The topical organization of the afferents to the caudatoputamen of the rat. A horseradish peroxidase study

The aim of the present study was to assess (1) whether the various brain areas known to send projections to the neostriatum of the rat (neocortex, thalamus, substantia nigra, ventral tegmental area and dorsal raphe nucleus) project to all parts of this structure, and (2) whether the subcortical projections show a topical organization. For these purposes, small deposits of horseradish peroxidase were delivered by iontophoretic application, so that the whole extent of the caudatoputamen could be covered in a total of 40 rats.Labeled cortical cells were present mainly in lamina V, and showed a roughly topographical organization. Small numbers of labelled cells were observed in the basal nucleus of the amygdala after injections into the dorsal and central parts of the caudatoputamen. The cells of origin of thalamic afferents to the neostriatum were found not only in the intralaminar nuclei, but also in various other anterior, ‘midline’, and posterior nuclei (e.g. the medial part of the medial geniculate body). In the thalamostriatal projection a topical organization was demonstrated, consisting of oblique thalamic zones, which cross the borders of several thalamic nuclei and project to different parts of the neostriatum. In the substantia nigra and ventral tegmental area many retrogradely labelled cells were present. This nigrostriatal projection appears to be organized along an oblique longitudinal neostriatal axis. The nucleus raphes dorsalis was labelled most abundantly after caudal and ventrolateral injections into the caudatoputamen.It is concluded that, despite the homogeneous cytoarchitectonic structure of the caudatoputamen in the rat, this brain area is rather heterogeneous as regards its afferent connections. In fact each part of the neostriatum receives a specific and unique combination of afferents. The main changes in the input of the neostriatum appear to occur along an oblique longitudinal axis, from the most rostromedial and dorsal part to the caudolateral and ventral part. Such a topographical organization suggests that the neostriatum is likely to be involved in very complex integrative functions involving several brain areas.     

Injection of substance P (SP) N-terminal fragment SP(1-7) into the ventral tegmental area modulates the levels of nucleus accumbens dopamine and dihydroxyphenylacetic acid in male rats during morphine withdrawal

The biologically active substance P (SP) N-terminal metabolite SP_1–7 has been reported to modulate several neural processes such as learning, locomotor activity and reaction to opioid withdrawal. Although all these processes are believed to be associated with dopaminergic transmission no evidence of an interaction between SP_1–7 and dopamine in the case of morphine withdrawal has so far been reported. Therefore, in this work we applied in vivo microdialysis to investigate the effect of SP_1–7 injection into the ventral tegmental area on dopamine release in nucleus accumbens of male rats during naloxone precipitated morphine withdrawal. The result showed that the heptapeptide enhances dopamine release and also elevates the level of the dopamine metabolite dihydroxyphenylacetic acid in this brain area. It was suggested that the observed action of the SP fragment on the dopamine system represents the underlying mechanism for a previously observed ability of SP_1–7 to counteract the aversion response to morphine withdrawal.     

胰腺外科学分段的解剖学基础及其意义

目的：为胰腺外科学分段提供解剖学基础。方法：在６４具灌注标本和４具铸型标本上观察胰内动脉分布、吻合。结果：头由胰十二指肠上动脉和胰十二指肠下动脉供血；颈为一乏血管区；体和尾由胰背动脉、胰支、胰大动脉和胰尾动脉供血。结论：全部胰腺可分为左侧段和右侧段     

Late onset type I familial amyloidotic polyneuropathy: Presentation of three autopsy cases in comparison with 19 autopsy cases of the ordinary type

Clinicopathological features of three autopsy cases of extremely rare late onset type I familial amyloldotic polyneuropathy were presented and compared with 19 autopsy cases of the ordinary type. In the late onset cases, the ages at onset and at death were 27.5 and 24.5 years older, respectively, compared with the ordinary type. Also, duration of the total clinical course form onset to death was 3.7 years less than in the late onset cases. The degree of amyloid deposition was more marked in the heart of the late onset cases, causing prominent cardiac hypertrophy. It was also marked In the kidneys or thyroid of two cases, but slight to moderate in the peripheral or autonomic nervous tissues in all cases. Immunohistochemical Investigation demonstrated the presence of transthyretin (TTR) as an amyloid precursor protein and of serum amyloid P-component in amyloid deposits in various organs and tissues of the late onset type. These findings, as well as serum levels of variant TTR, were similar to those of the ordinary type. These results suggest that there are some factors other than the amyloid precursor protein that effect the degree of amyloid deposition.     

Movement-related potentials preceding voluntary movement are modulated by the mode of movement selection

In two experiments movement-related cortical potentials preceding voluntary movement were recorded. In experiment 1, subjects performed four motor tasks involving joystick movements. The four tasks differed in complexity (single vs sequential movements) and in the mode of movement selection, i.e., whether a movement or movement sequence was made in fixed or in self-determined directions. The choice of these tasks was based, firstly, on previous electrophysiological studies suggesting an effect of task-complexity on the amplitude of the readiness potential (RP) and, secondly, on previous positron emission tomography (PET) studies showing that activity of the supplementary motor area (SMA) is influenced by the mode of movement selection. The results show that, for single movements, RP amplitude is higher preceding freely selected movements than preceding movements in a fixed direction. In experiment 2 this effect was replicated using button presses instead of joystick movements. The results converge with PET evidence obtained in similar tasks and establish that the RP is modulated by the mode of movement selection. This modulation is probably related to differential involvement of the SMA.     

Organization and expression of agonistic and socio-sexual behavior in golden hamsters over the estrous cycle and after ovariectomy

Paris of hamsters were housed in large enclosures that contained separate male and female living areas and observed over the 4-day estrous cycle and after ovariectomy. Agonistic elements exhibited frequently by females included on-back, boxing, lateral posturing, and biting, whereas males engaged frequently in boxing and on-back patterns of behavior. Furthermore, on-back and boxing by females were significantly higher on estrus than on any other day of the estrous cycle. Agonistic acts performed after ovariectomy did not differ in occurrence from those shown by animals on diestrus and proestrus. Vaginal marking increased during diestrus and attained a peak 24 hr prior to sexual receptivity. Both vaginal marking and mating occurred more frequently in the female's than male's home area suggesting that vaginal marks on days preceding behavioral estrus serve to attract males to the nest of females. Males also organized their marking patterns by location as shown by more flank marking in their own than their partner's area, albeit the significance for this difference in location is not known. The results demonstrate that when heterosexual paris of hamsters are tested in large and partially familiar habitats, a wide range of behavior is exhibited and organized in a manner that is not observed in small and unfamiliar cages.     

帕金森病模型大鼠中脑腹侧被盖区多巴胺能神经元改变的实验研究

目的：探讨帕金森病（Parkinson’s disease，PD）大鼠模型中脑腹侧被盖区（ventral tegmentalarea，VTA）多巴胺能神经元的改变。方法：应用6-羟基多巴胺（6-hydroxydopamine，6-OHDA）注射右侧黑质致密区（substantia nigra compacta，SNc）制作PD大鼠模型，进行阿朴吗啡（apomorphine，APO）诱发行为学观察、电镜、尼氏染色观察中脑VTA神经元的改变、酪氨酸羟化酶（tyrosine hydroxylase，TH）免疫组织化学ABC观察其DA能神经元的改变并进行图像分析。结果：APO诱发PD大鼠模型异常旋转行为，尼氏染色见PD大鼠中脑VTA有神经细胞肿胀、坏死等变化，VTA TH阳性神经元数量减少，形态学改变。结论：中脑VTA DA能神经参与PD模型大鼠的改变；APO能诱导6-OHDAPD模型大鼠的旋转行为，其强弱可能与TH^＋神经元数量直接相关。     

Changes in myocardial capillary diffusion capacity during infusion of vasoactive drugs

The present study investigated how variations in coronary vascular resistance and metabolic demand affected myocardial capillary diffusion capacity. Hearts from Wistar rats were perfused with Krebs-Henseleit-albumin buffer in a Langendorff preparation, where heart rate (HR), contractility (dP/dt_max) and myocardial oxygen consumption (MVO₂) were recorded continuously. Myocardial capillary diffusion capacity was measured as the permeability surface area product (PS) for Cr-EDTA and vitamin B₁₂ by the single injection colorimetric indicator dilution method. After base-line recordings without drugs, angiotensin II + arginine-vasopressin was infused, which increased coronary vascular resistance by 90%, stimulated HR by 11%, decreased dP/dt_max by 21% and reduced MVO₂ by 4%. PS_Cr-EDTA and PS_B12, decreased by 24 and 27%, respectively, leaving the ratio PS_Cr-EDTA/PS_B12 unchanged indicating unaltered capillary permeability. Moreover, the reductions in MVO₂ and PS correlated significantly. During vasodilation: (1) nitroprusside-NA stimulated HR by 7% and decreased dP/dt_max by 14%; (2) adenosine reduced dP/dt_max by 37% and decreased MVO₂ by 9%; and (3) isoproterenol increased HR, dP/dt_max and MVO₂ by 53, 76 and 9%, respectively. However, all three vasodilators reduced PS_Cr-EDTA and PS_B12 in parallel by 7–25% leaving PS_Cr-EDTA/PS_B12 unchanged. Thus, maximal estimated diffusion capacities were obtained during spontaneous coronary vascular tone, most likely reflecting maximal capillary recruitment in the Krebs-Henseleit-albumin perfused heart. The derecruiting effects of the vasoconstrictors were partly overridden by metabolic factors, while the reductions of PS after vasodilation more likely were due to increased heterogeneity in coronary flow.     

Electrodermal Orienting Responses to Onset and Offset of Auditory Stimulation under Nonsignal Conditions

It has previously been reported that the orienting reflex (OR) to the onset of a stimulus habituates more slowly than the OR to stimulus offset. In this paper, we attempted to account for this in terms of differences between the ON condition (whose presentation elicits the onset OR) and the OFF condition (whose “presentation” elicits the offset OR). Because the typical habituation paradigm begins with a period of adaptation to the OFF (stimulus absent) condition, the relative novelty of the ON condition is enhanced. This bias would contribute to the advantage of onset ORs over offset responses. This hypothesis was evaluated by comparing skin conductance responses (SCRs) to onset and offset of a 600 Hz tone in a group adapted in the presence of that tone (Tone Adaptation, TA) vs one adapted in its absence (Silent Adaptation, SA). The results supported our hypothesis; onset ORs habituated significantly more slowly than offset ORs in Group SA, but not in Group TA.     

Epidemiologic survey and genetic analysis of endemic hepatitis C virus infection in a Japanese town with a high prevalence of hepatitis B virus carriers

Mass screening for hepatitis C virus antibody was carried out in 875 inhabitants (313 men and 562 women) of a town in Japan with a high rate of hepatitis B virus infection. The overall rate of positivity for anti-HCV was 8.8% (6.4% in men and 10,1% in women). The rate of positivity for hepatitis B virus surface antigen was 11.2%. Five subjects (0.6%) were positive for both markers. HCV-RNA was detected in 65 (88.4%) of 77 individuals who were positive for anti-HCV and in 1 (1.5%) of 60 individuals negative for anti-HCV. The genotype of the HCV genome was determined by PCR analysis using type-specific primers in 60 individuals. HCV type 1b was detected in 51 subjects (85%), type 2a in 3 subjects (5%), and type 2b in 6 subjects (10%). None of the individuals was infected with more than one genotype. The nucleotide sequences of the partial nonstructural 5 region of HCV type 1b genotype obtained from 6 individuals showed at least 92.0% homology in the nucleotide sequence, and 94.8% homology in the amino acid sequence. Homology among these clones was greater than their homology with previously described type 1 b sequences. The findings suggest that there was a specific local origin of HCV infection, although it was not possible to identify any single source of HCV infection. The results also indicate the presence of asymptomatic HCV carriers. © 1995 Wiley-Liss, Inc.