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41.
BACKGROUND: Functional neuroimaging studies have detected abnormal limbic and paralimbic activation to emotional probes in posttraumatic stress disorder (PTSD), but few studies have examined neurochemical mechanisms that underlie functional alterations in regional cerebral blood flow. The mu-opioid neurotransmitter system, implicated in responses to stress and suppression of pain, is distributed in and is thought to regulate the function of brain regions that are implicated in affective processing. METHODS: Here we examined the micro-opioid system with positron emission tomography and the micro-opioid receptor-selective radiotracer [11C] carfentanil in 16 male patients with PTSD and two non-PTSD male control groups, with (n = 14) and without combat exposure (n = 15). Differences in micro-opioid receptor binding potential (BP2) were detected within discrete limbic and paralimbic regions. RESULTS: Relative to healthy controls, both trauma-exposed groups had lower micro-opioid receptor BP2 in extended amygdala, nucleus accumbens, and dorsal frontal and insular cortex but had higher BP2 in the orbitofrontal cortex. PTSD patients exhibited reduced BP2 in anterior cingulate cortex compared with both control groups. Micro-opioid receptor BP2 in combat-exposed subjects without PTSD was lower in the amygdala but higher in the orbitofrontal cortex compared with both PTSD patients and healthy controls. CONCLUSIONS: These findings differentiate the general response of the micro-opioid system to trauma from more specific changes associated with PTSD.  相似文献   
42.
BACKGROUND: Perfusion functional magnetic resonance imaging (fMRI) was used to investigate the effect of genetic variation of the human serotonin transporter (5-HTT) gene (5-HTTLPR, SLC6A4) on resting brain function of healthy individuals. METHODS: Twenty-six healthy subjects, half homozygous for the 5-HTTLPR short allele (s/s group) and half homozygous for the long allele (l/l group), underwent perfusion functional and structural magnetic resonance imaging during a resting state. The two genotype groups had no psychiatric illness and were similar in age, gender, and personality scores. RESULTS: Compared with the l/l group, the s/s group showed significantly increased resting cerebral blood flow (CBF) in the amygdala and decreased CBF in the ventromedial prefrontal cortex. The effect of functional modulation in these regions by 5-HTTLPR genotype cannot be accounted for by variations in brain anatomy, personality, or self-reported mood. CONCLUSIONS: The 5-HTTLPR genotype alters resting brain function in emotion-related regions in healthy individuals, including the amygdala and ventromedial prefrontal cortex. Such alterations suggest a broad role of the 5-HTT gene in brain function that may be associated with the genetic susceptibility for mood disorders such as depression.  相似文献   
43.
Objective To investigate a novel method of adrenocotical cells transplantation. Methods Adrenal glands of neonate rats were dissociated into adrenal cortical cells. Cells were cultured in self-made collagen type Ⅰ gel for one week, and then transplanted under the renal capsule of bilateral adrenalectomy mate rats. Blood samples were collected per week after surgery. Animals were sacrificed at the 8th week, and histological characteristics of the allografts, proliferation of transplanted cells, CYP11B1 and CYP11B2 expression as well as plasma aldosterone and corticosterone were observed. Results There were totally 15 rats receiving collagen gel transplantation, and 12 survived 8 weeks post-operation. The plasma cortocosterone level in collagen gel transplantation group was significantly higher than in adrenocortical cell transplantation group, and reached the normal level from 6th to 8th week, but the change in plasma aldosterone level in collagen gel transplantation group was similar to that of adrenocortical cell transplantation group. The adrenocortical cells cultured in gel grew well, and had a high proliferation rate. 95% of them were fasciculata cells which expressed CYP11B1, and the rest were glomerulosa cells which expressed CYP11B2. No inflammatory cell infiltration was observed. Conclusion The proliferation and function of adrenocortical cells could be promoted when they were cultured in collagen gel.  相似文献   
44.
Understanding the mechanisms of food intake and obesity   总被引:2,自引:1,他引:1  
  相似文献   
45.
目的 观察益气复智颗粒对多发脑梗死性痴呆模型大鼠脑皮质形态学、细胞凋亡的影响。方法 采用颈内动脉注射血栓的方法,复制多发梗死性痴呆大鼠模型,观察益气复智颗粒12.42g/kg分别于手术前、手术前后、手术后灌胃对实验动物脑皮质形态学、细胞凋亡的影响。结果 益气复智颗粒能使脑缺血后脑内神经细胞凋亡数目下降。结论 益气复智颗粒具有较好的保护脑神经元,阻断脑缺血致神经细胞死亡病理过程的作用。  相似文献   
46.
后腹腔镜治疗肾上腺肿瘤35例临床分析   总被引:15,自引:9,他引:6  
目的总结后腹腔镜技术治疗肾上腺肿瘤的临床经验.方法采用后腹腔镜切除肾上腺肿瘤35例,男12例,女23例.年龄25岁~72岁,平均49.8岁.左侧15例,右侧20例.其中嗜铬细胞瘤5例,原发性醛固酮增多症10,柯兴氏病2例,神经节细胞瘤2例,无功能性腺瘤16例.腰部取3个套管针穿刺入路,用自制的水囊扩张器扩张后腹腔,用超声刀将肿瘤切除.结果 35例手术均成功,无中转开放手术病例.术中出血量10~500 ml,平均74 ml.病人均未输血.手术时间45~200 min,平均90 min.结论后腹腔镜手术切除肾上腺肿瘤手术效果确切,手术时间短,术中出血少,损伤小,术后恢复快,可以替代绝大多数肾上腺肿瘤开放手术.  相似文献   
47.
Paul L. Booth  W. Eric Thomas   《Brain research》1991,548(1-2):163-171
Ramified microglial cells were investigated in primary cultures of dissociated cerebral cortical tissue from rats. The identification of these cells was confirmed through immunohistochemical staining with 7 monoclonal antibodies selective for microglia. While there was significant variation in staining intensity with different antibodies, all stained the identified ramified cells; the antibodies OX-42 and ED1 yielded the most intense immunoreactivity. Based on distinctive morphological features, the microglia could be identified in living cultures where they were monitored using time-lapse video recording. This technique revealed extremely dynamic features of cellular plasticity and motility. Ramified microglia exhibited constant and rapid alterations in the size and shape of their cell body with an associated extension and retraction of processes; concomitantly, the cells moved about in a circumscribed area. These features of plasticity and motility were unique to this cell type, and correlated with OX-42 immunostaining. The microglia also possessed a differentially high level of pinocytotic activity; this too was correlated with OX-42 staining. From the nature of their morphological plasticity and motility, high pinocytosis, and cellular distribution, it is hypothesized that the ramified microglia specifically function as a system of fluid cleansing in normal brain tissue.  相似文献   
48.
The mechanism of action of systemitically administered(±)-MDMA (3, 4-methylenedioxymethamphetamine) on spontaneously active neurons in the medial prefrontal cortex (mPFc) of chloral hydrate anesthetized rats was examined using standard single unit extracellular recording techniques. Intravenously administered MDMA dose-dependently decreased the firing rates of the majority of mPFc neurons in control rats. In contrast, in rats that were pretreated withp-chlorophenylalanine (PCPA), which depletes the brain serotonin (5-hydroxytryptamine, 5-HT) content by inhibiting tryptophan hydroxylase, the rate-limiting enzyme in the synthesis of 5-HT, MDMA was largely ineffective in inhibiting the firing of mPFc cells. In PCPA-treated animals, the administration of 5-hydroxytryptophan (5-HTP), which presumably restored the brain 5-HT content, but notl-DOPA, reinstated MDMA's inhibitory action in PCPA-treated rats. In rats that were pretreated withα-methyl-p-tyrosine (AMPT), which depletes the brain dopamine (DA) content by inhibiting tyrosine hydroxylase, the rate-limiting enzyme in the synthesis of DA, MDMA inhibited the firing of all of the mPFc cells. MDMA's effect on mPFc neurons was reversed by 5-HT receptor antagonists such as granisetron and metergoline. These results strongly suggest that MDMA exerts its action on mPFc cells indirectly by releasing endogenous 5-HT.  相似文献   
49.
50.
An investigation was made into the directional sensitivity of cells in the macaque anterior superior temporal polysensory region (STPa) to the motion of objects. The cells studied were sensitive to the presence of motion but showed little or no selectivity for the form of the stimulus. Directional tuning was not continuously distributed about all possible directions. The majority of cells were most responsive to motion in a direction within 15° of one of the three cartesian axes (up/down, left/right, towards/away). Tuning to direction varied in sharpness. For most (34/37) cells the angular change in direction required to reduce response to half maximal was between 45 and 70° (for 3/37 cells it was > 90°). The estimates of the directionality (median I d = 0.97) of STPa cells was similar to that reported for posterior motion processing areas (the middle temporal area, MT, and the medial superior temporal area, MST). The tuning for direction (sharpness, distribution and discrimination) of the motion-sensitive STPa cells were found to be similar to the tuning for perspective view of STPa cells selective for static form of the head and body. On average the STPa responses showed a 100- to 300-ms transient burst of activity followed by a tonic discharge maintained at approximately 20% of the peak firing rate for the duration of stimulation. The responses of motion-sensitive STPa cells occurred at an earlier latency (mean 91 ms) than responses of cells selective for static form (mean 119 ms), but the time course of responses of the two classes of cell were similar in many other respects. The early response latency and directional selectivity indicate that motion sensitivity in STPa cells derives from the dorsal visual pathway via MT/MST. The similarity of tuning for direction and perspective view within STPa may facilitate the integration of motion and form processing within this high-level brain area.  相似文献   
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