microsomal enzymes, we suggest that phenytoin-related Purkinje cell damage may be produced by an induction of Purkinje cell microsomes with proliferation of the smooth endoplasmic reticulum which causes a swelling and enlargement of presynaptic segments of Purkinje cell axons in deep cerebellar nuclei. Chronic phenytoin administration to mice is a new model of phenytoin-induced encephalopathy and of distal axonopathy of cerebellar neurons.Supported by the Deutsche ForschungsgemeinschaftPresented in Part at the Joint Meeting of the German and Scandinavian Neuropathologists, Turku, Finland, June 3–4, 1983     

Callosal projections from area SII to SI in monkeys: anatomical organization and comparison with association projections

The present research was aimed at ascertaining in the macaque monkey the reciprocity of the heterotopical callosal connections between SI and SII, with particular regard to the connectivity of the hand representation, and at comparing the topographical and laminar pattern of these callosal connections with those of association connections entertained by these areas. Horseradish peroxidase (HRP) was unilaterally injected into area SI in five monkeys. The sites of HRP delivery included the trunk and the hand zones preliminarily identified by recording multi-unit responses to peripheral stimulation by means of microelectrodes. Anterograde and retrograde labelling was studied in SII of both sides. The results showed the complete reciprocity of the heterotopical callosal connections between SI and SII. In the latter area both callosal axon terminals and neurones were found, which were labelled from either the trunk or the hand zone of contralateral SI. Labelling of callosal axon terminals occurred mainly in layer IV and in the lowermost part of layer III. Labelled callosal neurones were mainly in the lower half of layer III, whereas few occurred in infragranular layers. Topographically, the distribution of callosal terminals and cell bodies duplicated the distribution of association terminals and cell bodies labelled in SII on the side ipsilateral to HRP injection. The laminar pattern of termination of association fibres from SI was similar to that of callosal fibres. However, the distribution of association-projecting neurones in SII showed a striking difference from that of callosal-projecting neurones. Unlike the latter neurones, which were mainly located in supragranular layers, association cell bodies overwhelmingly dwelt in layers V and VI and were less numerous in layers II and III. This laminar pattern of association SII-SI cells corresponds to the "feed-backward" model and fits the laminar pattern of their axon terminations (Friedman: Brain Res. 273: 147-151, '83). The association and callosal inputs and outputs of area SII are discussed in relation to the function of the forward and backward type of reciprocal connections entertained with SI in the ipsilateral hemisphere and to the function of SII in the interhemispheric exchange of somatosensory information.     

长沙地区无偿献血人群隐匿性乙型肝炎病毒感染情况分析

目的 了解长沙地区无偿献血人群隐匿性乙型肝炎病毒感染(occult hepatitis B virus infection,OBI)流行情况,探讨HBV基因型分布特征和S区氨基酸突变的情况。方法 对长沙地区检测结果为HBsAg-/HBV DNA+的无偿献血血液样本进行HBV血清标志物检测,对其中的OBI样本进行HBV病毒载量检测和S区基因扩增,分析血清学标志物抗HBs与病毒载量检出与否的关系,并对扩增产物进行HBV基因分型和突变位点分析。结果 2019年1月—2020年1月长沙地区173 893份无偿献血标本共确认58例OBI样本,OBI流行率为0.033%;共发现7种血清学模式,抗HBc单独阳性最多,占38.98%,所有样本中抗HBc阳性率为89.83%;16例样本能检测出病毒载量,其中14例样本浓度小于100 IU/ml;抗HBs阳性组和阴性组间的病毒载量检出率无统计学差异;75.0%(12/16)样本扩增出S区序列,基因型均为B型,均发生突变,其中11例的HBsAg抗原决定簇及周边主要亲水区域(major hydrophilic region, MHR)发生氨基酸突变。结论 长沙地区无偿献血者中的OBI感染率在全国属于偏低水平;HBV基因型主要是B型,MHR区的氨基酸突变可能是造成OBI的原因,突变有本地特点。     

经典名方中藿香类药材的本草考证

通过查阅古代相关本草、医籍、经史及近现代文献资料,笔者对藿香类药材的名称、基原、产地、品质评价、栽培、采收加工及炮制方法等进行了系统梳理与考证,可为含藿香类药材的经典名方开发利用提供依据。通过本草考证分析可知,历代本草多以“藿香”为正名,所用主流基原均为Pogostemon cablin,为区别于明代以来我国民间习用的同科另一种植物土藿香Agastache rugosa及推崇道地产区而有“广藿香”之名;广藿香原产于越南等东南亚国家,早期因作香料经广东等地传入我国,宋代以来便已在我国南方引种成功;药用部位多为其干燥地上部分,亦有将其叶、梗分开单独使用;历代推崇的道地产区为广东,现广东广州、肇庆、湛江和海南省多有栽培,以石牌所产最为知名;广藿香主要为扦插繁殖,二月生苗,六月采收;产地加工方法主要为闷晒法,放置阳光下反复闷晒至有芳香气味、颜色转黄;炮制方法多以净选后生品入药。基于考证结果,建议养胃汤中所用藿香以P. cablin为基原,取叶片生品入药,而藿朴夏苓汤则建议选择土藿香A. rugosa除去根及老茎的生品入药。     

经典名方中杜仲的本草考证

通过查阅历代本草、医籍、方书并结合近现代文献资料,笔者对杜仲药材的名称、基原、产地、品质评价、采收加工、炮制历史沿革及产地变迁情况进行了系统梳理及考证,以期为含杜仲的经典名方开发提供参考依据。经考证可知,历代本草均以杜仲为正名,基原为杜仲科植物杜仲Eucommia ulmoides的干燥树皮,古今一致;杜仲最早的产地为河南、山西、陕西、四川一带,自明代以来产地扩展至全国大部分地区,且推崇四川、陕西、重庆、贵州、湖北等地为杜仲的道地产区;近代以来总结其品质以皮厚、块大、粗皮刮净、断面多丝、内表面色暗紫为佳;杜仲的古代炮制加工方法主要有去粗皮切制生用和加酥蜜、姜汁、盐水、酒等辅料炮制,近现代以来炮制方法日趋简化,沿用的炮制方法主要为净制后切制生用、盐炙,建议挖掘不同杜仲炮制品的现代科学内涵,通过标准恢复传统主流炮制方法。基于宋代陈自明的三痹汤中杜仲“去皮,切,姜汁炒”的要求,根据考证结果,建议使用姜杜仲,即参考2020年版《中华人民共和国药典》炒法,以姜汁为辅料进行炮制后入药。