Articles in 2009

In Drosophila, the connections between olfactory receptor neurons and projection neurons are highly specific. Here, the authors report that two leucine-rich repeat transmembrane proteins (Capricious and Tartan) serve as a mechanism for projection neuron dendrite targeting in the olfactory map.

During development of the peripheral ganglia, 50% of neurons die by apoptosis. This study finds that satellite glial cell precursors clear these neuronal corpses in developing dorsal root ganglia and identifies some of the molecular components involved in this phagocytosis.

Cue-evoked activity of midbrain dopamine neurons is proposed to encode the magnitude, delay and uncertainty of predicted rewards. Here the authors report that this activity separates costs and benefits, as it does not encode the costs of the action required to obtain predicted rewards.

Dendritic excitability is a plastic property of neurons. This study shows that exposure to an enriched environment increases propagation of dendritic sodium spikes in a subset of dendritic branches in CA1 pyramidal neurons. This effect is mediated by localized downregulation of A-type potassium channel function.

Notch signaling is essential for the maintenance of adult neural stem cells in vivo. Here, Andreu-Agulló and colleagues show that PEDF, released from endothelial cells, enhances Notch signaling in the mouse subependymal zone by inactivating a repressor of Notch target genes.

Severe stress in early childhood can increase an individual's vulnerability to depression later in life. This study found that early-life stress in mice resulted in persistent elevation of the stress hormone arginine vasopressin (AVP), which was caused by persistent hypomethylation of CpG islands in the Avp promoter in the hypothalamus.

Systematically monitoring the activities of various cortical pyramidal neurons and interneurons during different stages of locomotion, the authors characterize differential firing activities of motor cortex microcircuitry in behaving, head-restraint rats that were trained to push, pull or hold a lever for reward.

Studying a patient with selective damage to the insular and anterior cingulate cortex, the current study finds that these regions are not necessary for interoceptive awareness of one's own heartbeat, but the primary somatosensory cortex is required for such self-awareness.

The US National Institutes of Health (NIH) have funded an increasing number of grants from young investigators with merit scores below the payline. This policy is critical for retaining and encouraging our future scientific base.

During early development, rats show the unlikely behavior of becoming attracted to the very stimulus that they should avoid. A new study shows that this occurs as a result of a complex interplay of glucocorticoid secretion and dopaminergic tone in the amygdala.

The α₂δ-3 auxiliary subunit of voltage-dependent calcium channels promotes the formation of synaptic boutons in Drosophila neuromuscular junction independently of its role in channel localization.

Cholinergic neurons in the basal forebrain enable alert and attending brain states. A study now shows how basal forebrain activity increases coding abilities of cortical neurons and at what stages these changes occur.

Although numerous in vivo studies have suggested that hippocampal theta oscillations are generated by the extrinsic medial septal input, theoretical studies have suggested that the hippocampus has the minimal feedback circuitry necessary to intrinsically generate its own theta rhythm. Here, Goutagny et al. directly demonstrate such oscillation independently of external inputs.

The cortex is sensitive to weak stimuli, but also responds to stronger inputs without saturating. In this study, Scanziani and colleagues find some of the circuits that enable neuronal populations to respond to a wide range of input strengths.

Neural stem cells in the adult mouse SVZ are thought to only generate GABAergic olfactory bulb interneurons. This study reports that a dorsal region of the adult SVZ gives rise to a glutamatergic type of olfactory bulb neurons. These newborn glutamatergic neurons can be diverted to migrate into the cortex towards an injury, possibly contributing to repair.

Certain Drosophila dendrites undergo major remodeling during metamorphosis. This study shows that the severing of larval dendrites, which is the first step of remodeling, depends on the upregulation of the cytoskeleton-binding protein Mical by the transcription factor Sox14.

Monkeys were trained to switch rapidly between two category boundaries when classifying the speed of a moving dot pattern. Neurons in the frontal eye field changed their activity when the boundary changed and a subset of these neurons were used to classify the stimuli nearly as accurately as the monkeys' behavioral performance.

This study shows that the kinase Mst3b is required cell-autonomously for axon regeneration of both retinal ganglion cells and peripheral sensory neurons in vitro and in vivo.

Contrary to previous findings, this study finds that ablation of microglia, the resident macrophages of the brain, does not affect amyloid plaque or neuritic pathology in two mouse models of Alzheimer's disease.