Synaptic physiology

Roles of glutamate transporters in shaping excitatory synaptic currents in cerebellar Purkinje cells. Takayasu, Y. et al. Eur. J. Neurosci. 19, 1285–1295 (2004)

The authors used a blocker of glutamate transporters, DL-threo-β-benzyloxyaspartate (DL-TBOA) to investigate the role of these transporters in cerebellar synapses. Blocking glutamate transporters prolonged excitatory postsynaptic potentials in cerebellar Purkinje cells. DL-TBOA seems to increase the time for which synaptically released glutamate is present and also induces glutamate spillover to neighbouring targets. The results indicate that glutamate transporters are an important influence on synaptic transmission at these synapses.

Neural development

Columnar architecture sculpted by GABA circuits in developing cat visual cortex. Hensch, T. K. & Stryker, M. P. Science 303, 1678–1681 (2004)

Specific GABAA circuits for visual cortical plasticity. Fagiolini, M. et al. Science 303, 1681–1683 (2004)

Two papers from Hensch and colleagues give important new insights into the development of ocular dominance columns in the visual cortex. In the first, Hensch and Stryker used benzodiazepines to modulate the inhibitory activity in the visual cortex of kittens. Diazepam, which potentiates inhibitory activity, caused the columns to become broader, whereas treatment with DMCM, which reduces inhibition, made the columns narrower. To investigate further how inhibitory inputs shape the development of cortical segregation in the visual system, Fagiolini et al. used a mouse knock-in mutation to make specific types of GABAA (γ-aminobutyric acid, subtype A) receptor insensitive to diazepam. They found that receptors containing the α1 subunit were needed for diazepam to be able to influence ocular dominance plasticity, indicating that this subtype of receptor is responsible for shaping ocular dominance columns in the developing visual cortex.

Cognitive neuroscience

Your own action influences how you perceive another person's action. Hamilton, A. et al. Curr. Biol. 14, 493–498 (2004)

The authors tested the hypothesis that the motor system is responsible for decoding the observed action of others by asking subjects to judge the weight of a box being lifted by another person while they lifted or held a light or heavy box. Actively lifting a heavy box led to a perception of the observed box as being lighter, whereas lifting a light box meant that the observed box was judged to be heavier. The authors propose a model that can account for these results by using overlapping neural systems for motor control and action understanding to process multiple models of observed and performed actions.