抑郁症嗅觉功能缺陷的研究进展

抑郁症的嗅觉障碍在其发病过程中具有特征性表现。近年来,国外研究证实抑郁症存在嗅觉功能的缺陷并与嗅球体积的减小存在关联,但嗅觉功能障碍在抑郁症的临床表现和严重程度之间的机制尚不完全清楚,国内研究亦甚少。故开展抑郁症嗅觉障碍的研究有助于开展抑郁症的早期诊断、疗效评估。进一步研究有望为将来探索定位于嗅觉系统的非侵入性靶点式疗法提供思路。     

认知情绪调节策略与抑郁症状的相关性

目的 探讨认知情绪调节策略与抑郁症状水平的关系.方法 采用认知情绪调节问卷中文版(CERQ)和Beck抑郁自评问卷(BDI)对90例住院抑郁发作患者和90名健康对照组人群进行评定.结果 抑郁组CERQ非适应性策略得分[(38.38±11.68)分]高于健康对照组[(31.27±7.91)分],而适应性策略得分[(41.33±10.79)分]低于健康对照组[(45.43±12.08)分],差异均有统计学意义(P＜0.05);灾难化、积极重新评价、重新关注计划与抑郁组的抑郁症状水平显著相关(r值分别为0.429,-0.402,-0.384;P＜0.01);多元线性回归结果表明,灾难化和积极重新评价是预测抑郁发作患者抑郁症状最重要的变量,而沉思是预测健康人群抑郁症状的重要变量.结论 认知情绪调节与抑郁密切相关,提升积极重新评价策略可能有助于改善和缓解抑郁患者的抑郁症状水平.     

帕金森病与嗅觉障碍

帕金森病被认为是纯运动性疾病,近年来,越来越多的研究发现帕金森病患者存在感觉障碍,尤其是嗅觉障碍。帕金森病患者可出现嗅觉阀值增高,嗅觉辨别能力下降,嗅觉诱发电位潜伏期延长。嗅球、海马等部位神经元的破坏可能是导致嗅觉障碍的原因。嗅觉障碍的发生可能与遗传因素、病毒感染、环境因素或神经递质的改变有关。     

嗅觉障碍与阿尔茨海默病的研究进展

阿尔茨海默病(Alzheimer’s disease,AD)患者嗅觉系统病理改变与皮层退行性变的损害程度完全一致,而且嗅觉系统发生病变在时间上早于皮层病变。AD患者均有不同程度的嗅觉缺损,表现为嗅觉阈升高,嗅觉识别和嗅觉记忆减退。嗅觉缺损可见于AD的前期。是AD早期诊断的重要指标。嗅觉系统与大脑皮层许多部位有广泛联系,药物经嗅觉通路能被转运到脑内多个部位,通过嗅觉通路有可能找到治疗AD有效药物。     

嗅觉系统结构功能及经嗅觉给药通路的研究进展

嗅觉信号的感觉与传导包含:初级嗅觉系统、附属嗅觉系统、三叉神经系统和终神经系统。多种神经递质参与了嗅觉的形成及传导。嗅觉系统与大脑皮层许多部位有广泛联系。当气味受体被一种有气味的物质激活时,就会在嗅觉受体细胞触发一个电信号,经过神经轴突传递到大脑。嗅觉的脑通路可能成为中枢神经系统药物直接进入脑的一条新途径。     

精神分裂症的嗅觉缺陷

本文就与精神分裂症患者嗅觉缺陷的相关因素作了介绍。     

嗅觉障碍与阿尔茨海默病

阿尔茨海默病（AD）为老年期常见的退行性神经变性疾病,以进行性记忆力、智力和认知功能减退为主要表现,至今病因未明,现有药物仅对疾病早期有效,因此,早诊断、早治疗意义重大。阿尔茨海默病的典型病理改变最先累及内嗅区皮质（EC）,然后逐渐向海马等扩散,最终累及全脑皮质。     

嗅觉障碍与阿尔茨海默病

阿尔茨海默病(AD)为老年期常见的退行性神经变性疾病,以进行性记忆力、智力和认知功能减退为主要表现,至今病因未明,现有药物仅对疾病早期有效,因此,早诊断、早治疗意义重大.     

帕金森病患者嗅觉障碍与嗅觉相关脑区结构变化关系的研究

目的利用基于体素的形态学分析（VBM）研究原发性帕金森病患者嗅觉相关脑区结构改变及其与嗅觉障碍之间的关系,探讨其作为早期诊断的可能性。方法应用“五味嗅觉测试液”对26例诊断明确的早期原发性帕金森病患者进行嗅觉功能检测,并与年龄、病程和病情严重程度[帕金森病统一评价量表（UPDRS）]进行相关分析。磁化准备快速梯度回波序列获取三维结构图像,SPM5软件后处理,通过配准、分割获得白质密度图像,经调试获得白质体积图像。结果帕金森病组患者嗅觉察觉阈值和嗅觉识别阈值分别为0．66±0．84和2．41±0．74,显著高于对照组的-0．64±0．83和1．08±0．54（Z=4．455,P=0．000;t=4．898,P=0．000）。帕金森病组患者嗅觉功能与年龄（察觉阈值：n=0．199,P=0．330;识别阈值：n=0．256,P=0．207）、病程（察觉阈值：n=0．123,P=0．550;识别阈值：n=0．055,P=0．789）及UPDRSⅢ评分（察觉阈值：n=0．229,P=0．260;识别阈值：rs=0．379,P=0．056）无明显相关性;UPDRS总评分与嗅觉察觉阈值无相关性（rs=0．314,P=0．118）,但与嗅觉识别阈值呈正相关（n=0．397,P=0．045）。与对照组相比,原发性帕金森病组患者右侧枕叶（BA17～19区）、左侧扣带回后部（BA23,30,31区）、左侧枕叶（BA18,19区）和左侧中央旁小叶（BA3～5区）白质密度,以及双侧枕叶（BA17～19区）、左侧扣带回后部（BA23,30,31区）和左侧中央旁小叶（BA3～5区）白质体积均增加,且左侧扣带回后部白质密度增加与嗅觉识别阈值呈负相关（rs=0．496,P=0．010）。结论原发性帕金森病患者嗅觉功能明显减退,但与年龄及病程均无相关性。有嗅觉减退的早期帕金森病患者其嗅觉相关脑区,尤其是神经纤维通过的白质脑区存在明显的病理变化,可能提示帕金森病患者嗅觉障碍是中枢神经变性的结果。与此同时,VBM法作为一种客观分析方法,弥补了兴趣区分析法的缺点,可以广泛用于帕金森病或神经变性疾病的诊断分析。     

Gustatory and olfactory function in patients with unipolar and bipolar depression

Although the crucial distinction between unipolar depressive disorder and bipolar disorder is the presence of mania (or hypomania) in the course of the latter, significant differences between unipolar and bipolar depression have also been found in clinical studies. The primary aim of the present investigation was to assess pleasantness/unpleasantness ratings of chemosensory stimuli in depressed patients, including subjects with unipolar and bipolar depression. Sensory aspects (thresholds and identification abilities) of gustatory and olfactory function were also assessed. There were no major differences between a depression group, as a whole, and healthy controls in terms of gustatory and olfactory thresholds and identification abilities. Similarly, pleasantness ratings of various gustatory and olfactory stimuli did not differ between the control and depression group. Gustatory and olfactory thresholds and identification abilities did not differ between individuals with unipolar and bipolar depression. Bipolar patients tended to rate less gustatory stimuli as unpleasant and more olfactory stimuli as pleasant compared to unipolar patients. The present results suggest that: i) depression is not associated with any major deficit in sensory aspects of gustatory and olfactory function or altered hedonic ratings of chemosensory stimuli; ii) hedonic responses to chemosensory stimuli tend to be increased in bipolar as compared to unipolar depressed patients.     

Analysis of olfactory function and the depth of olfactory sulcus in patients with Parkinson's disease.

Olfactory deficit is known to occur frequently in Parkinson's disease (PD). This study aimed to explore olfactory deficit in PD and to investigate its possible correlation with the disease severity or the depth of the olfactory sulcus. Fifty-nine PD patients and 25 normal controls were examined by the odor identification test with the crosscultural smell identification test (CC-SIT). Among these subjects, the depth of the olfactory sulcus of 42 PD patients and 8 controls was measured in the plane of the posterior tangent through the eyeballs using the coronal view brain MRI. The CC-SIT scores of the PD patients were significantly lower than those of the normal control (P<0.001). However, CC-SIT did not correlate with the disease duration, H-Y stage, score of UPDRS Part III, or the depth of either side of the olfactory sulcus (P>0.05). Our study confirms that CC-SIT is a helpful test in detecting the olfactory deficit in Korean PD patients. The absence of correlation of olfactory deficit with the disease severity or the depth of olfactory sulcus may suggest that olfactory loss precede the development of motor signs and not be a primary consequence of damage to the olfactory sulcus.     

Depth of olfactory sulcus and olfactory function

The aim of this study was to identify whether the depth of the olfactory sulcus relates to olfactory function in healthy subjects. Forty-four healthy, male volunteers (age range 22-45 years, mean age 28.3 years) were included in this study. Olfactory function was measured for phenyl ethyl alcohol odor thresholds, odor discrimination, and odor identification. Magnetic resonance imaging of the olfactory sulcus was performed immediately following olfactometry. Based on previous investigations the depth of the olfactory sulcus was measured in the plane of the posterior tangent through the eyeballs. Olfactory function correlated significantly with left-sided depth of the olfactory sulcus (r(44)=0.33, P=0.03); no such correlation was seen for the right side. In addition, olfactory sulcus depth was found to be significantly deeper on the right compared to the left side (t=5.61, P<0.001). The present results suggest that there is small, but significant relation between morphological brain structures and measures of olfactory function. Further, lateralization of olfactory sulcus depth may correlate to functional lateralization in the olfactory system. Thus, it may be carefully speculated that sensory input in the olfactory system results in cortical growth in the area of the olfactory sulcus, at least at some developmental stage.     

首发与复发抑郁症患者的认知功能特征比较

目的 探讨首发与复发抑郁症患者的认知功能特征及两者间的差异,以及与疾病严重程度的相关性.方法 招募符合DSM-Ⅳ中抑郁症诊断标准的首发抑郁症患者共31例为首发组,复发性抑郁症患者30例为复发组,健康志愿者31名为对照组,对3组进行韦氏数字广度(DS)测验、威斯康星卡片分类测验(WCST)和爱荷华赌博任务(IGT)测验,比较3组被试在各测量指标上的差异,同时用HAMD-24评估患者组的抑郁程度,并分析其与认知功能各指标的相关性.结果 (1)3组患者DS评分的差异有统计学意义(P<0.05),其中复发组低于对照组(P<0.05),首发组与复发组及首发组与对照组差异均无统计学意义(P>0.05).(2)3组患者WCST评分的差异有统计学意义,其中复发组与对照组及复发组与首发组间差异均有统计学意义(P<0.05),首发组和对照组差异无统计学意义(P>0.05).(3)3组患者IGT评分的差异有统计学意义(P<0.05),其中复发组除第二模块外,其余各项指标均高于对照组(P<0.05),复发组的总分、第三模块和第五模块评分均高于首发组(P<0.05).(4)患者组(首发组+复发组)的HAMD总分与DS评分、WCST分类数呈负相关(r=-0.373,P=0.003;r=-0.299,P=0.019),与WCST的错误应答数、持续性错误应答数、非持续错误应答数和IG T的总分、第三模块评分、第五模块评分呈正相关(r=0.265~0.461,P<0.05),与IG T第一模块、第二模块和第四模块无相关性(P>0.05).结论 首发抑郁症患者无明显短时记忆和执行功能损害,在情感决策方面,其倾向于低收益,低风险决策;而复发抑郁症患者的短时记忆、执行功能均有明显损害,且在情感决策上比首发患者对损失更为敏感;抑郁症患者的抑郁程度与认知损害呈正相关.疾病复发和病情加重都会对抑郁症患者的认知损害造成不良影响.     

Cholinergic receptor subtypes in the olfactory bulbectomy model of depression

The connection between smoking and depression, the antidepressant actions of nicotine and the targeting of nicotinic acetylcholine receptors (nAChRs) by monoamine re-uptake inhibitors all point to a potential role of nAChRs in the etiology and/or symptomatology of depression. In the current study, we evaluated nAChR subtypes in brain regions of rats subjected to olfactory bulbectomy (OBX), a standard animal model that recapitulates many of the behavioral and neurochemical alterations thought to underlie human depression. Comparisons were made both to sham-operated controls and unoperated animals. OBX led to upregulation of cerebrocortical alpha4beta2 nAChRs and downregulation of striatal alpha7 nAChRs as compared to either the sham-operated or unoperated groups. Striatal alpha4beta2 nAChRs were also downregulated but the sham surgery by itself produced a partial effect, masking the contribution of the OBX lesion. In agreement with earlier studies, we also found downregulation of muscarinic AChRs (both m1 and m2 subtypes) in the striatum when comparing the OBX group to sham-operated controls, but because sham surgery evoked mAChR upregulation, the effect was not apparent when the OBX animals were contrasted to the unoperated group. Accordingly, caution needs to be exercised in interpreting studies of cholinergic function in the OBX model that do not include unoperated animals as an additional comparison group. Our results reinforce a relationship between depression and nAChR expression and point to the need for parallel studies in human depression that might lead to the design of novel therapies targeting specific nAChR subtypes.     

Increased olfactory bulb volume and olfactory function in early blind subjects

It has been shown that the volume of the olfactory bulb (OB) changes with function. The aim of this study was to investigate whether the OB volume and the olfactory function in early blind (EB) subjects increase compared with controls. Psychophysical testing of olfactory performances and OB volumetric measurements assessed by an MRI scan were studied. Quantitative olfactory function expressed in the odor discrimination and odor-free identification scores was higher in EB subjects compared with controls. The mean of right, left and total OB volume was 65.40, 75.48, and 140.89 mm, respectively for the EB subjects and 54.47, 52.11, and 106.60 mm, respectively for the controls, with these differences being significant. EB subjects have superior olfactory abilities and presented with significantly higher OB volume than the sighted controls. OB plasticity may explain this compensatory mechanism between visual deprivation and enhanced olfactory perception.     

Developmental changes in brain function underlying the influence of reward processing on inhibitory control

Adolescence is a period marked by changes in motivational and cognitive brain systems. However, the development of the interactions between reward and cognitive control processing are just beginning to be understood. Using event-related functional neuroimaging and an incentive modulated antisaccade task, we compared blood-oxygen level dependent activity underlying motivated response inhibition in children, adolescents, and adults. Behaviorally, children and adolescents performed significantly worse than adults during neutral trials. However, children and adolescents showed significant performance increases during reward trials. Adults showed no performance changes across conditions. fMRI results demonstrated that all groups recruited a similar circuitry to support task performance, including regions typically associated with rewards (striatum and orbital frontal cortex), and regions known to be involved in inhibitory control (putative frontal and supplementary eye fields, and posterior parietal cortex, and prefrontal loci). During rewarded trials adolescents showed increased activity in striatal regions, while adults demonstrated heightened activation in the OFC relative to children and adolescents. Children showed greater reliance on prefrontal executive regions that may be related to increased effort in inhibiting responses. Overall, these results indicate that response inhibition is enhanced with reward contingencies over development. Adolescents’ heightened response in striatal regions may be one factor contributing to reward-biased decision making and perhaps risk taking behavior.