Nature Neuroscience 11, 1256 (2008). doi:10.1038/nn.2195

Authors: Karina Alviña, Joy T Walter, Adam Kohn, Graham Ellis-Davies & Kamran Khodakhah

A key component of recent theories on cerebellar function is rebound firing in neurons of the deep cerebellar nuclei (DCN). Despite the robustness of this phenomenon in vitro, in vivo studies have provided little evidence for its prevalence. We found that intact mouse or rat DCN neurons rarely showed rebound firing under physiological conditions in vitro or in vivo. These observations necessitate a critical re-evaluation of recent cerebellar models.

Nature Neuroscience 11, 1253 (2008). doi:10.1038/nn.2203

Authors: Maarten H P Kole & Greg J Stuart

Action potential threshold is thought to be lowest in the axon, but when measured using conventional techniques, we found that action potential voltage threshold of rat cortical pyramidal neurons was higher in the axon than at other neuronal locations. In contrast, both current threshold and voltage threshold of the isolated somato-dendritic spike were substantially higher at the soma. These data indicate that action potential threshold is indeed lowest in the axon.

Nature Neuroscience 11, 1264 (2008). doi:10.1038/nn.2205

Author: Jonathan L C Lee

Memories are dynamic, rather than static, in nature. The reactivation of a memory through re-exposure to salient training stimuli results in its destabilization, necessitating a restabilization process known as reconsolidation, a disruption of which leads to amnesia. I found that one normal function of hippocampal memory reconsolidation in rats is to modify the strength of a contextual-fear memory as a result of further learning.

Nature Neuroscience 11, 1267 (2008). doi:10.1038/nn.2196

Authors: Lior Shmuelof & Ehud Zohary

Mimicking hand actions made by someone facing us (that is, allocentric viewpoint) is typically performed with the opposite hand. Using functional magnetic resonance imaging (fMRI), we found a similar mirror-image representation of others' actions in the human anterior parietal cortex. Viewing egocentric-based actions elicited greater fMRI activation in the contralteral hemisphere (as in, self action), whereas observation of action seen from an allocentric viewpoint generated greater activation in the ipsilateral hemisphere. This mirror-like mapping occurs without active imitation, providing further evidence for an automatic action-simulation system in the parietal cortex.

Nature Neuroscience 11, 1259 (2008). doi:10.1038/nn.2201

Authors: Paul V Watkins & Dennis L Barbour

Some neurons in auditory cortex respond to recent stimulus history by adapting their response functions to track stimulus statistics directly, as might be expected. In contrast, some neurons respond to loud sounds by adjusting their response functions away from high intensities and consequently remain sensitive to softer sounds. In marmoset monkey auditory cortex, the latter type of adaptation appears to exist only in neurons tuned to stimulus intensity.

Nature Neuroscience 11, 1262 (2008). doi:10.1038/nn.2211

Authors: Yang Yang, Michael R DeWeese, Gonzalo H Otazu & Anthony M Zador

Neurons in the auditory cortex can lock to the fine timing of acoustic stimuli with millisecond precision, but it is not known whether this precise spike timing can be used to guide decisions. We used chronically implanted microelectrode pairs to stimulate neurons in the rat auditory cortex directly and found that rats can exploit differences in the timing of cortical activity that are as short as 3 ms to guide decisions.

Nature Neuroscience 11, 1239 (2008). doi:10.1038/nn1108-1239

Author: Adriano Aguzzi

A recent paper reported the in vitro generation of new prion strains, supporting the idea that 'strain-ness' is encoded in the protein structure itself. This lays the groundwork for a reinvigorated study of prion structure–pathology relationships.

Nature Neuroscience 11, 1243 (2008). doi:10.1038/nn1108-1243

Author: James A Mazer

Previous work has focused on neuronal encoding of two-dimensional shapes. Using a new search algorithm and three-dimensional object primitives, a study in this issue identifies potential subunits of complex object recognition.

Nature Neuroscience 11, 1237 (2008). doi:10.1038/nn1108-1237

Author: Károly Mirnics

Oldham et al. present a systematic analysis of gene coexpression relationships in specific human brain regions with the goal of identifying groups of genes with common coexpression patterns. The study used the inherent structure of the brain's transcriptome to find data-driven organizational patterns rather than rely on external classification systems.

Nature Neuroscience 11, 1241 (2008). doi:10.1038/nn1108-1241

Author: Jerry W Rudy

A paper in this issue reports that the core mechanisms that strengthen memories have more in common with the mechanisms that support reconsolidation than those that participate in their initial storage.

Nature Neuroscience 11, 1245 (2008). doi:10.1038/nn1108-1245

Author: Stephen H Scott

Combined population activity is usually used to control neural prosthetics. A recent study in Nature finds that a single primary motor cortex neuron can control the artificial stimulation of paralyzed wrist muscles to move a computer cursor.

Nature Neuroscience 11, 1231 (2008). doi:10.1038/nn1108-1231

Lie-detection tests have not been scientifically proven to reliably detect deception at an individual level, yet they are being marketed by several companies and have even been admitted as evidence in an Indian court. This calls for a critical appraisal of these technologies and regulatory measures to prevent misuse.