News & Views in 2001

By making maps of the differences in cortical gray matter volume between twins, Thompson et al. describe which brain regions are strongly determined by genetic factors; they further investigate how these brain differences correlate with measures of cognitive performance.

Fluorescent synapsins were used to study the dissociation–reassociation cycle of this synaptic vesicle protein in situ, and how this process relates to regulation of exocytosis.

A new study finds two classes of synapses between layer 2/3 neurons in auditory cortex, and suggests they may be involved in processing transient versus sustained acoustic stimuli

Recordings from the human medial temporal lobe suggest that synchronization of oscillations between rhinal cortex and hippocampus may contribute to building declarative memories.

Local glutamate application is often achieved by removing a chemical 'cage' with ultraviolet light. Matsuzaki et al. report a new method for uncaging glutamate with infrared light, and show that the shape of individual dendritic spines correlates with AMPA receptor responses.

Two initially identical zebrafish motoneurons adopt different fates before their axons arrive at the final target. A new paper suggests that an intermediate target is critical for this choice.

Auditory cortex in anesthetized animals responds poorly to rapid stimulus trains. In awake marmosets, rapidly repeating sounds are now shown to be represented by a rate code.

An imaging study suggests memories may depend briefly on the hippocampus, and for a prolonged period on the entorhinal cortex, before being organized fully within the neocortex.

A characterization of C. elegans lacking the gene for Rim suggests that this protein may be involved in priming synaptic vesicles for fusion, not in docking or organizing active zones.

Two groups use a fluorescently tagged postsynaptic density protein and time-lapse imaging to track the location and timing of synapse formation in the developing brain.

Interactions between the ventral premotor area (PMv) and primary motor cortex may contribute to a sensorimotor transformation between intrinsic and extrinsic coordinates.

Target-derived neurotrophins are important for cell survival. A new study shows that neurotrophins activate different MAP kinase signaling pathways depending on whether they are applied to cell bodies or axon terminals, regulating distinct sets of genes.

Segregation of an image into figure and ground is an important step in visual processing. Two new papers show that responses in human and monkey brain areas known to be involved in shape perception depend critically on whether a region is perceived as figure or ground.

A newly identified Alzheimer's mutation leads to the suggestion that protofibril intermediates in amyloid plaque formation may be a crucial factor in pathogenicity.

A new study demonstrating a pathway for neuronal migration in humans, but not in monkeys, suggests that migration has a key role in the evolution of the brain, as well as its development.

Using transcranial magnetic stimulation to induce a 'virtual lesion' in the parietal lobe, a new study reveals the mechanisms of hemispatial neglect, a neurological disorder of attention.

A recent paper in Nature directly compares fMRI with simultaneously recorded neural activity in the monkey, yielding new insights into the interpretation of BOLD contrast.

After a learning experience, memories are vulnerable to disruption during a consolidation period. Antisense against the transcription factor C/EBPβ in the hippocampus is now reported to disrupt the initial consolidation of memories, but not their 'reconsolidation' after later recall.

Glial cells have been thought simply to respond to neural activity. A new report shows that slow glial calcium oscillations occur spontaneously and can cause excitation in nearby neurons.