Cell non-autonomous signaling through the conserved C. elegans glycoprotein hormone receptor FSHR-1 regulates cholinergic neurotransmission.

Modulation of neurotransmission is key for organismal responses to varying physiological contexts such as during infection, injury, or other stresses, as well as in learning and memory and for sensory adaptation. Roles for cell autonomous neuromodulatory mechanisms in these processes have been well described. The importance of cell non-autonomous pathways for inter-tissue signaling, such as gut-to-brain or glia-to-neuron, has emerged more recently, but the cellular mechanisms mediating such regulation remain comparatively unexplored.

Neural Circuit Remodeling: Mechanistic Insights from Invertebrates.

As nervous systems mature, neural circuit connections are reorganized to optimize the performance of specific functions in adults. This reorganization of connections is achieved through a remarkably conserved phase of developmental circuit remodeling that engages neuron-intrinsic and neuron-extrinsic molecular mechanisms to establish mature circuitry. Abnormalities in circuit remodeling and maturation are broadly linked with a variety of neurodevelopmental disorders, including autism spectrum disorders and schizophrenia.

Cell non-autonomous signaling through the conserved glycopeptide hormone receptor FSHR-1 regulates cholinergic neurotransmission.

Modulation of neurotransmission is key for organismal responses to varying physiological contexts such as during infection, injury, or other stresses, as well as in learning and memory and for sensory adaptation. Roles for cell autonomous neuromodulatory mechanisms in these processes have been well described. The importance of cell non-autonomous pathways for inter-tissue signaling, such as gut-to-brain or glia-to-neuron, has emerged more recently, but the cellular mechanisms mediating such regulation remain comparatively unexplored.

The homeodomain transcriptional regulator DVE-1 directs a program for synapse elimination during circuit remodeling.

The elimination of synapses during circuit remodeling is critical for brain maturation; however, the molecular mechanisms directing synapse elimination and its timing remain elusive. We show that the transcriptional regulator DVE-1, which shares homology with special AT-rich sequence-binding (SATB) family members previously implicated in human neurodevelopmental disorders, directs the elimination of juvenile synaptic inputs onto remodeling C. elegans GABAergic neurons.

Correction: Kinesin-3 mediated axonal delivery of presynaptic neurexin stabilizes dendritic spines and postsynaptic components.

[This corrects the article DOI: 10.1371/journal.pgen.

Reactive Oxygen Species: Angels and Demons in the Life of a Neuron.

Reactive oxygen species (ROS) have emerged as regulators of key processes supporting neuronal growth, function, and plasticity across lifespan. At normal physiological levels, ROS perform important roles as secondary messengers in diverse molecular processes such as regulating neuronal differentiation, polarization, synapse maturation, and neurotransmission. In contrast, high levels of ROS are toxic and can ultimately lead to cell death.

Kinesin-3 mediated axonal delivery of presynaptic neurexin stabilizes dendritic spines and postsynaptic components.

The functional properties of neural circuits are defined by the patterns of synaptic connections between their partnering neurons, but the mechanisms that stabilize circuit connectivity are poorly understood. We systemically examined this question at synapses onto newly characterized dendritic spines of C. elegans GABAergic motor neurons.

A conserved neuropeptide system links head and body motor circuits to enable adaptive behavior.

Neuromodulators promote adaptive behaviors that are often complex and involve concerted activity changes across circuits that are often not physically connected. It is not well understood how neuromodulatory systems accomplish these tasks. Here, we show that the NLP-12 neuropeptide system shapes responses to food availability by modulating the activity of head and body wall motor neurons through alternate G-protein coupled receptor (GPCR) targets, CKR-1 and CKR-2.

Repetitive Transcranial Magnetic Stimulation as a Therapeutic and Probe in Schizophrenia: Examining the Role of Neuroimaging and Future Directions.

Schizophrenia is a complex condition associated with perceptual disturbances, decreased motivation and affect, and disrupted cognition. Individuals living with schizophrenia may experience myriad poor outcomes, including impairment in independent living and function as well as decreased life expectancy. Though existing treatments may offer benefit, many individuals still experience treatment resistant and disabling symptoms.

Effects of fingolimod, a sphingosine-1-phosphate (S1P) receptor agonist, on white matter microstructure, cognition and symptoms in schizophrenia.

Several lines of evidence have implicated white matter (WM) deficits in schizophrenia, including microstructural alterations from diffusion tensor (DTI) brain imaging studies. It has been proposed that dysregulated inflammatory processes, including heightened activity of circulating lymphocytes, may contribute to WM pathology in this illness. Fingolimod is a sphingosine-1-phosphate (S1P) receptor agonist that is approved for the treatment of relapsing multiple sclerosis (MS).

Functional network connectivity in early-stage schizophrenia.

Schizophrenia is a disorder of altered neural connections resulting in impaired information integration. Whole brain assessment of within- and between-network connections may determine how information processing is disrupted in schizophrenia. Patients with early-stage schizophrenia (n = 56) and a matched control sample (n = 32) underwent resting-state fMRI scans.

Integrins Have Cell-Type-Specific Roles in the Development of Motor Neuron Connectivity.

Formation of the nervous system requires a complex series of events including proper extension and guidance of neuronal axons and dendrites. Here we investigate the requirement for integrins, a class of transmembrane cell adhesion receptors, in regulating these processes across classes of motor neurons. We show α integrin/ is expressed by both GABAergic and cholinergic motor neurons.

Gain-of-function mutations in the UNC-2/CaV2α channel lead to excitation-dominant synaptic transmission in .

Mutations in pre-synaptic voltage-gated calcium channels can lead to familial hemiplegic migraine type 1 (FHM1). While mammalian studies indicate that the migraine brain is hyperexcitable due to enhanced excitation or reduced inhibition, the molecular and cellular mechanisms underlying this excitatory/inhibitory (E/I) imbalance are poorly understood. We identified a gain-of-function (gf) mutation in the CaV2 channel α1 subunit, UNC-2, which leads to increased calcium currents.

Molecular Mechanisms Directing Spine Outgrowth and Synaptic Partner Selection in .

The development of the nervous system requires precise outgrowth, extension, and wiring of both axons and dendrites to generate properly functioning neural circuits. The molecular mechanisms that shape neurite development, in particular dendritic development, remain incompletely understood. Dendrites are often highly branched and coated with actin-filled, thorny protrusions, called dendritic spines, that allow for increased numbers of synaptic contacts with neighboring neurons.

Herpes simplex virus 1 infection and valacyclovir treatment in schizophrenia: Results from the VISTA study.

Background: Several studies have implicated herpes simplex virus-type 1 (HSV-1) in the pathophysiology of schizophrenia. A recent trial demonstrated that the anti-viral medication valacylovir, which prevents replication of activated HSV-1, improved selected cognitive deficits in people with schizophrenia. In this study, we examined demographic and illness related differences between HSV-1 positive versus HSV-1 negative subjects with early phase schizophrenia and attempted to replicate the previous valacyclovir treatment results in this population.

Neurexin directs partner-specific synaptic connectivity in .

In neural circuits, individual neurons often make projections onto multiple postsynaptic partners. Here, we investigate molecular mechanisms by which these divergent connections are generated, using dyadic synapses in as a model. We report that /neurexin directs divergent connectivity through differential actions at synapses with partnering neurons and muscles.

Cognitive effects of bilateral high frequency repetitive transcranial magnetic stimulation in early phase psychosis: a pilot study.

Cognitive dysfunction is a core facet of schizophrenia that is present early in the course of the illness and contributes to diminished functioning and outcomes. Repetitive transcranial magnetic stimulation (rTMS) is a relatively new neuropsychiatric intervention. Initially used in treatment resistant depression, investigators are now studying rTMS for other psychiatric diseases such as schizophrenia.

Effects of 12-month, double-blind N-acetyl cysteine on symptoms, cognition and brain morphology in early phase schizophrenia spectrum disorders.

Background: Currently approved medications for schizophrenia are relatively ineffective for negative symptoms and cognitive impairment. N-Acetyl Cysteine (NAC) is a neuroprotective agent that improved general symptoms, cognitive impairment and negative symptoms in some but not all studies, but failed to improve positive symptoms in patients with schizophrenia. Progressive brain mass loss (PBML) has been consistently observed in early phase schizophrenia.

Metacognitive Reflection and Insight Therapy for Early Psychosis: A preliminary study of a novel integrative psychotherapy.

Poor insight impedes treatment in early phase psychosis (EPP). This manuscript outlines preliminary findings of an investigation of the novel metacognitively oriented integrative psychotherapy, Metacognitive Reflection and Insight Therapy, for individuals with early phase psychosis (MERIT-EP). Twenty adults with EPP and poor insight were randomized to either six months of MERIT-EP or treatment as usual (TAU).

Excitatory neurons sculpt GABAergic neuronal connectivity in the motor circuit.

Establishing and maintaining the appropriate number of GABA synapses is key for balancing excitation and inhibition in the nervous system, though we have only a limited understanding of the mechanisms controlling GABA circuit connectivity. Here, we show that disrupting cholinergic innervation of GABAergic neurons in the motor circuit alters GABAergic neuron synaptic connectivity. These changes are accompanied by reduced frequency and increased amplitude of GABAergic synaptic events.

Local neuropeptide signaling modulates serotonergic transmission to shape the temporal organization of C. elegans egg-laying behavior.

Animal behaviors are often composed of distinct alternating behavioral states. Neuromodulatory signals are thought to be critical for establishing stable behavioral states and for orchestrating transitions between them. However, we have only a limited understanding of how neuromodulatory systems act in vivo to alter circuit performance and shape behavior.

Association of medial prefrontal resting state functional connectivity and metacognitive capacity in early phase psychosis.

Metacognition refers to a range of cognitive processes that allow one to form complex ideas of self and others and to use this information to navigate psychosocial challenges. Several studies in both early-phase and prolonged schizophrenia have demonstrated not only that significant deficits in metacognitive ability are present, but importantly that they are associated with significant functional impairment and decreased quality of life. In spite of the importance of metacognitive impairment in schizophrenia, relatively little is known about the biological substrates that may contribute to this dysfunction.

Utilization and Cost of Health Care Services During the First Episode of Psychosis.

Objective: Because of the chronicity, severity, and marked psychosocial impairment that may characterize the illness, schizophrenia is an incredibly costly disease. Recent data indicate that intervention earlier in the course of schizophrenia produces cost savings. This study compared health service utilization and associated costs for patients receiving treatment for first-episode psychosis (FEP) delivered within the early-intervention (EI) model at the Prevention and Recovery Center for Early Psychosis (PARC) and for a matched sample of FEP patients receiving treatment as usual at a geographically similar mental health clinic.

Characterization of white matter abnormalities in early-stage schizophrenia.

Aim: White matter abnormalities have been reported in schizophrenia and may indicate altered cortical network integrity and structural connectivity, which have been hypothesized as key pathophysiological components of this illness. In this study, we aimed to further characterize the nature and progression of white matter alterations during the early stages of the disorder.

Methods: We employed diffusion tensor imaging (DTI) approaches to investigate fractional anisotropy (FA), radial diffusivity (RD) and axial diffusivity (AD) in 40 patients with schizophrenia and related psychotic disorders (aged 18-30 years) who were within 5 years of illness, along with an age-, sex- and race-matched sample of 21 healthy controls.