Psychiatry lacks the objective clinical tests routinely used in other specializations. Novel computerized methods to characterize complex behaviors such as speech could be identify and predict psychiatric illness individuals.In this proof-of-principle study, our aim was test automated analyses combined with Machine Learning later psychosis onset youths at high-risk (CHR) for psychosis.Thirty-four CHR (11 females) had baseline interviews were assessed quarterly up 2.5 years; five transitioned...

The experiences induced by psychedelics share a wide variety of subjective features, related to the complex changes in perception and cognition this class drugs. A remarkable increase introspection is at core these altered states consciousness. Self-oriented mental activity has been consistently linked Default Mode Network (DMN), set brain regions more active during rest than execution goal-directed task. Here we used fMRI technique inspect DMN psychedelic state Ayahuasca ten experienced...

Background Psychosis has various causes, including mania and schizophrenia. Since the differential diagnosis of psychosis is exclusively based on subjective assessments oral interviews with patients, an objective quantification speech disturbances that characterize schizophrenia in order. In principle, such could be achieved by analysis graphs. A graph represents a network nodes connected edges; graphs, correspond to words edges semantic grammatical relationships. Methodology/Principal...

Since the first measurements of neuronal avalanches, critical brain hypothesis has gained traction. However, if is critical, what phase transition? For several decades, it been known that cerebral cortex operates in a diversity regimes, ranging from highly synchronous states (with higher spiking variability) to desynchronized lower variability). Here, using both new and publicly available data, we test independent signatures criticality show transition occurs an intermediate value...

The wake-sleep cycle, a spontaneous succession of global brain states that correspond to major overt behaviors, occurs in all higher vertebrates. transitions between these states, at once rapid and drastic, remain poorly understood. Here, intracranial local field potentials (LFPs) recorded the cortex, hippocampus, striatum, thalamus were used characterize neurophysiological correlates rat cycle. By way new method for objective classification quantitative investigation we demonstrate state...

Dopamine depletion is involved in the pathophysiology of Parkinson's disease, whereas hyperdopaminergia may play a fundamental role generating endophenotypes associated with schizophrenia. Sleep disturbances are known to occur both schizophrenia and suggesting that dopamine plays regulating sleep–wake cycle. Here, we show novelty-exposed hyperdopaminergic mice enter novel awake state characterized by spectral patterns hippocampal local field potentials resemble electrophysiological activity...

The discovery of experience-dependent brain reactivation during both slow-wave (SW) and rapid eye-movement (REM) sleep led to the notion that consolidation recently acquired memory traces requires neural replay sleep. To date, however, several observations continue undermine this hypothesis. address some these objections, we investigated effects a transient novel experience on long-term evolution ongoing neuronal activity in rat forebrain. We observed spatiotemporal patterns ensemble...

In most mammalian species studied, two distinct and successive phases of sleep, slow wave (SW), rapid eye movement (REM), can be recognized on the basis their EEG profiles associated behaviors. Both have been implicated in offline sensorimotor processing daytime events, but molecular mechanisms remain elusive. We studied brain expression plasticity-associated immediate-early gene (IEG) zif-268 during SW REM sleep rats exposed to rich experience preceding waking period. Whereas nonexposed...

Rapid-eye-movement (REM) sleep plays a key role in the consolidation of memories acquired during waking (WK). The search for mechanisms underlying that has revealed significant correlations patterns neuronal firing, regional blood flow, and expression activity-dependent gene <i>zif-268</i> between WK subsequent REM sleep. <i>Zif-268</i> integrates major calcium signal transduction pathway is implicated by several lines evidence synaptic plasticity. Here we report induction hippocampal...

When songbirds hear the song of another individual same species or when they sing, mRNA levels ZENK gene increase rapidly in forebrain areas involved vocal communication. This induction is thought to be related long-term neuronal change and possibly formation song-related memories. We used immunocytochemistry study distribution protein brain zebra finches canaries after presentation playbacks. Birds that heard playbacks did not sing response showed increased auditory areas, including...

The hallucinogenic brew Ayahuasca, a rich source of serotonergic agonists and reuptake inhibitors, has been used for ages by Amazonian populations during religious ceremonies. Among all perceptual changes induced the most remarkable are vivid "seeings." During such seeings, users report potent imagery. Using functional magnetic resonance imaging closed-eyes imagery task, we found that Ayahuasca produces robust increase in activation several occipital, temporal, frontal areas. In primary...

Scale-invariant neuronal avalanches have been observed in cell cultures and slices as well anesthetized awake brains, suggesting that the brain operates near criticality, i.e. within a narrow margin between avalanche propagation extinction. In theory, criticality provides many desirable features for behaving brain, optimizing computational capabilities, information transmission, sensitivity to sensory stimuli size of memory repertoires. However, thorough characterization freely-behaving (FB)...

It was recently proposed that fast gamma oscillations (60-150 Hz) convey spatial information from the medial entorhinal cortex (EC) to CA1 region of hippocampus. However, here we describe 2 functionally distinct within this frequency range, both coupled theta rhythm during active exploration and rapid eye movement sleep: an oscillation with peak activity at ∼80 Hz a faster centered ∼140 Hz. The are differentially modulated by phase depending on layer; theta-80 coupling is strongest stratum...

In chronic psychotic patients, word graph analysis shows potential as complementary psychiatric assessment. This relies mostly on connectedness, a structural feature of speech that is anti-correlated with negative symptoms. Here we aimed to verify whether disorganization during the first clinical contact, measured by can correctly classify symptoms and schizophrenia diagnosis 6 months in advance. Positive syndrome scale scores memory reports were collected from 21 patients undergoing contact...

Early psychiatry investigated dreams to understand psychopathologies. Contemporary psychiatry, which neglects dreams, has been criticized for lack of objectivity. In search quantitative insight into the structure psychotic speech, we speech graph attributes (SGA) in patients with schizophrenia, bipolar disorder type I, and non-psychotic controls as they reported waking dream contents. Schizophrenic subjects spoke reduced connectivity, tight correlation negative cognitive symptoms measured by...

Recent reports converge to the idea that high-frequency oscillations in local field potentials (LFPs) represent multiunit activity. In particular, amplitude of LFP activity above 100 Hz—commonly referred as “high-gamma” or “epsilon” band—was found correlate with firing rate. However, other studies suggest existence true at this frequency range are different from well established ripple oscillations. Using multisite recordings hippocampus freely moving rats, we show here can either spectral...

Abstract Recent studies show that higher order oscillatory interactions such as cross-frequency coupling are important for brain functions impaired in schizophrenia, including perception, attention and memory. Here we investigated the dynamics of hippocampus awake rats upon NMDA receptor blockade by ketamine, a pharmacological model schizophrenia. Ketamine (25, 50 75 mg/kg i.p.) increased gamma high-frequency oscillations (HFO) all depths CA1-dentate axis, while theta power changes depended...

Abstract Dimethyltryptamines are entheogenic serotonin-like molecules present in traditional Amerindian medicine recently associated with cognitive gains, antidepressant effects, and changes brain areas related to attention. Legal restrictions the lack of adequate experimental models have limited understanding how such substances impact human metabolism. Here we used shotgun mass spectrometry explore proteomic differences induced by 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) on cerebral...

The relationship between exercise and cognition is an important topic of research that only recently began to unravel. Here, we set out investigate the relation motor skills, cognitive function, school performance in 45 students from 8 14 years age. We used a cross-sectional design evaluate coordination (Touch Test Disc), agility (Shuttle Run Speed-running back forth), (Academic Achievement Test), Stroop test, six sub-tests Wechsler Intelligence Scale for Children-IV (WISC-IV). found, Touch...