Research articles

The role of pericytes in the regulation of cerebral blood flow (CBF) and neurovascular coupling remains unclear. Using loss-of-function pericyte-deficient mice, the authors report that pericyte degeneration reduces CBF responses to neuronal stimuli and oxygen supply to the brain, leading to metabolic stress, neuronal dysfunction and neurodegeneration.

Using magnetic resonance spectroscopy, Shibata et al. show that continuous training conducted after performance improvement has been maximized hyperstabilizes the skill learned and protects it from subsequent new learning by drastically changing early visual areas from excitatory (glutamate)-dominant to inhibitory (GABA)-dominant neurochemical environments.

Using large-network calcium imaging in alert mouse frontal cortex, the authors identify a significant covariance of responses of VIP interneurons and pyramidal cells. Optogenetic interrogation of this brain region revealed a pull–push inhibitory circuit driven by neuromodulation of VIP interneurons that contrasts with canonical feedforward push–pull excitation.

Effective social behavior requires comprehension of social cues and use of those cues to guide behavior. This study uncovers an amygdala circuit that is necessary for socially driven valuation of environmental cues. The strength of this circuit correlates with social learning, and augmentation of this circuit enhances abnormal social learning.

Inputs to midbrain dopamine neurons control rewarding and drug-related behaviors. The authors found that nucleus accumbens inputs and local GABA neurons inhibit dopamine neurons through distinct populations of GABA receptors. Furthermore, genetic deletion of GABA_B receptors from dopamine neurons selectively increased behavioral sensitivity to cocaine.

The authors investigate the role of inhibition in shaping spatial selectivity of CA1 place cells. Combining whole-cell recordings, optogenetics and computational modeling, they demonstrate that inhibition enhances both rate and temporal coding of space by counteracting noise from broad out-of-field excitation.

The function of rapid eye movement (REM) sleep remains unclear. By examining how REM sleep affects synapses in the mouse cortex, the authors show that REM sleep is fundamental to brain development, learning and memory consolidation by selectively pruning and maintaining newly formed synapses via dendritic calcium spike-dependent mechanisms.

Vision is processed across multiple cortical areas that are organized into two subnetworks in primates. However, the generality of this organization and its development are unclear. Smith and colleagues present functional evidence for the analogous two subnetworks in mice and map their differential developmental dynamics.

The authors describe cortical projections mediating the modulation of social behavior. Neural projections from the medial prefrontal cortex to the dorsal periaqueductal gray play a critical role in the behavioral adaptation to social defeat in mice.

Episodic memory involves encoding an event's temporal and spatial context. The authors show that temporal information is mediated by a direct projection from the dorsal CA1 field of the hippocampus to the medial prefrontal cortex, while spatial information is processed in a separate hippocampal–prefrontal cortex projection originating in intermediate CA1.

The authors show that postsynaptic deletion of neuroligin-3 from parvalbumin interneurons causes a decrease in NMDA-receptor-mediated excitatory postsynaptic currents and an increase in presynaptic glutamate release probability linked to a deficit in presynaptic Group III metabotropic glutamate receptor function. This selective disruption of excitatory transmission on parvalbumin interneurons leads to abnormal hippocampal network activity and a decrease in contextual fear extinction.