Review Articles in 2009

Studies into the role of different frontal cortex areas in cognitive control have suggested that there is a rostral-to-caudal processing gradient. Drawing on anatomical and functional data from humans and monkeys, Badre and D'Esposito discuss whether this gradient might reflect a hierarchical organization.

Biomaterials can be used to deliver drugs, cells and tissue transplants into regions of the brain damaged by neurodegenerative disease or trauma. Emerich and colleagues describe currently available biomaterials and show how the ability to manipulate biomaterial–cell interactions will improve their usefulness.

During the past decade it has become clear that the regulation of sleep is conserved across species. Cirelli discusses the genes that have been identified in sleep regulation and how sleep regulates the expression of genes in the brain.

The neurobiological underpinnings of anorexia nervosa are not well understood. Kaye and colleagues discuss how alterations in neurotransmitter systems and in the interacting brain circuits underlying reward, interoception and appetite might contribute to the vulnerability to and symptoms of this disorder.

How a reduction in the level of a ubiquitously expressed protein, SMN, causes the motor neuron–specific deficits that characterize spinal muscular atrophy is unknown. Burghes and Beattie discuss the function of SMN and the debate concerning the crucial pathways disrupted in SMA.

In addiction, the prefrontal cortex fails to control drug-seeking behaviours. Peter Kalivas reviews the hypothesis that a loss of glutamate homeostasis at prefrontal-to-accumbens synapses, resulting in altered dendritic spine morphology and synaptic plasticity, impairs the prefrontal regulation of striatal circuitry.

What sets highly skilled sportspeople apart from novices? This article discusses the neural basis of sporting skills and emerging computational and physiological theories that help explain, and potentially predict, elite athletic performance.

Intrinsic spinal cord networks generate the rhythmic patterns of motor activity that underlie locomotion. Goulding shows how genetic analyses, coupled with classical systems neuroscience approaches, are providing new information about the cellular components and functional organization of these circuits.

Kroemer and colleagues discuss the converging signalling mechanisms that lead to mitochondrial membrane permeabilization and trigger neuron death after severe brain injury. They also highlight how knowledge of these mechanisms might be exploited therapeutically.

Brooks and Dunnet provide an overview of available motor behaviour tests, with the aim of helping researchers choose the most appropriate tests for teasing out a transgenic phenotype or assessing the recovery of motor function following therapeutic intervention. An interview with Simon Brooks for Neuropod is available fordownload.

The different neuron types in the retina are electrically coupled. Bloomfield and Völgyi describe the various types of retinal gap junctions, their dynamic regulation through neuromodulator-activated signalling pathways and their specific roles in visual processing.

Stress affects cognition and increases noradrenaline and dopamine levels in the prefrontal cortex (PFC). Amy Arnsten discusses the intracellular signalling pathways that mediate the effects of these catecholamines on PFC function during acute and chronic stress, focusing on working memory. An interview with Amy Arnsten for Neuropod is available fordownload.

Although stress is associated with many physical and mental illnesses, most individuals cope well with it. Feder and colleagues review the factors that underlie stress resilience, showing that it involves adaptive changes in specific neural circuits, neuromodulator levels and molecular pathways.

The physiological response to stress is regulated by a complex neurocircuitry that integrates and interprets stress-related and homeostatic information. Ulrich-Lai and Herman describe this circuitry, including its adaptation to chronic stress and its overlap with circuits that underlie memory and reward.

Stressful events often leave strong memories. Roozendaal and colleagues discuss how stress hormones and neurotransmitters acting in the amygdala mediate this phenomenon at the behavioural and synaptic level, and describe how stress-induced remodelling of amygdala neurons might underlie anxiety.

Microtubules are key determinants of neuronal polarity, which provides the basis of unidirectional signal transmission in the mature nervous system. This Review focuses on the regulation of microtubule assembly, organization and dynamics in developing axons and dendrites.

The effects of stress on the brain depend on the age at which the stress occurs. Reviewing data from animal and human studies, Lupien and colleagues discuss why different disorders emerge in individuals exposed to stress at different times in their lives. An interview with Sonia Lupien for Neuropod is available fordownload.

Everyday object manipulation tasks require the brain to interpret the signals from tactile afferents in the hands. Johansson and Flanagan describe our current understanding of this process, showing how tactile signals are used to control and refine manipulations.

To integrate our visual environment into a unified and coherent perceptual experience, the brain uses multiple processing strategies. Here, Nassi and Callaway review how the primate primary visual cortex integrates parallel inputs and constructs new, parallel outputs to achieve this goal.

The ε4 allele of the apolipoprotein E (APOE) gene is a strong risk factor for late-onset Alzheimer's disease (AD). Bu discusses the contribution of the various APOE isoforms and APOE receptors to the pathophysiology of AD and emerging therapeutic opportunities.