Articles in 2015

Enhanced NMDA receptor function and social interaction deficits are observed in mice lacking the excitatory postsynaptic scaffolding protein IRSp53. Reducing NMDAR activity by pharmacological methods rescues the impaired social interaction observed in these mice. This suggests that enhanced NMDA receptor function may be associated with social deficits.

The authors find that behavioral habituation to the repeated presentation of visual stimuli, measured as reduced occurrence of a brief motor response called a 'vidget', depends on primary visual cortex in mice and is accompanied by a potentiation of layer 4 responses to visual stimuli. Local manipulations indicate that this form of recognition memory is stored in primary visual cortex.

Better analytical methods are needed to extract biological meaning from genome-wide association studies (GWAS) of psychiatric disorders. Here the authors take GWAS data from over 60,000 subjects, including patients with schizophrenia, bipolar disorder and major depression, and identify common etiological pathways shared amongst them.

Rapid developmental changes in the response properties of neurons in visual cortex enhance motion discriminability following eye opening. Here the authors show that increases in direction selectivity are accompanied by reductions in the density of active neurons and variability in their responses and levels of noise correlation, changes that depend on the nature of visual experience.

Previous studies have reported both increased and decreased functional brain connectivity in individuals with autism spectrum disorder (ASD). The authors find that instances of such over- and underconnectivity in adults with high-functioning ASD point to a deeper principle of increased individual variation (idiosyncrasy) of functional connectivity in individuals with ASD.

Donahue and Lee identify prefrontal neurons that integrate task-relevant information about past and current stimulus features and past action outcomes across trials during a probabilistic reversal task. The activity of these neurons is sensitive to past rewards and is predictive of imminent behavioral choices, suggesting that they dynamically contribute to the selection of actions that maximize reward during decision making under uncertainty.

The authors find that glutamate release increases the diffusion of the astrocytic glutamate transporter GLT-1 in the plasma membrane. This activity-dependent increase in mobility facilitates glutamate clearance from the synaptic cleft, which influences the kinetics of excitatory post-synaptic events in rat hippocampal neurons.

Due to their volatility, olfactory inputs are spatially and temporally dynamic. Here the authors find that, in contrast to previous studies, mitral/tufted cells of the olfactory bulb can sum inputs linearly across odors and time.

The authors report that neddylation is required for dendritic spine development and stability, and loss of neddylation in excitatory forebrain neurons leads to synaptic loss, impaired neurotransmission, and learning and memory deficits. The roles of neddylation in spine maturation and synaptic transmission could be attributed to neddylation of PSD-95.

In amyotrophic lateral sclerosis (ALS), some motor neuron types are more vulnerable to disease pathology. Here the authors show that resistant subtypes express the ER chaperone SIL1. Disease-associated loss of SIL1 impairs ER homeostasis and worsens ALS pathology, whereas its expression improves pathology and survival in an ALS mouse model.

During a single theta cycle, discrete groups of hippocampal place cells can produce a distributed series of spikes called a theta sequence. Such sequences represent the time-compressed trajectory of an animal running in its environment and usually extend ahead of the current position. Here, Wikenheiser and Redish find that the ‘look-ahead’ distance of rat theta sequences can predict the imminent choice of the animal in a value-guided decision making task.