Trevor W. Robbins

Bio: Trevor W. Robbins is an academic researcher from University of Cambridge. The author has contributed to research in topics: Prefrontal cortex & Impulsivity. The author has an hindex of 231, co-authored 1137 publications receiving 164437 citations. Previous affiliations of Trevor W. Robbins include Centre national de la recherche scientifique & Massachusetts Institute of Technology.

Does visuospatial memory in senile dementia of the Alzheimer type depend on the severity of the disorder

Abstract: Visuospatial memory was studied in patients suffering from senile dementia of the Alzheimer type (SDAT). They had been allocated into one of two groups depending on the severity of their disorder (mild or moderate), and a control group of healthy elderly subjects was included. Three different microcomputer-controlled tasks were used. The spatial span task was able to distinguish between the two SDAT groups. Both groups were impaired, relative to control, on spatial recognition. The deficit in spatial working memory was also equivalent in the mild and moderate groups and was accompanied by evidence of an intact strategic approach to the task. The normal positive relationship between spatial memory performance and strategy was in fact reversed in the SDAT groups, suggesting a pure spatial memory deficit. These results show that spatial memory processes are impaired in the early stages of SDAT and get worse as the disease progresses. They also suggest that the neuroanatomical foci of the deficits may be predominantly in posterior cortical regions (including hippocampus), rather than the frontal cortex.

Ethanol impairment of spontaneous alternation behaviour and associated changes in medial prefrontal glutamatergic gene expression precede putative markers of dependence

Abstract: Cognitive impairments are observable in over half of cases with alcoholism, deficits in spatial working memory being particularly common. Previously we observed that rats make more alternation errors in a Y-maze test of spontaneous alternation behaviour/spatial working memory after 5-day intermittent ethanol. Here we used qPCR to quantify changes in gene expression accompanying this behavioural impairment. Male Wistar rats were treated with either saline or ethanol (1 or 2.5 g/kg) for 5 days followed by 2 drug-free days. Brains were dissected after Y-maze analysis and RNA was extracted from the medial prefrontal cortex, hippocampus and nucleus accumbens. Using the Qiagen GABA & Glutamate PCR array we measured changes in these two neurotransmitter systems. A dose of 1 g/kg ethanol did not affect spontaneous alternation behaviour or any other behavioural variable. 2.5 g/kg significantly decreased % correct alternations (p = 0.028) without affecting total distance (p = 0.54) and increased time in the choice area (p = 0.023) at the Y-maze centre, indicating a possible impairment in decision-making. In the medial prefrontal cortex, 2.5 g/kg ethanol decreased mRNA expression of brain-derived neurotrophic factor, NMDA NR2A subunit, mGluR8 receptor, Homer1, the glutamate transporters SLC1a1 and SLC1a6 and Srr. In the nucleus accumbens this dose did not affect mRNA expression of the dopamine D1 or D2 receptors but did upregulate the GABA transporter GAT-3. Even if only correlational, these data suggest that gene expression changes in the medial prefrontal cortex and associated cognitive impairment occur before adaptation of the dopaminergic system and, presumably, drug dependence.

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

Abstract: 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。

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

Abstract: 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.

An integrative theory of prefrontal cortex function

Abstract: ▪ 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

Chapter 11 Working memory

Abstract: 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.