人类和猴子的急性子都是从婴儿时代就明显表现出来了,是日后精神病理学的一个重要风险因素,并且已知是可以遗传的。在一项将成像方法与遗传学方法结合起来的大型研究中,Oler等人对与这一特征相关的神经回路以及这个回路的功能的可遗传程度进行了定性。
研究中采用了超过200只来自同一个家系的猴子,在将这些猴子置于一个轻度紧张情境中之后,他们用正子发射断层扫描技术对其进行了扫描。扁桃体和海马体中的活动程度都能指示性情,但海马体活动的可遗传性大于扁桃体活动的可遗传性。这表明,在急性子中,基因和环境对这两个区域的功能可能有不同影响。这个发现也为焦虑症和抑郁症的遗传风险提供了新的见解。(生物谷Bioon.com)
生物谷推荐原文出处:
Nature doi:10.1038/nature09282
Amygdalar and hippocampal substrates of anxious temperament differ in their heritability
Jonathan A. Oler,Andrew S. Fox,Steven E. Shelton,Jeffrey Rogers,Thomas D. Dyer,Richard J. Davidson,Wendy Shelledy,Terrence R. Oakes,John Blangero& Ned H. Kalin
Anxious temperament (AT) in human and non-human primates is a trait-like phenotype evident early in life that is characterized by increased behavioural and physiological reactivity to mildly threatening stimuli1, 2, 3, 4. Studies in children demonstrate that AT is an important risk factor for the later development of anxiety disorders, depression and comorbid substance abuse5. Despite its importance as an early predictor of psychopathology, little is known about the factors that predispose vulnerable children to develop AT and the brain systems that underlie its expression. To characterize the neural circuitry associated with AT and the extent to which the function of this circuit is heritable, we studied a large sample of rhesus monkeys phenotyped for AT. Using 238 young monkeys from a multigenerational single-family pedigree, we simultaneously assessed brain metabolic activity and AT while monkeys were exposed to the relevant ethological condition that elicits the phenotype. High-resolution 18F-labelled deoxyglucose positron-emission tomography (FDG–PET) was selected as the imaging modality because it provides semi-quantitative indices of absolute glucose metabolic rate, allows for simultaneous measurement of behaviour and brain activity, and has a time course suited for assessing temperament-associated sustained brain responses. Here we demonstrate that the central nucleus region of the amygdala and the anterior hippocampus are key components of the neural circuit predictive of AT. We also show significant heritability of the AT phenotype by using quantitative genetic analysis. Additionally, using voxelwise analyses, we reveal significant heritability of metabolic activity in AT-associated hippocampal regions. However, activity in the amygdala region predictive of AT is not significantly heritable. Furthermore, the heritabilities of the hippocampal and amygdala regions significantly differ from each other. Even though these structures are closely linked, the results suggest differential influences of genes and environment on how these brain regions mediate AT and the ongoing risk of developing anxiety and depression.