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

The unity and diversity of executive functions and their contributions to complex "Frontal Lobe" tasks: a latent variable analysis.

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

Special issue on the psychopharmacology of prepulse inhibition: basic and clinical studies.

TW Robbins Dept. of Psychology and Behavioural & Clinical Neuroscience Institute, University of Cambridge, U.K. Downing St. Cambridge CB2 3EB U.K. twr2@cam.ac.uk 44-1223-333551 The review by Waters and Fearneyhough makes it clear that there is nothing especially distinctive about hallucinations in schizophrenia, not even to the extent of hallucinations in the auditory modality being more prevalent than in the visual one, or hallucinations in schizophrenia having a greater preponderance of angry, critical voices. Hallucinations may occur both in people without mental disturbances, and also as a consequence of many different pathologies, including tinnitus and Parkinson’s disease and other neuropsychiatric disorders such as post-traumatic stress disorder. This conclusion is consistent with a Research Domain Criteria (RDoc) approach to psychiatric nosology, as hallucinations are evidently trans-diagnostic with respect to the categorical diagnosis of schizophrenia or psychosis. What does this mean for animal models of hallucinations and, more indirectly, for understanding neurobiological mechanisms underlying hallucinations? Is the task of modeling hallucinatory behavior in animals any more revealing or useful than it was some 50 years ago when there was a major drive to understand the effects of hallucinogenic drugs acting at serotonin (5hydroxytryptamine, 5-HT) receptors, such as LSD? This commentary will endeavor to address these issues in the context of recent neuroscientific advances.

Animal Models of Hallucinations Observed Through the Modern Lens.

Modelling psychosis

This review aims to shed light on the symptoms of obsessive-compulsive disorder (OCD) with a focus on contamination fears. In addition, we will briefly review the current therapies for OCD and detail what their limitations are. A key focus will be on discussing how smartphone solutions may provide approaches to novel treatments, especially when considering global mental health and the challenges imposed by rural environments and limited resources; as well as restrictions imposed by world-wide pandemics such as COVID-19. In brief, research that questions this review will seek to address include: (1) What are the symptoms of contamination-related OCD? (2) How effective are current OCD therapies and what are their limitations? (3) How can novel technologies help mitigate challenges imposed by global mental health and pandemics/COVID-19.

Obsessive-compulsive disorder-contamination fears, features and treatment: Novel smartphone therapies in light of global mental health and pandemics (COVID-19)

Rationale
The neuropeptide Y (NPY) system acts in synergy with the classic neurotransmitters to regulate a large variety of functions including autonomic, affective, and cognitive processes. Research on the effects of NPY in the central nervous system has focused on food intake control and affective processes, but growing evidence of NPY involvement in attention-deficit/hyperactivity disorder (ADHD) and other psychiatric conditions motivated the present study.

Trevor W. Robbins

Papers

Special issue on the psychopharmacology of prepulse inhibition: basic and clinical studies.

Animal Models of Hallucinations Observed Through the Modern Lens.

Modelling psychosis

Obsessive-compulsive disorder-contamination fears, features and treatment: Novel smartphone therapies in light of global mental health and pandemics (COVID-19)

Enhanced inhibitory control by neuropeptide Y Y5 receptor blockade in rats