Project 2: Functional and neurochemical brain changes following successful trea..

抑郁状态是双相情感障碍的主要特征，也是发病率和 躁郁症患者的死亡率。症状包括情感变化、神经植物性体征和显著 认知缺陷。有几条证据表明这些症状与神经病理有关。 构成前缘网络(ALN)的结构异常，这是一个假设为 调节情绪动态平衡。这些异常表现为神经功能成像的改变。 参与情绪控制的区域包括腹外侧额叶皮质(VLPFC)、前扣带回 大脑皮质(ACC)和杏仁核，以及与神经元新陈代谢升高相一致的神经化学变化。 双相抑郁患者的磁共振波谱(MRS)研究表明 能量代谢可能是前额叶和内侧颞叶活动增加的基础，在功能性 磁共振成像(FMRI)和正电子发射断层扫描(PET)。双相情感障碍患者 显示N-乙酰天冬氨酸(NAA)前额叶浓度的显著变化，以及 磷酸单酯(PME)的变化和乳酸的存在，表明能量代谢发生了变化。 前额叶皮质谷氨酸增加的证据表明，这种增加的神经元活动是 与前额叶皮质内神经元内兴奋性信号的增加有关。总而言之，这些数据 支持一种模型，在该模型中，双相抑郁的特征是与以下因素相关的情绪调节丧失 增强ACC和VLPFC的激活，抑制或干扰其他大脑区域，包括 背外侧前额叶皮质，它调节受双相情感障碍影响的认知域。这些 前额叶神经元活动的变化似乎对药物干预有反应。 考虑到这些因素，本研究的目标是：1)使用1H-MRS来识别神经代谢 早期抑郁双相患者的异常，并确定异常如何改变在 对特定治疗的反应；以及2)识别功能磁共振脑激活的相应变化，按顺序 提供神经功能与治疗反应的神经化学标记物的相关性。要实现这些目标 AIMS，我们将在发病早期获得综合神经代谢(MRS)和神经功能(FMRI)测量 抑郁的双相情感障碍患者和一组匹配的健康受试者，以完善 双相情感障碍的神经生理学模型(中心目标1)；确定MRS和fMRI标志物 双相抑郁患者对两种不同药物的治疗反应(中心目标2)； 确定未来研究治疗反应的潜在预测因素(中心目标3)。

Depressive states are the predominant feature of bipolar disorder and a major source of morbidity and mortality in bipolar patients. Symptoms include affective changes, neurovegetative signs, and significant cognitive deficits. Several lines of evidence suggest that these symptoms are linked to neuropathological abnormalities in structures making up the anterior limbic network (ALN), a brain network hypothesized to modulate emotional homeostasis. These abnormalities are manifest by functional neuroimaging changes in regions involved in emotional control including the ventrolateral prefrontal cortex (VLPFC), anterior cingulate (ACC) and amygdala, as well as by neurochemical changes consistent with elevated neuronal metabolism. Magnetic resonance spectroscopy (MRS) studies of depressed bipolar patients suggest that abnormalities in energy metabolism may underlie increased prefrontal and medial temporal activity observed with functional magnetic resonance imaging (fMRI) and positron emission tomography (PET). Patients with bipolar disorder demonstrate significant changes in prefrontal concentrations of N-acetyl aspartate (NAA), as well as changes in phosphomonoesters (PME) and the presence of lactate, that suggest altered energy metabolism. Evidence of increased glutamate in the prefrontal cortex suggests that this increased neuronal activity is related to increased intraneuronal excitatory signaling within the prefrontal cortex. Together, these data support a model in which bipolar depression is marked by a loss of emotional modulation linked with increased ACC and VLPFC activation, and inhibition of, or interference with other brain regions, including the dorsolateral prefrontal cortex, which mediates cognitive domains impacted by bipolar disorder. These prefrontal changes in neuronal activity appear to be responsive to pharmacologic intervention. With these consideration in mind, the goals of this study are: 1) To use 1H-MRS to identify neurometabolic abnormalities in early-episode depressed bipolar patients, and to determine how abnormalities change in response to specific treatments; and 2) To identify corresponding changes in fMRI brain activation, in order to provide neurofunctional correlates to neurochemical markers of treatment response. To accomplish these aims, we will acquire integrated neurometabolic (MRS) and neurofunctional (fMRI) measurements in earlyepisode depressed bipolar patients and a matched cohort of healthy subjects in order to refine neurophysiological models of bipolar disorder (Center goal 1); to identify MRS and fMRI markers of treatment response in bipolar depression to two mechanistically different medications (Center goal 2); and to identify potential predictors of treatment response for future studies (Center goal 3).