抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Automated Anatomical Labeling of Activations in SPM Using a Macroscopic Anatomical Parcellation of the MNI MRI Single-Subject Brain

We review evidence for partially segregated networks of brain areas that carry out different attentional functions. One system, which includes parts of the intraparietal cortex and superior frontal cortex, is involved in preparing and applying goal-directed (top-down) selection for stimuli and responses. This system is also modulated by the detection of stimuli. The other system, which includes the temporoparietal cortex and inferior frontal cortex, and is largely lateralized to the right hemisphere, is not involved in top-down selection. Instead, this system is specialized for the detection of behaviourally relevant stimuli, particularly when they are salient or unexpected. This ventral frontoparietal network works as a 'circuit breaker' for the dorsal system, directing attention to salient events. Both attentional systems interact during normal vision, and both are disrupted in unilateral spatial neglect.

Control of goal-directed and stimulus-driven attention in the brain

▪ Abstract The prefrontal cortex has long been suspected to play an important role in cognitive control, in the ability to orchestrate thought and action in accordance with internal goals. Its neural basis, however, has remained a mystery. Here, we propose that cognitive control stems from the active maintenance of patterns of activity in the prefrontal cortex that represent goals and the means to achieve them. They provide bias signals to other brain structures whose net effect is to guide the flow of activity along neural pathways that establish the proper mappings between inputs, internal states, and outputs needed to perform a given task. We review neurophysiological, neurobiological, neuroimaging, and computational studies that support this theory and discuss its implications as well as further issues to be addressed

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An integrative theory of prefrontal cortex function

Publisher Summary This chapter focuses on the modern notion of short-term memory, called working memory. Working memory refers to the temporary maintenance of information that was just experienced or just retrieved from long-term memory but no longer exists in the external environment. These internal representations are short-lived, but can be maintained for longer periods of time through active rehearsal strategies, and can be subjected to various operations that manipulate the information in such a way that makes it useful for goal-directed behavior. Working memory is a system that is critically important in cognition and seems necessary in the course of performing many other cognitive functions, such as reasoning, language comprehension, planning, and spatial processing. This chapter demonstrates the functional importance of dopamine to working memory function in several ways. Elucidation of the cognitive and neural mechanisms underlying human working memory is an important focus of cognitive neuroscience and neurology for much of the past decade. One conclusion that arises from research is that working memory, a faculty that enables temporary storage and manipulation of information in the service of behavioral goals, can be viewed as neither a unitary, nor a dedicated system. Data from numerous neuropsychological and neurophysiological studies in animals and humans demonstrates that a network of brain regions, including the prefrontal cortex, is critical for the active maintenance of internal representations.

Chapter 11 Working memory

Commentary on Garety & Freeman II: ‘Cognitive approaches to delusions ‐ A critical review of theories and evidence’

Is our attitude to money like that to any other tool even though its use is symbolic and is not implemented in its physical structure? Knowledge of the functional use of concrete tools, such as hammers or screwdrivers, has been associated with activation of a left hemisphere network including the posterior temporal cortex, supramarginal gyrus, inferior parietal lobule, and lateral precuneus. Here we demonstrate that observing bank notes being cut up or torn, a critical violation of their function, elicits activation within the same temporo-parietal network. Moreover, this activation is the greater the higher the value of the banknote. This lends plausibility to a genuinely psychological interpretation of the explanation of money as a tool for parametrically symbolizing exchange.

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How the Brain Responds to the Destruction of Money

What Can We Learn from Structural and Functional Brain Imaging

Attempts to understand the relationship between the brain and the mind began with the study of patients with lesions. Much has been learned through such studies about how psychological functions map onto specific cortical regions, particularly with regard to sensory and motor cortex. If the location and extent of the brain lesion is known it is often possible to predict the psychological effect of the lesion. But this approach only works if the mapping relationship is relatively static. This assumption clearly does not apply to the developing brain and recent evidence suggests that the adult brain is also not as static as we once supposed (e.g., Draganski et al., 2004). To study the developing brain we need to look at brain structure and function at different stages in development. The new, non-invasive, brain imaging techniques allow such examination in both healthy and damaged brains without any known risk in the case of magnetic resonance imaging (MRI), magentoencephalography (MEG) and electroencephalography (EEG). These techniques allow us to look at brain structure (location of grey and white matter), brain function (location and timing of changes in brain activity) and brain connectivity (tracing white matter tracts and detecting functional connectivity) (see Primer on Brain Imaging by D.S. Pine). In principle these methods should revolutionize our understanding of brain development and allow us to pinpoint deviations underlying abnormal development, but in practice progress has been slow.

Chris D. Frith

Papers

Commentary on Garety & Freeman II: ‘Cognitive approaches to delusions ‐ A critical review of theories and evidence’

How the Brain Responds to the Destruction of Money

What Can We Learn from Structural and Functional Brain Imaging

The value of brain imaging in the study of development and its disorders.

Inattentional blindness versus inattentional amnesia for