Reviews & Analysis

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.

Understanding the mode of cortical cholinergic neurotransmission, which is thought to mediate attentional tasks, is key to finding effective treatments for a range of cognitive disorders. Sarter and colleagues contrast evidence for volume and phasic transmission and conclude that the latter is more significant for attentional tasks.

Two neurons can be connected by multiple synaptic contacts with different likelihoods of neurotransmitter release. Branco and staras discuss the role of feedback regulation from the postsynaptic site in determining this probability at individual synapses and consider the possible functional advantages of variable neurotransmitter release.

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.

Stress induces the release of many stress mediators in the brain. Joëls and Baram show that the spatial and temporal niches of action of these mediators overlap and discuss how different mediators interact to enable appropriate responses to diverse stressors.

The connections within and between the hippocampus and the parahippocampal region form an intricate network. Here, Witter and colleagues present an interactive diagram of all known connections in these regions and discuss possible functional implications of some of the underexposed projections.

Transient cell–cell interactions aid the formation of neural circuits by providing positional cues for axon guidance and synaptogenesis. Shen and colleagues describe the mechanisms by which they help to organize neural connections in different contexts.

Imaging studies show activation of the motor cortex during speech perception. In this Perspective, Scott and colleagues discuss different possible roles for the motor system in speech processing and propose that it has a specific function in conversation.

Neuronal growth and regeneration require the continuous synthesis and insertion of membrane. Pfenninger reviews our current understanding of the mechanisms involved in generating and maintaining the neuron's huge surface membrane.

Difficulties in translating basic research findings into safe and effective analgesics have called into question the usefulness of current animal models of pain. Jeffrey Mogil discusses the factors that must be considered when selecting subjects, assays and measures for pain studies.

The effects of the glial scar on regeneration after injury have traditionally been viewed as inhibitory. Schwartz and colleagues discuss the evidence that scar tissue can have a beneficial role in the repair process and propose that the timing of scar generation and degradation is crucial in determining its effects.