The afferent connections of the preoptic region in the rat were studied with retrograde horseradish peroxidase (HRP) method.The mico-injection syringe needle or microelectrophoretic pipette was inserted vertically into the brain. In some cases, the injection was made with the needle inclined and directed contralaterally or in inclined direction through the cerebellum.The results were as follows:Following HRP injection into the medial preoptic area, labeled neurons were found in periventricular hypothalamic gray, paraventricular nucleus, anterior hypothalamic nucleus, supraoptic nucleus, ventromedial hypothalamic nucleus, posterior hypothalamic nucleus and locus coeruleus in all cases. In some cases, labeled cells were also observed within bed nucleus of stria terminalis, dorsal raphe nucleus. In addition, in a few cases, a small number of labeled cells could be found in lateral septal nucleus, medial septal nucleus, periaqueductal gray matter and interpeduncular nucleus.After injection into the region between the medial and lateral preoptic area, besides the above mentioned labeled nuclei, there were still a number of labeled cells found in paratenial nucleus, nucleus reuniens and lateral hypothalamic nucleus, in some cases also found in the supramammillar nucleus, and in one case even in the cortical and medial amygdalar nuclei.Following the injection of HRP into the anterior hypothalamic nucleus, retrograde labeling of neurons was observed within the lateral septal nucleus, preoptic periventricular nucleus, medial preoptic nucleus, supraoptic nucleus, periventricular hypothalamic nucleus, paraventricular nucleus, ventromedial hypothalamic nucleus, periaqueductal gray matter and locus coeruleus in all cases. Among them, supraoptic and paraventricular nuclei were labeled bilaterally in some cases.

The afferent connections of the lateral hypothalamic nucleus in the rat werestudied with retrograde horseradish peroxidase(HRP)method using microinjection andmicroelectrophoretic technique.The microinjection syringe needle or microelectrophoretic pipette was insertedvertically into the brain or in inclined direction through the cerebellum.The results were as follows:Following HRP introduced into the lateral hypothalamic nucleus,labeled neuronswere found in the anterior hypothalamic nucleus,the paraventricular nucleus,thedorsal raphe nucleus,the locus coeruleus and substantia grisea periventricularis inall cases.In most cases,labeled cells were also observed within the lateral septal nucleus,the interstitial nucleus of stria terminalis,the medial preoptic nucleus,the lateralpreoptic nucleus,the supraoptic nucleus,the ventromedial hypothalamic nucleus,themedial and central amygdaloid nuclei,the nucleus reunius,the interpeduncular nuc-leus,the nucleus parabrachialis dorsalis,the nucleus parabrachialis ventralis,and thenucleus tractus solitanii.In a few cases,retrograde labeling of neurons was observed within the medialseptal nucleus,pars medialis of the nucleus medialis thalami,the supramammilarynucleus and nucleus raphe medianus.In certain cases,a small number of cells could be found in the dorsal tegmentalnucleus of Gudden and the nucleus dorsalis nervi vagi.Among those nuclei,the locus coeruleus,the supraoptic nucleus,the paraventri-cular nucleus and the dorsal parabrachial nucleus were labeled bilaterally.

The contents of dopamine (DA) and its metabolites, homovanillic acid (HVA) and 3,4-dihydroxyphenyl acetic acid(DOPAC), in both striata were determined with HPLC-EC technique in each of 28 albino rats, which were divided into 3 groups (bilateral lesioned, unilateral lesioned and healthy control groups). Among the unilateral lesioned rats, three indices such as DA, HVA/DA and DOPAC/DA in the lesioned striata were 22.27％, 420.00％ and 199.75％ of those of the intact striata, respectively. This suggests that there may be an enhanced compensatory DA release in the striatum ipsilateral to the lesion of the rat. Having compared the lesioned striata of unilateral lesioned rats with those of bilateral lesioned animals, and the intact striata of unilateral lesioned rats with those of the control ones, we did not find any significant differences in DA, HVA/DA or DOPAC/DA. The result implies that the compensatory DA release in the lesioned striatum probably accounts for the mechanism of the ipsilateral nigrostriatal system, not for the crossed nigrostriatal fibers.

The human venous valve of the brachial,femoral and long saphenous veins wereexamined with light,transmission and scanning electron microscopy.The observationshows that the venous valve is composed of three functional layers covered withendothelium on both surfaces.A loosely structured layer is located underlying theendothelium.A network mainly containing randomly oriented elastic fibers was foundnear the side towards the lumen.To the side towards the venous wall,there is adense layer composed of eircumferentially and transversly oriented collagen bundles.Some smooth muscle cells extend from the wall of the vein to the base of thevenous valve.The elastic fibers and smooth muscle cells together with the collagenfibers contribute to the mechanical load-bearing performance of the valve and to thepassive closing and openning mechanism.In addition,the smooth muscle cells mightplay an active role in the normal functioning of the valve.The scanning and transmission electron microscopy of venous valve showdifferent arrangement of the endothelium.On the surface of the valve next to the wallof the vein,the endothelial cells are transversely arranged,while on the othersurface over which the current of blood flows,the cells are longitudinally arrangedin the direction of the current.These accord with the role of fluid mechanics.12 normal venous valves were tested by universal testing instrument (Instrontype 1122).The mean value of the maximum tension of the valve is 1 N.Theaverage value of the tensile ultimate strength is 10N/mm~2.