Peak-alpha frequency varies across individuals and mental states, but it also forms a negative gradient from posterior to anterior regions in association with increases in cortical thickness and connectivity, reflecting a cortical hierarchy in temporal integration. Tracking the spatial standard deviation of peak-alpha frequency in scalp EEG, we observed that a posterior-to-anterior gradient dynamically formed and dissolved. Periods of high spatial standard deviation yielded robustly negative posterior-to-anterior gradients—the “gradient state”—while periods of low spatial standard deviation yielded globally converged peak-alpha frequency—the “uniform state.” The state variations were characterized by a combination of slow (0.3 Hz-0.5 Hz) oscillations and random-walk-like fluctuations. They were relatively independently correlated with peak-alpha frequency variations in anterior regions and peak-alpha power variations in central regions driven by posterior regions (together accounting for ∼50% of the state ...

The auditory brainstem response (ABR) is a measure of subcortical activity in response to auditory stimuli. The wave V peak of the ABR depends on stimulus intensity level, and has been widely used for clinical hearing assessment. Conventional methods to estimate the ABR average electroencephalography (EEG) responses to short unnatural stimuli such as clicks. Recent work has moved towards more eco­logically relevant continuous speech stimuli using linear deconvolution models called Temporal Response Functions (TRFs). Investigating whether the TRF waveform changes with stimulus intensity is a crucial step towards the use of natural speech stimuli for hearing assessments involving subcortical responses. Here, we develop methods to estimate level-dependent subcortical TRFs using EEG data collected from 21 participants listening to continuous speech presented at 4 different intensity levels. We find that level-dependent changes can be detected in the wave V peak of the subcortical TRF for almost all par­ticipan...

Sensory axons projecting to the central nervous system are organized into topographic maps that represent the locations of sensory stimuli. In some sensory systems, even adjacent sensory axons are arranged topographically, forming “fine-scale” topographic maps. Although several broad molecular gradients are known to instruct coarse topography, we know little about the molecular signaling that regulates fine-scale topography at the level of two adjacent axons. Here, we provide evidence that trans-synaptic BMP signaling mediates local inter-neuronal communication to regulate fine-scale topography in the nociceptive system of Drosophila larvae. We first show that the topographic separation of the axon terminals of adjacent nociceptors requires their common postsynaptic target, the A08n neurons. This phenotype is recapitulated by knockdown of the BMP ligand, Dpp, in these neurons. In addition, removing the type-II BMP receptors or their effector (Mad transcription factor) in single nociceptors impairs the fine...

Adolescent inhibition of thalamo-cortical projections from postnatal day P20-50 leads to long-lasting deficits in prefrontal-cortex function and cognition in the adult mouse. While this suggests a role of thalamic activity in prefrontal-cortex maturation, it is unclear how inhibition of these projections affect prefrontal circuitry during adolescence. Here, we used chemogenetic tools to inhibit thalamo-prefrontal projections in male/female mice from P20-35 and measured synaptic inputs to prefrontal pyramidal neurons by layer (either II/III or V/VI) and projection target (MD, NAc or callosal mPFC) twenty-four hours later using slice physiology. We chose mPFC and MD-projecting cells as they are largely distinguished by cortical layer (II/III versus V/VI, respectively) and NAc-projecting cells as they span both layers and therefore provide a within-layer comparison for the other two populations. We found a decrease in the frequency of excitatory and inhibitory currents in layer-II/III-nucleus-accumbens (NAc) ...

Public outreach can expand your professional perspective, make you a stronger communicator, and strengthen public support for science. There are many ways to get involved. In this webinar, experienced neuroscientists share ways to find outreach activities that connect to your personal strengths and interests and offer you a chance to educate the public about neuroscience.

This resource was featured in the NeuroJobs Career Center. Visit today to search the world’s largest source of neuroscience opportunities. Six seconds. That’s all it takes for a reviewer to put your resume or CV in the “keep” or “discard” pile. So to be a successful candidate, you need to make a strong impression. Watch this webinar to learn the strategies that will best showcase your value on a CV or resume and earn you that coveted position.

Reverberation, a ubiquitous feature of real-world acoustic environments, exhibits statistical regularities that human listeners leverage to self-orient, facilitate auditory perception, and understand their environment. Despite the extensive research on sound source representation in the auditory system, it remains unclear how the brain represents real-world reverberant environments. Here, we characterized the neural response to reverberation of varying realism by applying multivariate pattern analysis to electroencephalographic (EEG) brain signals. Human listeners (12 male and 8 female) heard speech samples convolved with real-world and synthetic reverberant impulse responses and judged whether the speech samples were in a “real” or “fake” environment, focusing on the reverberant background rather than the properties of speech itself. Participants distinguished real from synthetic reverberation with ∼75% accuracy; EEG decoding reveals a multistage decoding time course, with dissociable components early in ...

This resource was featured in the NeuroJobs Career Center. Visit today to search the world’s largest source of neuroscience opportunities. If you’re looking at career options, or wondering where to start, an Individual Development Plan (IDP) can help. The IDP is a tool to help you critically assess your skills and values, which will help you address your career goals in an achievable way. Get a step-by-step guide for the AAAS myIDP tool by one of the creators and hear from two postdocs about their experiences using the IDP.

Animal studies consistently demonstrate that testosterone is protective against pain in multiple models, including an animal model of activity-induced muscle pain . In this model, females develop widespread muscle hyperalgesia, and reducing testosterone levels in males results in widespread muscle hyperalgesia. Widespread pain is believed to be mediated by changes in the central nervous system, including the rostral ventromedial medulla (RVM). The enzyme that converts testosterone to estradiol, aromatase, is highly expressed in the RVM. Therefore, we hypothesized that testosterone is converted by aromatase to estradiol locally in the RVM to prevent development of widespread muscle hyperalgesia in male mice. This was tested through pharmacological inhibition of estrogen receptors (ER), aromatase, or ER-α in the RVM which resulted in contralateral hyperalgesia in male mice (C57BL/6J). ER inhibition in the RVM had no effect on hyperalgesia in female mice. As prior studies show modulation of estradiol signalin...

ATP1A3 is a Na,K-ATPase gene expressed specifically in neurons in the brain. Human mutations are dominant and produce an unusually wide spectrum of neurological phenotypes, most notably rapid-onset dystonia- parkinsonism (RDP) and alternating hemiplegia childhood (AHC). Here we compared heterozygotes of two mouse lines, a line with little or no expression ( Atp1a 3tm1Ling/+) and a knock-in expressing p.Asp801Tyr (D801Y, Atp1a3 +/D801Y). Both mouse lines had normal lifespans, but Atp1a3 +/D801Y had mild perinatal mortality contrasting with D801N mice ( Atp1a3 +/D801N), which had high mortality. The phenotypes of Atp1a 3tm1Ling/+ and Atp1a3 +/D801Y were different, and testing of each strain was tailored to its symptom range. Atp1a 3tm1Ling/+ mice displayed little at baseline, but repeated ethanol intoxication produced hyperkinetic motor abnormalities not seen in littermate controls. Atp1a3 +/D801Y mice displayed robust phenotypes: hyperactivity, diminished posture consistent with hypotonia, and deficiencies ...