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Sample records for auditory brain regions

  1. Brain Region-Specific Activity Patterns after Recent or Remote Memory Retrieval of Auditory Conditioned Fear

    ERIC Educational Resources Information Center

    Kwon, Jeong-Tae; Jhang, Jinho; Kim, Hyung-Su; Lee, Sujin; Han, Jin-Hee

    2012-01-01

    Memory is thought to be sparsely encoded throughout multiple brain regions forming unique memory trace. Although evidence has established that the amygdala is a key brain site for memory storage and retrieval of auditory conditioned fear memory, it remains elusive whether the auditory brain regions may be involved in fear memory storage or…

  2. Sex differences in brain structure in auditory and cingulate regions.

    PubMed

    Brun, Caroline C; Leporé, Natasha; Luders, Eileen; Chou, Yi-Yu; Madsen, Sarah K; Toga, Arthur W; Thompson, Paul M

    2009-07-01

    We applied a new method to visualize the three-dimensional profile of sex differences in brain structure based on MRI scans of 100 young adults. We compared 50 men with 50 women, matched for age and other relevant demographics. As predicted, left hemisphere auditory and language-related regions were proportionally expanded in women versus men, suggesting a possible structural basis for the widely replicated sex differences in language processing. In men, primary visual, and visuo-spatial association areas of the parietal lobes were proportionally expanded, in line with prior reports of relative strengths in visuo-spatial processing in men. We relate these three-dimensional patterns to prior functional and structural studies, and to theoretical predictions based on nonlinear scaling of brain morphometry.

  3. Quantitative map of multiple auditory cortical regions with a stereotaxic fine-scale atlas of the mouse brain

    PubMed Central

    Tsukano, Hiroaki; Horie, Masao; Hishida, Ryuichi; Takahashi, Kuniyuki; Takebayashi, Hirohide; Shibuki, Katsuei

    2016-01-01

    Optical imaging studies have recently revealed the presence of multiple auditory cortical regions in the mouse brain. We have previously demonstrated, using flavoprotein fluorescence imaging, at least six regions in the mouse auditory cortex, including the anterior auditory field (AAF), primary auditory cortex (AI), the secondary auditory field (AII), dorsoanterior field (DA), dorsomedial field (DM), and dorsoposterior field (DP). While multiple regions in the visual cortex and somatosensory cortex have been annotated and consolidated in recent brain atlases, the multiple auditory cortical regions have not yet been presented from a coronal view. In the current study, we obtained regional coordinates of the six auditory cortical regions of the C57BL/6 mouse brain and illustrated these regions on template coronal brain slices. These results should reinforce the existing mouse brain atlases and support future studies in the auditory cortex. PMID:26924462

  4. High Resolution Quantitative Synaptic Proteome Profiling of Mouse Brain Regions After Auditory Discrimination Learning

    PubMed Central

    Kolodziej, Angela; Smalla, Karl-Heinz; Richter, Sandra; Engler, Alexander; Pielot, Rainer; Dieterich, Daniela C.; Tischmeyer, Wolfgang; Naumann, Michael; Kähne, Thilo

    2016-01-01

    The molecular synaptic mechanisms underlying auditory learning and memory remain largely unknown. Here, the workflow of a proteomic study on auditory discrimination learning in mice is described. In this learning paradigm, mice are trained in a shuttle box Go/NoGo-task to discriminate between rising and falling frequency-modulated tones in order to avoid a mild electric foot-shock. The protocol involves the enrichment of synaptosomes from four brain areas, namely the auditory cortex, frontal cortex, hippocampus, and striatum, at different stages of training. Synaptic protein expression patterns obtained from trained mice are compared to naïve controls using a proteomic approach. To achieve sufficient analytical depth, samples are fractionated in three different ways prior to mass spectrometry, namely 1D SDS-PAGE/in-gel digestion, in-solution digestion and phospho-peptide enrichment. High-resolution proteomic analysis on a mass spectrometer and label-free quantification are used to examine synaptic protein profiles in phospho-peptide-depleted and phospho-peptide-enriched fractions of synaptosomal protein samples. A commercial software package is utilized to reveal proteins and phospho-peptides with significantly regulated relative synaptic abundance levels (trained/naïve controls). Common and differential regulation modes for the synaptic proteome in the investigated brain regions of mice after training were observed. Subsequently, meta-analyses utilizing several databases are employed to identify underlying cellular functions and biological pathways. PMID:28060347

  5. High Resolution Quantitative Synaptic Proteome Profiling of Mouse Brain Regions After Auditory Discrimination Learning.

    PubMed

    Kolodziej, Angela; Smalla, Karl-Heinz; Richter, Sandra; Engler, Alexander; Pielot, Rainer; Dieterich, Daniela C; Tischmeyer, Wolfgang; Naumann, Michael; Kähne, Thilo

    2016-12-15

    The molecular synaptic mechanisms underlying auditory learning and memory remain largely unknown. Here, the workflow of a proteomic study on auditory discrimination learning in mice is described. In this learning paradigm, mice are trained in a shuttle box Go/NoGo-task to discriminate between rising and falling frequency-modulated tones in order to avoid a mild electric foot-shock. The protocol involves the enrichment of synaptosomes from four brain areas, namely the auditory cortex, frontal cortex, hippocampus, and striatum, at different stages of training. Synaptic protein expression patterns obtained from trained mice are compared to naïve controls using a proteomic approach. To achieve sufficient analytical depth, samples are fractionated in three different ways prior to mass spectrometry, namely 1D SDS-PAGE/in-gel digestion, in-solution digestion and phospho-peptide enrichment. High-resolution proteomic analysis on a mass spectrometer and label-free quantification are used to examine synaptic protein profiles in phospho-peptide-depleted and phospho-peptide-enriched fractions of synaptosomal protein samples. A commercial software package is utilized to reveal proteins and phospho-peptides with significantly regulated relative synaptic abundance levels (trained/naïve controls). Common and differential regulation modes for the synaptic proteome in the investigated brain regions of mice after training were observed. Subsequently, meta-analyses utilizing several databases are employed to identify underlying cellular functions and biological pathways.

  6. Expression of c-fos in auditory and non-auditory brain regions of the gerbil after manipulations that induce tinnitus.

    PubMed

    Wallhäusser-Franke, E; Mahlke, C; Oliva, R; Braun, S; Wenz, G; Langner, G

    2003-12-01

    Subjective tinnitus is a phantom sound sensation that does not result from acoustic stimulation and is audible to the affected subject only. Tinnitus-like sensations in animals can be evoked by procedures that also cause tinnitus in humans. In gerbils, we investigated brain activation after systemic application of sodium salicylate or exposure to loud noise, both known to be reliable tinnitus-inductors. Brains were screened for neurons containing the c-fos protein. After salicylate injections, auditory cortex was the only auditory area with consistently increased numbers of immunoreactive neurons compared to controls. Exposure to impulse noise led to prolonged c-fos expression in auditory cortex and dorsal cochlear nucleus. After both manipulations c-fos expression was increased in the amygdala, in thalamic midline, and intralaminar areas, in frontal cortex, as well as in hypothalamic and brainstem regions involved in behavioral and physiological defensive reactions. Activation of these non-auditory areas was attributed to acute stress, to aversive-affective components and autonomous reactions associated with the treatments and a resulting tinnitus. The present findings are in accordance with former results that provided evidence for suppressed activation in auditory midbrain but enhanced activation of the auditory cortex after injecting high doses of salicylate. In addition, our present results provide evidence that acute stress coinciding with a disruption of hearing may evoke activation of the auditory cortex. We interpret these results in favor of our model of central tinnitus generation.

  7. Synaptic proteome changes in mouse brain regions upon auditory discrimination learning.

    PubMed

    Kähne, Thilo; Kolodziej, Angela; Smalla, Karl-Heinz; Eisenschmidt, Elke; Haus, Utz-Uwe; Weismantel, Robert; Kropf, Siegfried; Wetzel, Wolfram; Ohl, Frank W; Tischmeyer, Wolfgang; Naumann, Michael; Gundelfinger, Eckart D

    2012-08-01

    Changes in synaptic efficacy underlying learning and memory processes are assumed to be associated with alterations of the protein composition of synapses. Here, we performed a quantitative proteomic screen to monitor changes in the synaptic proteome of four brain areas (auditory cortex, frontal cortex, hippocampus striatum) during auditory learning. Mice were trained in a shuttle box GO/NO-GO paradigm to discriminate between rising and falling frequency modulated tones to avoid mild electric foot shock. Control-treated mice received corresponding numbers of either the tones or the foot shocks. Six hours and 24 h later, the composition of a fraction enriched in synaptic cytomatrix-associated proteins was compared to that obtained from naïve mice by quantitative mass spectrometry. In the synaptic protein fraction obtained from trained mice, the average percentage (±SEM) of downregulated proteins (59.9 ± 0.5%) exceeded that of upregulated proteins (23.5 ± 0.8%) in the brain regions studied. This effect was significantly smaller in foot shock (42.7 ± 0.6% down, 40.7 ± 1.0% up) and tone controls (43.9 ± 1.0% down, 39.7 ± 0.9% up). These data suggest that learning processes initially induce removal and/or degradation of proteins from presynaptic and postsynaptic cytoskeletal matrices before these structures can acquire a new, postlearning organisation. In silico analysis points to a general role of insulin-like signalling in this process.

  8. Research of brain activation regions of "yes" and "no" responses by auditory stimulations in human EEG

    NASA Astrophysics Data System (ADS)

    Hu, Min; Liu, GuoZhong

    2011-11-01

    People with neuromuscular disorders are difficult to communicate with the outside world. It is very important to the clinician and the patient's family that how to distinguish vegetative state (VS) and minimally conscious state (MCS) for a disorders of consciousness (DOC) patient. If a patient is diagnosed with VS, this means that the hope of recovery is greatly reduced, thus leading to the family to abandon the treatment. Brain-computer interface (BCI) is aiming to help those people by analyzing patients' electroencephalogram (EEG). This paper focus on analyzing the corresponding activated regions of the brain when a subject responses "yes" or "no" to an auditory stimuli question. When the brain concentrates, the phase of the related area will become orderly from desultorily. So in this paper we analyzed EEG from the angle of phase. Seven healthy subjects volunteered to participate in the experiment. A total of 84 groups of repeatability stimulation test were done. Firstly, the frequency is fragmented by using wavelet method. Secondly, the phase of EEG is extracted by Hilbert. At last, we obtained approximate entropy and information entropy of each frequency band of EEG. The results show that brain areas are activated of the central area when people say "yes", and the areas are activated of the central area and temporal when people say "no". This conclusion is corresponding to magnetic resonance imaging technology. This study provides the theory basis and the algorithm design basis for designing BCI equipment for people with neuromuscular disorders.

  9. Enhanced peripheral visual processing in congenitally deaf humans is supported by multiple brain regions, including primary auditory cortex.

    PubMed

    Scott, Gregory D; Karns, Christina M; Dow, Mark W; Stevens, Courtney; Neville, Helen J

    2014-01-01

    Brain reorganization associated with altered sensory experience clarifies the critical role of neuroplasticity in development. An example is enhanced peripheral visual processing associated with congenital deafness, but the neural systems supporting this have not been fully characterized. A gap in our understanding of deafness-enhanced peripheral vision is the contribution of primary auditory cortex. Previous studies of auditory cortex that use anatomical normalization across participants were limited by inter-subject variability of Heschl's gyrus. In addition to reorganized auditory cortex (cross-modal plasticity), a second gap in our understanding is the contribution of altered modality-specific cortices (visual intramodal plasticity in this case), as well as supramodal and multisensory cortices, especially when target detection is required across contrasts. Here we address these gaps by comparing fMRI signal change for peripheral vs. perifoveal visual stimulation (11-15° vs. 2-7°) in congenitally deaf and hearing participants in a blocked experimental design with two analytical approaches: a Heschl's gyrus region of interest analysis and a whole brain analysis. Our results using individually-defined primary auditory cortex (Heschl's gyrus) indicate that fMRI signal change for more peripheral stimuli was greater than perifoveal in deaf but not in hearing participants. Whole-brain analyses revealed differences between deaf and hearing participants for peripheral vs. perifoveal visual processing in extrastriate visual cortex including primary auditory cortex, MT+/V5, superior-temporal auditory, and multisensory and/or supramodal regions, such as posterior parietal cortex (PPC), frontal eye fields, anterior cingulate, and supplementary eye fields. Overall, these data demonstrate the contribution of neuroplasticity in multiple systems including primary auditory cortex, supramodal, and multisensory regions, to altered visual processing in congenitally deaf adults.

  10. Noise Trauma Induced Plastic Changes in Brain Regions outside the Classical Auditory Pathway

    PubMed Central

    Chen, Guang-Di; Sheppard, Adam; Salvi, Richard

    2017-01-01

    The effects of intense noise exposure on the classical auditory pathway have been extensively investigated; however, little is known about the effects of noise-induced hearing loss on non-classical auditory areas in the brain such as the lateral amygdala (LA) and striatum (Str). To address this issue, we compared the noise-induced changes in spontaneous and tone-evoked responses from multiunit clusters (MUC) in the LA and Str with those seen in auditory cortex (AC). High-frequency octave band noise (10–20 kHz) and narrow band noise (16–20 kHz) induced permanent thresho ld shifts (PTS) at high-frequencies within and above the noise band but not at low frequencies. While the noise trauma significantly elevated spontaneous discharge rate (SR) in the AC, SRs in the LA and Str were only slightly increased across all frequencies. The high-frequency noise trauma affected tone-evoked firing rates in frequency and time dependent manner and the changes appeared to be related to severity of noise trauma. In the LA, tone-evoked firing rates were reduced at the high-frequencies (trauma area) whereas firing rates were enhanced at the low-frequencies or at the edge-frequency dependent on severity of hearing loss at the high frequencies. The firing rate temporal profile changed from a broad plateau to one sharp, delayed peak. In the AC, tone-evoked firing rates were depressed at high frequencies and enhanced at the low frequencies while the firing rate temporal profiles became substantially broader. In contrast, firing rates in the Str were generally decreased and firing rate temporal profiles become more phasic and less prolonged. The altered firing rate and pattern at low frequencies induced by high frequency hearing loss could have perceptual consequences. The tone-evoked hyperactivity in low-frequency MUC could manifest as hyperacusis whereas the discharge pattern changes could affect temporal resolution and integration. PMID:26701290

  11. Amplitude-modulated stimuli reveal auditory-visual interactions in brain activity and brain connectivity

    PubMed Central

    Laing, Mark; Rees, Adrian; Vuong, Quoc C.

    2015-01-01

    The temporal congruence between auditory and visual signals coming from the same source can be a powerful means by which the brain integrates information from different senses. To investigate how the brain uses temporal information to integrate auditory and visual information from continuous yet unfamiliar stimuli, we used amplitude-modulated tones and size-modulated shapes with which we could manipulate the temporal congruence between the sensory signals. These signals were independently modulated at a slow or a fast rate. Participants were presented with auditory-only, visual-only, or auditory-visual (AV) trials in the fMRI scanner. On AV trials, the auditory and visual signal could have the same (AV congruent) or different modulation rates (AV incongruent). Using psychophysiological interaction analyses, we found that auditory regions showed increased functional connectivity predominantly with frontal regions for AV incongruent relative to AV congruent stimuli. We further found that superior temporal regions, shown previously to integrate auditory and visual signals, showed increased connectivity with frontal and parietal regions for the same contrast. Our findings provide evidence that both activity in a network of brain regions and their connectivity are important for AV integration, and help to bridge the gap between transient and familiar AV stimuli used in previous studies. PMID:26483710

  12. Auditory multistability and neurotransmitter concentrations in the human brain.

    PubMed

    Kondo, Hirohito M; Farkas, Dávid; Denham, Susan L; Asai, Tomohisa; Winkler, István

    2017-02-19

    Multistability in perception is a powerful tool for investigating sensory-perceptual transformations, because it produces dissociations between sensory inputs and subjective experience. Spontaneous switching between different perceptual objects occurs during prolonged listening to a sound sequence of tone triplets or repeated words (termed auditory streaming and verbal transformations, respectively). We used these examples of auditory multistability to examine to what extent neurochemical and cognitive factors influence the observed idiosyncratic patterns of switching between perceptual objects. The concentrations of glutamate-glutamine (Glx) and γ-aminobutyric acid (GABA) in brain regions were measured by magnetic resonance spectroscopy, while personality traits and executive functions were assessed using questionnaires and response inhibition tasks. Idiosyncratic patterns of perceptual switching in the two multistable stimulus configurations were identified using a multidimensional scaling (MDS) analysis. Intriguingly, although switching patterns within each individual differed between auditory streaming and verbal transformations, similar MDS dimensions were extracted separately from the two datasets. Individual switching patterns were significantly correlated with Glx and GABA concentrations in auditory cortex and inferior frontal cortex but not with the personality traits and executive functions. Our results suggest that auditory perceptual organization depends on the balance between neural excitation and inhibition in different brain regions.This article is part of the themed issue 'Auditory and visual scene analysis'.

  13. Brain metabolism during hallucination-like auditory stimulation in schizophrenia.

    PubMed

    Horga, Guillermo; Fernández-Egea, Emilio; Mané, Anna; Font, Mireia; Schatz, Kelly C; Falcon, Carles; Lomeña, Francisco; Bernardo, Miguel; Parellada, Eduard

    2014-01-01

    Auditory verbal hallucinations (AVH) in schizophrenia are typically characterized by rich emotional content. Despite the prominent role of emotion in regulating normal perception, the neural interface between emotion-processing regions such as the amygdala and auditory regions involved in perception remains relatively unexplored in AVH. Here, we studied brain metabolism using FDG-PET in 9 remitted patients with schizophrenia that previously reported severe AVH during an acute psychotic episode and 8 matched healthy controls. Participants were scanned twice: (1) at rest and (2) during the perception of aversive auditory stimuli mimicking the content of AVH. Compared to controls, remitted patients showed an exaggerated response to the AVH-like stimuli in limbic and paralimbic regions, including the left amygdala. Furthermore, patients displayed abnormally strong connections between the amygdala and auditory regions of the cortex and thalamus, along with abnormally weak connections between the amygdala and medial prefrontal cortex. These results suggest that abnormal modulation of the auditory cortex by limbic-thalamic structures might be involved in the pathophysiology of AVH and may potentially account for the emotional features that characterize hallucinatory percepts in schizophrenia.

  14. Brain Metabolism during Hallucination-Like Auditory Stimulation in Schizophrenia

    PubMed Central

    Horga, Guillermo; Fernández-Egea, Emilio; Mané, Anna; Font, Mireia; Schatz, Kelly C.; Falcon, Carles; Lomeña, Francisco; Bernardo, Miguel; Parellada, Eduard

    2014-01-01

    Auditory verbal hallucinations (AVH) in schizophrenia are typically characterized by rich emotional content. Despite the prominent role of emotion in regulating normal perception, the neural interface between emotion-processing regions such as the amygdala and auditory regions involved in perception remains relatively unexplored in AVH. Here, we studied brain metabolism using FDG-PET in 9 remitted patients with schizophrenia that previously reported severe AVH during an acute psychotic episode and 8 matched healthy controls. Participants were scanned twice: (1) at rest and (2) during the perception of aversive auditory stimuli mimicking the content of AVH. Compared to controls, remitted patients showed an exaggerated response to the AVH-like stimuli in limbic and paralimbic regions, including the left amygdala. Furthermore, patients displayed abnormally strong connections between the amygdala and auditory regions of the cortex and thalamus, along with abnormally weak connections between the amygdala and medial prefrontal cortex. These results suggest that abnormal modulation of the auditory cortex by limbic-thalamic structures might be involved in the pathophysiology of AVH and may potentially account for the emotional features that characterize hallucinatory percepts in schizophrenia. PMID:24416328

  15. Infant Auditory Processing and Event-related Brain Oscillations

    PubMed Central

    Musacchia, Gabriella; Ortiz-Mantilla, Silvia; Realpe-Bonilla, Teresa; Roesler, Cynthia P.; Benasich, April A.

    2015-01-01

    Rapid auditory processing and acoustic change detection abilities play a critical role in allowing human infants to efficiently process the fine spectral and temporal changes that are characteristic of human language. These abilities lay the foundation for effective language acquisition; allowing infants to hone in on the sounds of their native language. Invasive procedures in animals and scalp-recorded potentials from human adults suggest that simultaneous, rhythmic activity (oscillations) between and within brain regions are fundamental to sensory development; determining the resolution with which incoming stimuli are parsed. At this time, little is known about oscillatory dynamics in human infant development. However, animal neurophysiology and adult EEG data provide the basis for a strong hypothesis that rapid auditory processing in infants is mediated by oscillatory synchrony in discrete frequency bands. In order to investigate this, 128-channel, high-density EEG responses of 4-month old infants to frequency change in tone pairs, presented in two rate conditions (Rapid: 70 msec ISI and Control: 300 msec ISI) were examined. To determine the frequency band and magnitude of activity, auditory evoked response averages were first co-registered with age-appropriate brain templates. Next, the principal components of the response were identified and localized using a two-dipole model of brain activity. Single-trial analysis of oscillatory power showed a robust index of frequency change processing in bursts of Theta band (3 - 8 Hz) activity in both right and left auditory cortices, with left activation more prominent in the Rapid condition. These methods have produced data that are not only some of the first reported evoked oscillations analyses in infants, but are also, importantly, the product of a well-established method of recording and analyzing clean, meticulously collected, infant EEG and ERPs. In this article, we describe our method for infant EEG net

  16. Specific activation of operculum 3 (OP3) brain region during provoked tinnitus-related phantom auditory perceptions in humans.

    PubMed

    Job, Agnès; Jacob, Roland; Pons, Yoann; Raynal, Marc; Kossowski, Michel; Gauthier, Jérôme; Lombard, Bertrand; Delon-Martin, Chantal

    2016-03-01

    The phantom sound perception mechanism by which a sound perception occurs without any external sound source is still enigmatic. According to our previous fMRI study, a small region in the parietal operculum 3 was hyperactivated as a function of tinnitus periodicity in subjects with acoustic trauma tinnitus sequelae. This region was localized in the vicinity of neural correlates of middle-ear tympano-ossicular chain movements due to pressure variations. Disturbed proprioceptors are known to trigger illusory perceptions; therefore, we hypothesized that a disturbance of middle-ear proprioceptors may originate phantom sound perceptions. We designed an fMRI study that aimed to stimulate middle-ear proprioceptors by repetitive vibrations using various rates of click trains. In this study, we report that exposure to specific rates of stimuli for a few minutes at comfortable intensity level in healthy subjects distinctly triggered transient tinnitus-like aftereffects. The fMRI neural correlates of the aftereffects were unequivocally localized in the same parietal region as in acoustic trauma tinnitus sufferers. Our results strongly suggest that a middle-ear kinesthetic/proprioceptive illusion exists at the origin of acoustic trauma tinnitus via a somatosensory pathway encompassing the trigeminal system.

  17. Bilinguals at the "cocktail party": dissociable neural activity in auditory-linguistic brain regions reveals neurobiological basis for nonnative listeners' speech-in-noise recognition deficits.

    PubMed

    Bidelman, Gavin M; Dexter, Lauren

    2015-04-01

    We examined a consistent deficit observed in bilinguals: poorer speech-in-noise (SIN) comprehension for their nonnative language. We recorded neuroelectric mismatch potentials in mono- and bi-lingual listeners in response to contrastive speech sounds in noise. Behaviorally, late bilinguals required ∼10dB more favorable signal-to-noise ratios to match monolinguals' SIN abilities. Source analysis of cortical activity demonstrated monotonic increase in response latency with noise in superior temporal gyrus (STG) for both groups, suggesting parallel degradation of speech representations in auditory cortex. Contrastively, we found differential speech encoding between groups within inferior frontal gyrus (IFG)-adjacent to Broca's area-where noise delays observed in nonnative listeners were offset in monolinguals. Notably, brain-behavior correspondences double dissociated between language groups: STG activation predicted bilinguals' SIN, whereas IFG activation predicted monolinguals' performance. We infer higher-order brain areas act compensatorily to enhance impoverished sensory representations but only when degraded speech recruits linguistic brain mechanisms downstream from initial auditory-sensory inputs.

  18. [Brain stem auditory evoked potentials in brain death state].

    PubMed

    Kojder, I; Garell, S; Włodarczyk, E; Sagan, L; Jezewski, D; Slósarek, J

    1998-01-01

    The authors studied auditory brainstem evoked potentials (BAEP) in 27 organ donors aged 40 to 68 years treated in neurosurgery units in Szczecin and Grenoble. Abnormal results were found in all cases. In 63% of cases no evoked action potentials were obtained, in 34% only the 1st wave was obtained, and in two cases evolution was observed with activity extinction. The authors believe that in the process of shaping of BAEP morphotic extinction begins from the later waves to earlier ones in agreement with the rostrocaudal direction of extinction of the functions or brain midline structures, and in a single study various findings may be obtained.

  19. Network Analysis of Functional Brain Connectivity Driven by Gamma-Band Auditory Steady-State Response in Auditory Hallucinations.

    PubMed

    Ying, Jun; Zhou, Dan; Lin, Ke; Gao, Xiaorong

    The auditory steady-state response (ASSR) may reflect activity from different regions of the brain. Particularly, it was reported that the gamma-band ASSR plays an important role in working memory, speech understanding, and recognition. Traditionally, the ASSR has been determined by power spectral density analysis, which cannot detect the exact overall distributed properties of the ASSR. Functional network analysis has recently been applied in electroencephalography studies. Previous studies on resting or working state found a small-world organization of the brain network. Some researchers have studied dysfunctional networks caused by diseases. The present study investigates the brain connection networks of schizophrenia patients with auditory hallucinations during an ASSR task. A directed transfer function is utilized to estimate the brain connectivity patterns. Moreover, the structures of brain networks are analyzed by converting the connectivity matrices into graphs. It is found that for normal subjects, network connections are mainly distributed at the central and frontal-temporal regions. This indicates that the central regions act as transmission hubs of information under ASSR stimulation. For patients, network connections seem unordered. The finding that the path length was larger in patients compared to that in normal subjects under most thresholds provides insight into the structures of connectivity patterns. The results suggest that there are more synchronous oscillations that cover a long distance on the cortex but a less efficient network for patients with auditory hallucinations.

  20. Are Auditory Hallucinations Related to the Brain's Resting State Activity? A 'Neurophenomenal Resting State Hypothesis'

    PubMed Central

    2014-01-01

    While several hypotheses about the neural mechanisms underlying auditory verbal hallucinations (AVH) have been suggested, the exact role of the recently highlighted intrinsic resting state activity of the brain remains unclear. Based on recent findings, we therefore developed what we call the 'resting state hypotheses' of AVH. Our hypothesis suggest that AVH may be traced back to abnormally elevated resting state activity in auditory cortex itself, abnormal modulation of the auditory cortex by anterior cortical midline regions as part of the default-mode network, and neural confusion between auditory cortical resting state changes and stimulus-induced activity. We discuss evidence in favour of our 'resting state hypothesis' and show its correspondence with phenomenal, i.e., subjective-experiential features as explored in phenomenological accounts. Therefore I speak of a 'neurophenomenal resting state hypothesis' of auditory hallucinations in schizophrenia. PMID:25598821

  1. Gonadotropin-releasing hormone (GnRH) modulates auditory processing in the fish brain.

    PubMed

    Maruska, Karen P; Tricas, Timothy C

    2011-04-01

    Gonadotropin-releasing hormone 1 (GnRH1) neurons control reproductive activity, but GnRH2 and GnRH3 neurons have widespread projections and function as neuromodulators in the vertebrate brain. While these extra-hypothalamic GnRH forms function as olfactory and visual neuromodulators, their potential effect on processing of auditory information is unknown. To test the hypothesis that GnRH modulates the processing of auditory information in the brain, we used immunohistochemistry to determine seasonal variations in these neuropeptide systems, and in vivo single-neuron recordings to identify neuromodulation in the midbrain torus semicircularis of the soniferous damselfish Abudefduf abdominalis. Our results show abundant GnRH-immunoreactive (-ir) axons in auditory processing regions of the midbrain and hindbrain. The number of extra-hypothalamic GnRH somata and the density of GnRH-ir axons within the auditory torus semicircularis also varied across the year, suggesting seasonal changes in GnRH influence of auditory processing. Exogenous application of GnRH (sGnRH and cGnRHII) caused a primarily inhibitory effect on auditory-evoked single neuron responses in the torus semicircularis. In the majority of neurons, GnRH caused a long-lasting decrease in spike rate in response to both tone bursts and playbacks of complex natural sounds. GnRH also decreased response latency and increased auditory thresholds in a frequency and stimulus type-dependent manner. To our knowledge, these results show for the first time in any vertebrate that GnRH can influence context-specific auditory processing in vivo in the brain, and may function to modulate seasonal auditory-mediated social behaviors.

  2. Diffusion tensor imaging of dolphin brains reveals direct auditory pathway to temporal lobe

    PubMed Central

    Berns, Gregory S.; Cook, Peter F.; Foxley, Sean; Jbabdi, Saad; Miller, Karla L.; Marino, Lori

    2015-01-01

    The brains of odontocetes (toothed whales) look grossly different from their terrestrial relatives. Because of their adaptation to the aquatic environment and their reliance on echolocation, the odontocetes' auditory system is both unique and crucial to their survival. Yet, scant data exist about the functional organization of the cetacean auditory system. A predominant hypothesis is that the primary auditory cortex lies in the suprasylvian gyrus along the vertex of the hemispheres, with this position induced by expansion of ‘associative′ regions in lateral and caudal directions. However, the precise location of the auditory cortex and its connections are still unknown. Here, we used a novel diffusion tensor imaging (DTI) sequence in archival post-mortem brains of a common dolphin (Delphinus delphis) and a pantropical dolphin (Stenella attenuata) to map their sensory and motor systems. Using thalamic parcellation based on traditionally defined regions for the primary visual (V1) and auditory cortex (A1), we found distinct regions of the thalamus connected to V1 and A1. But in addition to suprasylvian-A1, we report here, for the first time, the auditory cortex also exists in the temporal lobe, in a region near cetacean-A2 and possibly analogous to the primary auditory cortex in related terrestrial mammals (Artiodactyla). Using probabilistic tract tracing, we found a direct pathway from the inferior colliculus to the medial geniculate nucleus to the temporal lobe near the sylvian fissure. Our results demonstrate the feasibility of post-mortem DTI in archival specimens to answer basic questions in comparative neurobiology in a way that has not previously been possible and shows a link between the cetacean auditory system and those of terrestrial mammals. Given that fresh cetacean specimens are relatively rare, the ability to measure connectivity in archival specimens opens up a plethora of possibilities for investigating neuroanatomy in cetaceans and other species

  3. Oscillatory alpha modulations in right auditory regions reflect the validity of acoustic cues in an auditory spatial attention task.

    PubMed

    Weisz, Nathan; Müller, Nadia; Jatzev, Sabine; Bertrand, Olivier

    2014-10-01

    Anticipation of targets in the left or right hemifield leads to alpha modulations in posterior brain areas. Recently using magnetoencephalography, we showed increased right auditory alpha activity when attention was cued ipsilaterally. Here, we investigated the issue how cue validity itself influences oscillatory alpha activity. Acoustic cues were presented either to the right or left ear, followed by a compound dichotically presented target plus distractor. The preceding cue was either informative (75% validity) or uninformative (50%) about the location of the upcoming target. Cue validity × side-related alpha modulations were identified in pre- and posttarget periods in a right lateralized network, comprising auditory and nonauditory regions. This replicates and extends our previous finding of the right hemispheric dominance of auditory attentional modulations. Importantly, effective connectivity analysis showed that, in the pretarget period, this effect is accompanied by a pronounced and time-varying connectivity pattern of the right auditory cortex to the right intraparietal sulcus (IPS), with influence of IPS on superior temporal gyrus dominating at earlier intervals of the cue-target period. Our study underlines the assumption that alpha oscillations may play a similar functional role in auditory cortical regions as reported in other sensory modalities and suggests that these effects may be mediated via IPS.

  4. [Analysis of auditory information in the brain of the cetacean].

    PubMed

    Popov, V V; Supin, A Ia

    2006-01-01

    The cetacean brain specifics involve an exceptional development of the auditory neural centres. The place of projection sensory areas including the auditory that in the cetacean brain cortex is essentially different from that in other mammals. The EP characteristics indicated presence of several functional divisions in the auditory cortex. Physiological studies of the cetacean auditory centres were mainly performed using the EP technique. Of several types of the EPs, the short-latency auditory EP was most thoroughly studied. In cetacean, it is characterised by exceptionally high temporal resolution with the integration time about 0.3 ms which corresponds to the cut-off frequency 1700 Hz. This much exceeds the temporal resolution of the hearing in terranstrial mammals. The frequency selectivity of hearing in cetacean was measured using a number of variants of the masking technique. The hearing frequency selectivity acuity in cetacean exceeds that of most terraneous mammals (excepting the bats). This acute frequency selectivity provides the differentiation among the finest spectral patterns of auditory signals.

  5. The human brain maintains contradictory and redundant auditory sensory predictions.

    PubMed

    Pieszek, Marika; Widmann, Andreas; Gruber, Thomas; Schröger, Erich

    2013-01-01

    Computational and experimental research has revealed that auditory sensory predictions are derived from regularities of the current environment by using internal generative models. However, so far, what has not been addressed is how the auditory system handles situations giving rise to redundant or even contradictory predictions derived from different sources of information. To this end, we measured error signals in the event-related brain potentials (ERPs) in response to violations of auditory predictions. Sounds could be predicted on the basis of overall probability, i.e., one sound was presented frequently and another sound rarely. Furthermore, each sound was predicted by an informative visual cue. Participants' task was to use the cue and to discriminate the two sounds as fast as possible. Violations of the probability based prediction (i.e., a rare sound) as well as violations of the visual-auditory prediction (i.e., an incongruent sound) elicited error signals in the ERPs (Mismatch Negativity [MMN] and Incongruency Response [IR]). Particular error signals were observed even in case the overall probability and the visual symbol predicted different sounds. That is, the auditory system concurrently maintains and tests contradictory predictions. Moreover, if the same sound was predicted, we observed an additive error signal (scalp potential and primary current density) equaling the sum of the specific error signals. Thus, the auditory system maintains and tolerates functionally independently represented redundant and contradictory predictions. We argue that the auditory system exploits all currently active regularities in order to optimally prepare for future events.

  6. Methods for the analysis of auditory processing in the brain.

    PubMed

    Theunissen, Frédéric E; Woolley, Sarah M N; Hsu, Anne; Fremouw, Thane

    2004-06-01

    Understanding song perception and singing behavior in birds requires the study of auditory processing of complex sounds throughout the avian brain. We can divide the basics of auditory perception into two general processes: (1) encoding, the process whereby sound is transformed into neural activity and (2) decoding, the process whereby patterns of neural activity take on perceptual meaning and therefore guide behavioral responses to sounds. In birdsong research, most studies have focused on the decoding process: What are the responses of the specialized auditory neurons in the song control system? and What do they mean for the bird? Recently, new techniques addressing both encoding and decoding have been developed for use in songbirds. Here, we first describe some powerful methods for analyzing what acoustical aspects of complex sounds like songs are encoded by auditory processing neurons in songbird brain. These methods include the estimation and analysis of spectro-temporal receptive fields (STRFs) for auditory neurons. Then we discuss the decoding methods that have been used to understand how songbird neurons may discriminate among different songs and other sounds based on mean spike-count rates.

  7. The TLC: a novel auditory nucleus of the mammalian brain.

    PubMed

    Saldaña, Enrique; Viñuela, Antonio; Marshall, Allen F; Fitzpatrick, Douglas C; Aparicio, M-Auxiliadora

    2007-11-28

    We have identified a novel nucleus of the mammalian brain and termed it the tectal longitudinal column (TLC). Basic histologic stains, tract-tracing techniques and three-dimensional reconstructions reveal that the rat TLC is a narrow, elongated structure spanning the midbrain tectum longitudinally. This paired nucleus is located close to the midline, immediately dorsal to the periaqueductal gray matter. It occupies what has traditionally been considered the most medial region of the deep superior colliculus and the most medial region of the inferior colliculus. The TLC differs from the neighboring nuclei of the superior and inferior colliculi and the periaqueductal gray by its distinct connections and cytoarchitecture. Extracellular electrophysiological recordings show that TLC neurons respond to auditory stimuli with physiologic properties that differ from those of neurons in the inferior or superior colliculi. We have identified the TLC in rodents, lagomorphs, carnivores, nonhuman primates, and humans, which indicates that the nucleus is conserved across mammals. The discovery of the TLC reveals an unexpected level of longitudinal organization in the mammalian tectum and raises questions as to the participation of this mesencephalic region in essential, yet completely unexplored, aspects of multisensory and/or sensorimotor integration.

  8. Analysis of auditory information in the brains of cetaceans.

    PubMed

    Popov, V V; Supin, A Ya

    2007-03-01

    A characteristic feature of the brains of toothed cetaceans is the exclusive development of the auditory neural centers. The location of the projection sensory zones, including the auditory zones, in the cetacean cortex is significantly different from that in other mammals. The characteristics of evoked potentials demonstrate the existence of several functional subdivisions in the auditory cortex. Physiological studies of the auditory neural centers of cetaceans have been performed predominantly using the evoked potentials method. Of the several types of evoked potentials available for non-invasive recording, the most detailed studies have been performed using short-latency auditory evoked potentials (SLAEP). SLAEP in cetaceans are characterized by exclusively high time resolution, with integration times of about 0.3 msec, which on the frequency scale corresponds to a cut-off frequency of 1700 Hz. This is more than an order of magnitude greater than the time resolution of hearing in terrestrial mammals. The frequency selectivity of hearing in cetaceans has been measured using several versions of the masking method. The acuity of frequency selectivity in cetaceans is several times greater than that in most terrestrial mammals (except bats). The acute frequency selectivity allows the discrimination of very fine spectral patterns of sound signals.

  9. Effect of prenatal lignocaine on auditory brain stem evoked response.

    PubMed Central

    Bozynski, M E; Schumacher, R E; Deschner, L S; Kileny, P

    1989-01-01

    To test the hypothesis that there would be a positive correlation between the interpeak wave (I-V) interval as measured by auditory brain stem evoked response and the ratio of umbilical cord blood arterial to venous lignocaine concentrations in infants born after maternal epidural anaesthesia, 10 normal infants born at full term by elective caesarean section were studied. Umbilical cord arterial and venous plasma samples were assayed for lignocaine, and auditory brain stem evoked responses were elicited at 35 and 70 dB at less than 4 (test 1) and greater than or equal to 48 hours (test 2). Mean wave I-V intervals were prolonged in test 1 when compared with test 2. Linear regression showed the arterial:venous ratio accounted for 66% (left ear) and 43% (right ear) of the variance in test 1 intervals. No association was found in test 2. In newborn infants, changes in serial auditory brain stem evoked response tests occur after maternal lignocaine epidural anaesthesia and these changes correlate with blood lignocaine concentrations. PMID:2774635

  10. Interaction of language, auditory and memory brain networks in auditory verbal hallucinations.

    PubMed

    Ćurčić-Blake, Branislava; Ford, Judith M; Hubl, Daniela; Orlov, Natasza D; Sommer, Iris E; Waters, Flavie; Allen, Paul; Jardri, Renaud; Woodruff, Peter W; David, Olivier; Mulert, Christoph; Woodward, Todd S; Aleman, André

    2017-01-01

    Auditory verbal hallucinations (AVH) occur in psychotic disorders, but also as a symptom of other conditions and even in healthy people. Several current theories on the origin of AVH converge, with neuroimaging studies suggesting that the language, auditory and memory/limbic networks are of particular relevance. However, reconciliation of these theories with experimental evidence is missing. We review 50 studies investigating functional (EEG and fMRI) and anatomic (diffusion tensor imaging) connectivity in these networks, and explore the evidence supporting abnormal connectivity in these networks associated with AVH. We distinguish between functional connectivity during an actual hallucination experience (symptom capture) and functional connectivity during either the resting state or a task comparing individuals who hallucinate with those who do not (symptom association studies). Symptom capture studies clearly reveal a pattern of increased coupling among the auditory, language and striatal regions. Anatomical and symptom association functional studies suggest that the interhemispheric connectivity between posterior auditory regions may depend on the phase of illness, with increases in non-psychotic individuals and first episode patients and decreases in chronic patients. Leading hypotheses involving concepts as unstable memories, source monitoring, top-down attention, and hybrid models of hallucinations are supported in part by the published connectivity data, although several caveats and inconsistencies remain. Specifically, possible changes in fronto-temporal connectivity are still under debate. Precise hypotheses concerning the directionality of connections deduced from current theoretical approaches should be tested using experimental approaches that allow for discrimination of competing hypotheses.

  11. PARATHYROID HORMONE 2 RECEPTOR AND ITS ENDOGENOUS LIGAND TIP39 ARE CONCENTRATED IN ENDOCRINE, VISCEROSENSORY AND AUDITORY BRAIN REGIONS IN MACAQUE AND HUMAN

    PubMed Central

    Bagó, Attila G.; Dimitrov, Eugene; Saunders, Richard; Seress, László; Palkovits, Miklós; Usdin, Ted B.; Dobolyi, Arpád

    2009-01-01

    Parathyroid hormone receptor 2 (PTH2R) and its ligand, tuberoinfundibular peptide of 39 residues (TIP39) constitute a neuromodulator system implicated in endocrine and nociceptive regulations. We now describe the presence and distribution of the PTH2R and TIP39 in the brain of primates using a range of tissues and ages from macaque and human brain. In situ hybridization histochemistry of TIP39 mRNA, studied in young macaque brain, due to its possible decline beyond late postnatal ages, was present only in the thalamic subparafascicular area and the pontine medial paralemniscal nucleus. In contrast in situ hybridization histochemistry in macaque identified high levels of PTH2R expression in the central amygdaloid nucleus, medial preoptic area, hypothalamic paraventricular and periventricular nuclei, medial geniculate, and the pontine tegmentum. PTH2R mRNA was also detected in several human brain areas by RT-PCR. The distribution of PTH2R-immunoreactive fibers in human, determined by immunocytochemistry, was similar to that in rodents including dense fiber networks in the medial preoptic area, hypothalamic paraventricular, periventricular and infundibular (arcuate) nuclei, lateral hypothalamic area, median eminence, thalamic paraventricular nucleus, periaqueductal gray, lateral parabrachial nucleus, nucleus of the solitary tract, sensory trigeminal nuclei, medullary dorsal reticular nucleus, and dorsal horn of the spinal cord. Co-localization suggested that PTH2R fibers are glutamatergic, and that TIP39 may directly influence hypophysiotropic somatostatin containing and indirectly influence corticotropin releasing-hormone containing neurons. The results demonstrate that TIP39 and the PTH2R are expressed in the brain of primates in locations that suggest involvement in regulation of fear, anxiety, reproductive behaviors, release of pituitary hormones, and nociception. PMID:19401215

  12. Connections for auditory language in the human brain.

    PubMed

    Gierhan, Sarah M E

    2013-11-01

    The white matter bundles that underlie comprehension and production of language have been investigated for a number of years. Several studies have examined which fiber bundles (or tracts) are involved in auditory language processing, and which kind of language information is transmitted by which fiber tract. However, there is much debate about exactly which fiber tracts are involved, their precise course in the brain, how they should be named, and which functions they fulfill. Therefore, the present article reviews the available language-related literature, and educes a neurocognitive model of the pathways for auditory language processing. Besides providing an overview of the current methods used for relating fiber anatomy to function, this article details the precise anatomy of the fiber tracts and their roles in phonological, semantic and syntactic processing, articulation, and repetition.

  13. Localized brain activation related to the strength of auditory learning in a parrot.

    PubMed

    Eda-Fujiwara, Hiroko; Imagawa, Takuya; Matsushita, Masanori; Matsuda, Yasushi; Takeuchi, Hiro-Aki; Satoh, Ryohei; Watanabe, Aiko; Zandbergen, Matthijs A; Manabe, Kazuchika; Kawashima, Takashi; Bolhuis, Johan J

    2012-01-01

    Parrots and songbirds learn their vocalizations from a conspecific tutor, much like human infants acquire spoken language. Parrots can learn human words and it has been suggested that they can use them to communicate with humans. The caudomedial pallium in the parrot brain is homologous with that of songbirds, and analogous to the human auditory association cortex, involved in speech processing. Here we investigated neuronal activation, measured as expression of the protein product of the immediate early gene ZENK, in relation to auditory learning in the budgerigar (Melopsittacus undulatus), a parrot. Budgerigar males successfully learned to discriminate two Japanese words spoken by another male conspecific. Re-exposure to the two discriminanda led to increased neuronal activation in the caudomedial pallium, but not in the hippocampus, compared to untrained birds that were exposed to the same words, or were not exposed to words. Neuronal activation in the caudomedial pallium of the experimental birds was correlated significantly and positively with the percentage of correct responses in the discrimination task. These results suggest that in a parrot, the caudomedial pallium is involved in auditory learning. Thus, in parrots, songbirds and humans, analogous brain regions may contain the neural substrate for auditory learning and memory.

  14. The brain's voices: comparing nonclinical auditory hallucinations and imagery.

    PubMed

    Linden, David E J; Thornton, Katy; Kuswanto, Carissa N; Johnston, Stephen J; van de Ven, Vincent; Jackson, Michael C

    2011-02-01

    Although auditory verbal hallucinations are often thought to denote mental illness, the majority of voice hearers do not satisfy the criteria for a psychiatric disorder. Here, we report the first functional imaging study of such nonclinical hallucinations in 7 healthy voice hearers comparing them with auditory imagery. The human voice area in the superior temporal sulcus was activated during both hallucinations and imagery. Other brain areas supporting both hallucinations and imagery included fronto temporal language areas in the left hemisphere and their contralateral homologues and the supplementary motor area (SMA). Hallucinations are critically distinguished from imagery by lack of voluntary control. We expected this difference to be reflected in the relative timing of prefrontal and sensory areas. Activity of the SMA indeed preceded that of auditory areas during imagery, whereas during hallucinations, the 2 processes occurred instantaneously. Voluntary control was thus represented in the relative timing of prefrontal and sensory activation, whereas the sense of reality of the sensory experience may be a product of the voice area activation. Our results reveal mechanisms of the generation of sensory experience in the absence of external stimulation and suggest new approaches to the investigation of the neurobiology of psychopathology.

  15. Early auditory processing in area V5/MT+ of the congenitally blind brain.

    PubMed

    Watkins, Kate E; Shakespeare, Timothy J; O'Donoghue, M Clare; Alexander, Iona; Ragge, Nicola; Cowey, Alan; Bridge, Holly

    2013-11-13

    Previous imaging studies of congenital blindness have studied individuals with heterogeneous causes of blindness, which may influence the nature and extent of cross-modal plasticity. Here, we scanned a homogeneous group of blind people with bilateral congenital anophthalmia, a condition in which both eyes fail to develop, and, as a result, the visual pathway is not stimulated by either light or retinal waves. This model of congenital blindness presents an opportunity to investigate the effects of very early visual deafferentation on the functional organization of the brain. In anophthalmic animals, the occipital cortex receives direct subcortical auditory input. We hypothesized that this pattern of subcortical reorganization ought to result in a topographic mapping of auditory frequency information in the occipital cortex of anophthalmic people. Using functional MRI, we examined auditory-evoked activity to pure tones of high, medium, and low frequencies. Activity in the superior temporal cortex was significantly reduced in anophthalmic compared with sighted participants. In the occipital cortex, a region corresponding to the cytoarchitectural area V5/MT+ was activated in the anophthalmic participants but not in sighted controls. Whereas previous studies in the blind indicate that this cortical area is activated to auditory motion, our data show it is also active for trains of pure tone stimuli and in some anophthalmic participants shows a topographic mapping (tonotopy). Therefore, this region appears to be performing early sensory processing, possibly served by direct subcortical input from the pulvinar to V5/MT+.

  16. Behavioral and electrophysiological auditory processing measures in traumatic brain injury after acoustically controlled auditory training: a long-term study

    PubMed Central

    Figueiredo, Carolina Calsolari; de Andrade, Adriana Neves; Marangoni-Castan, Andréa Tortosa; Gil, Daniela; Suriano, Italo Capraro

    2015-01-01

    ABSTRACT Objective To investigate the long-term efficacy of acoustically controlled auditory training in adults after tarumatic brain injury. Methods A total of six audioogically normal individuals aged between 20 and 37 years were studied. They suffered severe traumatic brain injury with diffuse axional lesion and underwent an acoustically controlled auditory training program approximately one year before. The results obtained in the behavioral and electrophysiological evaluation of auditory processing immediately after acoustically controlled auditory training were compared to reassessment findings, one year later. Results Quantitative analysis of auditory brainsteim response showed increased absolute latency of all waves and interpeak intervals, bilaterraly, when comparing both evaluations. Moreover, increased amplitude of all waves, and the wave V amplitude was statistically significant for the right ear, and wave III for the left ear. As to P3, decreased latency and increased amplitude were found for both ears in reassessment. The previous and current behavioral assessment showed similar results, except for the staggered spondaic words in the left ear and the amount of errors on the dichotic consonant-vowel test. Conclusion The acoustically controlled auditory training was effective in the long run, since better latency and amplitude results were observed in the electrophysiological evaluation, in addition to stability of behavioral measures after one-year training. PMID:26676270

  17. Brain Network Interactions in Auditory, Visual and Linguistic Processing

    ERIC Educational Resources Information Center

    Horwitz, Barry; Braun, Allen R.

    2004-01-01

    In the paper, we discuss the importance of network interactions between brain regions in mediating performance of sensorimotor and cognitive tasks, including those associated with language processing. Functional neuroimaging, especially PET and fMRI, provide data that are obtained essentially simultaneously from much of the brain, and thus are…

  18. Bigger Brains or Bigger Nuclei? Regulating the Size of Auditory Structures in Birds

    PubMed Central

    Kubke, M. Fabiana; Massoglia, Dino P.; Carr, Catherine E.

    2012-01-01

    Increases in the size of the neuronal structures that mediate specific behaviors are believed to be related to enhanced computational performance. It is not clear, however, what developmental and evolutionary mechanisms mediate these changes, nor whether an increase in the size of a given neuronal population is a general mechanism to achieve enhanced computational ability. We addressed the issue of size by analyzing the variation in the relative number of cells of auditory structures in auditory specialists and generalists. We show that bird species with different auditory specializations exhibit variation in the relative size of their hindbrain auditory nuclei. In the barn owl, an auditory specialist, the hind-brain auditory nuclei involved in the computation of sound location show hyperplasia. This hyperplasia was also found in songbirds, but not in non-auditory specialists. The hyperplasia of auditory nuclei was also not seen in birds with large body weight suggesting that the total number of cells is selected for in auditory specialists. In barn owls, differences observed in the relative size of the auditory nuclei might be attributed to modifications in neurogenesis and cell death. Thus, hyperplasia of circuits used for auditory computation accompanies auditory specialization in different orders of birds. PMID:14726625

  19. Proteome rearrangements after auditory learning: high-resolution profiling of synapse-enriched protein fractions from mouse brain.

    PubMed

    Kähne, Thilo; Richter, Sandra; Kolodziej, Angela; Smalla, Karl-Heinz; Pielot, Rainer; Engler, Alexander; Ohl, Frank W; Dieterich, Daniela C; Seidenbecher, Constanze; Tischmeyer, Wolfgang; Naumann, Michael; Gundelfinger, Eckart D

    2016-07-01

    Learning and memory processes are accompanied by rearrangements of synaptic protein networks. While various studies have demonstrated the regulation of individual synaptic proteins during these processes, much less is known about the complex regulation of synaptic proteomes. Recently, we reported that auditory discrimination learning in mice is associated with a relative down-regulation of proteins involved in the structural organization of synapses in various brain regions. Aiming at the identification of biological processes and signaling pathways involved in auditory memory formation, here, a label-free quantification approach was utilized to identify regulated synaptic junctional proteins and phosphoproteins in the auditory cortex, frontal cortex, hippocampus, and striatum of mice 24 h after the learning experiment. Twenty proteins, including postsynaptic scaffolds, actin-remodeling proteins, and RNA-binding proteins, were regulated in at least three brain regions pointing to common, cross-regional mechanisms. Most of the detected synaptic proteome changes were, however, restricted to individual brain regions. For example, several members of the Septin family of cytoskeletal proteins were up-regulated only in the hippocampus, while Septin-9 was down-regulated in the hippocampus, the frontal cortex, and the striatum. Meta analyses utilizing several databases were employed to identify underlying cellular functions and biological pathways. Data are available via ProteomeExchange with identifier PXD003089. How does the protein composition of synapses change in different brain areas upon auditory learning? We unravel discrete proteome changes in mouse auditory cortex, frontal cortex, hippocampus, and striatum functionally implicated in the learning process. We identify not only common but also area-specific biological pathways and cellular processes modulated 24 h after training, indicating individual contributions of the regions to memory processing.

  20. Connectivity in the human brain dissociates entropy and complexity of auditory inputs☆

    PubMed Central

    Nastase, Samuel A.; Iacovella, Vittorio; Davis, Ben; Hasson, Uri

    2015-01-01

    Complex systems are described according to two central dimensions: (a) the randomness of their output, quantified via entropy; and (b) their complexity, which reflects the organization of a system's generators. Whereas some approaches hold that complexity can be reduced to uncertainty or entropy, an axiom of complexity science is that signals with very high or very low entropy are generated by relatively non-complex systems, while complex systems typically generate outputs with entropy peaking between these two extremes. In understanding their environment, individuals would benefit from coding for both input entropy and complexity; entropy indexes uncertainty and can inform probabilistic coding strategies, whereas complexity reflects a concise and abstract representation of the underlying environmental configuration, which can serve independent purposes, e.g., as a template for generalization and rapid comparisons between environments. Using functional neuroimaging, we demonstrate that, in response to passively processed auditory inputs, functional integration patterns in the human brain track both the entropy and complexity of the auditory signal. Connectivity between several brain regions scaled monotonically with input entropy, suggesting sensitivity to uncertainty, whereas connectivity between other regions tracked entropy in a convex manner consistent with sensitivity to input complexity. These findings suggest that the human brain simultaneously tracks the uncertainty of sensory data and effectively models their environmental generators. PMID:25536493

  1. Connectivity in the human brain dissociates entropy and complexity of auditory inputs.

    PubMed

    Nastase, Samuel A; Iacovella, Vittorio; Davis, Ben; Hasson, Uri

    2015-03-01

    Complex systems are described according to two central dimensions: (a) the randomness of their output, quantified via entropy; and (b) their complexity, which reflects the organization of a system's generators. Whereas some approaches hold that complexity can be reduced to uncertainty or entropy, an axiom of complexity science is that signals with very high or very low entropy are generated by relatively non-complex systems, while complex systems typically generate outputs with entropy peaking between these two extremes. In understanding their environment, individuals would benefit from coding for both input entropy and complexity; entropy indexes uncertainty and can inform probabilistic coding strategies, whereas complexity reflects a concise and abstract representation of the underlying environmental configuration, which can serve independent purposes, e.g., as a template for generalization and rapid comparisons between environments. Using functional neuroimaging, we demonstrate that, in response to passively processed auditory inputs, functional integration patterns in the human brain track both the entropy and complexity of the auditory signal. Connectivity between several brain regions scaled monotonically with input entropy, suggesting sensitivity to uncertainty, whereas connectivity between other regions tracked entropy in a convex manner consistent with sensitivity to input complexity. These findings suggest that the human brain simultaneously tracks the uncertainty of sensory data and effectively models their environmental generators.

  2. Selective attention in an overcrowded auditory scene: implications for auditory-based brain-computer interface design.

    PubMed

    Maddox, Ross K; Cheung, Willy; Lee, Adrian K C

    2012-11-01

    Listeners are good at attending to one auditory stream in a crowded environment. However, is there an upper limit of streams present in an auditory scene at which this selective attention breaks down? Here, participants were asked to attend one stream of spoken letters amidst other letter streams. In half of the trials, an initial primer was played, cueing subjects to the sound configuration. Results indicate that performance increases with token repetitions. Priming provided a performance benefit, suggesting that stream selection, not formation, is the bottleneck associated with attention in an overcrowded scene. Results' implications for brain-computer interfaces are discussed.

  3. Characteristics of auditory agnosia in a child with severe traumatic brain injury: a case report.

    PubMed

    Hattiangadi, Nina; Pillion, Joseph P; Slomine, Beth; Christensen, James; Trovato, Melissa K; Speedie, Lynn J

    2005-01-01

    We present a case that is unusual in many respects from other documented incidences of auditory agnosia, including the mechanism of injury, age of the individual, and location of neurological insult. The clinical presentation is one of disturbance in the perception of spoken language, music, pitch, emotional prosody, and temporal auditory processing in the absence of significant deficits in the comprehension of written language, expressive language production, or peripheral auditory function. Furthermore, the patient demonstrates relatively preserved function in other aspects of audition such as sound localization, voice recognition, and perception of animal noises and environmental sounds. This case study demonstrates that auditory agnosia is possible following traumatic brain injury in a child, and illustrates the necessity of assessment with a wide variety of auditory stimuli to fully characterize auditory agnosia in a single individual.

  4. Resolving the neural dynamics of visual and auditory scene processing in the human brain: a methodological approach.

    PubMed

    Cichy, Radoslaw Martin; Teng, Santani

    2017-02-19

    In natural environments, visual and auditory stimulation elicit responses across a large set of brain regions in a fraction of a second, yielding representations of the multimodal scene and its properties. The rapid and complex neural dynamics underlying visual and auditory information processing pose major challenges to human cognitive neuroscience. Brain signals measured non-invasively are inherently noisy, the format of neural representations is unknown, and transformations between representations are complex and often nonlinear. Further, no single non-invasive brain measurement technique provides a spatio-temporally integrated view. In this opinion piece, we argue that progress can be made by a concerted effort based on three pillars of recent methodological development: (i) sensitive analysis techniques such as decoding and cross-classification, (ii) complex computational modelling using models such as deep neural networks, and (iii) integration across imaging methods (magnetoencephalography/electroencephalography, functional magnetic resonance imaging) and models, e.g. using representational similarity analysis. We showcase two recent efforts that have been undertaken in this spirit and provide novel results about visual and auditory scene analysis. Finally, we discuss the limits of this perspective and sketch a concrete roadmap for future research.This article is part of the themed issue 'Auditory and visual scene analysis'.

  5. Resolving the neural dynamics of visual and auditory scene processing in the human brain: a methodological approach

    PubMed Central

    Teng, Santani

    2017-01-01

    In natural environments, visual and auditory stimulation elicit responses across a large set of brain regions in a fraction of a second, yielding representations of the multimodal scene and its properties. The rapid and complex neural dynamics underlying visual and auditory information processing pose major challenges to human cognitive neuroscience. Brain signals measured non-invasively are inherently noisy, the format of neural representations is unknown, and transformations between representations are complex and often nonlinear. Further, no single non-invasive brain measurement technique provides a spatio-temporally integrated view. In this opinion piece, we argue that progress can be made by a concerted effort based on three pillars of recent methodological development: (i) sensitive analysis techniques such as decoding and cross-classification, (ii) complex computational modelling using models such as deep neural networks, and (iii) integration across imaging methods (magnetoencephalography/electroencephalography, functional magnetic resonance imaging) and models, e.g. using representational similarity analysis. We showcase two recent efforts that have been undertaken in this spirit and provide novel results about visual and auditory scene analysis. Finally, we discuss the limits of this perspective and sketch a concrete roadmap for future research. This article is part of the themed issue ‘Auditory and visual scene analysis’. PMID:28044019

  6. Abnormal Effective Connectivity in the Brain is Involved in Auditory Verbal Hallucinations in Schizophrenia.

    PubMed

    Li, Baojuan; Cui, Long-Biao; Xi, Yi-Bin; Friston, Karl J; Guo, Fan; Wang, Hua-Ning; Zhang, Lin-Chuan; Bai, Yuan-Han; Tan, Qing-Rong; Yin, Hong; Lu, Hongbing

    2017-02-21

    Information flow among auditory and language processing-related regions implicated in the pathophysiology of auditory verbal hallucinations (AVHs) in schizophrenia (SZ) remains unclear. In this study, we used stochastic dynamic causal modeling (sDCM) to quantify connections among the left dorsolateral prefrontal cortex (inner speech monitoring), auditory cortex (auditory processing), hippocampus (memory retrieval), thalamus (information filtering), and Broca's area (language production) in 17 first-episode drug-naïve SZ patients with AVHs, 15 without AVHs, and 19 healthy controls using resting-state functional magnetic resonance imaging. Finally, we performed receiver operating characteristic (ROC) analysis and correlation analysis between image measures and symptoms. sDCM revealed an increased sensitivity of auditory cortex to its thalamic afferents and a decrease in hippocampal sensitivity to auditory inputs in SZ patients with AVHs. The area under the ROC curve showed the diagnostic value of these two connections to distinguish SZ patients with AVHs from those without AVHs. Furthermore, we found a positive correlation between the strength of the connectivity from Broca's area to the auditory cortex and the severity of AVHs. These findings demonstrate, for the first time, augmented AVH-specific excitatory afferents from the thalamus to the auditory cortex in SZ patients, resulting in auditory perception without external auditory stimuli. Our results provide insights into the neural mechanisms underlying AVHs in SZ. This thalamic-auditory cortical-hippocampal dysconnectivity may also serve as a diagnostic biomarker of AVHs in SZ and a therapeutic target based on direct in vivo evidence.

  7. An auditory brain-computer interface evoked by natural speech

    NASA Astrophysics Data System (ADS)

    Lopez-Gordo, M. A.; Fernandez, E.; Romero, S.; Pelayo, F.; Prieto, Alberto

    2012-06-01

    Brain-computer interfaces (BCIs) are mainly intended for people unable to perform any muscular movement, such as patients in a complete locked-in state. The majority of BCIs interact visually with the user, either in the form of stimulation or biofeedback. However, visual BCIs challenge their ultimate use because they require the subjects to gaze, explore and shift eye-gaze using their muscles, thus excluding patients in a complete locked-in state or under the condition of the unresponsive wakefulness syndrome. In this study, we present a novel fully auditory EEG-BCI based on a dichotic listening paradigm using human voice for stimulation. This interface has been evaluated with healthy volunteers, achieving an average information transmission rate of 1.5 bits min-1 in full-length trials and 2.7 bits min-1 using the optimal length of trials, recorded with only one channel and without formal training. This novel technique opens the door to a more natural communication with users unable to use visual BCIs, with promising results in terms of performance, usability, training and cognitive effort.

  8. Auditory Hallucinations and the Brain's Resting-State Networks: Findings and Methodological Observations.

    PubMed

    Alderson-Day, Ben; Diederen, Kelly; Fernyhough, Charles; Ford, Judith M; Horga, Guillermo; Margulies, Daniel S; McCarthy-Jones, Simon; Northoff, Georg; Shine, James M; Turner, Jessica; van de Ven, Vincent; van Lutterveld, Remko; Waters, Flavie; Jardri, Renaud

    2016-09-01

    In recent years, there has been increasing interest in the potential for alterations to the brain's resting-state networks (RSNs) to explain various kinds of psychopathology. RSNs provide an intriguing new explanatory framework for hallucinations, which can occur in different modalities and population groups, but which remain poorly understood. This collaboration from the International Consortium on Hallucination Research (ICHR) reports on the evidence linking resting-state alterations to auditory hallucinations (AH) and provides a critical appraisal of the methodological approaches used in this area. In the report, we describe findings from resting connectivity fMRI in AH (in schizophrenia and nonclinical individuals) and compare them with findings from neurophysiological research, structural MRI, and research on visual hallucinations (VH). In AH, various studies show resting connectivity differences in left-hemisphere auditory and language regions, as well as atypical interaction of the default mode network and RSNs linked to cognitive control and salience. As the latter are also evident in studies of VH, this points to a domain-general mechanism for hallucinations alongside modality-specific changes to RSNs in different sensory regions. However, we also observed high methodological heterogeneity in the current literature, affecting the ability to make clear comparisons between studies. To address this, we provide some methodological recommendations and options for future research on the resting state and hallucinations.

  9. The Relationship between Phonological and Auditory Processing and Brain Organization in Beginning Readers

    ERIC Educational Resources Information Center

    Pugh, Kenneth R.; Landi, Nicole; Preston, Jonathan L.; Mencl, W. Einar; Austin, Alison C.; Sibley, Daragh; Fulbright, Robert K.; Seidenberg, Mark S.; Grigorenko, Elena L.; Constable, R. Todd; Molfese, Peter; Frost, Stephen J.

    2013-01-01

    We employed brain-behavior analyses to explore the relationship between performance on tasks measuring phonological awareness, pseudoword decoding, and rapid auditory processing (all predictors of reading (dis)ability) and brain organization for print and speech in beginning readers. For print-related activation, we observed a shared set of…

  10. Attention to human speakers in a virtual auditory environment: brain potential evidence.

    PubMed

    Nager, Wido; Dethlefsen, Christina; Münte, Thomas F

    2008-07-18

    Listening to a speech message requires the accurate selection of the relevant auditory input especially when distracting background noise or other speech messages are present. To investigate such auditory selection processes we presented three different speech messages simultaneously spoken by different actors at separate spatial locations (-70, 0, 70/ azimuth). Stimuli were recorded using an artificial head with microphones embedded in the "auditory canals" to capture the interaural time and level differences as well as some of the filter properties of the outer ear structures as auditory spatial cues, thus creating a realistic virtual auditory space. In a given experimental run young healthy participants listened via headphones and either attended to the rightmost or the leftmost message in order to comprehend the story. Superimposed on the speech messages task irrelevant probe stimuli (syllables sharing spatial and spectral characteristics, 4 probes/s) were presented that were used for the generation of event-related brain potentials computed from 29 channels of EEG. ERPs to probe stimuli were characterized by a negativity starting at 250 ms with a contralateral frontal maximum for the probes sharing spatial/spectral features of the attended story relative to those for the unattended message. The relatively late onset of this attention effect was interpreted to reflect the task demands in this complex auditory environment. This study demonstrates the feasibility to use virtual auditory environments in conjunction with the probe technique to study auditory selection under realistic conditions.

  11. Cognitive factors shape brain networks for auditory skills: spotlight on auditory working memory

    PubMed Central

    Kraus, Nina; Strait, Dana; Parbery-Clark, Alexandra

    2012-01-01

    Musicians benefit from real-life advantages such as a greater ability to hear speech in noise and to remember sounds, although the biological mechanisms driving such advantages remain undetermined. Furthermore, the extent to which these advantages are a consequence of musical training or innate characteristics that predispose a given individual to pursue music training is often debated. Here, we examine biological underpinnings of musicians’ auditory advantages and the mediating role of auditory working memory. Results from our laboratory are presented within a framework that emphasizes auditory working memory as a major factor in the neural processing of sound. Within this framework, we provide evidence for music training as a contributing source of these abilities. PMID:22524346

  12. Combining functional and anatomical connectivity reveals brain networks for auditory language comprehension.

    PubMed

    Saur, Dorothee; Schelter, Björn; Schnell, Susanne; Kratochvil, David; Küpper, Hanna; Kellmeyer, Philipp; Kümmerer, Dorothee; Klöppel, Stefan; Glauche, Volkmar; Lange, Rüdiger; Mader, Wolfgang; Feess, David; Timmer, Jens; Weiller, Cornelius

    2010-02-15

    Cognitive functions are organized in distributed, overlapping, and interacting brain networks. Investigation of those large-scale brain networks is a major task in neuroimaging research. Here, we introduce a novel combination of functional and anatomical connectivity to study the network topology subserving a cognitive function of interest. (i) In a given network, direct interactions between network nodes are identified by analyzing functional MRI time series with the multivariate method of directed partial correlation (dPC). This method provides important improvements over shortcomings that are typical for ordinary (partial) correlation techniques. (ii) For directly interacting pairs of nodes, a region-to-region probabilistic fiber tracking on diffusion tensor imaging data is performed to identify the most probable anatomical white matter fiber tracts mediating the functional interactions. This combined approach is applied to the language domain to investigate the network topology of two levels of auditory comprehension: lower-level speech perception (i.e., phonological processing) and higher-level speech recognition (i.e., semantic processing). For both processing levels, dPC analyses revealed the functional network topology and identified central network nodes by the number of direct interactions with other nodes. Tractography showed that these interactions are mediated by distinct ventral (via the extreme capsule) and dorsal (via the arcuate/superior longitudinal fascicle fiber system) long- and short-distance association tracts as well as commissural fibers. Our findings demonstrate how both processing routines are segregated in the brain on a large-scale network level. Combining dPC with probabilistic tractography is a promising approach to unveil how cognitive functions emerge through interaction of functionally interacting and anatomically interconnected brain regions.

  13. Prediction of Auditory and Visual P300 Brain-Computer Interface Aptitude

    PubMed Central

    Halder, Sebastian; Hammer, Eva Maria; Kleih, Sonja Claudia; Bogdan, Martin; Rosenstiel, Wolfgang; Birbaumer, Niels; Kübler, Andrea

    2013-01-01

    Objective Brain-computer interfaces (BCIs) provide a non-muscular communication channel for patients with late-stage motoneuron disease (e.g., amyotrophic lateral sclerosis (ALS)) or otherwise motor impaired people and are also used for motor rehabilitation in chronic stroke. Differences in the ability to use a BCI vary from person to person and from session to session. A reliable predictor of aptitude would allow for the selection of suitable BCI paradigms. For this reason, we investigated whether P300 BCI aptitude could be predicted from a short experiment with a standard auditory oddball. Methods Forty healthy participants performed an electroencephalography (EEG) based visual and auditory P300-BCI spelling task in a single session. In addition, prior to each session an auditory oddball was presented. Features extracted from the auditory oddball were analyzed with respect to predictive power for BCI aptitude. Results Correlation between auditory oddball response and P300 BCI accuracy revealed a strong relationship between accuracy and N2 amplitude and the amplitude of a late ERP component between 400 and 600 ms. Interestingly, the P3 amplitude of the auditory oddball response was not correlated with accuracy. Conclusions Event-related potentials recorded during a standard auditory oddball session moderately predict aptitude in an audiory and highly in a visual P300 BCI. The predictor will allow for faster paradigm selection. Significance Our method will reduce strain on patients because unsuccessful training may be avoided, provided the results can be generalized to the patient population. PMID:23457444

  14. Brain activity during divided and selective attention to auditory and visual sentence comprehension tasks.

    PubMed

    Moisala, Mona; Salmela, Viljami; Salo, Emma; Carlson, Synnöve; Vuontela, Virve; Salonen, Oili; Alho, Kimmo

    2015-01-01

    Using functional magnetic resonance imaging (fMRI), we measured brain activity of human participants while they performed a sentence congruence judgment task in either the visual or auditory modality separately, or in both modalities simultaneously. Significant performance decrements were observed when attention was divided between the two modalities compared with when one modality was selectively attended. Compared with selective attention (i.e., single tasking), divided attention (i.e., dual-tasking) did not recruit additional cortical regions, but resulted in increased activity in medial and lateral frontal regions which were also activated by the component tasks when performed separately. Areas involved in semantic language processing were revealed predominantly in the left lateral prefrontal cortex by contrasting incongruent with congruent sentences. These areas also showed significant activity increases during divided attention in relation to selective attention. In the sensory cortices, no crossmodal inhibition was observed during divided attention when compared with selective attention to one modality. Our results suggest that the observed performance decrements during dual-tasking are due to interference of the two tasks because they utilize the same part of the cortex. Moreover, semantic dual-tasking did not appear to recruit additional brain areas in comparison with single tasking, and no crossmodal inhibition was observed during intermodal divided attention.

  15. Klinefelter syndrome has increased brain responses to auditory stimuli and motor output, but not to visual stimuli or Stroop adaptation.

    PubMed

    Wallentin, Mikkel; Skakkebæk, Anne; Bojesen, Anders; Fedder, Jens; Laurberg, Peter; Østergaard, John R; Hertz, Jens Michael; Pedersen, Anders Degn; Gravholt, Claus Højbjerg

    2016-01-01

    Klinefelter syndrome (47, XXY) (KS) is a genetic syndrome characterized by the presence of an extra X chromosome and low level of testosterone, resulting in a number of neurocognitive abnormalities, yet little is known about brain function. This study investigated the fMRI-BOLD response from KS relative to a group of Controls to basic motor, perceptual, executive and adaptation tasks. Participants (N: KS = 49; Controls = 49) responded to whether the words "GREEN" or "RED" were displayed in green or red (incongruent versus congruent colors). One of the colors was presented three times as often as the other, making it possible to study both congruency and adaptation effects independently. Auditory stimuli saying "GREEN" or "RED" had the same distribution, making it possible to study effects of perceptual modality as well as Frequency effects across modalities. We found that KS had an increased response to motor output in primary motor cortex and an increased response to auditory stimuli in auditory cortices, but no difference in primary visual cortices. KS displayed a diminished response to written visual stimuli in secondary visual regions near the Visual Word Form Area, consistent with the widespread dyslexia in the group. No neural differences were found in inhibitory control (Stroop) or in adaptation to differences in stimulus frequencies. Across groups we found a strong positive correlation between age and BOLD response in the brain's motor network with no difference between groups. No effects of testosterone level or brain volume were found. In sum, the present findings suggest that auditory and motor systems in KS are selectively affected, perhaps as a compensatory strategy, and that this is not a systemic effect as it is not seen in the visual system.

  16. Klinefelter syndrome has increased brain responses to auditory stimuli and motor output, but not to visual stimuli or Stroop adaptation

    PubMed Central

    Wallentin, Mikkel; Skakkebæk, Anne; Bojesen, Anders; Fedder, Jens; Laurberg, Peter; Østergaard, John R.; Hertz, Jens Michael; Pedersen, Anders Degn; Gravholt, Claus Højbjerg

    2016-01-01

    Klinefelter syndrome (47, XXY) (KS) is a genetic syndrome characterized by the presence of an extra X chromosome and low level of testosterone, resulting in a number of neurocognitive abnormalities, yet little is known about brain function. This study investigated the fMRI-BOLD response from KS relative to a group of Controls to basic motor, perceptual, executive and adaptation tasks. Participants (N: KS = 49; Controls = 49) responded to whether the words “GREEN” or “RED” were displayed in green or red (incongruent versus congruent colors). One of the colors was presented three times as often as the other, making it possible to study both congruency and adaptation effects independently. Auditory stimuli saying “GREEN” or “RED” had the same distribution, making it possible to study effects of perceptual modality as well as Frequency effects across modalities. We found that KS had an increased response to motor output in primary motor cortex and an increased response to auditory stimuli in auditory cortices, but no difference in primary visual cortices. KS displayed a diminished response to written visual stimuli in secondary visual regions near the Visual Word Form Area, consistent with the widespread dyslexia in the group. No neural differences were found in inhibitory control (Stroop) or in adaptation to differences in stimulus frequencies. Across groups we found a strong positive correlation between age and BOLD response in the brain's motor network with no difference between groups. No effects of testosterone level or brain volume were found. In sum, the present findings suggest that auditory and motor systems in KS are selectively affected, perhaps as a compensatory strategy, and that this is not a systemic effect as it is not seen in the visual system. PMID:26958463

  17. Are you listening? Brain activation associated with sustained nonspatial auditory attention in the presence and absence of stimulation.

    PubMed

    Seydell-Greenwald, Anna; Greenberg, Adam S; Rauschecker, Josef P

    2014-05-01

    Neuroimaging studies investigating the voluntary (top-down) control of attention largely agree that this process recruits several frontal and parietal brain regions. Since most studies used attention tasks requiring several higher-order cognitive functions (e.g. working memory, semantic processing, temporal integration, spatial orienting) as well as different attentional mechanisms (attention shifting, distractor filtering), it is unclear what exactly the observed frontoparietal activations reflect. The present functional magnetic resonance imaging study investigated, within the same participants, signal changes in (1) a "Simple Attention" task in which participants attended to a single melody, (2) a "Selective Attention" task in which they simultaneously ignored another melody, and (3) a "Beep Monitoring" task in which participants listened in silence for a faint beep. Compared to resting conditions with identical stimulation, all tasks produced robust activation increases in auditory cortex, cross-modal inhibition in visual and somatosensory cortex, and decreases in the default mode network, indicating that participants were indeed focusing their attention on the auditory domain. However, signal increases in frontal and parietal brain areas were only observed for tasks 1 and 2, but completely absent for task 3. These results lead to the following conclusions: under most conditions, frontoparietal activations are crucial for attention since they subserve higher-order cognitive functions inherently related to attention. However, under circumstances that minimize other demands, nonspatial auditory attention in the absence of stimulation can be maintained without concurrent frontal or parietal activations.

  18. Auditory-musical processing in autism spectrum disorders: a review of behavioral and brain imaging studies.

    PubMed

    Ouimet, Tia; Foster, Nicholas E V; Tryfon, Ana; Hyde, Krista L

    2012-04-01

    Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by atypical social and communication skills, repetitive behaviors, and atypical visual and auditory perception. Studies in vision have reported enhanced detailed ("local") processing but diminished holistic ("global") processing of visual features in ASD. Individuals with ASD also show enhanced processing of simple visual stimuli but diminished processing of complex visual stimuli. Relative to the visual domain, auditory global-local distinctions, and the effects of stimulus complexity on auditory processing in ASD, are less clear. However, one remarkable finding is that many individuals with ASD have enhanced musical abilities, such as superior pitch processing. This review provides a critical evaluation of behavioral and brain imaging studies of auditory processing with respect to current theories in ASD. We have focused on auditory-musical processing in terms of global versus local processing and simple versus complex sound processing. This review contributes to a better understanding of auditory processing differences in ASD. A deeper comprehension of sensory perception in ASD is key to better defining ASD phenotypes and, in turn, may lead to better interventions.

  19. A blueprint for vocal learning: auditory predispositions from brains to genomes

    PubMed Central

    Wheatcroft, David; Qvarnström, Anna

    2015-01-01

    Memorizing and producing complex strings of sound are requirements for spoken human language. We share these behaviours with likely more than 4000 species of songbirds, making birds our primary model for studying the cognitive basis of vocal learning and, more generally, an important model for how memories are encoded in the brain. In songbirds, as in humans, the sounds that a juvenile learns later in life depend on auditory memories formed early in development. Experiments on a wide variety of songbird species suggest that the formation and lability of these auditory memories, in turn, depend on auditory predispositions that stimulate learning when a juvenile hears relevant, species-typical sounds. We review evidence that variation in key features of these auditory predispositions are determined by variation in genes underlying the development of the auditory system. We argue that increased investigation of the neuronal basis of auditory predispositions expressed early in life in combination with modern comparative genomic approaches may provide insights into the evolution of vocal learning. PMID:26246333

  20. Turning down the noise: the benefit of musical training on the aging auditory brain.

    PubMed

    Alain, Claude; Zendel, Benjamin Rich; Hutka, Stefanie; Bidelman, Gavin M

    2014-02-01

    Age-related decline in hearing abilities is a ubiquitous part of aging, and commonly impacts speech understanding, especially when there are competing sound sources. While such age effects are partially due to changes within the cochlea, difficulties typically exist beyond measurable hearing loss, suggesting that central brain processes, as opposed to simple peripheral mechanisms (e.g., hearing sensitivity), play a critical role in governing hearing abilities late into life. Current training regimens aimed to improve central auditory processing abilities have experienced limited success in promoting listening benefits. Interestingly, recent studies suggest that in young adults, musical training positively modifies neural mechanisms, providing robust, long-lasting improvements to hearing abilities as well as to non-auditory tasks that engage cognitive control. These results offer the encouraging possibility that musical training might be used to counteract age-related changes in auditory cognition commonly observed in older adults. Here, we reviewed studies that have examined the effects of age and musical experience on auditory cognition with an emphasis on auditory scene analysis. We infer that musical training may offer potential benefits to complex listening and might be utilized as a means to delay or even attenuate declines in auditory perception and cognition that often emerge later in life.

  1. Descending brain neurons in the cricket Gryllus bimaculatus (de Geer): auditory responses and impact on walking.

    PubMed

    Zorović, Maja; Hedwig, Berthold

    2013-01-01

    The activity of four types of sound-sensitive descending brain neurons in the cricket Gryllus bimaculatus was recorded intracellularly while animals were standing or walking on an open-loop trackball system. In a neuron with a contralaterally descending axon, the male calling song elicited responses that copied the pulse pattern of the song during standing and walking. The accuracy of pulse copying increased during walking. Neurons with ipsilaterally descending axons responded weakly to sound only during standing. The responses were mainly to the first pulse of each chirp, whereas the complete pulse pattern of a chirp was not copied. During walking the auditory responses were suppressed in these neurons. The spiking activity of all four neuron types was significantly correlated to forward walking velocity, indicating their relevance for walking. Additionally, injection of depolarizing current elicited walking and/or steering in three of four neuron types described. In none of the neurons was the spiking activity both sufficient and necessary to elicit and maintain walking behaviour. Some neurons showed arborisations in the lateral accessory lobes, pointing to the relevance of this brain region for cricket audition and descending motor control.

  2. Human auditory evoked potentials in the assessment of brain function during major cardiovascular surgery.

    PubMed

    Rodriguez, Rosendo A

    2004-06-01

    Focal neurologic and intellectual deficits or memory problems are relatively frequent after cardiac surgery. These complications have been associated with cerebral hypoperfusion, embolization, and inflammation that occur during or after surgery. Auditory evoked potentials, a neurophysiologic technique that evaluates the function of neural structures from the auditory nerve to the cortex, provide useful information about the functional status of the brain during major cardiovascular procedures. Skepticism regarding the presence of artifacts or difficulty in their interpretation has outweighed considerations of its potential utility and noninvasiveness. This paper reviews the evidence of their potential applications in several aspects of the management of cardiac surgery patients. The sensitivity of auditory evoked potentials to the effects of changes in brain temperature makes them useful for monitoring cerebral hypothermia and rewarming during cardiopulmonary bypass. The close relationship between evoked potential waveforms and specific anatomic structures facilitates the assessment of the functional integrity of the central nervous system in cardiac surgery patients. This feature may also be relevant in the management of critical patients under sedation and coma or in the evaluation of their prognosis during critical care. Their objectivity, reproducibility, and relative insensitivity to learning effects make auditory evoked potentials attractive for the cognitive assessment of cardiac surgery patients. From a clinical perspective, auditory evoked potentials represent an additional window for the study of underlying cerebral processes in healthy and diseased patients. From a research standpoint, this technology offers opportunities for a better understanding of the particular cerebral deficits associated with patients who are undergoing major cardiovascular procedures.

  3. Atypical Bilateral Brain Synchronization in the Early Stage of Human Voice Auditory Processing in Young Children with Autism

    PubMed Central

    Kurita, Toshiharu; Kikuchi, Mitsuru; Yoshimura, Yuko; Hiraishi, Hirotoshi; Hasegawa, Chiaki; Takahashi, Tetsuya; Hirosawa, Tetsu; Furutani, Naoki; Higashida, Haruhiro; Ikeda, Takashi; Mutou, Kouhei; Asada, Minoru; Minabe, Yoshio

    2016-01-01

    Autism spectrum disorder (ASD) has been postulated to involve impaired neuronal cooperation in large-scale neural networks, including cortico-cortical interhemispheric circuitry. In the context of ASD, alterations in both peripheral and central auditory processes have also attracted a great deal of interest because these changes appear to represent pathophysiological processes; therefore, many prior studies have focused on atypical auditory responses in ASD. The auditory evoked field (AEF), recorded by magnetoencephalography, and the synchronization of these processes between right and left hemispheres was recently suggested to reflect various cognitive abilities in children. However, to date, no previous study has focused on AEF synchronization in ASD subjects. To assess global coordination across spatially distributed brain regions, the analysis of Omega complexity from multichannel neurophysiological data was proposed. Using Omega complexity analysis, we investigated the global coordination of AEFs in 3–8-year-old typically developing (TD) children (n = 50) and children with ASD (n = 50) in 50-ms time-windows. Children with ASD displayed significantly higher Omega complexities compared with TD children in the time-window of 0–50 ms, suggesting lower whole brain synchronization in the early stage of the P1m component. When we analyzed the left and right hemispheres separately, no significant differences in any time-windows were observed. These results suggest lower right-left hemispheric synchronization in children with ASD compared with TD children. Our study provides new evidence of aberrant neural synchronization in young children with ASD by investigating auditory evoked neural responses to the human voice. PMID:27074011

  4. You can't stop the music: reduced auditory alpha power and coupling between auditory and memory regions facilitate the illusory perception of music during noise.

    PubMed

    Müller, Nadia; Keil, Julian; Obleser, Jonas; Schulz, Hannah; Grunwald, Thomas; Bernays, René-Ludwig; Huppertz, Hans-Jürgen; Weisz, Nathan

    2013-10-01

    Our brain has the capacity of providing an experience of hearing even in the absence of auditory stimulation. This can be seen as illusory conscious perception. While increasing evidence postulates that conscious perception requires specific brain states that systematically relate to specific patterns of oscillatory activity, the relationship between auditory illusions and oscillatory activity remains mostly unexplained. To investigate this we recorded brain activity with magnetoencephalography and collected intracranial data from epilepsy patients while participants listened to familiar as well as unknown music that was partly replaced by sections of pink noise. We hypothesized that participants have a stronger experience of hearing music throughout noise when the noise sections are embedded in familiar compared to unfamiliar music. This was supported by the behavioral results showing that participants rated the perception of music during noise as stronger when noise was presented in a familiar context. Time-frequency data show that the illusory perception of music is associated with a decrease in auditory alpha power pointing to increased auditory cortex excitability. Furthermore, the right auditory cortex is concurrently synchronized with the medial temporal lobe, putatively mediating memory aspects associated with the music illusion. We thus assume that neuronal activity in the highly excitable auditory cortex is shaped through extensive communication between the auditory cortex and the medial temporal lobe, thereby generating the illusion of hearing music during noise.

  5. Effect of stimulus intensity level on auditory middle latency response brain maps in human adults.

    PubMed

    Tucker, D A; Dietrich, S; McPherson, D L; Salamat, M T

    2001-05-01

    Auditory middle latency response (AMLR) brain maps were obtained in 11 young adults with normal hearing. AMLR waveforms were elicited with monaural clicks presented at three stimulus intensity levels (50, 70, and 90 dB nHL). Recordings were made for right and left ear stimulus presentations. All recordings were obtained in an eyes open/awake status for each subject. Peak-to-peak amplitudes and absolute latencies of the AMLR Pa and Pb waveforms were measured at the Cz electrode site. Pa and Pb waveforms were present 100 percent of the time in response to the 90 dB nHL presentation. The prevalence of Pa and Pb to the 70 dB nHL presentation varied from 86 to 95 percent. The prevalence of Pa and Pb to the 50 dB nHL stimulus never reached 100 percent, ranging in prevalence from 77 to 68 percent. No significant ear effect was seen for amplitude or latency measures of Pa or Pb. AMLR brain maps of the voltage field distributions of Pa and Pb waveforms showed different topographic features. Scalp topography of the Pa waveform was altered by a reduction in stimulus intensity level. At 90 dB nHL, the Pa brain map showed a large positivity midline over the frontal and central scalp areas. At lower stimulus intensity levels, frontal positivity was reduced, and scalp negativity over occipital regions was increased. Pb scalp topography was also altered by a reduction in stimulus intensity level. Varying the stimulus intensity significantly altered Pa and Pb distributions of amplitude and latency measures. Pa and Pb distributions were skewed regardless of stimulus intensity.

  6. Neurogenesis in the brain auditory pathway of a marsupial, the northern native cat (Dasyurus hallucatus)

    SciTech Connect

    Aitkin, L.; Nelson, J.; Farrington, M.; Swann, S. )

    1991-07-08

    Neurogenesis in the auditory pathway of the marsupial Dasyurus hallucatus was studied. Intraperitoneal injections of tritiated thymidine (20-40 microCi) were made into pouch-young varying from 1 to 56 days pouch-life. Animals were killed as adults and brain sections were prepared for autoradiography and counterstained with a Nissl stain. Neurons in the ventral cochlear nucleus were generated prior to 3 days pouch-life, in the superior olive at 5-7 days, and in the dorsal cochlear nucleus over a prolonged period. Inferior collicular neurogenesis lagged behind that in the medial geniculate, the latter taking place between days 3 and 9 and the former between days 7 and 22. Neurogenesis began in the auditory cortex on day 9 and was completed by about day 42. Thus neurogenesis was complete in the medullary auditory nuclei before that in the midbrain commenced, and in the medial geniculate before that in the auditory cortex commenced. The time course of neurogenesis in the auditory pathway of the native cat was very similar to that in another marsupial, the brushtail possum. For both, neurogenesis occurred earlier than in eutherian mammals of a similar size but was more protracted.

  7. Auditory perception and syntactic cognition: brain activity-based decoding within and across subjects.

    PubMed

    Herrmann, Björn; Maess, Burkhard; Kalberlah, Christian; Haynes, John-Dylan; Friederici, Angela D

    2012-05-01

    The present magnetoencephalography study investigated whether the brain states of early syntactic and auditory-perceptual processes can be decoded from single-trial recordings with a multivariate pattern classification approach. In particular, it was investigated whether the early neural activation patterns in response to rule violations in basic auditory perception and in high cognitive processes (syntax) reflect a functional organization that largely generalizes across individuals or is subject-specific. On this account, subjects were auditorily presented with correct sentences, syntactically incorrect sentences, correct sentences including an interaural time difference change, and sentences containing both violations. For the analysis, brain state decoding was carried out within and across subjects with three pairwise classifications. Neural patterns elicited by each of the violation sentences were separately classified with the patterns elicited by the correct sentences. The results revealed the highest decoding accuracies over temporal cortex areas for all three classification types. Importantly, both the magnitude and the spatial distribution of decoding accuracies for the early neural patterns were very similar for within-subject and across-subject decoding. At the same time, across-subject decoding suggested a hemispheric bias, with the most consistent patterns in the left hemisphere. Thus, the present data show that not only auditory-perceptual processing brain states but also cognitive brain states of syntactic rule processing can be decoded from single-trial brain activations. Moreover, the findings indicate that the neural patterns in response to syntactic cognition and auditory perception reflect a functional organization that is highly consistent across individuals.

  8. Development and modulation of intrinsic membrane properties control the temporal precision of auditory brain stem neurons.

    PubMed

    Franzen, Delwen L; Gleiss, Sarah A; Berger, Christina; Kümpfbeck, Franziska S; Ammer, Julian J; Felmy, Felix

    2015-01-15

    Passive and active membrane properties determine the voltage responses of neurons. Within the auditory brain stem, refinements in these intrinsic properties during late postnatal development usually generate short integration times and precise action-potential generation. This developmentally acquired temporal precision is crucial for auditory signal processing. How the interactions of these intrinsic properties develop in concert to enable auditory neurons to transfer information with high temporal precision has not yet been elucidated in detail. Here, we show how the developmental interaction of intrinsic membrane parameters generates high firing precision. We performed in vitro recordings from neurons of postnatal days 9-28 in the ventral nucleus of the lateral lemniscus of Mongolian gerbils, an auditory brain stem structure that converts excitatory to inhibitory information with high temporal precision. During this developmental period, the input resistance and capacitance decrease, and action potentials acquire faster kinetics and enhanced precision. Depending on the stimulation time course, the input resistance and capacitance contribute differentially to action-potential thresholds. The decrease in input resistance, however, is sufficient to explain the enhanced action-potential precision. Alterations in passive membrane properties also interact with a developmental change in potassium currents to generate the emergence of the mature firing pattern, characteristic of coincidence-detector neurons. Cholinergic receptor-mediated depolarizations further modulate this intrinsic excitability profile by eliciting changes in the threshold and firing pattern, irrespective of the developmental stage. Thus our findings reveal how intrinsic membrane properties interact developmentally to promote temporally precise information processing.

  9. Event-related brain potentials to irrelevant auditory stimuli during selective listening: effects of channel probability.

    PubMed

    Akai, Toshiyuki

    2004-03-01

    The purpose of this study was to identify the cognitive process reflected by a positive deflection to irrelevant auditory stimuli (Pdi) during selective listening. Event-related brain potentials were recorded from 9 participants in a two-channel (left/right ears) selective listening task. Relative event probabilities of the relevant/irrelevant channels were 25%/75%, 50%/50%, and 75%/25%. With increasing probability of the relevant channel, behavioral performances (the reaction time and hit rate) for the targets within the relevant channel improved, reflecting development of a more robust attentional trace. At the same time, the amplitude of the early Pdi (200-300 ms after stimulus onset) elicited by the stimuli in the irrelevant channel with a decreased probability was enhanced in the central region. This positive relation between the strength of the attentional trace and the amplitude of the early Pdi suggests that the early Pdi is elicited by a mismatching between an incoming irrelevant stimulus and an attentional trace.

  10. Brain stem auditory evoked responses in human infants and adults

    NASA Technical Reports Server (NTRS)

    Hecox, K.; Galambos, R.

    1974-01-01

    Brain stem evoked potentials were recorded by conventional scalp electrodes in infants (3 weeks to 3 years of age) and adults. The latency of one of the major response components (wave V) is shown to be a function both of click intensity and the age of the subject; this latency at a given signal strength shortens postnatally to reach the adult value (about 6 msec) by 12 to 18 months of age. The demonstrated reliability and limited variability of these brain stem electrophysiological responses provide the basis for an optimistic estimate of their usefulness as an objective method for assessing hearing in infants and adults.

  11. “Where Do Auditory Hallucinations Come From?”—A Brain Morphometry Study of Schizophrenia Patients With Inner or Outer Space Hallucinations

    PubMed Central

    Plaze, Marion; Paillère-Martinot, Marie-Laure; Penttilä, Jani; Januel, Dominique; de Beaurepaire, Renaud; Bellivier, Franck; Andoh, Jamila; Galinowski, André; Gallarda, Thierry; Artiges, Eric; Olié, Jean-Pierre; Mangin, Jean-François; Martinot, Jean-Luc

    2011-01-01

    Auditory verbal hallucinations are a cardinal symptom of schizophrenia. Bleuler and Kraepelin distinguished 2 main classes of hallucinations: hallucinations heard outside the head (outer space, or external, hallucinations) and hallucinations heard inside the head (inner space, or internal, hallucinations). This distinction has been confirmed by recent phenomenological studies that identified 3 independent dimensions in auditory hallucinations: language complexity, self-other misattribution, and spatial location. Brain imaging studies in schizophrenia patients with auditory hallucinations have already investigated language complexity and self-other misattribution, but the neural substrate of hallucination spatial location remains unknown. Magnetic resonance images of 45 right-handed patients with schizophrenia and persistent auditory hallucinations and 20 healthy right-handed subjects were acquired. Two homogeneous subgroups of patients were defined based on the hallucination spatial location: patients with only outer space hallucinations (N = 12) and patients with only inner space hallucinations (N = 15). Between-group differences were then assessed using 2 complementary brain morphometry approaches: voxel-based morphometry and sulcus-based morphometry. Convergent anatomical differences were detected between the patient subgroups in the right temporoparietal junction (rTPJ). In comparison to healthy subjects, opposite deviations in white matter volumes and sulcus displacements were found in patients with inner space hallucination and patients with outer space hallucination. The current results indicate that spatial location of auditory hallucinations is associated with the rTPJ anatomy, a key region of the “where” auditory pathway. The detected tilt in the sulcal junction suggests deviations during early brain maturation, when the superior temporal sulcus and its anterior terminal branch appear and merge. PMID:19666833

  12. Fast reconfiguration of high-frequency brain networks in response to surprising changes in auditory input.

    PubMed

    Nicol, Ruth M; Chapman, Sandra C; Vértes, Petra E; Nathan, Pradeep J; Smith, Marie L; Shtyrov, Yury; Bullmore, Edward T

    2012-03-01

    How do human brain networks react to dynamic changes in the sensory environment? We measured rapid changes in brain network organization in response to brief, discrete, salient auditory stimuli. We estimated network topology and distance parameters in the immediate central response period, <1 s following auditory presentation of standard tones interspersed with occasional deviant tones in a mismatch-negativity (MMN) paradigm, using magnetoencephalography (MEG) to measure synchronization of high-frequency (gamma band; 33-64 Hz) oscillations in healthy volunteers. We found that global small-world parameters of the networks were conserved between the standard and deviant stimuli. However, surprising or unexpected auditory changes were associated with local changes in clustering of connections between temporal and frontal cortical areas and with increased interlobar, long-distance synchronization during the 120- to 250-ms epoch (coinciding with the MMN-evoked response). Network analysis of human MEG data can resolve fast local topological reconfiguration and more long-range synchronization of high-frequency networks as a systems-level representation of the brain's immediate response to salient stimuli in the dynamically changing sensory environment.

  13. Rey's Auditory Verbal Learning Test scores can be predicted from whole brain MRI in Alzheimer's disease.

    PubMed

    Moradi, Elaheh; Hallikainen, Ilona; Hänninen, Tuomo; Tohka, Jussi

    2017-01-01

    Rey's Auditory Verbal Learning Test (RAVLT) is a powerful neuropsychological tool for testing episodic memory, which is widely used for the cognitive assessment in dementia and pre-dementia conditions. Several studies have shown that an impairment in RAVLT scores reflect well the underlying pathology caused by Alzheimer's disease (AD), thus making RAVLT an effective early marker to detect AD in persons with memory complaints. We investigated the association between RAVLT scores (RAVLT Immediate and RAVLT Percent Forgetting) and the structural brain atrophy caused by AD. The aim was to comprehensively study to what extent the RAVLT scores are predictable based on structural magnetic resonance imaging (MRI) data using machine learning approaches as well as to find the most important brain regions for the estimation of RAVLT scores. For this, we built a predictive model to estimate RAVLT scores from gray matter density via elastic net penalized linear regression model. The proposed approach provided highly significant cross-validated correlation between the estimated and observed RAVLT Immediate (R = 0.50) and RAVLT Percent Forgetting (R = 0.43) in a dataset consisting of 806 AD, mild cognitive impairment (MCI) or healthy subjects. In addition, the selected machine learning method provided more accurate estimates of RAVLT scores than the relevance vector regression used earlier for the estimation of RAVLT based on MRI data. The top predictors were medial temporal lobe structures and amygdala for the estimation of RAVLT Immediate and angular gyrus, hippocampus and amygdala for the estimation of RAVLT Percent Forgetting. Further, the conversion of MCI subjects to AD in 3-years could be predicted based on either observed or estimated RAVLT scores with an accuracy comparable to MRI-based biomarkers.

  14. Comparison of cerebral regional glucose metabolic relationships in resting and auditory stimulated states

    SciTech Connect

    Metter, E.J.; Riege, W.H.; Mazziotta, J.C.; Phelps, M.E.; Kuhl, D.E.

    1984-01-01

    FDG positron computed tomography has demonstrated strong correlations between high frontal and occipital glucose metabolism in normal resting subjects, which varied by age and were lost in Huntington's and Parkinson's Diseases. The studies raised the question whether the findings may be explained by anatomic and not metabolic factors. An approach to the issue was to examine subjects scanned under two states, where functional and not anatomic features would account for relationship differences. Seventeen subjects were identified who had scans under resting and auditory stimulated states. Measurements were taken from 12 brain regions and were expressed as percentage of mean metabolism. A principal components analysis of the resting state demonstrated 3 components (73% of variance), while the stimulated states showed 4 (79% of variance). The first resting factor related frontal, right posterior inferior frontal and superior temporal regions, while in the stimulated, the frontal associated with the occipital. The second resting factor related both angular gyri and posterior temporal, while the third related left posterior inferior frontal, superior temporal and right occipital. With stimulation both factors were replaced by three others. The change in the first factor and its presence in other subject groups points to a functional relationship between the regions. Comparison to previous studies suggest the frontal-occipital association may involve aspects of attention. The variability in other factors was similar to loose correlations noted in normal studies and may reflect the differential response to several tasks.

  15. Brain stem auditory evoked potentials: effects of ovarian steroids correlated with increased incidence of Bell's palsy in pregnancy.

    PubMed

    Ben David, Y; Tal, J; Podoshin, L; Fradis, M; Sharf, M; Pratt, H; Faraggi, D

    1995-07-01

    To investigate the effect of ovarian steroids on the brain stem during changes of estrogen and progesterone blood levels, we recorded brain stem auditory evoked potentials with increased stimulus rates from 26 women treated for sterility by menotropins (Pergonal and Metrodin). These women were divided into three groups according to their estrogen and progesterone blood levels. The brain stem auditory evoked potential results revealed a significant delay of peak III only, with an increased stimulus rate in the group with the highest estrogen level. Estrogen may cause a brain stem synaptic impairment, presumably because of ischemic changes, and thus also may be responsible for a higher incidence of Bell's palsy during pregnancy.

  16. Effect of acupuncture on the auditory evoked brain stem potential in Parkinson's disease.

    PubMed

    Wang, Lingling; He, Chong; Liu, Yueguang; Zhu, Lili

    2002-03-01

    Under the auditory evoked brain stem potential (ABP) examination, the latent period of V wave and the intermittent periods of III-V peak and I-V peak were significantly shortened in Parkinson's disease patients of the treatment group (N = 29) after acupuncture treatment. The difference of cumulative scores in Webster's scale was also decreased in correlation analysis. The increase of dopamine in the brain and the excitability of the dopamine neurons may contribute to the therapeutic effects, in TCM terms, of subduing the pathogenic wind and tranquilizing the mind.

  17. A vision-free brain-computer interface (BCI) paradigm based on auditory selective attention.

    PubMed

    Kim, Do-Won; Cho, Jae-Hyun; Hwang, Han-Jeong; Lim, Jeong-Hwan; Im, Chang-Hwan

    2011-01-01

    Majority of the recently developed brain computer interface (BCI) systems have been using visual stimuli or visual feedbacks. However, the BCI paradigms based on visual perception might not be applicable to severe locked-in patients who have lost their ability to control their eye movement or even their vision. In the present study, we investigated the feasibility of a vision-free BCI paradigm based on auditory selective attention. We used the power difference of auditory steady-state responses (ASSRs) when the participant modulates his/her attention to the target auditory stimulus. The auditory stimuli were constructed as two pure-tone burst trains with different beat frequencies (37 and 43 Hz) which were generated simultaneously from two speakers located at different positions (left and right). Our experimental results showed high classification accuracies (64.67%, 30 commands/min, information transfer rate (ITR) = 1.89 bits/min; 74.00%, 12 commands/min, ITR = 2.08 bits/min; 82.00%, 6 commands/min, ITR = 1.92 bits/min; 84.33%, 3 commands/min, ITR = 1.12 bits/min; without any artifact rejection, inter-trial interval = 6 sec), enough to be used for a binary decision. Based on the suggested paradigm, we implemented a first online ASSR-based BCI system that demonstrated the possibility of materializing a totally vision-free BCI system.

  18. Brain activity in predominantly-inattentive subtype attention-deficit/hyperactivity disorder during an auditory oddball attention task.

    PubMed

    Orinstein, Alyssa J; Stevens, Michael C

    2014-08-30

    Previous functional neuroimaging studies have found brain activity abnormalities in attention-deficit/hyperactivity disorder (ADHD) on numerous cognitive tasks. However, little is known about brain dysfunction unique to the predominantly-inattentive subtype of ADHD (ADHD-I), despite debate as to whether DSM-IV-defined ADHD subtypes differ in etiology. This study compared brain activity of 18 ADHD-I adolescents (ages 12-18) and 20 non-psychiatric age-matched control participants on a functional magnetic resonance image (fMRI) auditory oddball attention task. ADHD-I participants had significant activation deficits to infrequent target stimuli in bilateral superior temporal gyri, bilateral insula, several midline cingulate/medial frontal gyrus regions, right posterior parietal cortex, thalamus, cerebellum, and brainstem. To novel stimuli, ADHD-I participants had reduced activation in bilateral lateral temporal lobe structures. There were no brain regions where ADHD-I participants had greater hemodynamic activity to targets or novels than controls. Brain activity deficits in ADHD-I participants were found in several regions important to attentional orienting and working memory-related cognitive processes involved in target identification. These results differ from those in previously studied adolescents with combined-subtype ADHD, who had a lesser magnitude of activation abnormalities in frontoparietal regions and relatively more discrete regional deficits to novel stimuli. The divergent findings suggest different etiological factors might underlie attention deficits in different DSM-IV-defined ADHD subtypes, and they have important implications for the DSM-V reconceptualization of subtypes as varying clinical presentations of the same core disorder.

  19. Electrical Brain Responses to an Auditory Illusion and the Impact of Musical Expertise.

    PubMed

    Ioannou, Christos I; Pereda, Ernesto; Lindsen, Job P; Bhattacharya, Joydeep

    2015-01-01

    The presentation of two sinusoidal tones, one to each ear, with a slight frequency mismatch yields an auditory illusion of a beating frequency equal to the frequency difference between the two tones; this is known as binaural beat (BB). The effect of brief BB stimulation on scalp EEG is not conclusively demonstrated. Further, no studies have examined the impact of musical training associated with BB stimulation, yet musicians' brains are often associated with enhanced auditory processing. In this study, we analysed EEG brain responses from two groups, musicians and non-musicians, when stimulated by short presentation (1 min) of binaural beats with beat frequency varying from 1 Hz to 48 Hz. We focused our analysis on alpha and gamma band EEG signals, and they were analysed in terms of spectral power, and functional connectivity as measured by two phase synchrony based measures, phase locking value and phase lag index. Finally, these measures were used to characterize the degree of centrality, segregation and integration of the functional brain network. We found that beat frequencies belonging to alpha band produced the most significant steady-state responses across groups. Further, processing of low frequency (delta, theta, alpha) binaural beats had significant impact on cortical network patterns in the alpha band oscillations. Altogether these results provide a neurophysiological account of cortical responses to BB stimulation at varying frequencies, and demonstrate a modulation of cortico-cortical connectivity in musicians' brains, and further suggest a kind of neuronal entrainment of a linear and nonlinear relationship to the beating frequencies.

  20. The WIN-speller: a new intuitive auditory brain-computer interface spelling application.

    PubMed

    Kleih, Sonja C; Herweg, Andreas; Kaufmann, Tobias; Staiger-Sälzer, Pit; Gerstner, Natascha; Kübler, Andrea

    2015-01-01

    The objective of this study was to test the usability of a new auditory Brain-Computer Interface (BCI) application for communication. We introduce a word based, intuitive auditory spelling paradigm the WIN-speller. In the WIN-speller letters are grouped by words, such as the word KLANG representing the letters A, G, K, L, and N. Thereby, the decoding step between perceiving a code and translating it to the stimuli it represents becomes superfluous. We tested 11 healthy volunteers and four end-users with motor impairment in the copy spelling mode. Spelling was successful with an average accuracy of 84% in the healthy sample. Three of the end-users communicated with average accuracies of 80% or higher while one user was not able to communicate reliably. Even though further evaluation is required, the WIN-speller represents a potential alternative for BCI based communication in end-users.

  1. Role of auditory brain function assessment by SPECT in cochlear implant side selection.

    PubMed

    Di Nardo, W; Giannantonio, S; Di Giuda, D; De Corso, E; Schinaia, L; Paludetti, G

    2013-02-01

    Pre-surgery evaluation, indications for cochlear implantation and expectations in terms of post-operative functional results remain challenging topics in pre-lingually deaf adults. Our study has the purpose of determining the benefits of Single Photon Emission Tomography (SPECT) assessment in pre-surgical evaluation of pre-lingually deaf adults who are candidates for cochlear implantation. In 7 pre-lingually profoundly deaf patients, brain SPECT was performed at baseline conditions and in bilateral simultaneous multi-frequency acoustic stimulation. Six sagittal tomograms of both temporal cortices were used for semi-quantitative analysis in each patient. Percentage increases in cortical perfusion resulting from auditory stimulation were calculated. The results showed an inter-hemispherical asymmetry of the activation extension and intensity in the stimulated temporal areas. Consistent with the obtained brain activation data, patients were implanted preferring the side that showed higher activation after acoustic stimulus. Considering the increment in auditory perception performances, it was possible to point out a relationship between cortical brain activity shown by SPECT and hearing performances, and, even more significant, a correlation between post-operative functional performances and the activation of the most medial part of the sagittal temporal tomograms, corresponding to medium-high frequencies. In light of these findings, we believe that brain SPECT could be considered in the evaluation of deaf patients candidate for cochlear implantation, and that it plays a major role in functional assessment of the auditory cortex of pre-lingually deaf subjects, even if further studies are necessary to conclusively establish its utility. Further developments of this technique are possible by using trans-tympanic electrical stimulation of the cochlear promontory, which could give the opportunity to study completely deaf patients, whose evaluation is objectively difficult

  2. Intrinsic Connections of the Core Auditory Cortical Regions and Rostral Supratemporal Plane in the Macaque Monkey.

    PubMed

    Scott, Brian H; Leccese, Paul A; Saleem, Kadharbatcha S; Kikuchi, Yukiko; Mullarkey, Matthew P; Fukushima, Makoto; Mishkin, Mortimer; Saunders, Richard C

    2017-01-01

    In the ventral stream of the primate auditory cortex, cortico-cortical projections emanate from the primary auditory cortex (AI) along 2 principal axes: one mediolateral, the other caudorostral. Connections in the mediolateral direction from core, to belt, to parabelt, have been well described, but less is known about the flow of information along the supratemporal plane (STP) in the caudorostral dimension. Neuroanatomical tracers were injected throughout the caudorostral extent of the auditory core and rostral STP by direct visualization of the cortical surface. Auditory cortical areas were distinguished by SMI-32 immunostaining for neurofilament, in addition to established cytoarchitectonic criteria. The results describe a pathway comprising step-wise projections from AI through the rostral and rostrotemporal fields of the core (R and RT), continuing to the recently identified rostrotemporal polar field (RTp) and the dorsal temporal pole. Each area was strongly and reciprocally connected with the areas immediately caudal and rostral to it, though deviations from strictly serial connectivity were observed. In RTp, inputs converged from core, belt, parabelt, and the auditory thalamus, as well as higher order cortical regions. The results support a rostrally directed flow of auditory information with complex and recurrent connections, similar to the ventral stream of macaque visual cortex.

  3. Speech acquisition predicts regions of enhanced cortical response to auditory stimulation in autism spectrum individuals.

    PubMed

    Samson, F; Zeffiro, T A; Doyon, J; Benali, H; Mottron, L

    2015-09-01

    A continuum of phenotypes makes up the autism spectrum (AS). In particular, individuals show large differences in language acquisition, ranging from precocious speech to severe speech onset delay. However, the neurological origin of this heterogeneity remains unknown. Here, we sought to determine whether AS individuals differing in speech acquisition show different cortical responses to auditory stimulation and morphometric brain differences. Whole-brain activity following exposure to non-social sounds was investigated. Individuals in the AS were classified according to the presence or absence of Speech Onset Delay (AS-SOD and AS-NoSOD, respectively) and were compared with IQ-matched typically developing individuals (TYP). AS-NoSOD participants displayed greater task-related activity than TYP in the inferior frontal gyrus and peri-auditory middle and superior temporal gyri, which are associated with language processing. Conversely, the AS-SOD group only showed enhanced activity in the vicinity of the auditory cortex. We detected no differences in brain structure between groups. This is the first study to demonstrate the existence of differences in functional brain activity between AS individuals divided according to their pattern of speech development. These findings support the Trigger-threshold-target model and indicate that the occurrence of speech onset delay in AS individuals depends on the location of cortical functional reallocation, which favors perception in AS-SOD and language in AS-NoSOD.

  4. Brain stem auditory evoked potentials in patients with multiple system atrophy with progressive autonomic failure (Shy-Drager syndrome).

    PubMed Central

    Prasher, D; Bannister, R

    1986-01-01

    Brain stem potentials from three groups of patients, namely those with pure progressive autonomic failure, Parkinson's disease and multisystem atrophy with progressive autonomic failure (Shy-Drager syndrome) were compared with each other and a group of normal subjects. In virtually all the patients with multisystem atrophy with progressive autonomic failure the brain stem potentials were abnormal in contrast to normal findings with Parkinson's disease. The closely associated group of patients with progressive autonomic failure alone also revealed no abnormalities of the BAEP. This separation of the two groups, Parkinson's disease and progressive autonomic failure from multisystem atrophy with progressive autonomic failure is important clinically as multiple system atrophy of the Shy-Drager type has extra-pyramidal features closely resembling Parkinsonism or a late onset cerebellar degeneration. From the abnormalities of the brain stem response in multisystem atrophy with progressive autonomic failure, it is clear that some disruption of the auditory pathway occurs in the ponto-medullary region as in nearly all patients there is a significant delay or reduction in the amplitude of components of the response generated beyond this region. The most likely area involved is the superior olivary complex. Images PMID:3958741

  5. Experience-based Auditory Predictions Modulate Brain Activity to Silence as do Real Sounds.

    PubMed

    Chouiter, Leila; Tzovara, Athina; Dieguez, Sebastian; Annoni, Jean-Marie; Magezi, David; De Lucia, Marzia; Spierer, Lucas

    2015-10-01

    Interactions between stimuli's acoustic features and experience-based internal models of the environment enable listeners to compensate for the disruptions in auditory streams that are regularly encountered in noisy environments. However, whether auditory gaps are filled in predictively or restored a posteriori remains unclear. The current lack of positive statistical evidence that internal models can actually shape brain activity as would real sounds precludes accepting predictive accounts of filling-in phenomenon. We investigated the neurophysiological effects of internal models by testing whether single-trial electrophysiological responses to omitted sounds in a rule-based sequence of tones with varying pitch could be decoded from the responses to real sounds and by analyzing the ERPs to the omissions with data-driven electrical neuroimaging methods. The decoding of the brain responses to different expected, but omitted, tones in both passive and active listening conditions was above chance based on the responses to the real sound in active listening conditions. Topographic ERP analyses and electrical source estimations revealed that, in the absence of any stimulation, experience-based internal models elicit an electrophysiological activity different from noise and that the temporal dynamics of this activity depend on attention. We further found that the expected change in pitch direction of omitted tones modulated the activity of left posterior temporal areas 140-200 msec after the onset of omissions. Collectively, our results indicate that, even in the absence of any stimulation, internal models modulate brain activity as do real sounds, indicating that auditory filling in can be accounted for by predictive activity.

  6. Cross-modal activation of auditory regions during visuo-spatial working memory in early deafness.

    PubMed

    Ding, Hao; Qin, Wen; Liang, Meng; Ming, Dong; Wan, Baikun; Li, Qiang; Yu, Chunshui

    2015-09-01

    Early deafness can reshape deprived auditory regions to enable the processing of signals from the remaining intact sensory modalities. Cross-modal activation has been observed in auditory regions during non-auditory tasks in early deaf subjects. In hearing subjects, visual working memory can evoke activation of the visual cortex, which further contributes to behavioural performance. In early deaf subjects, however, whether and how auditory regions participate in visual working memory remains unclear. We hypothesized that auditory regions may be involved in visual working memory processing and activation of auditory regions may contribute to the superior behavioural performance of early deaf subjects. In this study, 41 early deaf subjects (22 females and 19 males, age range: 20-26 years, age of onset of deafness < 2 years) and 40 age- and gender-matched hearing controls underwent functional magnetic resonance imaging during a visuo-spatial delayed recognition task that consisted of encoding, maintenance and recognition stages. The early deaf subjects exhibited faster reaction times on the spatial working memory task than did the hearing controls. Compared with hearing controls, deaf subjects exhibited increased activation in the superior temporal gyrus bilaterally during the recognition stage. This increased activation amplitude predicted faster and more accurate working memory performance in deaf subjects. Deaf subjects also had increased activation in the superior temporal gyrus bilaterally during the maintenance stage and in the right superior temporal gyrus during the encoding stage. These increased activation amplitude also predicted faster reaction times on the spatial working memory task in deaf subjects. These findings suggest that cross-modal plasticity occurs in auditory association areas in early deaf subjects. These areas are involved in visuo-spatial working memory. Furthermore, amplitudes of cross-modal activation during the maintenance stage were

  7. Auditory pathways: are 'what' and 'where' appropriate?

    PubMed

    Hall, Deborah A

    2003-05-13

    New evidence confirms that the auditory system encompasses temporal, parietal and frontal brain regions, some of which partly overlap with the visual system. But common assumptions about the functional homologies between sensory systems may be misleading.

  8. [Effect of sleep deprivation on visual evoked potentials and brain stem auditory evoked potentials in epileptics].

    PubMed

    Urumova, L T; Kovalenko, G A; Tsunikov, A I; Sumskiĭ, L I

    1984-01-01

    The article reports on the first study of the evoked activity of the brain in epileptic patients (n = 20) following sleep deprivation. An analysis of the data obtained has revealed a tendency to the shortening of the peak latent intervals of visual evoked potentials in the range of 100-200 mu sec and the V component and the interpeak interval III-V of evoked auditory trunk potentials in patients with temporal epilepsy. The phenomenon may indicate the elimination of stabilizing control involving the specific conductive pathways and, possibly, an accelerated conduction of a specific sensor signal.

  9. Effects of Visual and Auditory Background on Reading Achievement Test Performance of Brain-Injured and Non Brain-Injured Children.

    ERIC Educational Resources Information Center

    Carter, John L.

    Forty-two brain injured boys and 42 non brain injured boys (aged 11-6 to 12-6) were tested to determine the effects of increasing amounts of visual and auditory distraction on reading performance. The Stanford Achievement Reading Comprehension Test was administered with three degrees of distraction. The visual distraction consisted of either very…

  10. A trade-off between somatosensory and auditory related brain activity during object naming but not reading.

    PubMed

    Seghier, Mohamed L; Hope, Thomas M H; Prejawa, Susan; Parker Jones, 'Ōiwi; Vitkovitch, Melanie; Price, Cathy J

    2015-03-18

    The parietal operculum, particularly the cytoarchitectonic area OP1 of the secondary somatosensory area (SII), is involved in somatosensory feedback. Using fMRI with 58 human subjects, we investigated task-dependent differences in SII/OP1 activity during three familiar speech production tasks: object naming, reading and repeatedly saying "1-2-3." Bilateral SII/OP1 was significantly suppressed (relative to rest) during object naming, to a lesser extent when repeatedly saying "1-2-3" and not at all during reading. These results cannot be explained by task difficulty but the contrasting difference between naming and reading illustrates how the demands on somatosensory activity change with task, even when motor output (i.e., production of object names) is matched. To investigate what determined SII/OP1 deactivation during object naming, we searched the whole brain for areas where activity increased as that in SII/OP1 decreased. This across subject covariance analysis revealed a region in the right superior temporal sulcus (STS) that lies within the auditory cortex, and is activated by auditory feedback during speech production. The tradeoff between activity in SII/OP1 and STS was not observed during reading, which showed significantly more activation than naming in both SII/OP1 and STS bilaterally. These findings suggest that, although object naming is more error prone than reading, subjects can afford to rely more or less on somatosensory or auditory feedback during naming. In contrast, fast and efficient error-free reading places more consistent demands on both types of feedback, perhaps because of the potential for increased competition between lexical and sublexical codes at the articulatory level.

  11. Positron emission tomography (PET) analysis of the effects of auditory stimulation on the distribution of /sup 11/C-N-methylchlorphentermine in the brain

    SciTech Connect

    Paschal, C.B.

    1986-06-01

    This experimental work was launched to study how auditory stimulation effects blood flow in the brain. The technique used was Positron Emission Tomography (PET) with /sup 11/C-N-methylchlorphentermine (/sup 11/C-NMCP) as the tracer. /sup 11/C-NMCP acts as a molecular microsphere and thus measures blood flow. The objectives of this work were: to develop, test, and refine an experimental procedure, to design and construct a universally applicable positioning device, and to develop and test a synthesis for a radiopure solution of /sup 11/C-NMCP; all were accomplished. PET was used to observe the brain distribution of /sup 11/C-NMCP during binaural and monaural stimulation states. The data was analyzed by finding the signal intensity in regions of the image that represented the left and right interior colliculi (IC's), brain structures dedicated to the processing of auditory signals. The binaural tests indicated a statistically significant tendency for slightly higher concentration of the tracer in the left IC than in the right IC. The monaural tests combined with those of the binaural state were not solidly conclusive, however, three of the four cases showed a decrease in tracer uptake in the IC opposite the zero-stimulus ear, as expected. There is some indication that the anesthesia used in the majority of this work may have interferred with blood flow response to auditory stimulation. 39 refs., 17 figs., 3 tabs.

  12. HVC lesions modify immediate early gene expression in auditory forebrain regions of female songbirds.

    PubMed

    Lynch, Kathleen S; Kleitz-Nelson, Hayley K; Ball, Gregory F

    2013-04-01

    It is well established that auditory forebrain regions of oscine birds are essential for the encoding of species-typical songs and are, therefore, vital for recognition of song during sociosexual interactions. Regions such as the caudal medial nidopallium (NCM) and the caudal medial mesopallium (CMM) are involved in perceptual processing of song and the formation of auditory memories. There is an additional telencephalic nucleus, however, that has also been implicated in species recognition. This nucleus is HVC, a prominent nucleus that sits at the apex of the song system, and is well known for its critical role in song learning and song production in male songbirds. Here, we explore the functional relationship between auditory forebrain regions (i.e., NCM and CMM) and HVC in female canaries (Serinus canaria). We lesion HVC and examine immediate early gene responses to conspecific song presentation within CMM and NCM to explore whether HVC can modulate auditory responses within these forebrain regions. Our results reveal robust deficits in ZENK-ir in CMM and NCM of HVC-lesioned females when compared with control- and sham-lesioned females, indicating that functional connections exists between HVC and NCM/CMM. Although these connected regions have been implicated in song learning and production in males, they likely serve distinct functions in female songbirds that face the task of song recognition rather than song production. Identifying functional connections between HVC and auditory regions involved in song perception is an essential step toward developing a comprehensive understanding of the neural basis of song recognition.

  13. Subcortical processing in auditory communication.

    PubMed

    Pannese, Alessia; Grandjean, Didier; Frühholz, Sascha

    2015-10-01

    The voice is a rich source of information, which the human brain has evolved to decode and interpret. Empirical observations have shown that the human auditory system is especially sensitive to the human voice, and that activity within the voice-sensitive regions of the primary and secondary auditory cortex is modulated by the emotional quality of the vocal signal, and may therefore subserve, with frontal regions, the cognitive ability to correctly identify the speaker's affective state. So far, the network involved in the processing of vocal affect has been mainly characterised at the cortical level. However, anatomical and functional evidence suggests that acoustic information relevant to the affective quality of the auditory signal might be processed prior to the auditory cortex. Here we review the animal and human literature on the main subcortical structures along the auditory pathway, and propose a model whereby the distinction between different types of vocal affect in auditory communication begins at very early stages of auditory processing, and relies on the analysis of individual acoustic features of the sound signal. We further suggest that this early feature-based decoding occurs at a subcortical level along the ascending auditory pathway, and provides a preliminary coarse (but fast) characterisation of the affective quality of the auditory signal before the more refined (but slower) cortical processing is completed.

  14. Case study: auditory brain responses in a minimally verbal child with autism and cerebral palsy

    PubMed Central

    Yau, Shu H.; McArthur, Genevieve; Badcock, Nicholas A.; Brock, Jon

    2015-01-01

    An estimated 30% of individuals with autism spectrum disorders (ASD) remain minimally verbal into late childhood, but research on cognition and brain function in ASD focuses almost exclusively on those with good or only moderately impaired language. Here we present a case study investigating auditory processing of GM, a nonverbal child with ASD and cerebral palsy. At the age of 8 years, GM was tested using magnetoencephalography (MEG) whilst passively listening to speech sounds and complex tones. Where typically developing children and verbal autistic children all demonstrated similar brain responses to speech and nonspeech sounds, GM produced much stronger responses to nonspeech than speech, particularly in the 65–165 ms (M50/M100) time window post-stimulus onset. GM was retested aged 10 years using electroencephalography (EEG) whilst passively listening to pure tone stimuli. Consistent with her MEG response to complex tones, GM showed an unusually early and strong response to pure tones in her EEG responses. The consistency of the MEG and EEG data in this single case study demonstrate both the potential and the feasibility of these methods in the study of minimally verbal children with ASD. Further research is required to determine whether GM's atypical auditory responses are characteristic of other minimally verbal children with ASD or of other individuals with cerebral palsy. PMID:26150768

  15. Electrical Brain Responses to an Auditory Illusion and the Impact of Musical Expertise

    PubMed Central

    Ioannou, Christos I.; Pereda, Ernesto; Lindsen, Job P.; Bhattacharya, Joydeep

    2015-01-01

    The presentation of two sinusoidal tones, one to each ear, with a slight frequency mismatch yields an auditory illusion of a beating frequency equal to the frequency difference between the two tones; this is known as binaural beat (BB). The effect of brief BB stimulation on scalp EEG is not conclusively demonstrated. Further, no studies have examined the impact of musical training associated with BB stimulation, yet musicians' brains are often associated with enhanced auditory processing. In this study, we analysed EEG brain responses from two groups, musicians and non-musicians, when stimulated by short presentation (1 min) of binaural beats with beat frequency varying from 1 Hz to 48 Hz. We focused our analysis on alpha and gamma band EEG signals, and they were analysed in terms of spectral power, and functional connectivity as measured by two phase synchrony based measures, phase locking value and phase lag index. Finally, these measures were used to characterize the degree of centrality, segregation and integration of the functional brain network. We found that beat frequencies belonging to alpha band produced the most significant steady-state responses across groups. Further, processing of low frequency (delta, theta, alpha) binaural beats had significant impact on cortical network patterns in the alpha band oscillations. Altogether these results provide a neurophysiological account of cortical responses to BB stimulation at varying frequencies, and demonstrate a modulation of cortico-cortical connectivity in musicians' brains, and further suggest a kind of neuronal entrainment of a linear and nonlinear relationship to the beating frequencies. PMID:26065708

  16. Experience-dependent modulation of right anterior insula and sensorimotor regions as a function of noise-masked auditory feedback in singers and nonsingers.

    PubMed

    Kleber, Boris; Friberg, Anders; Zeitouni, Anthony; Zatorre, Robert

    2017-02-15

    Previous studies on vocal motor production in singing suggest that the right anterior insula (AI) plays a role in experience-dependent modulation of feedback integration. Specifically, when somatosensory input was reduced via anesthesia of the vocal fold mucosa, right AI activity was down regulated in trained singers. In the current fMRI study, we examined how masking of auditory feedback affects pitch-matching accuracy and corresponding brain activity in the same participants. We found that pitch-matching accuracy was unaffected by masking in trained singers yet declined in nonsingers. The corresponding brain region with the most differential and interesting activation pattern was the right AI, which was up regulated during masking in singers but down regulated in nonsingers. Likewise, its functional connectivity with inferior parietal, frontal, and voice-relevant sensorimotor areas was increased in singers yet decreased in nonsingers. These results indicate that singers relied more on somatosensory feedback, whereas nonsingers depended more critically on auditory feedback. When comparing auditory vs somatosensory feedback involvement, the right anterior insula emerged as the only region for correcting intended vocal output by modulating what is heard or felt as a function of singing experience. We propose the right anterior insula as a key node in the brain's singing network for the integration of signals of salience across multiple sensory and cognitive domains to guide vocal behavior.

  17. Brain region mapping using global metabolomics.

    PubMed

    Ivanisevic, Julijana; Epstein, Adrian A; Kurczy, Michael E; Benton, Paul H; Uritboonthai, Winnie; Fox, Howard S; Boska, Michael D; Gendelman, Howard E; Siuzdak, Gary

    2014-11-20

    Historically, studies of brain metabolism have been based on targeted analyses of a limited number of metabolites. Here we present an untargeted mass spectrometry-based metabolomic strategy that has successfully uncovered differences in a broad array of metabolites across anatomical regions of the mouse brain. The NSG immunodeficient mouse model was chosen because of its ability to undergo humanization leading to numerous applications in oncology and infectious disease research. Metabolic phenotyping by hydrophilic interaction liquid chromatography and nanostructure imaging mass spectrometry revealed both water-soluble and lipid metabolite patterns across brain regions. Neurochemical differences in metabolic phenotypes were mainly defined by various phospholipids and several intriguing metabolites including carnosine, cholesterol sulfate, lipoamino acids, uric acid, and sialic acid, whose physiological roles in brain metabolism are poorly understood. This study helps define regional homeostasis for the normal mouse brain to give context to the reaction to pathological events.

  18. Brain Region Mapping using Global Metabolomics

    PubMed Central

    Ivanisevic, Julijana; Epstein, Adrian; Kurczy, Michael E.; Benton, H. Paul; Uritboonthai, Winnie; Fox, Howard S.; Boska, Michael D.; Gendelman, Howard E.; Siuzdak, Gary

    2014-01-01

    SUMMARY Historically, studies of brain metabolism have been based on targeted analyses of a limited number of metabolites. Here we present a novel untargeted mass spectrometry-based metabolomics approach that has successfully uncovered differences in broad array of metabolites across anatomical regions of the mouse brain. The NSG immunodeficient mouse model was chosen because of its ability to undergo humanization leading to numerous applications in oncology and infectious disease research. Metabolic phenotyping by hydrophilic interaction liquid chromatography and nanostructure imaging mass spectrometry revealed unique water-soluble and lipid metabolite patterns between brain regions. Neurochemical differences in metabolic phenotypes were mainly defined by various phospholipids and several intriguing metabolites including carnosine, cholesterol sulfate, lipoamino acids, uric and sialic acid whose physiological roles in brain metabolism are poorly understood. This study lays important groundwork by defining regional homeostasis for the normal mouse brain to give context to the reaction to pathological events. PMID:25457182

  19. Auditory agnosia.

    PubMed

    Slevc, L Robert; Shell, Alison R

    2015-01-01

    Auditory agnosia refers to impairments in sound perception and identification despite intact hearing, cognitive functioning, and language abilities (reading, writing, and speaking). Auditory agnosia can be general, affecting all types of sound perception, or can be (relatively) specific to a particular domain. Verbal auditory agnosia (also known as (pure) word deafness) refers to deficits specific to speech processing, environmental sound agnosia refers to difficulties confined to non-speech environmental sounds, and amusia refers to deficits confined to music. These deficits can be apperceptive, affecting basic perceptual processes, or associative, affecting the relation of a perceived auditory object to its meaning. This chapter discusses what is known about the behavioral symptoms and lesion correlates of these different types of auditory agnosia (focusing especially on verbal auditory agnosia), evidence for the role of a rapid temporal processing deficit in some aspects of auditory agnosia, and the few attempts to treat the perceptual deficits associated with auditory agnosia. A clear picture of auditory agnosia has been slow to emerge, hampered by the considerable heterogeneity in behavioral deficits, associated brain damage, and variable assessments across cases. Despite this lack of clarity, these striking deficits in complex sound processing continue to inform our understanding of auditory perception and cognition.

  20. Mature brain tissue in the sacrococcygeal region

    PubMed Central

    Shrestha, Binod Bade; Ghimire, Pradeep; Ghartimagar, Dilasma; Jwarchan, Bishnu; Lalchan, Subita; Karmacharya, Mikesh

    2016-01-01

    Complete mature brain tissue in sacrococcygeal region is a rare congenital anomaly in a newborn, which usually is misdiagnosed for sacrococcygeal teratoma. Glial tumor-like ependymoma is also common in sacrococcygeal area but mostly appears later in life. We present a case of complete heterotopic brain tissue in the sacrococcygeal region. The patient underwent total excision of mass with coccygectomy. To our knowledge it is the second case being reported. PMID:27194682

  1. Subthalamic nucleus deep brain stimulation affects distractor interference in auditory working memory.

    PubMed

    Camalier, Corrie R; Wang, Alice Y; McIntosh, Lindsey G; Park, Sohee; Neimat, Joseph S

    2017-03-01

    Computational and theoretical accounts hypothesize the basal ganglia play a supramodal "gating" role in the maintenance of working memory representations, especially in preservation from distractor interference. There are currently two major limitations to this account. The first is that supporting experiments have focused exclusively on the visuospatial domain, leaving questions as to whether such "gating" is domain-specific. The second is that current evidence relies on correlational measures, as it is extremely difficult to causally and reversibly manipulate subcortical structures in humans. To address these shortcomings, we examined non-spatial, auditory working memory performance during reversible modulation of the basal ganglia, an approach afforded by deep brain stimulation of the subthalamic nucleus. We found that subthalamic nucleus stimulation impaired auditory working memory performance, specifically in the group tested in the presence of distractors, even though the distractors were predictable and completely irrelevant to the encoding of the task stimuli. This study provides key causal evidence that the basal ganglia act as a supramodal filter in working memory processes, further adding to our growing understanding of their role in cognition.

  2. Learning to modulate sensorimotor rhythms with stereo auditory feedback for a brain-computer interface.

    PubMed

    McCreadie, Karl A; Coyle, Damien H; Prasad, Girijesh

    2012-01-01

    Motor imagery can be used to modulate sensorimotor rhythms (SMR) enabling detection of voltage fluctuations on the surface of the scalp using electroencephalographic (EEG) electrodes. Feedback is essential in learning how to intentionally modulate SMR in non-muscular communication using a brain-computer interface (BCI). A BCI that is not reliant upon the visual modality for feedback is an attractive means of communication for the blind and the vision impaired and to release the visual channel for other purposes during BCI usage. The aim of this study is to demonstrate the feasibility of replacing the traditional visual feedback modality with stereo auditory feedback. Twenty participants split into equal groups took part in ten BCI sessions involving motor imagery. The visual feedback group performed best using two performance measures but did not show improvement over time whilst the auditory group improved as the study progressed. Multiple loudspeaker presentation of audio allows the listener to intuitively assign each of two classes to the corresponding lateral position in a free-field listening environment.

  3. Sources of variability in auditory brain stem evoked potential measures over time.

    PubMed

    Edwards, R M; Buchwald, J S; Tanguay, P E; Schwafel, J A

    1982-02-01

    Auditory brain stem EPs elicited in 10 normal adults by monaural clicks delivered at 72 dB HL, 20/sec showed no significant change in wave latencies or in the ratio of wave I to wave Y amplitude across 250 trial subsets, across 250 trial subsets, across 1500 trial blocks within a test session, or across two test sessions separated by several months. Sources of maximum variability were determined by using mean squared differences with all but one condition constant. 'Subjects' was shown to contribute the most variability followed by 'ears', 'sessions' and 'runs'; collapsing across conditions, wave III latencies were found to be the least variable, while wave II showed the most variability. Some EP morphologies showed extra peaks between waves II and IV, missing wave IV or wave IV fused with wave V. Such variations in wave form morphology were independent of EMG amplitude and were characteristic of certain individuals.

  4. Brain dynamics in the auditory Go/NoGo task as a function of EEG frequency.

    PubMed

    Barry, Robert J; De Blasio, Frances; Rushby, Jacqueline A; Clarke, Adam R

    2010-11-01

    We examined relationships between the phase of narrow-band electroencephalographic (EEG) activity at stimulus onset and the resultant event-related potentials (ERPs) in an equiprobable auditory Go/NoGo task with a fixed SOA, in the context of a novel conceptualisation of orthogonal phase effects (cortical negativity vs. positivity, negative driving vs. positive driving, waxing vs. waning). ERP responses to each stimulus type were analysed. Prestimulus narrow-band EEG activity (in 1Hz bands from 1 to 13Hz) at Cz was assessed for each trial using FFT decomposition of the EEG data. For each frequency, the cycle at stimulus onset was used to sort trials into four phases, for which ERPs were derived from the raw EEG activity at 9 central sites. The occurrence of preferred phase-defined brain states was confirmed at a number of frequencies, crossing the traditional frequency bands. As expected, these did not differ between Go and NoGo stimuli. These preferred states were associated with more efficient processing of the stimulus, as reflected in differences in latency and amplitude of the N1 and P3 ERP components. The present results, although derived in a different paradigm by EEG decomposition methods different from those used previously, confirm the existence of preferred brain states and their impact on the efficiency of brain dynamics involved in perceptual and cognitive processing.

  5. The musical centers of the brain: Vladimir E. Larionov (1857-1929) and the functional neuroanatomy of auditory perception.

    PubMed

    Triarhou, Lazaros C; Verina, Tatyana

    2016-11-01

    In 1899 a landmark paper entitled "On the musical centers of the brain" was published in Pflügers Archiv, based on work carried out in the Anatomo-Physiological Laboratory of the Neuropsychiatric Clinic of Vladimir M. Bekhterev (1857-1927) in St. Petersburg, Imperial Russia. The author of that paper was Vladimir E. Larionov (1857-1929), a military doctor and devoted brain scientist, who pursued the problem of the localization of function in the canine and human auditory cortex. His data detailed the existence of tonotopy in the temporal lobe and further demonstrated centrifugal auditory pathways emanating from the auditory cortex and directed to the opposite hemisphere and lower brain centers. Larionov's discoveries have been largely considered as findings of the Bekhterev school. Perhaps this is why there are limited resources on Larionov, especially keeping in mind his military medical career and the fact that after 1917 he just seems to have practiced otorhinolaryngology in Odessa. Larionov died two years after Bekhterev's mysterious death of 1927. The present study highlights the pioneering contributions of Larionov to auditory neuroscience, trusting that the life and work of Vladimir Efimovich will finally, and deservedly, emerge from the shadow of his celebrated master, Vladimir Mikhailovich.

  6. Bigger brains or bigger nuclei? Regulating the size of auditory structures in birds.

    PubMed

    Kubke, M Fabiana; Massoglia, Dino P; Carr, Catherine E

    2004-01-01

    Increases in the size of the neuronal structures that mediate specific behaviors are believed to be related to enhanced computational performance. It is not clear, however, what developmental and evolutionary mechanisms mediate these changes, nor whether an increase in the size of a given neuronal population is a general mechanism to achieve enhanced computational ability. We addressed the issue of size by analyzing the variation in the relative number of cells of auditory structures in auditory specialists and generalists. We show that bird species with different auditory specializations exhibit variation in the relative size of their hindbrain auditory nuclei. In the barn owl, an auditory specialist, the hindbrain auditory nuclei involved in the computation of sound location show hyperplasia. This hyperplasia was also found in songbirds, but not in non-auditory specialists. The hyperplasia of auditory nuclei was also not seen in birds with large body weight suggesting that the total number of cells is selected for in auditory specialists. In barn owls, differences observed in the relative size of the auditory nuclei might be attributed to modifications in neurogenesis and cell death. Thus, hyperplasia of circuits used for auditory computation accompanies auditory specialization in different orders of birds.

  7. Physiological modulators of Kv3.1 channels adjust firing patterns of auditory brain stem neurons.

    PubMed

    Brown, Maile R; El-Hassar, Lynda; Zhang, Yalan; Alvaro, Giuseppe; Large, Charles H; Kaczmarek, Leonard K

    2016-07-01

    Many rapidly firing neurons, including those in the medial nucleus of the trapezoid body (MNTB) in the auditory brain stem, express "high threshold" voltage-gated Kv3.1 potassium channels that activate only at positive potentials and are required for stimuli to generate rapid trains of actions potentials. We now describe the actions of two imidazolidinedione derivatives, AUT1 and AUT2, which modulate Kv3.1 channels. Using Chinese hamster ovary cells stably expressing rat Kv3.1 channels, we found that lower concentrations of these compounds shift the voltage of activation of Kv3.1 currents toward negative potentials, increasing currents evoked by depolarization from typical neuronal resting potentials. Single-channel recordings also showed that AUT1 shifted the open probability of Kv3.1 to more negative potentials. Higher concentrations of AUT2 also shifted inactivation to negative potentials. The effects of lower and higher concentrations could be mimicked in numerical simulations by increasing rates of activation and inactivation respectively, with no change in intrinsic voltage dependence. In brain slice recordings of mouse MNTB neurons, both AUT1 and AUT2 modulated firing rate at high rates of stimulation, a result predicted by numerical simulations. Our results suggest that pharmaceutical modulation of Kv3.1 currents represents a novel avenue for manipulation of neuronal excitability and has the potential for therapeutic benefit in the treatment of hearing disorders.

  8. Noninvasive brain stimulation for the treatment of auditory verbal hallucinations in schizophrenia: methods, effects and challenges

    PubMed Central

    Kubera, Katharina M.; Barth, Anja; Hirjak, Dusan; Thomann, Philipp A.; Wolf, Robert C.

    2015-01-01

    This mini-review focuses on noninvasive brain stimulation techniques as an augmentation method for the treatment of persistent auditory verbal hallucinations (AVH) in patients with schizophrenia. Paradigmatically, we place emphasis on transcranial magnetic stimulation (TMS). We specifically discuss rationales of stimulation and consider methodological questions together with issues of phenotypic diversity in individuals with drug-refractory and persistent AVH. Eventually, we provide a brief outlook for future investigations and treatment directions. Taken together, current evidence suggests TMS as a promising method in the treatment of AVH. Low-frequency stimulation of the superior temporal cortex (STC) may reduce symptom severity and frequency. Yet clinical effects are of relatively short duration and effect sizes appear to decrease over time along with publication of larger trials. Apart from considering other innovative stimulation techniques, such as transcranial Direct Current Stimulation (tDCS), and optimizing stimulation protocols, treatment of AVH using noninvasive brain stimulation will essentially rely on accurate identification of potential responders and non-responders for these treatment modalities. In this regard, future studies will need to consider distinct phenotypic presentations of AVH in patients with schizophrenia, together with the putative functional neurocircuitry underlying these phenotypes. PMID:26528145

  9. An online brain-computer interface based on shifting attention to concurrent streams of auditory stimuli

    NASA Astrophysics Data System (ADS)

    Hill, N. J.; Schölkopf, B.

    2012-04-01

    We report on the development and online testing of an electroencephalogram-based brain-computer interface (BCI) that aims to be usable by completely paralysed users—for whom visual or motor-system-based BCIs may not be suitable, and among whom reports of successful BCI use have so far been very rare. The current approach exploits covert shifts of attention to auditory stimuli in a dichotic-listening stimulus design. To compare the efficacy of event-related potentials (ERPs) and steady-state auditory evoked potentials (SSAEPs), the stimuli were designed such that they elicited both ERPs and SSAEPs simultaneously. Trial-by-trial feedback was provided online, based on subjects' modulation of N1 and P3 ERP components measured during single 5 s stimulation intervals. All 13 healthy subjects were able to use the BCI, with performance in a binary left/right choice task ranging from 75% to 96% correct across subjects (mean 85%). BCI classification was based on the contrast between stimuli in the attended stream and stimuli in the unattended stream, making use of every stimulus, rather than contrasting frequent standard and rare ‘oddball’ stimuli. SSAEPs were assessed offline: for all subjects, spectral components at the two exactly known modulation frequencies allowed discrimination of pre-stimulus from stimulus intervals, and of left-only stimuli from right-only stimuli when one side of the dichotic stimulus pair was muted. However, attention modulation of SSAEPs was not sufficient for single-trial BCI communication, even when the subject's attention was clearly focused well enough to allow classification of the same trials via ERPs. ERPs clearly provided a superior basis for BCI. The ERP results are a promising step towards the development of a simple-to-use, reliable yes/no communication system for users in the most severely paralysed states, as well as potential attention-monitoring and -training applications outside the context of assistive technology.

  10. Auditory spatial processing in Alzheimer's disease.

    PubMed

    Golden, Hannah L; Nicholas, Jennifer M; Yong, Keir X X; Downey, Laura E; Schott, Jonathan M; Mummery, Catherine J; Crutch, Sebastian J; Warren, Jason D

    2015-01-01

    The location and motion of sounds in space are important cues for encoding the auditory world. Spatial processing is a core component of auditory scene analysis, a cognitively demanding function that is vulnerable in Alzheimer's disease. Here we designed a novel neuropsychological battery based on a virtual space paradigm to assess auditory spatial processing in patient cohorts with clinically typical Alzheimer's disease (n = 20) and its major variant syndrome, posterior cortical atrophy (n = 12) in relation to healthy older controls (n = 26). We assessed three dimensions of auditory spatial function: externalized versus non-externalized sound discrimination, moving versus stationary sound discrimination and stationary auditory spatial position discrimination, together with non-spatial auditory and visual spatial control tasks. Neuroanatomical correlates of auditory spatial processing were assessed using voxel-based morphometry. Relative to healthy older controls, both patient groups exhibited impairments in detection of auditory motion, and stationary sound position discrimination. The posterior cortical atrophy group showed greater impairment for auditory motion processing and the processing of a non-spatial control complex auditory property (timbre) than the typical Alzheimer's disease group. Voxel-based morphometry in the patient cohort revealed grey matter correlates of auditory motion detection and spatial position discrimination in right inferior parietal cortex and precuneus, respectively. These findings delineate auditory spatial processing deficits in typical and posterior Alzheimer's disease phenotypes that are related to posterior cortical regions involved in both syndromic variants and modulated by the syndromic profile of brain degeneration. Auditory spatial deficits contribute to impaired spatial awareness in Alzheimer's disease and may constitute a novel perceptual model for probing brain network disintegration across the Alzheimer's disease

  11. A Case of Generalized Auditory Agnosia with Unilateral Subcortical Brain Lesion

    PubMed Central

    Suh, Hyee; Kim, Soo Yeon; Kim, Sook Hee; Chang, Jae Hyeok; Shin, Yong Beom; Ko, Hyun-Yoon

    2012-01-01

    The mechanisms and functional anatomy underlying the early stages of speech perception are still not well understood. Auditory agnosia is a deficit of auditory object processing defined as a disability to recognize spoken languages and/or nonverbal environmental sounds and music despite adequate hearing while spontaneous speech, reading and writing are preserved. Usually, either the bilateral or unilateral temporal lobe, especially the transverse gyral lesions, are responsible for auditory agnosia. Subcortical lesions without cortical damage rarely causes auditory agnosia. We present a 73-year-old right-handed male with generalized auditory agnosia caused by a unilateral subcortical lesion. He was not able to repeat or dictate but to perform fluent and comprehensible speech. He could understand and read written words and phrases. His auditory brainstem evoked potential and audiometry were intact. This case suggested that the subcortical lesion involving unilateral acoustic radiation could cause generalized auditory agnosia. PMID:23342322

  12. A case of generalized auditory agnosia with unilateral subcortical brain lesion.

    PubMed

    Suh, Hyee; Shin, Yong-Il; Kim, Soo Yeon; Kim, Sook Hee; Chang, Jae Hyeok; Shin, Yong Beom; Ko, Hyun-Yoon

    2012-12-01

    The mechanisms and functional anatomy underlying the early stages of speech perception are still not well understood. Auditory agnosia is a deficit of auditory object processing defined as a disability to recognize spoken languages and/or nonverbal environmental sounds and music despite adequate hearing while spontaneous speech, reading and writing are preserved. Usually, either the bilateral or unilateral temporal lobe, especially the transverse gyral lesions, are responsible for auditory agnosia. Subcortical lesions without cortical damage rarely causes auditory agnosia. We present a 73-year-old right-handed male with generalized auditory agnosia caused by a unilateral subcortical lesion. He was not able to repeat or dictate but to perform fluent and comprehensible speech. He could understand and read written words and phrases. His auditory brainstem evoked potential and audiometry were intact. This case suggested that the subcortical lesion involving unilateral acoustic radiation could cause generalized auditory agnosia.

  13. Expression of androgen receptor mRNA in the brain of Gekko gecko: implications for understanding the role of androgens in controlling auditory and vocal processes.

    PubMed

    Tang, Y Z; Piao, Y S; Zhuang, L Z; Wang, Z W

    2001-09-17

    The neuroanatomical distribution of androgen receptor (AR) mRNA-containing cells in the brain of a vocal lizard, Gekko gecko, was mapped using in situ hybridization. Particular attention was given to auditory and vocal nuclei. Within the auditory system, the cochlear nuclei, the central nucleus of the torus semicircularis, the nucleus medialis, and the medial region of the dorsal ventricular ridge contained moderate numbers of labeled neurons. Neurons labeled with the AR probe were located in many nuclei related to vocalization. Within the hindbrain, the mesencephalic nucleus of the trigeminal nerve, the vagal part of the nucleus ambiguus, and the dosal motor nucleus of the vagus nerve contained many neurons that exhibited strong expression of AR mRNA. Neurons located in the peripheral nucleus of the torus in the mesencephalon exhibited moderate levels of hybridization. Intense AR mRNA expression was also observed in neurons within two other areas that may be involved in vocalization, the medial preoptic area and the hypoglossal nucleus. The strongest mRNA signals identified in this study were found in cells of the pallium, hypothalamus, and inferior nucleus of the raphe. The expression patterns of AR mRNA in the auditory and vocal control nuclei of G. gecko suggest that neurons involved in acoustic communication in this species, and perhaps related species, are susceptible to regulation by androgens during the breeding season. The significance of these results for understanding the evolution of reptilian vocal communication is discussed.

  14. Simultaneous recording of fluorescence and electrical signals by photometric patch electrode in deep brain regions in vivo.

    PubMed

    Hirai, Yasuharu; Nishino, Eri; Ohmori, Harunori

    2015-06-01

    Despite its widespread use, high-resolution imaging with multiphoton microscopy to record neuronal signals in vivo is limited to the surface of brain tissue because of limited light penetration. Moreover, most imaging studies do not simultaneously record electrical neural activity, which is, however, crucial to understanding brain function. Accordingly, we developed a photometric patch electrode (PME) to overcome the depth limitation of optical measurements and also enable the simultaneous recording of neural electrical responses in deep brain regions. The PME recoding system uses a patch electrode to excite a fluorescent dye and to measure the fluorescence signal as a light guide, to record electrical signal, and to apply chemicals to the recorded cells locally. The optical signal was analyzed by either a spectrometer of high light sensitivity or a photomultiplier tube depending on the kinetics of the responses. We used the PME in Oregon Green BAPTA-1 AM-loaded avian auditory nuclei in vivo to monitor calcium signals and electrical responses. We demonstrated distinct response patterns in three different nuclei of the ascending auditory pathway. On acoustic stimulation, a robust calcium fluorescence response occurred in auditory cortex (field L) neurons that outlasted the electrical response. In the auditory midbrain (inferior colliculus), both responses were transient. In the brain-stem cochlear nucleus magnocellularis, calcium response seemed to be effectively suppressed by the activity of metabotropic glutamate receptors. In conclusion, the PME provides a powerful tool to study brain function in vivo at a tissue depth inaccessible to conventional imaging devices.

  15. Diagnostic System Based on the Human AUDITORY-BRAIN Model for Measuring Environmental NOISE—AN Application to Railway Noise

    NASA Astrophysics Data System (ADS)

    SAKAI, H.; HOTEHAMA, T.; ANDO, Y.; PRODI, N.; POMPOLI, R.

    2002-02-01

    Measurements of railway noise were conducted by use of a diagnostic system of regional environmental noise. The system is based on the model of the human auditory-brain system. The model consists of the interplay of autocorrelators and an interaural crosscorrelator acting on the pressure signals arriving at the ear entrances, and takes into account the specialization of left and right human cerebral hemispheres. Different kinds of railway noise were measured through binaural microphones of a dummy head. To characterize the railway noise, physical factors, extracted from the autocorrelation functions (ACF) and interaural crosscorrelation function (IACF) of binaural signals, were used. The factors extracted from ACF were (1) energy represented at the origin of the delay, Φ (0), (2) effective duration of the envelope of the normalized ACF, τe, (3) the delay time of the first peak, τ1, and (4) its amplitude,ø1 . The factors extracted from IACF were (5) IACC, (6) interaural delay time at which the IACC is defined, τIACC, and (7) width of the IACF at the τIACC,WIACC . The factor Φ (0) can be represented as a geometrical mean of energies at both ears as listening level, LL.

  16. Brain stem auditory nuclei and their connections in a carnivorous marsupial, the northern native cat (Dasyurus hallucatus).

    PubMed

    Aitkin, L M; Byers, M; Nelson, J E

    1986-01-01

    The cytoarchitecture and connections of the brain stem auditory nuclei in the marsupial native cat (Dasyurus hallucatus) were studied using Nissl material in conjunction with the retrograde transport of horseradish peroxidase injected into the inferior colliculus. Some features different from those of Eutheria include the disposition of the cochlear nuclear complex medial to the restiform body, a lack of large spherical cells in the anteroventral cochlear nucleus, a small medial superior olive, and a large superior paraolivary nucleus.

  17. Auditory Selective Attention Reveals Preparatory Activity in Different Cortical Regions for Selection Based on Source Location and Source Pitch

    PubMed Central

    Lee, Adrian K. C.; Rajaram, Siddharth; Xia, Jing; Bharadwaj, Hari; Larson, Eric; Hämäläinen, Matti S.; Shinn-Cunningham, Barbara G.

    2012-01-01

    In order to extract information in a rich environment, we focus on different features that allow us to direct attention to whatever source is of interest. The cortical network deployed during spatial attention, especially in vision, is well characterized. For example, visuospatial attention engages a frontoparietal network including the frontal eye fields (FEFs), which modulate activity in visual sensory areas to enhance the representation of an attended visual object. However, relatively little is known about the neural circuitry controlling attention directed to non-spatial features, or to auditory objects or features (either spatial or non-spatial). Here, using combined magnetoencephalography (MEG) and anatomical information obtained from MRI, we contrasted cortical activity when observers attended to different auditory features given the same acoustic mixture of two simultaneous spoken digits. Leveraging the fine temporal resolution of MEG, we establish that activity in left FEF is enhanced both prior to and throughout the auditory stimulus when listeners direct auditory attention to target location compared to when they focus on target pitch. In contrast, activity in the left posterior superior temporal sulcus (STS), a region previously associated with auditory pitch categorization, is greater when listeners direct attention to target pitch rather than target location. This differential enhancement is only significant after observers are instructed which cue to attend, but before the acoustic stimuli begin. We therefore argue that left FEF participates more strongly in directing auditory spatial attention, while the left STS aids auditory object selection based on the non-spatial acoustic feature of pitch. PMID:23335874

  18. Auditory-vocal mirroring in songbirds.

    PubMed

    Mooney, Richard

    2014-01-01

    Mirror neurons are theorized to serve as a neural substrate for spoken language in humans, but the existence and functions of auditory-vocal mirror neurons in the human brain remain largely matters of speculation. Songbirds resemble humans in their capacity for vocal learning and depend on their learned songs to facilitate courtship and individual recognition. Recent neurophysiological studies have detected putative auditory-vocal mirror neurons in a sensorimotor region of the songbird's brain that plays an important role in expressive and receptive aspects of vocal communication. This review discusses the auditory and motor-related properties of these cells, considers their potential role on song learning and communication in relation to classical studies of birdsong, and points to the circuit and developmental mechanisms that may give rise to auditory-vocal mirroring in the songbird's brain.

  19. Recovery function of the human brain stem auditory-evoked potential.

    PubMed

    Kevanishvili, Z; Lagidze, Z

    1979-01-01

    Amplitude reduction and peak latency prolongation were observed in the human brain stem auditory-evoked potential (BEP) with preceding (conditioning) stimulation. At a conditioning interval (CI) of 5 ms the alteration of BEP was greater than at a CI of 10 ms. At a CI of 10 ms the amplitudes of some BEP components (e.g. waves I and II) were more decreased than those of others (e.g. wave V), while the peak latency prolongation did not show any obvious component selectivity. At a CI of 5 ms, the extent of the amplitude decrement of individual BEP components differed less, while the increase in the peak latencies of the later components was greater than that of the earlier components. The alterations of the parameters of the test BEPs at both CIs are ascribed to the desynchronization of intrinsic neural events. The differential amplitude reduction at a CI of 10 ms is explained by the different durations of neural firings determining various effects of desynchronization upon the amplitudes of individual BEP components. The decrease in the extent of the component selectivity and the preferential increase in the peak latencies of the later BEP components observed at a CI of 5 ms are explained by the intensification of the mechanism of the relative refractory period.

  20. Hyperpolarization-independent maturation and refinement of GABA/glycinergic connections in the auditory brain stem

    PubMed Central

    Lee, Hanmi; Bach, Eva; Noh, Jihyun; Delpire, Eric

    2015-01-01

    During development GABA and glycine synapses are initially excitatory before they gradually become inhibitory. This transition is due to a developmental increase in the activity of neuronal potassium-chloride cotransporter 2 (KCC2), which shifts the chloride equilibrium potential (ECl) to values more negative than the resting membrane potential. While the role of early GABA and glycine depolarizations in neuronal development has become increasingly clear, the role of the transition to hyperpolarization in synapse maturation and circuit refinement has remained an open question. Here we investigated this question by examining the maturation and developmental refinement of GABA/glycinergic and glutamatergic synapses in the lateral superior olive (LSO), a binaural auditory brain stem nucleus, in KCC2-knockdown mice, in which GABA and glycine remain depolarizing. We found that many key events in the development of synaptic inputs to the LSO, such as changes in neurotransmitter phenotype, strengthening and elimination of GABA/glycinergic connection, and maturation of glutamatergic synapses, occur undisturbed in KCC2-knockdown mice compared with wild-type mice. These results indicate that maturation of inhibitory and excitatory synapses in the LSO is independent of the GABA and glycine depolarization-to-hyperpolarization transition. PMID:26655825

  1. Frontal brain activation in premature infants' response to auditory stimuli in neonatal intensive care unit.

    PubMed

    Saito, Yuri; Fukuhara, Rie; Aoyama, Shiori; Toshima, Tamotsu

    2009-07-01

    The present study was focusing on the very few contacts with the mother's voice that NICU infants have in the womb as well as after birth, we examined whether they can discriminate between their mothers' utterances and those of female nurses in terms of the emotional bonding that is facilitated by prosodic utterances. Twenty-six premature infants were included in this study, and their cerebral blood flows were measured by near-infrared spectroscopy. They were exposed to auditory stimuli in the form of utterances made by their mothers and female nurses. A two (stimulus: mother and nurse) x two (recording site: right frontal area and left frontal area) analysis of variance (ANOVA) for these relative oxy-Hb values was conducted. The ANOVA showed a significant interaction between stimulus and recording site. The mother's and the nurse's voices were activated in the same way in the left frontal area, but showed different reactions in the right frontal area. We presume that the nurse's voice might become associated with pain and stress for premature infants. Our results showed that the premature infants reacted differently to the different voice stimuli. Therefore, we presume that both mothers' and nurses' voices represent positive stimuli for premature infants because both activate the frontal brain. Accordingly, we cannot explain our results only in terms of the state-dependent marker for infantile individual differences, but must also address the stressful trigger of nurses' voices for NICU infants.

  2. Non-invasive Brain Stimulation and Auditory Verbal Hallucinations: New Techniques and Future Directions

    PubMed Central

    Moseley, Peter; Alderson-Day, Ben; Ellison, Amanda; Jardri, Renaud; Fernyhough, Charles

    2016-01-01

    Auditory verbal hallucinations (AVHs) are the experience of hearing a voice in the absence of any speaker. Results from recent attempts to treat AVHs with neurostimulation (rTMS or tDCS) to the left temporoparietal junction have not been conclusive, but suggest that it may be a promising treatment option for some individuals. Some evidence suggests that the therapeutic effect of neurostimulation on AVHs may result from modulation of cortical areas involved in the ability to monitor the source of self-generated information. Here, we provide a brief overview of cognitive models and neurostimulation paradigms associated with treatment of AVHs, and discuss techniques that could be explored in the future to improve the efficacy of treatment, including alternating current and random noise stimulation. Technical issues surrounding the use of neurostimulation as a treatment option are discussed (including methods to localize the targeted cortical area, and the state-dependent effects of brain stimulation), as are issues surrounding the acceptability of neurostimulation for adolescent populations and individuals who experience qualitatively different types of AVH. PMID:26834541

  3. Auditory neglect.

    PubMed Central

    De Renzi, E; Gentilini, M; Barbieri, C

    1989-01-01

    Auditory neglect was investigated in normal controls and in patients with a recent unilateral hemispheric lesion, by requiring them to detect the interruptions that occurred in one ear in a sound delivered through earphones either mono-aurally or binaurally. Control patients accurately detected interruptions. One left brain damaged (LBD) patient missed only once in the ipsilateral ear while seven of the 30 right brain damaged (RBD) patients missed more than one signal in the monoaural test and nine patients did the same in the binaural test. Omissions were always more marked in the left ear and in the binaural test with a significant ear by test interaction. The lesion of these patients was in the parietal lobe (five patients) and the thalamus (four patients). The relation of auditory neglect to auditory extinction was investigated and found to be equivocal, in that there were seven RBD patients who showed extinction, but not neglect and, more importantly, two patients who exhibited the opposite pattern, thus challenging the view that extinction is a minor form of neglect. Also visual and auditory neglect were not consistently correlated, the former being present in nine RBD patients without auditory neglect and the latter in two RBD patients without visual neglect. The finding that in some RBD patients with auditory neglect omissions also occurred, though with less frequency, in the right ear, points to a right hemisphere participation in the deployment of attention not only to the contralateral, but also to the ipsilateral space. PMID:2732732

  4. Brain stem auditory-evoked potentials in different strains of rodents.

    PubMed

    Chen, T J; Chen, S S

    1990-04-01

    This study was conducted to evaluate variations in brain stem auditory-evoked potentials (BAEPs) among different strains of rodents. BAEPs were recorded by routine procedures from rodents of different strains or species. These included 22 Long-Evans, 28 Wistar and 28 Sprague-Dawley rats, and six hamsters. Within the first 10 ms, there were five consistent and reproducible positive waves of BAEPs in each rodent, named I, II, III, IV and V in correspondence with the nomenclature of waves I-VII in human BAEPs. These BAEPs were also similar to those observed in other vertebrates and in human controls. However, there were variations in waveforms and peak latencies among rodents, even in the rats of the same strain that came from different laboratory centres. At optimal stimulation intensity, usually around 90 dB, the mean latencies of the waves varied as follows: I, 1.23-1.53 ms; II, 1.88-2.28 ms; III, 2.62-2.94 ms; IV, 3.49-3.97 ms; and V, 4.47-5.14 ms. They were significantly different between species, but not in different strains of rats if they came from the same animal centre. The conduction time in the central portion illustrated by interpeak latencies between I and III, III and V, and I and V was dependent on the species (P less than 0.05). When recorded in a soundproof incubator, the minimal hearing threshold showed a significant species difference. The animal BAEP model can be employed for evaluating the physiological function or the pathological conditions of the brain stem. The confirmation of BAEP variations among different species or strains will be helpful in deciding which kind of rodents will be appropriate to serve as animal models for the various purposes of BAEP studies.

  5. Top-down controlled and bottom-up triggered orienting of auditory attention to pitch activate overlapping brain networks.

    PubMed

    Alho, Kimmo; Salmi, Juha; Koistinen, Sonja; Salonen, Oili; Rinne, Teemu

    2015-11-11

    A number of previous studies have suggested segregated networks of brain areas for top-down controlled and bottom-up triggered orienting of visual attention. However, the corresponding networks involved in auditory attention remain less studied. Our participants attended selectively to a tone stream with either a lower pitch or higher pitch in order to respond to infrequent changes in duration of attended tones. The participants were also required to shift their attention from one stream to the other when guided by a visual arrow cue. In addition to these top-down controlled cued attention shifts, infrequent task-irrelevant louder tones occurred in both streams to trigger attention in a bottom-up manner. Both cued shifts and louder tones were associated with enhanced activity in the superior temporal gyrus and sulcus, temporo-parietal junction, superior parietal lobule, inferior and middle frontal gyri, frontal eye field, supplementary motor area, and anterior cingulate gyrus. Thus, the present findings suggest that in the auditory modality, unlike in vision, top-down controlled and bottom-up triggered attention activate largely the same cortical networks. Comparison of the present results with our previous results from a similar experiment on spatial auditory attention suggests that fronto-parietal networks of attention to location or pitch overlap substantially. However, the auditory areas in the anterior superior temporal cortex might have a more important role in attention to the pitch than location of sounds. This article is part of a Special Issue entitled SI: Prediction and Attention.

  6. An Evaluation of Training with an Auditory P300 Brain-Computer Interface for the Japanese Hiragana Syllabary

    PubMed Central

    Halder, Sebastian; Takano, Kouji; Ora, Hiroki; Onishi, Akinari; Utsumi, Kota; Kansaku, Kenji

    2016-01-01

    Gaze-independent brain-computer interfaces (BCIs) are a possible communication channel for persons with paralysis. We investigated if it is possible to use auditory stimuli to create a BCI for the Japanese Hiragana syllabary, which has 46 Hiragana characters. Additionally, we investigated if training has an effect on accuracy despite the high amount of different stimuli involved. Able-bodied participants (N = 6) were asked to select 25 syllables (out of fifty possible choices) using a two step procedure: First the consonant (ten choices) and then the vowel (five choices). This was repeated on 3 separate days. Additionally, a person with spinal cord injury (SCI) participated in the experiment. Four out of six healthy participants reached Hiragana syllable accuracies above 70% and the information transfer rate increased from 1.7 bits/min in the first session to 3.2 bits/min in the third session. The accuracy of the participant with SCI increased from 12% (0.2 bits/min) to 56% (2 bits/min) in session three. Reliable selections from a 10 × 5 matrix using auditory stimuli were possible and performance is increased by training. We were able to show that auditory P300 BCIs can be used for communication with up to fifty symbols. This enables the use of the technology of auditory P300 BCIs with a variety of applications. PMID:27746716

  7. Auditory properties in the parabelt regions of the superior temporal gyrus in the awake macaque monkey: an initial survey.

    PubMed

    Kajikawa, Yoshinao; Frey, Stephen; Ross, Deborah; Falchier, Arnaud; Hackett, Troy A; Schroeder, Charles E

    2015-03-11

    The superior temporal gyrus (STG) is on the inferior-lateral brain surface near the external ear. In macaques, 2/3 of the STG is occupied by an auditory cortical region, the "parabelt," which is part of a network of inferior temporal areas subserving communication and social cognition as well as object recognition and other functions. However, due to its location beneath the squamous temporal bone and temporalis muscle, the STG, like other inferior temporal regions, has been a challenging target for physiological studies in awake-behaving macaques. We designed a new procedure for implanting recording chambers to provide direct access to the STG, allowing us to evaluate neuronal properties and their topography across the full extent of the STG in awake-behaving macaques. Initial surveys of the STG have yielded several new findings. Unexpectedly, STG sites in monkeys that were listening passively responded to tones with magnitudes comparable to those of responses to 1/3 octave band-pass noise. Mapping results showed longer response latencies in more rostral sites and possible tonotopic patterns parallel to core and belt areas, suggesting the reversal of gradients between caudal and rostral parabelt areas. These results will help further exploration of parabelt areas.

  8. Auditory Properties in the Parabelt Regions of the Superior Temporal Gyrus in the Awake Macaque Monkey: An Initial Survey

    PubMed Central

    Frey, Stephen; Ross, Deborah; Falchier, Arnaud; Hackett, Troy A.; Schroeder, Charles E.

    2015-01-01

    The superior temporal gyrus (STG) is on the inferior–lateral brain surface near the external ear. In macaques, 2/3 of the STG is occupied by an auditory cortical region, the “parabelt,” which is part of a network of inferior temporal areas subserving communication and social cognition as well as object recognition and other functions. However, due to its location beneath the squamous temporal bone and temporalis muscle, the STG, like other inferior temporal regions, has been a challenging target for physiological studies in awake-behaving macaques. We designed a new procedure for implanting recording chambers to provide direct access to the STG, allowing us to evaluate neuronal properties and their topography across the full extent of the STG in awake-behaving macaques. Initial surveys of the STG have yielded several new findings. Unexpectedly, STG sites in monkeys that were listening passively responded to tones with magnitudes comparable to those of responses to 1/3 octave band-pass noise. Mapping results showed longer response latencies in more rostral sites and possible tonotopic patterns parallel to core and belt areas, suggesting the reversal of gradients between caudal and rostral parabelt areas. These results will help further exploration of parabelt areas. PMID:25762661

  9. Task-dependent modulation of regions in the left temporal cortex during auditory sentence comprehension.

    PubMed

    Zhang, Linjun; Yue, Qiuhai; Zhang, Yang; Shu, Hua; Li, Ping

    2015-01-01

    Numerous studies have revealed the essential role of the left lateral temporal cortex in auditory sentence comprehension along with evidence of the functional specialization of the anterior and posterior temporal sub-areas. However, it is unclear whether task demands (e.g., active vs. passive listening) modulate the functional specificity of these sub-areas. In the present functional magnetic resonance imaging (fMRI) study, we addressed this issue by applying both independent component analysis (ICA) and general linear model (GLM) methods. Consistent with previous studies, intelligible sentences elicited greater activity in the left lateral temporal cortex relative to unintelligible sentences. Moreover, responses to intelligibility in the sub-regions were differentially modulated by task demands. While the overall activation patterns of the anterior and posterior superior temporal sulcus and middle temporal gyrus (STS/MTG) were equivalent during both passive and active tasks, a middle portion of the STS/MTG was found to be selectively activated only during the active task under a refined analysis of sub-regional contributions. Our results not only confirm the critical role of the left lateral temporal cortex in auditory sentence comprehension but further demonstrate that task demands modulate functional specialization of the anterior-middle-posterior temporal sub-areas.

  10. Effects of Aging and Adult-Onset Hearing Loss on Cortical Auditory Regions

    PubMed Central

    Cardin, Velia

    2016-01-01

    Hearing loss is a common feature in human aging. It has been argued that dysfunctions in central processing are important contributing factors to hearing loss during older age. Aging also has well documented consequences for neural structure and function, but it is not clear how these effects interact with those that arise as a consequence of hearing loss. This paper reviews the effects of aging and adult-onset hearing loss in the structure and function of cortical auditory regions. The evidence reviewed suggests that aging and hearing loss result in atrophy of cortical auditory regions and stronger engagement of networks involved in the detection of salient events, adaptive control and re-allocation of attention. These cortical mechanisms are engaged during listening in effortful conditions in normal hearing individuals. Therefore, as a consequence of aging and hearing loss, all listening becomes effortful and cognitive load is constantly high, reducing the amount of available cognitive resources. This constant effortful listening and reduced cognitive spare capacity could be what accelerates cognitive decline in older adults with hearing loss. PMID:27242405

  11. Mother’s voice and heartbeat sounds elicit auditory plasticity in the human brain before full gestation

    PubMed Central

    Webb, Alexandra R.; Heller, Howard T.; Benson, Carol B.; Lahav, Amir

    2015-01-01

    Brain development is largely shaped by early sensory experience. However, it is currently unknown whether, how early, and to what extent the newborn’s brain is shaped by exposure to maternal sounds when the brain is most sensitive to early life programming. The present study examined this question in 40 infants born extremely prematurely (between 25- and 32-wk gestation) in the first month of life. Newborns were randomized to receive auditory enrichment in the form of audio recordings of maternal sounds (including their mother’s voice and heartbeat) or routine exposure to hospital environmental noise. The groups were otherwise medically and demographically comparable. Cranial ultrasonography measurements were obtained at 30 ± 3 d of life. Results show that newborns exposed to maternal sounds had a significantly larger auditory cortex (AC) bilaterally compared with control newborns receiving standard care. The magnitude of the right and left AC thickness was significantly correlated with gestational age but not with the duration of sound exposure. Measurements of head circumference and the widths of the frontal horn (FH) and the corpus callosum (CC) were not significantly different between the two groups. This study provides evidence for experience-dependent plasticity in the primary AC before the brain has reached full-term maturation. Our results demonstrate that despite the immaturity of the auditory pathways, the AC is more adaptive to maternal sounds than environmental noise. Further studies are needed to better understand the neural processes underlying this early brain plasticity and its functional implications for future hearing and language development. PMID:25713382

  12. Brain-computer interfaces using capacitive measurement of visual or auditory steady-state responses

    NASA Astrophysics Data System (ADS)

    Baek, Hyun Jae; Kim, Hyun Seok; Heo, Jeong; Lim, Yong Gyu; Park, Kwang Suk

    2013-04-01

    Objective. Brain-computer interface (BCI) technologies have been intensely studied to provide alternative communication tools entirely independent of neuromuscular activities. Current BCI technologies use electroencephalogram (EEG) acquisition methods that require unpleasant gel injections, impractical preparations and clean-up procedures. The next generation of BCI technologies requires practical, user-friendly, nonintrusive EEG platforms in order to facilitate the application of laboratory work in real-world settings. Approach. A capacitive electrode that does not require an electrolytic gel or direct electrode-scalp contact is a potential alternative to the conventional wet electrode in future BCI systems. We have proposed a new capacitive EEG electrode that contains a conductive polymer-sensing surface, which enhances electrode performance. This paper presents results from five subjects who exhibited visual or auditory steady-state responses according to BCI using these new capacitive electrodes. The steady-state visual evoked potential (SSVEP) spelling system and the auditory steady-state response (ASSR) binary decision system were employed. Main results. Offline tests demonstrated BCI performance high enough to be used in a BCI system (accuracy: 95.2%, ITR: 19.91 bpm for SSVEP BCI (6 s), accuracy: 82.6%, ITR: 1.48 bpm for ASSR BCI (14 s)) with the analysis time being slightly longer than that when wet electrodes were employed with the same BCI system (accuracy: 91.2%, ITR: 25.79 bpm for SSVEP BCI (4 s), accuracy: 81.3%, ITR: 1.57 bpm for ASSR BCI (12 s)). Subjects performed online BCI under the SSVEP paradigm in copy spelling mode and under the ASSR paradigm in selective attention mode with a mean information transfer rate (ITR) of 17.78 ± 2.08 and 0.7 ± 0.24 bpm, respectively. Significance. The results of these experiments demonstrate the feasibility of using our capacitive EEG electrode in BCI systems. This capacitive electrode may become a flexible and

  13. An online brain-computer interface based on shifting attention to concurrent streams of auditory stimuli

    PubMed Central

    Hill, N J; Schölkopf, B

    2012-01-01

    We report on the development and online testing of an EEG-based brain-computer interface (BCI) that aims to be usable by completely paralysed users—for whom visual or motor-system-based BCIs may not be suitable, and among whom reports of successful BCI use have so far been very rare. The current approach exploits covert shifts of attention to auditory stimuli in a dichotic-listening stimulus design. To compare the efficacy of event-related potentials (ERPs) and steady-state auditory evoked potentials (SSAEPs), the stimuli were designed such that they elicited both ERPs and SSAEPs simultaneously. Trial-by-trial feedback was provided online, based on subjects’ modulation of N1 and P3 ERP components measured during single 5-second stimulation intervals. All 13 healthy subjects were able to use the BCI, with performance in a binary left/right choice task ranging from 75% to 96% correct across subjects (mean 85%). BCI classification was based on the contrast between stimuli in the attended stream and stimuli in the unattended stream, making use of every stimulus, rather than contrasting frequent standard and rare “oddball” stimuli. SSAEPs were assessed offline: for all subjects, spectral components at the two exactly-known modulation frequencies allowed discrimination of pre-stimulus from stimulus intervals, and of left-only stimuli from right-only stimuli when one side of the dichotic stimulus pair was muted. However, attention-modulation of SSAEPs was not sufficient for single-trial BCI communication, even when the subject’s attention was clearly focused well enough to allow classification of the same trials via ERPs. ERPs clearly provided a superior basis for BCI. The ERP results are a promising step towards the development of a simple-to-use, reliable yes/no communication system for users in the most severely paralysed states, as well as potential attention-monitoring and -training applications outside the context of assistive technology. PMID:22333135

  14. Auditory perception in the aging brain: the role of inhibition and facilitation in early processing.

    PubMed

    Stothart, George; Kazanina, Nina

    2016-11-01

    Aging affects the interplay between peripheral and cortical auditory processing. Previous studies have demonstrated that older adults are less able to regulate afferent sensory information and are more sensitive to distracting information. Using auditory event-related potentials we investigated the role of cortical inhibition on auditory and audiovisual processing in younger and older adults. Across puretone, auditory and audiovisual speech paradigms older adults showed a consistent pattern of inhibitory deficits, manifested as increased P50 and/or N1 amplitudes and an absent or significantly reduced N2. Older adults were still able to use congruent visual articulatory information to aid auditory processing but appeared to require greater neural effort to resolve conflicts generated by incongruent visual information. In combination, the results provide support for the Inhibitory Deficit Hypothesis of aging. They extend previous findings into the audiovisual domain and highlight older adults' ability to benefit from congruent visual information during speech processing.

  15. Cortical connections of auditory cortex in marmoset monkeys: lateral belt and parabelt regions.

    PubMed

    de la Mothe, Lisa A; Blumell, Suzanne; Kajikawa, Yoshinao; Hackett, Troy A

    2012-05-01

    The current working model of primate auditory cortex is constructed from a number of studies of both new and old world monkeys. It includes three levels of processing. A primary level, the core region, is surrounded both medially and laterally by a secondary belt region. A third level of processing, the parabelt region, is located lateral to the belt. The marmoset monkey (Callithrix jacchus jacchus) has become an important model system to study auditory processing, but its anatomical organization has not been fully established. In previous studies, we focused on the architecture and connections of the core and medial belt areas (de la Mothe et al., 2006a, J Comp Neurol 496:27-71; de la Mothe et al., 2006b, J Comp Neurol 496:72-96). In this study, the corticocortical connections of the lateral belt and parabelt were examined in the marmoset. Tracers were injected into both rostral and caudal portions of the lateral belt and parabelt. Both regions revealed topographic connections along the rostrocaudal axis, where caudal areas of injection had stronger connections with caudal areas, and rostral areas of injection with rostral areas. The lateral belt had strong connections with the core, belt, and parabelt, whereas the parabelt had strong connections with the belt but not the core. Label in the core from injections in the parabelt was significantly reduced or absent, consistent with the idea that the parabelt relies mainly on the belt for its cortical input. In addition, the present and previous studies indicate hierarchical principles of anatomical organization in the marmoset that are consistent with those observed in other primates.

  16. Repetition suppression and repetition enhancement underlie auditory memory-trace formation in the human brain: an MEG study.

    PubMed

    Recasens, Marc; Leung, Sumie; Grimm, Sabine; Nowak, Rafal; Escera, Carles

    2015-03-01

    The formation of echoic memory traces has traditionally been inferred from the enhanced responses to its deviations. The mismatch negativity (MMN), an auditory event-related potential (ERP) elicited between 100 and 250ms after sound deviation is an indirect index of regularity encoding that reflects a memory-based comparison process. Recently, repetition positivity (RP) has been described as a candidate ERP correlate of direct memory trace formation. RP consists of repetition suppression and enhancement effects occurring in different auditory components between 50 and 250ms after sound onset. However, the neuronal generators engaged in the encoding of repeated stimulus features have received little interest. This study intends to investigate the neuronal sources underlying the formation and strengthening of new memory traces by employing a roving-standard paradigm, where trains of different frequencies and different lengths are presented randomly. Source generators of repetition enhanced (RE) and suppressed (RS) activity were modeled using magnetoencephalography (MEG) in healthy subjects. Our results show that, in line with RP findings, N1m (~95-150ms) activity is suppressed with stimulus repetition. In addition, we observed the emergence of a sustained field (~230-270ms) that showed RE. Source analysis revealed neuronal generators of RS and RE located in both auditory and non-auditory areas, like the medial parietal cortex and frontal areas. The different timing and location of neural generators involved in RS and RE points to the existence of functionally separated mechanisms devoted to acoustic memory-trace formation in different auditory processing stages of the human brain.

  17. Formulae Describing Subjective Attributes for Sound Fields Based on a Model of the Auditory-Brain System

    NASA Astrophysics Data System (ADS)

    ANDO, Y.; SAKAI, H.; SATO, S.

    2000-04-01

    This article reviews the background of a workable model of the auditory-brain system, and formulae of calculating fundamental subjective attributes derived from the model. The model consists of the autocorrelation mechanisms, the interaural cross-correlation mechanism between the two auditory pathways, and the specialization of the human cerebral hemispheres for temporal and spatial factors of the sound field. Typical fundamental attributes, the apparent source width, the missing fundamental, and the speech intelligibility of sound fields, for example, in opera houses, are described in terms of the orthogonal spatial factors extracted from the interaural cross-correlation function, and the orthogonal temporal factors extracted from the autocorrelation function, respectively. Also, other important subjective attributes of the sound fields, the subjective diffuseness, and subjective preferences of both listeners and performers for single reflection are demonstrated here.

  18. Regional brain hypometabolism is unrelated to regional amyloid plaque burden

    PubMed Central

    Altmann, Andre; Ng, Bernard; Landau, Susan M.; Jagust, William J.

    2015-01-01

    See Sorg and Grothe (doi:10.1093/brain/awv302) for a scientific commentary on this article. In its original form, the amyloid cascade hypothesis of Alzheimer’s disease holds that fibrillar deposits of amyloid are an early, driving force in pathological events leading ultimately to neuronal death. Early clinicopathological investigations highlighted a number of inconsistencies leading to an updated hypothesis in which amyloid plaques give way to amyloid oligomers as the driving force in pathogenesis. Rather than focusing on the inconsistencies, amyloid imaging studies have tended to highlight the overlap between regions that show early amyloid plaque signal on positron emission tomography and that also happen to be affected early in Alzheimer’s disease. Recent imaging studies investigating the regional dependency between metabolism and amyloid plaque deposition have arrived at conflicting results, with some showing regional associations and other not. We extracted multimodal neuroimaging data from the Alzheimer’s disease neuroimaging database for 227 healthy controls and 434 subjects with mild cognitive impairment. We analysed regional patterns of amyloid deposition, regional glucose metabolism and regional atrophy using florbetapir (18F) positron emission tomography, 18F-fluordeoxyglucose positron emission tomography and T1-weighted magnetic resonance imaging, respectively. Specifically, we derived grey matter density and standardized uptake value ratios for both positron emission tomography tracers in 404 functionally defined regions of interest. We examined the relation between regional glucose metabolism and amyloid plaques using linear models. For each region of interest, correcting for regional grey matter density, age, education and disease status, we tested the association of regional glucose metabolism with (i) cortex-wide florbetapir uptake; (ii) regional (i.e. in the same region of interest) florbetapir uptake; and (iii) regional florbetapir uptake

  19. On the temporal window of auditory-brain system in connection with subjective responses

    NASA Astrophysics Data System (ADS)

    Mouri, Kiminori

    2003-08-01

    The human auditory-brain system processes information extracted from autocorrelation function (ACF) of the source signal and interaural cross correlation function (IACF) of binaural sound signals which are associated with the left and right cerebral hemispheres, respectively. The purpose of this dissertation is to determine the desirable temporal window (2T: integration interval) for ACF and IACF mechanisms. For the ACF mechanism, the visual change of Φ(0), i.e., the power of ACF, was associated with the change of loudness, and it is shown that the recommended temporal window is given as about 30(τe)min [s]. The value of (τe)min is the minimum value of effective duration of the running ACF of the source signal. It is worth noticing from the experiment of EEG that the most preferred delay time of the first reflection sound is determined by the piece indicating (τe)min in the source signal. For the IACF mechanism, the temporal window is determined as below: The measured range of τIACC corresponding to subjective angle for the moving image sound depends on the temporal window. Here, the moving image was simulated by the use of two loudspeakers located at +/-20° in the horizontal plane, reproducing amplitude modulated band-limited noise alternatively. It is found that the temporal window has a wide range of values from 0.03 to 1 [s] for the modulation frequency below 0.2 Hz. Thesis advisor: Yoichi Ando Copies of this thesis written in English can be obtained from Kiminori Mouri, 5-3-3-1110 Harayama-dai, Sakai city, Osaka 590-0132, Japan. E-mail address: km529756@aol.com

  20. Immuno-modulator inter-alpha inhibitor proteins ameliorate complex auditory processing deficits in rats with neonatal hypoxic-ischemic brain injury.

    PubMed

    Threlkeld, Steven W; Lim, Yow-Pin; La Rue, Molly; Gaudet, Cynthia; Stonestreet, Barbara S

    2017-03-10

    Hypoxic-ischemic (HI) brain injury is recognized as a significant problem in the perinatal period, contributing to life-long language-learning and other cognitive impairments. Central auditory processing deficits are common in infants with hypoxic-ischemic encephalopathy and have been shown to predict language learning deficits in other at risk infant populations. Inter-alpha inhibitor proteins (IAIPs) are a family of structurally related plasma proteins that modulate the systemic inflammatory response to infection and have been shown to attenuate cell death and improve learning outcomes after neonatal brain injury in rats. Here, we show that systemic administration of IAIPs during the early HI injury cascade ameliorates complex auditory discrimination deficits as compared to untreated HI injured subjects, despite reductions in brain weight. These findings have significant clinical implications for improving central auditory processing deficits linked to language learning in neonates with HI related brain injury.

  1. Delineation of a frequency-organized region isolated from the mouse primary auditory cortex.

    PubMed

    Tsukano, Hiroaki; Horie, Masao; Bo, Takeshi; Uchimura, Arikuni; Hishida, Ryuichi; Kudoh, Masaharu; Takahashi, Kuniyuki; Takebayashi, Hirohide; Shibuki, Katsuei

    2015-04-01

    The primary auditory cortex (AI) is the representative recipient of information from the ears in the mammalian cortex. However, the delineation of the AI is still controversial in a mouse. Recently, it was reported, using optical imaging, that two distinct areas of the AI, located ventrally and dorsally, are activated by high-frequency tones, whereas only one area is activated by low-frequency tones. Here, we show that the dorsal high-frequency area is an independent region that is separated from the rest of the AI. We could visualize the two distinct high-frequency areas using flavoprotein fluorescence imaging, as reported previously. SMI-32 immunolabeling revealed that the dorsal region had a different cytoarchitectural pattern from the rest of the AI. Specifically, the ratio of SMI-32-positive pyramidal neurons to nonpyramidal neurons was larger in the dorsal high-frequency area than the rest of the AI. We named this new region the dorsomedial field (DM). Retrograde tracing showed that neurons projecting to the DM were localized in the rostral part of the ventral division of the medial geniculate body with a distinct frequency organization, where few neurons projected to the AI. Furthermore, the responses of the DM to ultrasonic courtship songs presented by males were significantly greater in females than in males; in contrast, there was no sex difference in response to artificial pure tones. Our findings offer a basic outline on the processing of ultrasonic vocal information on the basis of the precisely subdivided, multiple frequency-organized auditory cortex map in mice.

  2. Delineation of a frequency-organized region isolated from the mouse primary auditory cortex

    PubMed Central

    Horie, Masao; Bo, Takeshi; Uchimura, Arikuni; Hishida, Ryuichi; Kudoh, Masaharu; Takahashi, Kuniyuki; Takebayashi, Hirohide; Shibuki, Katsuei

    2015-01-01

    The primary auditory cortex (AI) is the representative recipient of information from the ears in the mammalian cortex. However, the delineation of the AI is still controversial in a mouse. Recently, it was reported, using optical imaging, that two distinct areas of the AI, located ventrally and dorsally, are activated by high-frequency tones, whereas only one area is activated by low-frequency tones. Here, we show that the dorsal high-frequency area is an independent region that is separated from the rest of the AI. We could visualize the two distinct high-frequency areas using flavoprotein fluorescence imaging, as reported previously. SMI-32 immunolabeling revealed that the dorsal region had a different cytoarchitectural pattern from the rest of the AI. Specifically, the ratio of SMI-32-positive pyramidal neurons to nonpyramidal neurons was larger in the dorsal high-frequency area than the rest of the AI. We named this new region the dorsomedial field (DM). Retrograde tracing showed that neurons projecting to the DM were localized in the rostral part of the ventral division of the medial geniculate body with a distinct frequency organization, where few neurons projected to the AI. Furthermore, the responses of the DM to ultrasonic courtship songs presented by males were significantly greater in females than in males; in contrast, there was no sex difference in response to artificial pure tones. Our findings offer a basic outline on the processing of ultrasonic vocal information on the basis of the precisely subdivided, multiple frequency-organized auditory cortex map in mice. PMID:25695649

  3. Thermal Imaging of the Periorbital Regions during the Presentation of an Auditory Startle Stimulus

    PubMed Central

    Gane, Luke; Power, Sarah; Kushki, Azadeh; Chau, Tom

    2011-01-01

    Infrared thermal imaging of the inner canthi of the periorbital regions of the face can potentially serve as an input signal modality for an alternative access system for individuals with conditions that preclude speech or voluntary movement, such as total locked-in syndrome. However, it is unknown if the temperature of these regions is affected by the human startle response, as changes in the facial temperature of the periorbital regions manifested during the startle response could generate false positives in a thermography-based access system. This study presents an examination of the temperature characteristics of the periorbital regions of 11 able-bodied adult participants before and after a 102 dB auditory startle stimulus. The results indicate that the startle response has no substantial effect on the mean temperature of the periorbital regions. This indicates that thermography-based access solutions would be insensitive to startle reactions in their user, an important advantage over other modalities being considered in the context of access solutions for individuals with a severe motor disability. PMID:22073302

  4. Asymmetries of the human social brain in the visual, auditory and chemical modalities

    PubMed Central

    Brancucci, Alfredo; Lucci, Giuliana; Mazzatenta, Andrea; Tommasi, Luca

    2008-01-01

    Structural and functional asymmetries are present in many regions of the human brain responsible for motor control, sensory and cognitive functions and communication. Here, we focus on hemispheric asymmetries underlying the domain of social perception, broadly conceived as the analysis of information about other individuals based on acoustic, visual and chemical signals. By means of these cues the brain establishes the border between ‘self’ and ‘other’, and interprets the surrounding social world in terms of the physical and behavioural characteristics of conspecifics essential for impression formation and for creating bonds and relationships. We show that, considered from the standpoint of single- and multi-modal sensory analysis, the neural substrates of the perception of voices, faces, gestures, smells and pheromones, as evidenced by modern neuroimaging techniques, are characterized by a general pattern of right-hemispheric functional asymmetry that might benefit from other aspects of hemispheric lateralization rather than constituting a true specialization for social information. PMID:19064350

  5. Asymmetries of the human social brain in the visual, auditory and chemical modalities.

    PubMed

    Brancucci, Alfredo; Lucci, Giuliana; Mazzatenta, Andrea; Tommasi, Luca

    2009-04-12

    Structural and functional asymmetries are present in many regions of the human brain responsible for motor control, sensory and cognitive functions and communication. Here, we focus on hemispheric asymmetries underlying the domain of social perception, broadly conceived as the analysis of information about other individuals based on acoustic, visual and chemical signals. By means of these cues the brain establishes the border between 'self' and 'other', and interprets the surrounding social world in terms of the physical and behavioural characteristics of conspecifics essential for impression formation and for creating bonds and relationships. We show that, considered from the standpoint of single- and multi-modal sensory analysis, the neural substrates of the perception of voices, faces, gestures, smells and pheromones, as evidenced by modern neuroimaging techniques, are characterized by a general pattern of right-hemispheric functional asymmetry that might benefit from other aspects of hemispheric lateralization rather than constituting a true specialization for social information.

  6. A unique cellular scaling rule in the avian auditory system.

    PubMed

    Corfield, Jeremy R; Long, Brendan; Krilow, Justin M; Wylie, Douglas R; Iwaniuk, Andrew N

    2016-06-01

    Although it is clear that neural structures scale with body size, the mechanisms of this relationship are not well understood. Several recent studies have shown that the relationship between neuron numbers and brain (or brain region) size are not only different across mammalian orders, but also across auditory and visual regions within the same brains. Among birds, similar cellular scaling rules have not been examined in any detail. Here, we examine the scaling of auditory structures in birds and show that the scaling rules that have been established in the mammalian auditory pathway do not necessarily apply to birds. In galliforms, neuronal densities decrease with increasing brain size, suggesting that auditory brainstem structures increase in size faster than neurons are added; smaller brains have relatively more neurons than larger brains. The cellular scaling rules that apply to auditory brainstem structures in galliforms are, therefore, different to that found in primate auditory pathway. It is likely that the factors driving this difference are associated with the anatomical specializations required for sound perception in birds, although there is a decoupling of neuron numbers in brain structures and hair cell numbers in the basilar papilla. This study provides significant insight into the allometric scaling of neural structures in birds and improves our understanding of the rules that govern neural scaling across vertebrates.

  7. Music and natural sounds in an auditory steady-state response based brain-computer interface to increase user acceptance.

    PubMed

    Heo, Jeong; Baek, Hyun Jae; Hong, Seunghyeok; Chang, Min Hye; Lee, Jeong Su; Park, Kwang Suk

    2017-03-18

    Patients with total locked-in syndrome are conscious; however, they cannot express themselves because most of their voluntary muscles are paralyzed, and many of these patients have lost their eyesight. To improve the quality of life of these patients, there is an increasing need for communication-supporting technologies that leverage the remaining senses of the patient along with physiological signals. The auditory steady-state response (ASSR) is an electro-physiologic response to auditory stimulation that is amplitude-modulated by a specific frequency. By leveraging the phenomenon whereby ASSR is modulated by mind concentration, a brain-computer interface paradigm was proposed to classify the selective attention of the patient. In this paper, we propose an auditory stimulation method to minimize auditory stress by replacing the monotone carrier with familiar music and natural sounds for an ergonomic system. Piano and violin instrumentals were employed in the music sessions; the sounds of water streaming and cicadas singing were used in the natural sound sessions. Six healthy subjects participated in the experiment. Electroencephalograms were recorded using four electrodes (Cz, Oz, T7 and T8). Seven sessions were performed using different stimuli. The spectral power at 38 and 42Hz and their ratio for each electrode were extracted as features. Linear discriminant analysis was utilized to classify the selections for each subject. In offline analysis, the average classification accuracies with a modulation index of 1.0 were 89.67% and 87.67% using music and natural sounds, respectively. In online experiments, the average classification accuracies were 88.3% and 80.0% using music and natural sounds, respectively. Using the proposed method, we obtained significantly higher user-acceptance scores, while maintaining a high average classification accuracy.

  8. Brain bases for auditory stimulus-driven figure-ground segregation.

    PubMed

    Teki, Sundeep; Chait, Maria; Kumar, Sukhbinder; von Kriegstein, Katharina; Griffiths, Timothy D

    2011-01-05

    Auditory figure-ground segregation, listeners' ability to selectively hear out a sound of interest from a background of competing sounds, is a fundamental aspect of scene analysis. In contrast to the disordered acoustic environment we experience during everyday listening, most studies of auditory segregation have used relatively simple, temporally regular signals. We developed a new figure-ground stimulus that incorporates stochastic variation of the figure and background that captures the rich spectrotemporal complexity of natural acoustic scenes. Figure and background signals overlap in spectrotemporal space, but vary in the statistics of fluctuation, such that the only way to extract the figure is by integrating the patterns over time and frequency. Our behavioral results demonstrate that human listeners are remarkably sensitive to the appearance of such figures. In a functional magnetic resonance imaging experiment, aimed at investigating preattentive, stimulus-driven, auditory segregation mechanisms, naive subjects listened to these stimuli while performing an irrelevant task. Results demonstrate significant activations in the intraparietal sulcus (IPS) and the superior temporal sulcus related to bottom-up, stimulus-driven figure-ground decomposition. We did not observe any significant activation in the primary auditory cortex. Our results support a role for automatic, bottom-up mechanisms in the IPS in mediating stimulus-driven, auditory figure-ground segregation, which is consistent with accumulating evidence implicating the IPS in structuring sensory input and perceptual organization.

  9. Evaluation of region selective bilirubin-induced brain damage as a basis for a pharmacological treatment

    PubMed Central

    Dal Ben, Matteo; Bottin, Cristina; Zanconati, Fabrizio; Tiribelli, Claudio; Gazzin, Silvia

    2017-01-01

    The neurologic manifestations of neonatal hyperbilirubinemia in the central nervous system (CNS) exhibit high variations in the severity and appearance of motor, auditory and cognitive symptoms, which is suggestive of a still unexplained selective topography of bilirubin-induced damage. By applying the organotypic brain culture (OBC: preserving in vitro the cellular complexity, connection and architecture of the in vivo brain) technique to study hyperbilirubinemia, we mapped the regional target of bilirubin-induced damage, demonstrated a multifactorial toxic action of bilirubin, and used this information to evaluate the efficacy of drugs applicable to newborns to protect the brain. OBCs from 8-day-old rat pups showed a 2–13 fold higher sensitivity to bilirubin damage than 2-day-old preparations. The hippocampus, inferior colliculus and cerebral cortex were the only brain regions affected, presenting a mixed inflammatory-oxidative mechanism. Glutamate excitotoxicity was appreciable in only the hippocampus and inferior colliculus. Single drug treatment (indomethacin, curcumin, MgCl2) significantly improved cell viability in all regions, while the combined (cocktail) administration of the three drugs almost completely prevented damage in the most affected area (hippocampus). Our data may supports an innovative (complementary to phototherapy) approach for directly protecting the newborn brain from bilirubin neurotoxicity. PMID:28102362

  10. Zenk expression in auditory regions changes with breeding condition in male Black-capped chickadees (Poecile atricapillus).

    PubMed

    Phillmore, Leslie S; Veysey, Andrew S; Roach, Sean P

    2011-12-01

    Black-capped chickadees (Poecile atricapillus) produce different vocalizations at different times of year: the fee-bee song is produced by males primarily in spring, whereas the chick-a-dee call is produced year-round but most frequently in the fall and winter. We wanted to determine if neural response to playback in auditory regions of the songbird brain varied with season in parallel to production. We captured adult male black-capped chickadees from the wild in either breeding condition or non-breeding condition and within 24-48 h of bringing them into the laboratory setting, played them recordings of either conspecific vocalizations (fee-bee songs or chick-a-dee calls), heterospecific vocalizations (Song Sparrow, Melospiza melodia, song), or silence. We then measured ZENK protein immunoreactivity (Zenk-ir) in caudomedial nidopallium (NCM) and caudomedial mesopallium (CMM), two regions important for perception of conspecific vocalizations. We found that, overall, non-breeding birds had greater Zenk-ir than breeding birds. In addition, we found that birds in non-breeding condition had significantly greater Zenk-ir to heterospecific song than birds in breeding condition, but this difference was not seen in birds that heard conspecific songs or calls. Finally, in NCMd chickadees had greater response to playback of conspecific vocalizations (when combining song and call groups) than playback of heterospecific vocalizations but only while in breeding condition. Our results qualify the claim that Zenk-ir is biased toward conspecific vocalizations, and indicate that specificity of neural response varies with season. Variation could be a result of increased production and perceptual demand in spring, or hormonal changes in breeding birds, possibly because chickadees display vocal plasticity in chick-a-dee calls in the fall, requiring a degree of neural plasticity across seasons.

  11. Specific Regional and Age-Related Small Noncoding RNA Expression Patterns Within Superior Temporal Gyrus of Typical Human Brains Are Less Distinct in Autism Brains

    PubMed Central

    Stamova, Boryana; Ander, Bradley P.; Barger, Nicole; Sharp, Frank R.

    2015-01-01

    Small noncoding RNAs play a critical role in regulating messenger RNA throughout brain development and when altered could have profound effects leading to disorders such as autism spectrum disorders (ASD). We assessed small noncoding RNAs, including microRNA and small nucleolar RNA, in superior temporal sulcus association cortex and primary auditory cortex in typical and ASD brains from early childhood to adulthood. Typical small noncoding RNA expression profiles were less distinct in ASD, both between regions and changes with age. Typical micro-RNA coexpression associations were absent in ASD brains. miR-132, miR-103, and miR-320 micro-RNAs were dysregulated in ASD and have previously been associated with autism spectrum disorders. These diminished region- and age-related micro-RNA expression profiles are in line with previously reported findings of attenuated messenger RNA and long noncoding RNA in ASD brain. This study demonstrates alterations in superior temporal sulcus in ASD, a region implicated in social impairment, and is the first to demonstrate molecular alterations in the primary auditory cortex. PMID:26350727

  12. Towards User-Friendly Spelling with an Auditory Brain-Computer Interface: The CharStreamer Paradigm

    PubMed Central

    Höhne, Johannes; Tangermann, Michael

    2014-01-01

    Realizing the decoding of brain signals into control commands, brain-computer interfaces (BCI) aim to establish an alternative communication pathway for locked-in patients. In contrast to most visual BCI approaches which use event-related potentials (ERP) of the electroencephalogram, auditory BCI systems are challenged with ERP responses, which are less class-discriminant between attended and unattended stimuli. Furthermore, these auditory approaches have more complex interfaces which imposes a substantial workload on their users. Aiming for a maximally user-friendly spelling interface, this study introduces a novel auditory paradigm: “CharStreamer”. The speller can be used with an instruction as simple as “please attend to what you want to spell”. The stimuli of CharStreamer comprise 30 spoken sounds of letters and actions. As each of them is represented by the sound of itself and not by an artificial substitute, it can be selected in a one-step procedure. The mental mapping effort (sound stimuli to actions) is thus minimized. Usability is further accounted for by an alphabetical stimulus presentation: contrary to random presentation orders, the user can foresee the presentation time of the target letter sound. Healthy, normal hearing users (n = 10) of the CharStreamer paradigm displayed ERP responses that systematically differed between target and non-target sounds. Class-discriminant features, however, varied individually from the typical N1-P2 complex and P3 ERP components found in control conditions with random sequences. To fully exploit the sequential presentation structure of CharStreamer, novel data analysis approaches and classification methods were introduced. The results of online spelling tests showed that a competitive spelling speed can be achieved with CharStreamer. With respect to user rating, it clearly outperforms a control setup with random presentation sequences. PMID:24886978

  13. Reduced auditory M100 asymmetry in schizophrenia and dyslexia: applying a developmental instability approach to assess atypical brain asymmetry.

    PubMed

    Edgar, J Christopher; Yeo, Ron A; Gangestad, Steven W; Blake, Melissa B; Davis, John T; Lewine, Jeffrey D; Cañive, José M

    2006-01-01

    Although atypical structural and functional superior temporal gyrus (STG) asymmetries are frequently observed in patients with schizophrenia and individuals with dyslexia, their significance is unclear. One possibility is that atypical asymmetries reflect a general risk factor that can be seen across multiple neurodevelopmental conditions--a risk factor whose origins are best understood in the context of Developmental Instability (DI) theory. DI measures (minor physical anomalies (MPAs) and fluctuating asymmetries (FAs)) reflect perturbation of the genetic plan. The present study sought to assess whether the presence of peripheral indices of DI predicts anomalous functional auditory cortex asymmetry in schizophrenia patients and dyslexia subjects. The location of the auditory M100 response was used as a measure of functional STG asymmetry, as it has been reported that in controls (but not in subjects with schizophrenia or dyslexia) the M100 source location in the right hemisphere is shifted anterior to that seen for the left hemisphere. Whole-brain auditory evoked magnetic field data were successfully recorded from 14 male schizophrenia patients, 21 male subjects with dyslexia, and 16 normal male control subjects. MPA and FA measures were also obtained. Replicating previous studies, both schizophrenia and dyslexia groups showed less M100 asymmetry than did controls. Schizophrenia and dyslexia subjects also had higher MPA scores than normal controls. Although neither total MPA nor FA measures predicted M100 asymmetry, analyses on individual MPA items revealed a relationship between high palate and M100 asymmetry. Findings suggest that M100 positional asymmetry is not a diagnostically specific feature in several neurodevelopmental conditions. Continued research examining DI and brain asymmetry relationships is warranted.

  14. Evidence for distinct human auditory cortex regions for sound location versus identity processing.

    PubMed

    Ahveninen, Jyrki; Huang, Samantha; Nummenmaa, Aapo; Belliveau, John W; Hung, An-Yi; Jääskeläinen, Iiro P; Rauschecker, Josef P; Rossi, Stephanie; Tiitinen, Hannu; Raij, Tommi

    2013-01-01

    Neurophysiological animal models suggest that anterior auditory cortex (AC) areas process sound identity information, whereas posterior ACs specialize in sound location processing. In humans, inconsistent neuroimaging results and insufficient causal evidence have challenged the existence of such parallel AC organization. Here we transiently inhibit bilateral anterior or posterior AC areas using MRI-guided paired-pulse transcranial magnetic stimulation (TMS) while subjects listen to Reference/Probe sound pairs and perform either sound location or identity discrimination tasks. The targeting of TMS pulses, delivered 55-145 ms after Probes, is confirmed with individual-level cortical electric-field estimates. Our data show that TMS to posterior AC regions delays reaction times (RT) significantly more during sound location than identity discrimination, whereas TMS to anterior AC regions delays RTs significantly more during sound identity than location discrimination. This double dissociation provides direct causal support for parallel processing of sound identity features in anterior AC and sound location in posterior AC.

  15. Song and speech: brain regions involved with perception and covert production.

    PubMed

    Callan, Daniel E; Tsytsarev, Vassiliy; Hanakawa, Takashi; Callan, Akiko M; Katsuhara, Maya; Fukuyama, Hidenao; Turner, Robert

    2006-07-01

    This 3-T fMRI study investigates brain regions similarly and differentially involved with listening and covert production of singing relative to speech. Given the greater use of auditory-motor self-monitoring and imagery with respect to consonance in singing, brain regions involved with these processes are predicted to be differentially active for singing more than for speech. The stimuli consisted of six Japanese songs. A block design was employed in which the tasks for the subject were to listen passively to singing of the song lyrics, passively listen to speaking of the song lyrics, covertly sing the song lyrics visually presented, covertly speak the song lyrics visually presented, and to rest. The conjunction of passive listening and covert production tasks used in this study allow for general neural processes underlying both perception and production to be discerned that are not exclusively a result of stimulus induced auditory processing nor to low level articulatory motor control. Brain regions involved with both perception and production for singing as well as speech were found to include the left planum temporale/superior temporal parietal region, as well as left and right premotor cortex, lateral aspect of the VI lobule of posterior cerebellum, anterior superior temporal gyrus, and planum polare. Greater activity for the singing over the speech condition for both the listening and covert production tasks was found in the right planum temporale. Greater activity in brain regions involved with consonance, orbitofrontal cortex (listening task), subcallosal cingulate (covert production task) were also present for singing over speech. The results are consistent with the PT mediating representational transformation across auditory and motor domains in response to consonance for singing over that of speech. Hemispheric laterality was assessed by paired t tests between active voxels in the contrast of interest relative to the left-right flipped contrast of

  16. Characteristics of Auditory Agnosia in a Child with Severe Traumatic Brain Injury: A Case Report

    ERIC Educational Resources Information Center

    Hattiangadi, Nina; Pillion, Joseph P.; Slomine, Beth; Christensen, James; Trovato, Melissa K.; Speedie, Lynn J.

    2005-01-01

    We present a case that is unusual in many respects from other documented incidences of auditory agnosia, including the mechanism of injury, age of the individual, and location of neurological insult. The clinical presentation is one of disturbance in the perception of spoken language, music, pitch, emotional prosody, and temporal auditory…

  17. Testing domain-general theories of perceptual awareness with auditory brain responses.

    PubMed

    Snyder, Joel S; Yerkes, Breanne D; Pitts, Michael A

    2015-06-01

    Past research has identified several candidate neural correlates of consciousness (NCCs) during visual perception. Recent research on auditory perception shows promise for establishing the generality of various NCCs across sensory modalities, as well as for revealing differences in how conscious processing unfolds in different sensory systems.

  18. Auditory spatial processing in Alzheimer’s disease

    PubMed Central

    Golden, Hannah L.; Nicholas, Jennifer M.; Yong, Keir X. X.; Downey, Laura E.; Schott, Jonathan M.; Mummery, Catherine J.; Crutch, Sebastian J.

    2015-01-01

    The location and motion of sounds in space are important cues for encoding the auditory world. Spatial processing is a core component of auditory scene analysis, a cognitively demanding function that is vulnerable in Alzheimer’s disease. Here we designed a novel neuropsychological battery based on a virtual space paradigm to assess auditory spatial processing in patient cohorts with clinically typical Alzheimer’s disease (n = 20) and its major variant syndrome, posterior cortical atrophy (n = 12) in relation to healthy older controls (n = 26). We assessed three dimensions of auditory spatial function: externalized versus non-externalized sound discrimination, moving versus stationary sound discrimination and stationary auditory spatial position discrimination, together with non-spatial auditory and visual spatial control tasks. Neuroanatomical correlates of auditory spatial processing were assessed using voxel-based morphometry. Relative to healthy older controls, both patient groups exhibited impairments in detection of auditory motion, and stationary sound position discrimination. The posterior cortical atrophy group showed greater impairment for auditory motion processing and the processing of a non-spatial control complex auditory property (timbre) than the typical Alzheimer’s disease group. Voxel-based morphometry in the patient cohort revealed grey matter correlates of auditory motion detection and spatial position discrimination in right inferior parietal cortex and precuneus, respectively. These findings delineate auditory spatial processing deficits in typical and posterior Alzheimer’s disease phenotypes that are related to posterior cortical regions involved in both syndromic variants and modulated by the syndromic profile of brain degeneration. Auditory spatial deficits contribute to impaired spatial awareness in Alzheimer’s disease and may constitute a novel perceptual model for probing brain network disintegration across the Alzheimer

  19. Brain regions responsible for tinnitus distress and loudness: a resting-state FMRI study.

    PubMed

    Ueyama, Takashi; Donishi, Tomohiro; Ukai, Satoshi; Ikeda, Yorihiko; Hotomi, Muneki; Yamanaka, Noboru; Shinosaki, Kazuhiro; Terada, Masaki; Kaneoke, Yoshiki

    2013-01-01

    Subjective tinnitus is characterized by the perception of phantom sound without an external auditory stimulus. We hypothesized that abnormal functionally connected regions in the central nervous system might underlie the pathophysiology of chronic subjective tinnitus. Statistical significance of functional connectivity (FC) strength is affected by the regional autocorrelation coefficient (AC). In this study, we used resting-state functional MRI (fMRI) and measured regional mean FC strength (mean cross-correlation coefficient between a region and all other regions without taking into account the effect of AC (rGC) and with taking into account the effect of AC (rGCa) to elucidate brain regions related to tinnitus symptoms such as distress, depression and loudness. Consistent with previous studies, tinnitus loudness was not related to tinnitus-related distress and depressive state. Although both rGC and rGCa revealed similar brain regions where the values showed a statistically significant relationship with tinnitus-related symptoms, the regions for rGCa were more localized and more clearly delineated the regions related specifically to each symptom. The rGCa values in the bilateral rectus gyri were positively correlated and those in the bilateral anterior and middle cingulate gyri were negatively correlated with distress and depressive state. The rGCa values in the bilateral thalamus, the bilateral hippocampus, and the left caudate were positively correlated and those in the left medial superior frontal gyrus and the left posterior cingulate gyrus were negatively correlated with tinnitus loudness. These results suggest that distinct brain regions are responsible for tinnitus symptoms. The regions for distress and depressive state are known to be related to depression, while the regions for tinnitus loudness are known to be related to the default mode network and integration of multi-sensory information.

  20. Far-field brainstem responses evoked by vestibular and auditory stimuli exhibit increases in interpeak latency as brain temperature is decreased

    NASA Technical Reports Server (NTRS)

    Hoffman, L. F.; Horowitz, J. M.

    1984-01-01

    The effect of decreasing of brain temperature on the brainstem auditory evoked response (BAER) in rats was investigated. Voltage pulses, applied to a piezoelectric crystal attached to the skull, were used to evoke stimuli in the auditory system by means of bone-conducted vibrations. The responses were recorded at 37 C and 34 C brain temperatures. The peaks of the BAER recorded at 34 C were delayed in comparison with the peaks from the 37 C wave, and the later peaks were more delayed than the earlier peaks. These results indicate that an increase in the interpeak latency occurs as the brain temperature is decreased. Preliminary experiments, in which responses to brief angular acceleration were used to measure the brainstem vestibular evoked response (BVER), have also indicated increases in the interpeak latency in response to the lowering of brain temperature.

  1. Conserved mechanisms of vocalization coding in mammalian and songbird auditory midbrain.

    PubMed

    Woolley, Sarah M N; Portfors, Christine V

    2013-11-01

    The ubiquity of social vocalizations among animals provides the opportunity to identify conserved mechanisms of auditory processing that subserve communication. Identifying auditory coding properties that are shared across vocal communicators will provide insight into how human auditory processing leads to speech perception. Here, we compare auditory response properties and neural coding of social vocalizations in auditory midbrain neurons of mammalian and avian vocal communicators. The auditory midbrain is a nexus of auditory processing because it receives and integrates information from multiple parallel pathways and provides the ascending auditory input to the thalamus. The auditory midbrain is also the first region in the ascending auditory system where neurons show complex tuning properties that are correlated with the acoustics of social vocalizations. Single unit studies in mice, bats and zebra finches reveal shared principles of auditory coding including tonotopy, excitatory and inhibitory interactions that shape responses to vocal signals, nonlinear response properties that are important for auditory coding of social vocalizations and modulation tuning. Additionally, single neuron responses in the mouse and songbird midbrain are reliable, selective for specific syllables, and rely on spike timing for neural discrimination of distinct vocalizations. We propose that future research on auditory coding of vocalizations in mouse and songbird midbrain neurons adopt similar experimental and analytical approaches so that conserved principles of vocalization coding may be distinguished from those that are specialized for each species. This article is part of a Special Issue entitled "Communication Sounds and the Brain: New Directions and Perspectives".

  2. Brain networks of novelty-driven involuntary and cued voluntary auditory attention shifting.

    PubMed

    Huang, Samantha; Belliveau, John W; Tengshe, Chinmayi; Ahveninen, Jyrki

    2012-01-01

    In everyday life, we need a capacity to flexibly shift attention between alternative sound sources. However, relatively little work has been done to elucidate the mechanisms of attention shifting in the auditory domain. Here, we used a mixed event-related/sparse-sampling fMRI approach to investigate this essential cognitive function. In each 10-sec trial, subjects were instructed to wait for an auditory "cue" signaling the location where a subsequent "target" sound was likely to be presented. The target was occasionally replaced by an unexpected "novel" sound in the uncued ear, to trigger involuntary attention shifting. To maximize the attention effects, cues, targets, and novels were embedded within dichotic 800-Hz vs. 1500-Hz pure-tone "standard" trains. The sound of clustered fMRI acquisition (starting at t = 7.82 sec) served as a controlled trial-end signal. Our approach revealed notable activation differences between the conditions. Cued voluntary attention shifting activated the superior intra--parietal sulcus (IPS), whereas novelty-triggered involuntary orienting activated the inferior IPS and certain subareas of the precuneus. Clearly more widespread activations were observed during voluntary than involuntary orienting in the premotor cortex, including the frontal eye fields. Moreover, we found -evidence for a frontoinsular-cingular attentional control network, consisting of the anterior insula, inferior frontal cortex, and medial frontal cortices, which were activated during both target discrimination and voluntary attention shifting. Finally, novels and targets activated much wider areas of superior temporal auditory cortices than shifting cues.

  3. Suppression and facilitation of auditory neurons through coordinated acoustic and midbrain stimulation: investigating a deep brain stimulator for tinnitus

    NASA Astrophysics Data System (ADS)

    Offutt, Sarah J.; Ryan, Kellie J.; Konop, Alexander E.; Lim, Hubert H.

    2014-12-01

    Objective. The inferior colliculus (IC) is the primary processing center of auditory information in the midbrain and is one site of tinnitus-related activity. One potential option for suppressing the tinnitus percept is through deep brain stimulation via the auditory midbrain implant (AMI), which is designed for hearing restoration and is already being implanted in deaf patients who also have tinnitus. However, to assess the feasibility of AMI stimulation for tinnitus treatment we first need to characterize the functional connectivity within the IC. Previous studies have suggested modulatory projections from the dorsal cortex of the IC (ICD) to the central nucleus of the IC (ICC), though the functional properties of these projections need to be determined. Approach. In this study, we investigated the effects of electrical stimulation of the ICD on acoustic-driven activity within the ICC in ketamine-anesthetized guinea pigs. Main Results. We observed ICD stimulation induces both suppressive and facilitatory changes across ICC that can occur immediately during stimulation and remain after stimulation. Additionally, ICD stimulation paired with broadband noise stimulation at a specific delay can induce greater suppressive than facilitatory effects, especially when stimulating in more rostral and medial ICD locations. Significance. These findings demonstrate that ICD stimulation can induce specific types of plastic changes in ICC activity, which may be relevant for treating tinnitus. By using the AMI with electrode sites positioned with the ICD and the ICC, the modulatory effects of ICD stimulation can be tested directly in tinnitus patients.

  4. Prestimulus Network Integration of Auditory Cortex Predisposes Near-Threshold Perception Independently of Local Excitability.

    PubMed

    Leske, Sabine; Ruhnau, Philipp; Frey, Julia; Lithari, Chrysa; Müller, Nadia; Hartmann, Thomas; Weisz, Nathan

    2015-12-01

    An ever-increasing number of studies are pointing to the importance of network properties of the brain for understanding behavior such as conscious perception. However, with regards to the influence of prestimulus brain states on perception, this network perspective has rarely been taken. Our recent framework predicts that brain regions crucial for a conscious percept are coupled prior to stimulus arrival, forming pre-established pathways of information flow and influencing perceptual awareness. Using magnetoencephalography (MEG) and graph theoretical measures, we investigated auditory conscious perception in a near-threshold (NT) task and found strong support for this framework. Relevant auditory regions showed an increased prestimulus interhemispheric connectivity. The left auditory cortex was characterized by a hub-like behavior and an enhanced integration into the brain functional network prior to perceptual awareness. Right auditory regions were decoupled from non-auditory regions, presumably forming an integrated information processing unit with the left auditory cortex. In addition, we show for the first time for the auditory modality that local excitability, measured by decreased alpha power in the auditory cortex, increases prior to conscious percepts. Importantly, we were able to show that connectivity states seem to be largely independent from local excitability states in the context of a NT paradigm.

  5. Prestimulus Network Integration of Auditory Cortex Predisposes Near-Threshold Perception Independently of Local Excitability

    PubMed Central

    Leske, Sabine; Ruhnau, Philipp; Frey, Julia; Lithari, Chrysa; Müller, Nadia; Hartmann, Thomas; Weisz, Nathan

    2015-01-01

    An ever-increasing number of studies are pointing to the importance of network properties of the brain for understanding behavior such as conscious perception. However, with regards to the influence of prestimulus brain states on perception, this network perspective has rarely been taken. Our recent framework predicts that brain regions crucial for a conscious percept are coupled prior to stimulus arrival, forming pre-established pathways of information flow and influencing perceptual awareness. Using magnetoencephalography (MEG) and graph theoretical measures, we investigated auditory conscious perception in a near-threshold (NT) task and found strong support for this framework. Relevant auditory regions showed an increased prestimulus interhemispheric connectivity. The left auditory cortex was characterized by a hub-like behavior and an enhanced integration into the brain functional network prior to perceptual awareness. Right auditory regions were decoupled from non-auditory regions, presumably forming an integrated information processing unit with the left auditory cortex. In addition, we show for the first time for the auditory modality that local excitability, measured by decreased alpha power in the auditory cortex, increases prior to conscious percepts. Importantly, we were able to show that connectivity states seem to be largely independent from local excitability states in the context of a NT paradigm. PMID:26408799

  6. Long-range correlation properties in timing of skilled piano performance: the influence of auditory feedback and deep brain stimulation

    PubMed Central

    Herrojo Ruiz, María; Hong, Sang Bin; Hennig, Holger; Altenmüller, Eckart; Kühn, Andrea A.

    2014-01-01

    Unintentional timing deviations during musical performance can be conceived of as timing errors. However, recent research on humanizing computer-generated music has demonstrated that timing fluctuations that exhibit long-range temporal correlations (LRTC) are preferred by human listeners. This preference can be accounted for by the ubiquitous presence of LRTC in human tapping and rhythmic performances. Interestingly, the manifestation of LRTC in tapping behavior seems to be driven in a subject-specific manner by the LRTC properties of resting-state background cortical oscillatory activity. In this framework, the current study aimed to investigate whether propagation of timing deviations during the skilled, memorized piano performance (without metronome) of 17 professional pianists exhibits LRTC and whether the structure of the correlations is influenced by the presence or absence of auditory feedback. As an additional goal, we set out to investigate the influence of altering the dynamics along the cortico-basal-ganglia-thalamo-cortical network via deep brain stimulation (DBS) on the LRTC properties of musical performance. Specifically, we investigated temporal deviations during the skilled piano performance of a non-professional pianist who was treated with subthalamic-deep brain stimulation (STN-DBS) due to severe Parkinson's disease, with predominant tremor affecting his right upper extremity. In the tremor-affected right hand, the timing fluctuations of the performance exhibited random correlations with DBS OFF. By contrast, DBS restored long-range dependency in the temporal fluctuations, corresponding with the general motor improvement on DBS. Overall, the present investigations demonstrate the presence of LRTC in skilled piano performances, indicating that unintentional temporal deviations are correlated over a wide range of time scales. This phenomenon is stable after removal of the auditory feedback, but is altered by STN-DBS, which suggests that cortico

  7. Potassium conductance dynamics confer robust spike-time precision in a neuromorphic model of the auditory brain stem

    PubMed Central

    Boahen, Kwabena

    2013-01-01

    A fundamental question in neuroscience is how neurons perform precise operations despite inherent variability. This question also applies to neuromorphic engineering, where low-power microchips emulate the brain using large populations of diverse silicon neurons. Biological neurons in the auditory pathway display precise spike timing, critical for sound localization and interpretation of complex waveforms such as speech, even though they are a heterogeneous population. Silicon neurons are also heterogeneous, due to a key design constraint in neuromorphic engineering: smaller transistors offer lower power consumption and more neurons per unit area of silicon, but also more variability between transistors and thus between silicon neurons. Utilizing this variability in a neuromorphic model of the auditory brain stem with 1,080 silicon neurons, we found that a low-voltage-activated potassium conductance (gKL) enables precise spike timing via two mechanisms: statically reducing the resting membrane time constant and dynamically suppressing late synaptic inputs. The relative contribution of these two mechanisms is unknown because blocking gKL in vitro eliminates dynamic adaptation but also lengthens the membrane time constant. We replaced gKL with a static leak in silico to recover the short membrane time constant and found that silicon neurons could mimic the spike-time precision of their biological counterparts, but only over a narrow range of stimulus intensities and biophysical parameters. The dynamics of gKL were required for precise spike timing robust to stimulus variation across a heterogeneous population of silicon neurons, thus explaining how neural and neuromorphic systems may perform precise operations despite inherent variability. PMID:23554436

  8. Differences in brain circuitry for appetitive and reactive aggression as revealed by realistic auditory scripts

    PubMed Central

    Moran, James K.; Weierstall, Roland; Elbert, Thomas

    2014-01-01

    Aggressive behavior is thought to divide into two motivational elements: The first being a self-defensively motivated aggression against threat and a second, hedonically motivated “appetitive” aggression. Appetitive aggression is the less understood of the two, often only researched within abnormal psychology. Our approach is to understand it as a universal and adaptive response, and examine the functional neural activity of ordinary men (N = 50) presented with an imaginative listening task involving a murderer describing a kill. We manipulated motivational context in a between-subjects design to evoke appetitive or reactive aggression, against a neutral control, measuring activity with Magnetoencephalography (MEG). Results show differences in left frontal regions in delta (2–5 Hz) and alpha band (8–12 Hz) for aggressive conditions and right parietal delta activity differentiating appetitive and reactive aggression. These results validate the distinction of reward-driven appetitive aggression from reactive aggression in ordinary populations at the level of functional neural brain circuitry. PMID:25538590

  9. Alterations in brain-stem auditory evoked potentials among drug addicts

    PubMed Central

    Garg, Sonia; Sharma, Rajeev; Mittal, Shilekh; Thapar, Satish

    2015-01-01

    Objective: To compare the absolute latencies, the interpeak latencies, and amplitudes of different waveforms of brainstem auditory evoked potentials (BAEP) in different drug abusers and controls, and to identify early neurological damage in persons who abuse different drugs so that proper counseling and timely intervention can be undertaken. Methods: In this cross-sectional study, BAEP’s were assessed by a data acquisition and analysis system in 58 male drug abusers in the age group of 15-45 years as well as in 30 age matched healthy controls. The absolute peak latencies and the interpeak latencies of BAEP were analyzed by applying one way ANOVA and student t-test. The study was carried out at the GGS Medical College, Faridkot, Punjab, India between July 2012 and May 2013. Results: The difference in the absolute peak latencies and interpeak latencies of BAEP in the 2 groups was found to be statistically significant in both the ears (p<0.05). However, the difference in the amplitude ratio in both the ears was found to be statistically insignificant. Conclusion: Chronic intoxication by different drugs has been extensively associated with prolonged absolute peak latencies and interpeak latencies of BAEP in drug abusers reflecting an adverse effect of drug dependence on neural transmission in central auditory nerve pathways. PMID:26166594

  10. Brain dynamics that correlate with effects of learning on auditory distance perception.

    PubMed

    Wisniewski, Matthew G; Mercado, Eduardo; Church, Barbara A; Gramann, Klaus; Makeig, Scott

    2014-01-01

    Accuracy in auditory distance perception can improve with practice and varies for sounds differing in familiarity. Here, listeners were trained to judge the distances of English, Bengali, and backwards speech sources pre-recorded at near (2-m) and far (30-m) distances. Listeners' accuracy was tested before and after training. Improvements from pre-test to post-test were greater for forward speech, demonstrating a learning advantage for forward speech sounds. Independent component (IC) processes identified in electroencephalographic (EEG) data collected during pre- and post-testing revealed three clusters of ICs across subjects with stimulus-locked spectral perturbations related to learning and accuracy. One cluster exhibited a transient stimulus-locked increase in 4-8 Hz power (theta event-related synchronization; ERS) that was smaller after training and largest for backwards speech. For a left temporal cluster, 8-12 Hz decreases in power (alpha event-related desynchronization; ERD) were greatest for English speech and less prominent after training. In contrast, a cluster of IC processes centered at or near anterior portions of the medial frontal cortex showed learning-related enhancement of sustained increases in 10-16 Hz power (upper-alpha/low-beta ERS). The degree of this enhancement was positively correlated with the degree of behavioral improvements. Results suggest that neural dynamics in non-auditory cortical areas support distance judgments. Further, frontal cortical networks associated with attentional and/or working memory processes appear to play a role in perceptual learning for source distance.

  11. Regional brain monitoring in the neurocritical care unit.

    PubMed

    Frontera, Jennifer; Ziai, Wendy; O'Phelan, Kristine; Leroux, Peter D; Kirkpatrick, Peter J; Diringer, Michael N; Suarez, Jose I

    2015-06-01

    Regional multimodality monitoring has evolved over the last several years as a tool to understand the mechanisms of brain injury and brain function at the cellular level. Multimodality monitoring offers an important augmentation to the clinical exam and is especially useful in comatose neurocritical care patients. Cerebral microdialysis, brain tissue oxygen monitoring, and cerebral blood flow monitoring all offer insight into permutations in brain chemistry and function that occur in the context of brain injury. These tools may allow for development of individual therapeutic strategies that are mechanistically driven and goal-directed. We present a summary of the discussions that took place during the Second Neurocritical Care Research Conference regarding regional brain monitoring.

  12. Effects of Location, Frequency Region, and Time Course of Selective Attention on Auditory Scene Analysis

    ERIC Educational Resources Information Center

    Cusack, Rhodri; Decks, John; Aikman, Genevieve; Carlyon, Robert P.

    2004-01-01

    Often, the sound arriving at the ears is a mixture from many different sources, but only 1 is of interest. To assist with selection, the auditory system structures the incoming input into streams, each of which ideally corresponds to a single source. Some authors have argued that this process of streaming is automatic and invariant, but recent…

  13. Impact of Repetitive Transcranial Magnetic Stimulation (rTMS) on Brain Functional Marker of Auditory Hallucinations in Schizophrenia Patients

    PubMed Central

    Maïza, Olivier; Hervé, Pierre-Yve; Etard, Olivier; Razafimandimby, Annick; Montagne-Larmurier, Aurélie; Dollfus, Sonia

    2013-01-01

    Several cross-sectional functional Magnetic Resonance Imaging (fMRI) studies reported a negative correlation between auditory verbal hallucination (AVH) severity and amplitude of the activations during language tasks. The present study assessed the time course of this correlation and its possible structural underpinnings by combining structural, functional MRI and repetitive Transcranial Magnetic Stimulation (rTMS). Methods: Nine schizophrenia patients with AVH (evaluated with the Auditory Hallucination Rating scale; AHRS) and nine healthy participants underwent two sessions of an fMRI speech listening paradigm. Meanwhile, patients received high frequency (20 Hz) rTMS. Results: Before rTMS, activations were negatively correlated with AHRS in a left posterior superior temporal sulcus (pSTS) cluster, considered henceforward as a functional region of interest (fROI). After rTMS, activations in this fROI no longer correlated with AHRS. This decoupling was explained by a significant decrease of AHRS scores after rTMS that contrasted with a relative stability of cerebral activations. A voxel-based-morphometry analysis evidenced a cluster of the left pSTS where grey matter volume negatively correlated with AHRS before rTMS and positively correlated with activations in the fROI at both sessions. Conclusion: rTMS decreases the severity of AVH leading to modify the functional correlate of AVH underlain by grey matter abnormalities. PMID:24961421

  14. Attention effects on auditory scene analysis: insights from event-related brain potentials.

    PubMed

    Spielmann, Mona Isabel; Schröger, Erich; Kotz, Sonja A; Bendixen, Alexandra

    2014-01-01

    Sounds emitted by different sources arrive at our ears as a mixture that must be disentangled before meaningful information can be retrieved. It is still a matter of debate whether this decomposition happens automatically or requires the listener's attention. These opposite positions partly stem from different methodological approaches to the problem. We propose an integrative approach that combines the logic of previous measurements targeting either auditory stream segregation (interpreting a mixture as coming from two separate sources) or integration (interpreting a mixture as originating from only one source). By means of combined behavioral and event-related potential (ERP) measures, our paradigm has the potential to measure stream segregation and integration at the same time, providing the opportunity to obtain positive evidence of either one. This reduces the reliance on zero findings (i.e., the occurrence of stream integration in a given condition can be demonstrated directly, rather than indirectly based on the absence of empirical evidence for stream segregation, and vice versa). With this two-way approach, we systematically manipulate attention devoted to the auditory stimuli (by varying their task relevance) and to their underlying structure (by delivering perceptual tasks that require segregated or integrated percepts). ERP results based on the mismatch negativity (MMN) show no evidence for a modulation of stream integration by attention, while stream segregation results were less clear due to overlapping attention-related components in the MMN latency range. We suggest future studies combining the proposed two-way approach with some improvements in the ERP measurement of sequential stream segregation.

  15. Brain dynamics that correlate with effects of learning on auditory distance perception

    PubMed Central

    Wisniewski, Matthew G.; Mercado, Eduardo; Church, Barbara A.; Gramann, Klaus; Makeig, Scott

    2014-01-01

    Accuracy in auditory distance perception can improve with practice and varies for sounds differing in familiarity. Here, listeners were trained to judge the distances of English, Bengali, and backwards speech sources pre-recorded at near (2-m) and far (30-m) distances. Listeners' accuracy was tested before and after training. Improvements from pre-test to post-test were greater for forward speech, demonstrating a learning advantage for forward speech sounds. Independent component (IC) processes identified in electroencephalographic (EEG) data collected during pre- and post-testing revealed three clusters of ICs across subjects with stimulus-locked spectral perturbations related to learning and accuracy. One cluster exhibited a transient stimulus-locked increase in 4–8 Hz power (theta event-related synchronization; ERS) that was smaller after training and largest for backwards speech. For a left temporal cluster, 8–12 Hz decreases in power (alpha event-related desynchronization; ERD) were greatest for English speech and less prominent after training. In contrast, a cluster of IC processes centered at or near anterior portions of the medial frontal cortex showed learning-related enhancement of sustained increases in 10–16 Hz power (upper-alpha/low-beta ERS). The degree of this enhancement was positively correlated with the degree of behavioral improvements. Results suggest that neural dynamics in non-auditory cortical areas support distance judgments. Further, frontal cortical networks associated with attentional and/or working memory processes appear to play a role in perceptual learning for source distance. PMID:25538550

  16. Focused ultrasound modulates region-specific brain activity

    PubMed Central

    Yoo, Seung-Schik; Bystritsky, Alexander; Lee, Jong-Hwan; Zhang, Yongzhi; Fischer, Krisztina; Min, Byoung-Kyong; McDannold, Nathan J.; Pascual-Leone, Alvaro; Jolesz, Ferenc A.

    2012-01-01

    We demonstrated the in vivo feasibility of using focused ultrasound (FUS) to transiently modulate (through either stimulation or suppression) the function of regional brain tissue in rabbits. FUS was delivered in a train of pulses at low acoustic energy, far below the cavitation threshold, to the animal's somatomotor and visual areas, as guided by anatomical and functional information from magnetic resonance imaging (MRI). The temporary alterations in the brain function affected by the sonication were characterized by both electrophysiological recordings and functional brain mapping achieved through the use of functional MRI (fMRI). The modulatory effects were bimodal, whereby the brain activity could either be stimulated or selectively suppressed. Histological analysis of the excised brain tissue after the sonication demonstrated that the FUS did not elicit any tissue damages. Unlike transcranial magnetic stimulation, FUS can be applied to deep structures in the brain with greater spatial precision. Transient modulation of brain function using image-guided and anatomically-targeted FUS would enable the investigation of functional connectivity between brain regions and will eventually lead to a better understanding of localized brain functions. It is anticipated that the use of this technology will have an impact on brain research and may offer novel therapeutic interventions in various neurological conditions and psychiatric disorders. PMID:21354315

  17. Brain Region and Cell Type Transcripts for Informative Diagnostics

    DTIC Science & Technology

    2010-09-01

    cerebral cortex (CTX) region that is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain and takes a key role in...the cerebrum of the mammalian brain and plays a role in memory, attention, perceptual awareness, thought, language, and consciousness. The MDRN

  18. Age-and Brain Region-Specific Differences in Mitochondrial ...

    EPA Pesticide Factsheets

    Mitochondria are central regulators of energy homeostasis and play a pivotal role in mechanisms of cellular senescence. The objective of the present study was to evaluate mitochondrial bio­-energetic parameters in five brain regions [brainstem (BS), frontal cortex (FC), cerebellum (CER), striatum (STR), hippocampus (HIP)] of four diverse age groups [1 Month (young), 4 Month (adult), 12 Month (middle-aged), 24 Month (old age)] to understand age-related differences in selected brain regions and their contribution to age-related chemical sensitivity. Mitochondrial bioenergetics parameters and enzyme activity were measured under identical conditions across multiple age groups and brain regions in Brown Norway rats (n = 5). The results indicate age- and brain region-specific patterns in mitochondrial functional endpoints. For example, an age-specific decline in ATP synthesis (State 111 respiration) was observed in BS and HIP. Similarly, the maximal respiratory capacities (State V1 and V2) showed age-specific declines in all brain regions examined (young > adult > middle-aged > old age). Amongst all regions, HIP had the greatest change in mitochondrial bioenergetics, showing declines in the 4, 12 and 24 Month age groups. Activities of mitochondrial pyruvate dehydrogenase complex (PDHC) and electron transport chain (ETC) complexes I, II, and IV enzymes were also age- and brain-region specific. In general changes associated with age were more pronounced, with

  19. Indices of Regional Brain Atrophy: Formulae and Nomenclature

    PubMed Central

    Arias-Carrión, Oscar

    2015-01-01

    The pattern of brain atrophy helps to discriminate normal age-related changes from neurodegenerative diseases. Albeit indices of regional brain atrophy have proven to be a parameter useful in the early diagnosis and differential diagnosis of some neurodegenerative diseases, indices of absolute regional atrophy still have some important limitations. We propose using indices of relative atrophy for representing how the volume of a given region of interest (ROI) changes over time in comparison to changes in global brain measures over the same time. A second problem in morphometric studies is terminology. There is a lack of systematization naming indices and the same measure can be named with different terms by different research groups or imaging softwares. This limits the understanding and discussion of studies. In this technological report, we provide a general description on how to compute indices of absolute and relative regional brain atrophy and propose a standardized nomenclature. PMID:26261753

  20. Monitoring therapeutic efficacy of decompressive craniotomy in space occupying cerebellar infarcts using brain-stem auditory evoked potentials.

    PubMed

    Krieger, D; Adams, H P; Rieke, K; Hacke, W

    1993-01-01

    Brain-stem auditory evoked potentials (BAEPs) have been used to gauge effects of brain-stem dysfunction in humans and animal models. The purpose of this study was to evaluate the usefulness of BAEP in monitoring patients undergoing decompressive surgery of the posterior fossa for space occupying cerebellar infarcts. We report on serial BAEP recordings in 11 comatose patients with space occupying cerebellar infarcts undergoing decompressive craniotomy. BAEP studies were performed within 12 h after admission, 24 h following surgery and prior to extubation. BAEP signals were analyzed using latency determination and cross-correlation. Following surgery, 9 patients regained consciousness; 2 patients persisted in a comatose state and died subsequently. BAEP interpeak latency (IPL) I-V assessed prior to surgery exceeded normal values in all patients in whom it could be reliably measured (N = 9). Following decompressive surgery BAEP wave I-V IPL normalized in 5 patients, but remained prolonged despite dramatic clinical improvement in 4 patients. We prospectively computed the coefficient of cross-correlation (MCC) of combined ipsilateral BAEP trials after right and left ear stimulation. In all patients increasing MCC was associated with clinical improvement. Unchanging or decreasing MCC indicated poor outcome. We conclude that serial BAEP studies are an appropriate perioperative monitoring modality in patients with space occupying cerebellar infarcts undergoing decompressive surgery of the posterior fossa. Our study suggests advantages of cross-correlation analysis as an objective signal processing strategy; relevant information can be extracted even if BAEP wave discrimination is impossible due to severe brain-stem dysfunction.

  1. 40 Hz auditory steady state response to linguistic features of stimuli during auditory hallucinations.

    PubMed

    Ying, Jun; Yan, Zheng; Gao, Xiao-rong

    2013-10-01

    The auditory steady state response (ASSR) may reflect activity from different regions of the brain, depending on the modulation frequency used. In general, responses induced by low rates (≤40 Hz) emanate mostly from central structures of the brain, and responses from high rates (≥80 Hz) emanate mostly from the peripheral auditory nerve or brainstem structures. Besides, it was reported that the gamma band ASSR (30-90 Hz) played an important role in working memory, speech understanding and recognition. This paper investigated the 40 Hz ASSR evoked by modulated speech and reversed speech. The speech was Chinese phrase voice, and the noise-like reversed speech was obtained by temporally reversing the speech. Both auditory stimuli were modulated with a frequency of 40 Hz. Ten healthy subjects and 5 patients with hallucination symptom participated in the experiment. Results showed reduction in left auditory cortex response when healthy subjects listened to the reversed speech compared with the speech. In contrast, when the patients who experienced auditory hallucinations listened to the reversed speech, the auditory cortex of left hemispheric responded more actively. The ASSR results were consistent with the behavior results of patients. Therefore, the gamma band ASSR is expected to be helpful for rapid and objective diagnosis of hallucination in clinic.

  2. Auditory Neuroimaging with fMRI and PET

    PubMed Central

    Talavage, Thomas M.; Gonzalez-Castillo, Javier; Scott, Sophie K.

    2013-01-01

    For much of the past 30 years, investigations of auditory perception and language have been enhanced or even driven by the use of functional neuroimaging techniques that specialize in localization of central responses. Beginning with investigations using positron emission tomography (PET) and gradually shifting primarily to usage of functional magnetic resonance imaging (fMRI), auditory neuroimaging has greatly advanced our understanding of the organization and response properties of brain regions critical to the perception of and communication with the acoustic world in which we live. As the complexity of the questions being addressed has increased, the techniques, experiments and analyses applied have also become more nuanced and specialized. A brief review of the history of these investigations sets the stage for an overview and analysis of how these neuroimaging modalities are becoming ever more effective tools for understanding the auditory brain. We conclude with a brief discussion of open methodological issues as well as potential clinical applications for auditory neuroimaging. PMID:24076424

  3. To Study Brain Stem Auditory Evoked Potential in Patients with Type 2 Diabetes Mellitus- A Cross- Sectional Comparative Study

    PubMed Central

    Muneshwar, J.N.; Afroz, Sayeeda

    2016-01-01

    Introduction Neuropathy is one of the commonest complications of Diabetes Mellitus (DM). Apart from having peripheral and autonomic neuropathy patients with type 2 DM may also suffer from sensory neural hearing loss, which is more severe at higher frequencies. However, few studies have done detailed evaluation of sensory pathway in these patients. In this study brain stem auditory evoked potential is used to detect the acoustic and central neuropathy in a group of patients with type 2 DM with controlled and uncontrolled blood sugar. Aim To study brain stem auditory evoked potential in patients of type 2 DM with controlled and uncontrolled blood sugar and to correlate the various parameters e.g., age (years), weight (kilograms), height (meters), BMI (kg/m2), HbA1c (%) in patients with type 2 DM with controlled and uncontrolled blood sugar. Materials and Methods Cross-sectional comparative study conducted from January 2014 to January 2015. Total 60 patients with type 2 DM of either sex, between age groups of 35-50 years were enrolled from the Diabetic Clinic of Medicine department, of a tertiary care hospital. Based on the value of HbA1c, patients were divided in two groups with controlled and uncontrolled blood sugar and with each group comprising of 30 patients. BERA (Brainstem Evoked Response Audiometry) was done in both the groups on RMS ALERON 201/401. Recordings were taken at 70dB, 80dB and 90dB at 2KHz frequency. Absolute latency of wave I, III, V and interpeak latencies I–III, III-V and I-V were recorded. Results Mean±SD of the absolute latency of BERA waves I, III, V and interpeak latencies I–III, III-V and I-V at 2 KHz and at varying intensity of 70dB, 80dB and 90dB in uncontrolled group of DM were delayed and were significant as compared to controlled group of DM. Conclusion If BERA is done in diabetic patients, central neuropathy can be detected earlier in uncontrolled groups of diabetic patients. PMID:28050358

  4. The dorsal auditory pathway is involved in performance of both visual and auditory rhythms.

    PubMed

    Karabanov, Anke; Blom, Orjan; Forsman, Lea; Ullén, Fredrik

    2009-01-15

    We used functional magnetic resonance imaging to investigate the effect of two factors on the neural control of temporal sequence performance: the modality in which the rhythms had been trained, and the modality of the pacing stimuli preceding performance. The rhythms were trained 1-2 days before scanning. Each participant learned two rhythms: one was presented visually, the other auditorily. During fMRI, the rhythms were performed in blocks. In each block, four beats of a visual or auditory pacing metronome were followed by repetitive self-paced rhythm performance from memory. Data from the self-paced performance phase was analysed in a 2x2 factorial design, with the two factors Training Modality (auditory or visual) and Metronome Modality (auditory or visual), as well as with a conjunction analysis across all active conditions, to identify activations that were independent of both Training Modality and Metronome Modality. We found a significant main effect only for visual versus auditory Metronome Modality, in the left angular gyrus, due to a deactivation of this region after auditory pacing. The conjunction analysis revealed a set of brain areas that included dorsal auditory pathway areas (left temporo-parietal junction area and ventral premotor cortex), dorsal premotor cortex, the supplementary and presupplementary premotor areas, the cerebellum and the basal ganglia. We conclude that these regions are involved in controlling performance of well-learned rhythms, regardless of the modality in which the rhythms are trained and paced. This suggests that after extensive short-term training, all rhythms, even those that were both trained and paced in visual modality, had been transformed into auditory-motor representations. The deactivation of the angular cortex following auditory pacing may represent cross-modal auditory-visual inhibition.

  5. Regional growth and atlasing of the developing human brain

    PubMed Central

    Makropoulos, Antonios; Aljabar, Paul; Wright, Robert; Hüning, Britta; Merchant, Nazakat; Arichi, Tomoki; Tusor, Nora; Hajnal, Joseph V.; Edwards, A. David; Counsell, Serena J.; Rueckert, Daniel

    2016-01-01

    Detailed morphometric analysis of the neonatal brain is required to characterise brain development and define neuroimaging biomarkers related to impaired brain growth. Accurate automatic segmentation of neonatal brain MRI is a prerequisite to analyse large datasets. We have previously presented an accurate and robust automatic segmentation technique for parcellating the neonatal brain into multiple cortical and subcortical regions. In this study, we further extend our segmentation method to detect cortical sulci and provide a detailed delineation of the cortical ribbon. These detailed segmentations are used to build a 4-dimensional spatio-temporal structural atlas of the brain for 82 cortical and subcortical structures throughout this developmental period. We employ the algorithm to segment an extensive database of 420 MR images of the developing brain, from 27 to 45 weeks post-menstrual age at imaging. Regional volumetric and cortical surface measurements are derived and used to investigate brain growth and development during this critical period and to assess the impact of immaturity at birth. Whole brain volume, the absolute volume of all structures studied, cortical curvature and cortical surface area increased with increasing age at scan. Relative volumes of cortical grey matter, cerebellum and cerebrospinal fluid increased with age at scan, while relative volumes of white matter, ventricles, brainstem and basal ganglia and thalami decreased. Preterm infants at term had smaller whole brain volumes, reduced regional white matter and cortical and subcortical grey matter volumes, and reduced cortical surface area compared with term born controls, while ventricular volume was greater in the preterm group. Increasing prematurity at birth was associated with a reduction in total and regional white matter, cortical and subcortical grey matter volume, an increase in ventricular volume, and reduced cortical surface area. PMID:26499811

  6. Regional development of glutamate dehydrogenase in the rat brain.

    PubMed

    Leong, S F; Clark, J B

    1984-07-01

    The development of glutamate dehydrogenase enzyme activity in rat brain regions has been followed from the late foetal stage to the adult and through to the aged (greater than 2 years) adult. In the adult brain the enzyme activity was greatest in the medulla oblongata and pons greater than midbrain = hypothalamus greater than cerebellum = striatum = cortex. In the aged adult brain, glutamate dehydrogenase activity was significantly lower in the medulla oblongata and pons when compared to the 90-day-old adult value, but not in other regions. The enzyme-specific activity of nonsynaptic (free) mitochondria purified from the medulla oblongata and pons of 90-day-old animals was about twice that of mitochondria purified from the striatum and the cortex. The specific activity of the enzyme in synaptic mitochondria purified from the above three brain regions, however, remained almost constant.

  7. Age-Related Changes in Transient and Oscillatory Brain Responses to Auditory Stimulation during Early Adolescence

    ERIC Educational Resources Information Center

    Poulsen, Catherine; Picton, Terence W.; Paus, Tomas

    2009-01-01

    Maturational changes in the capacity to process quickly the temporal envelope of sound have been linked to language abilities in typically developing individuals. As part of a longitudinal study of brain maturation and cognitive development during adolescence, we employed dense-array EEG and spatiotemporal source analysis to characterize…

  8. Neuronal coupling by endogenous electric fields: cable theory and applications to coincidence detector neurons in the auditory brain stem.

    PubMed

    Goldwyn, Joshua H; Rinzel, John

    2016-04-01

    The ongoing activity of neurons generates a spatially and time-varying field of extracellular voltage (Ve). This Ve field reflects population-level neural activity, but does it modulate neural dynamics and the function of neural circuits? We provide a cable theory framework to study how a bundle of model neurons generates Ve and how this Ve feeds back and influences membrane potential (Vm). We find that these "ephaptic interactions" are small but not negligible. The model neural population can generate Ve with millivolt-scale amplitude, and this Ve perturbs the Vm of "nearby" cables and effectively increases their electrotonic length. After using passive cable theory to systematically study ephaptic coupling, we explore a test case: the medial superior olive (MSO) in the auditory brain stem. The MSO is a possible locus of ephaptic interactions: sounds evoke large (millivolt scale)Vein vivo in this nucleus. The Ve response is thought to be generated by MSO neurons that perform a known neuronal computation with submillisecond temporal precision (coincidence detection to encode sound source location). Using a biophysically based model of MSO neurons, we find millivolt-scale ephaptic interactions consistent with the passive cable theory results. These subtle membrane potential perturbations induce changes in spike initiation threshold, spike time synchrony, and time difference sensitivity. These results suggest that ephaptic coupling may influence MSO function.

  9. The combined monitoring of brain stem auditory evoked potentials and intracranial pressure in coma. A study of 57 patients.

    PubMed Central

    García-Larrea, L; Artru, F; Bertrand, O; Pernier, J; Mauguière, F

    1992-01-01

    Continuous monitoring of brainstem auditory evoked potentials (BAEPs) was carried out in 57 comatose patients for periods ranging from 5 hours to 13 days. In 53 cases intracranial pressure (ICP) was also simultaneously monitored. The study of relative changes of evoked potentials over time proved more relevant to prognosis than the mere consideration of "statistical normality" of waveforms; thus progressive degradation of the BAEPs was associated with a bad outcome even if the responses remained within normal limits. Contrary to previous reports, a normal BAEP obtained during the second week of coma did not necessarily indicate a good vital outcome; it could, however, do so in cases with a low probability of secondary insults. The simultaneous study of BAEPs and ICP showed that apparently significant (greater than 40 mm Hg) acute rises in ICP were not always followed by BAEP changes. The stability of BAEP's despite "significant" ICP rises was associated in our patients with a high probability of survival, while prolongation of central latency of BAEPs in response to ICP modifications was almost invariably followed by brain death. Continuous monitoring of brainstem responses provided a useful physiological counterpart to physical parameters such as ICP. Serial recording of cortical EPs should be added to BAEP monitoring to permit the early detection of rostrocaudal deterioration. Images PMID:1402970

  10. Neuronal coupling by endogenous electric fields: cable theory and applications to coincidence detector neurons in the auditory brain stem

    PubMed Central

    Rinzel, John

    2016-01-01

    The ongoing activity of neurons generates a spatially and time-varying field of extracellular voltage (Ve). This Ve field reflects population-level neural activity, but does it modulate neural dynamics and the function of neural circuits? We provide a cable theory framework to study how a bundle of model neurons generates Ve and how this Ve feeds back and influences membrane potential (Vm). We find that these “ephaptic interactions” are small but not negligible. The model neural population can generate Ve with millivolt-scale amplitude, and this Ve perturbs the Vm of “nearby” cables and effectively increases their electrotonic length. After using passive cable theory to systematically study ephaptic coupling, we explore a test case: the medial superior olive (MSO) in the auditory brain stem. The MSO is a possible locus of ephaptic interactions: sounds evoke large (millivolt scale) Ve in vivo in this nucleus. The Ve response is thought to be generated by MSO neurons that perform a known neuronal computation with submillisecond temporal precision (coincidence detection to encode sound source location). Using a biophysically based model of MSO neurons, we find millivolt-scale ephaptic interactions consistent with the passive cable theory results. These subtle membrane potential perturbations induce changes in spike initiation threshold, spike time synchrony, and time difference sensitivity. These results suggest that ephaptic coupling may influence MSO function. PMID:26823512

  11. Effect of middle ear effusion on the brain-stem auditory evoked response of Cavalier King Charles Spaniels.

    PubMed

    Harcourt-Brown, Thomas R; Parker, John E; Granger, Nicolas; Jeffery, Nick D

    2011-06-01

    Brain-stem auditory evoked responses (BAER) were assessed in 23 Cavalier King Charles Spaniels with and without middle ear effusion at sound intensities ranging from 10 to 100 dB nHL. Significant differences were found between the median BAER threshold for ears where effusions were present (60 dB nHL), compared to those without (30 dB nHL) (P=0.001). The slopes of latency-intensity functions from both groups did not differ, but the y-axis intercept when the x value was zero was greater in dogs with effusions (P=0.009), consistent with conductive hearing loss. Analysis of latency-intensity functions suggested the degree of hearing loss due to middle ear effusion was 21 dB (95% confidence between 10 and 33 dB). Waves I-V inter-wave latency at 90 dB nHL was not significantly different between the two groups. These findings demonstrate that middle ear effusion is associated with a conductive hearing loss of 10-33 dB in affected dogs despite the fact that all animals studied were considered to have normal hearing by their owners.

  12. Extracellular matrix protein expression is brain region dependent.

    PubMed

    Dauth, Stephanie; Grevesse, Thomas; Pantazopoulos, Harry; Campbell, Patrick H; Maoz, Ben M; Berretta, Sabina; Parker, Kevin Kit

    2016-05-01

    In the brain, extracellular matrix (ECM) components form networks that contribute to structural and functional diversity. Maladaptive remodeling of ECM networks has been reported in neurodegenerative and psychiatric disorders, suggesting that the brain microenvironment is a dynamic structure. A lack of quantitative information about ECM distribution in the brain hinders an understanding of region-specific ECM functions and the role of ECM in health and disease. We hypothesized that each ECM protein as well as specific ECM structures, such as perineuronal nets (PNNs) and interstitial matrix, are differentially distributed throughout the brain, contributing to the unique structure and function in the various regions of the brain. To test our hypothesis, we quantitatively analyzed the distribution, colocalization, and protein expression of aggrecan, brevican, and tenascin-R throughout the rat brain utilizing immunohistochemistry and mass spectrometry analysis and assessed the effect of aggrecan, brevican, and/or tenascin-R on neurite outgrowth in vitro. We focused on aggrecan, brevican, and tenascin-R as they are especially expressed in the mature brain, and have established roles in brain development, plasticity, and neurite outgrowth. The results revealed a differentiated distribution of all three proteins throughout the brain and indicated that their presence significantly reduces neurite outgrowth in a 3D in vitro environment. These results underline the importance of a unique and complex ECM distribution for brain physiology and suggest that encoding the distribution of distinct ECM proteins throughout the brain will aid in understanding their function in physiology and in turn assist in identifying their role in disease. J. Comp. Neurol. 524:1309-1336, 2016. © 2016 Wiley Periodicals, Inc.

  13. Auditory verbal hallucinations and brain dysconnectivity in the perisylvian language network: a multimodal investigation.

    PubMed

    Benetti, Stefania; Pettersson-Yeo, William; Allen, Paul; Catani, Marco; Williams, Steven; Barsaglini, Alessio; Kambeitz-Ilankovic, Lana M; McGuire, Philip; Mechelli, Andrea

    2015-01-01

    Neuroimaging studies of schizophrenia have indicated that the development of auditory verbal hallucinations (AVHs) is associated with altered structural and functional connectivity within the perisylvian language network. However, these studies focussed mainly on either structural or functional alterations in patients with chronic schizophrenia. Therefore, they were unable to examine the relationship between the 2 types of measures and could not establish whether the observed alterations would be expressed in the early stage of the illness. We used diffusion tensor imaging and functional magnetic resonance imaging to examine white matter integrity and functional connectivity within the left perisylvian language network of 46 individuals with an at risk mental state for psychosis or a first episode of the illness, including 28 who had developed AVH group and 18 who had not (nonauditory verbal hallucination [nAVH] group), and 22 healthy controls. Inferences were made at P < .05 (corrected). The nAVH group relative to healthy controls showed a reduction of both white matter integrity and functional connectivity as well as a disruption of the normal structure-function relationship along the fronto-temporal pathway. For all measures, the AVH group showed intermediate values between healthy controls and the nAVH group. These findings seem to suggest that, in the early stage of the disorder, a significant impairment of fronto-temporal connectivity is evident in patients who do not experience AVHs. This is consistent with the hypothesis that, whilst mild disruption of connectivity might still enable the emergence of AVHs, more severe alterations may prevent the occurrence of the hallucinatory experience.

  14. Auditory Verbal Hallucinations and Brain Dysconnectivity in the Perisylvian Language Network: A Multimodal Investigation

    PubMed Central

    Pettersson-Yeo, William; Allen, Paul; Catani, Marco; Williams, Steven; Barsaglini, Alessio; Kambeitz-Ilankovic, Lana M.; McGuire, Philip; Mechelli, Andrea

    2015-01-01

    Neuroimaging studies of schizophrenia have indicated that the development of auditory verbal hallucinations (AVHs) is associated with altered structural and functional connectivity within the perisylvian language network. However, these studies focussed mainly on either structural or functional alterations in patients with chronic schizophrenia. Therefore, they were unable to examine the relationship between the 2 types of measures and could not establish whether the observed alterations would be expressed in the early stage of the illness. We used diffusion tensor imaging and functional magnetic resonance imaging to examine white matter integrity and functional connectivity within the left perisylvian language network of 46 individuals with an at risk mental state for psychosis or a first episode of the illness, including 28 who had developed AVH group and 18 who had not (nonauditory verbal hallucination [nAVH] group), and 22 healthy controls. Inferences were made at P < .05 (corrected). The nAVH group relative to healthy controls showed a reduction of both white matter integrity and functional connectivity as well as a disruption of the normal structure−function relationship along the fronto-temporal pathway. For all measures, the AVH group showed intermediate values between healthy controls and the nAVH group. These findings seem to suggest that, in the early stage of the disorder, a significant impairment of fronto-temporal connectivity is evident in patients who do not experience AVHs. This is consistent with the hypothesis that, whilst mild disruption of connectivity might still enable the emergence of AVHs, more severe alterations may prevent the occurrence of the hallucinatory experience. PMID:24361862

  15. Decreases in energy and increases in phase locking of event related oscillations to auditory stimuli occurs over adolescence in human and rodent brain

    PubMed Central

    Ehlers, Cindy L.; Wills, Derek N.; Desikan, Anita; Phillips, Evelyn; Havstad, James

    2014-01-01

    Synchrony of phase (phase locking) of event-related oscillations (EROs) within and between different brain areas has been suggested to reflect communication exchange between neural networks and as such may be a sensitive and translational measure of changes in brain remodeling that occurs during adolescence. This study sought to investigate developmental changes in EROs using a similar auditory event-related potential (ERP) paradigm in both rats and humans. Energy and phase variability of EROs collected from 38 young adult men (age 18-25 yrs), 33 periadolescent boys (age 10-14 yrs), 15 male periadolescent rats (@ Post Natal Day (PD) 36) and 19 male adult rats (@ PD 103) were investigated. Three channels of ERP data (Frontal Cortex, FZ; Central Cortex, CZ; Parietal Cortex, PZ) were collected from the humans using an oddball plus “noise” paradigm that was presented under passive (no behavioral response required) conditions in the periadolescents and under active conditions (where each subject was instructed to depress a counter each time he detected an infrequent (target) tone) in adults and adolescents. ERPs were recorded in rats using only the passive paradigm. In order to compare the tasks used in rats to those used in humans we first studied whether three ERO measures (energy, phase locking index (within an electrode site, PLI), phase difference locking index (between different electrode sites, PDLI)) differentiated the “active” from “passive” ERP tasks. Secondly we explored our main question of whether the three ERO measures, differentiated adults from periadolescents in a similar manner in both humans and rats. No significant changes were found in measures of ERO energy between the active and passive tasks in the periadolescent human participants. There was a smaller but significant increase in PLI but not PDLI as a function of “active” task requirements. Developmental differences were found in energy, PLI and PDLI values between the

  16. Abnormal regional activity and functional connectivity in resting-state brain networks associated with etiology confirmed unilateral pulsatile tinnitus in the early stage of disease.

    PubMed

    Lv, Han; Zhao, Pengfei; Liu, Zhaohui; Li, Rui; Zhang, Ling; Wang, Peng; Yan, Fei; Liu, Liheng; Wang, Guopeng; Zeng, Rong; Li, Ting; Dong, Cheng; Gong, Shusheng; Wang, Zhenchang

    2017-03-01

    Abnormal neural activities can be revealed by resting-state functional magnetic resonance imaging (rs-fMRI) using analyses of the regional activity and functional connectivity (FC) of the networks in the brain. This study was designed to demonstrate the functional network alterations in the patients with pulsatile tinnitus (PT). In this study, we recruited 45 patients with unilateral PT in the early stage of disease (less than 48 months of disease duration) and 45 normal controls. We used regional homogeneity (ReHo) and seed-based FC computational methods to reveal resting-state brain activity features associated with pulsatile tinnitus. Compared with healthy controls, PT patients showed regional abnormalities mainly in the left middle occipital gyrus (MOG), posterior cingulate gyrus (PCC), precuneus and right anterior insula (AI). When these regions were defined as seeds, we demonstrated widespread modification of interaction between the auditory and non-auditory networks. The auditory network was positively connected with the cognitive control network (CCN), which may associate with tinnitus related distress. Both altered regional activity and changed FC were found in the visual network. The modification of interactions of higher order networks were mainly found in the DMN, CCN and limbic networks. Functional connectivity between the left MOG and left parahippocampal gyrus could also be an index to reflect the disease duration. This study helped us gain a better understanding of the characteristics of neural network modifications in patients with pulsatile tinnitus.

  17. Hemodynamic responses in human multisensory and auditory association cortex to purely visual stimulation

    PubMed Central

    Meyer, Martin; Baumann, Simon; Marchina, Sarah; Jancke, Lutz

    2007-01-01

    Background Recent findings of a tight coupling between visual and auditory association cortices during multisensory perception in monkeys and humans raise the question whether consistent paired presentation of simple visual and auditory stimuli prompts conditioned responses in unimodal auditory regions or multimodal association cortex once visual stimuli are presented in isolation in a post-conditioning run. To address this issue fifteen healthy participants partook in a "silent" sparse temporal event-related fMRI study. In the first (visual control) habituation phase they were presented with briefly red flashing visual stimuli. In the second (auditory control) habituation phase they heard brief telephone ringing. In the third (conditioning) phase we coincidently presented the visual stimulus (CS) paired with the auditory stimulus (UCS). In the fourth phase participants either viewed flashes paired with the auditory stimulus (maintenance, CS-) or viewed the visual stimulus in isolation (extinction, CS+) according to a 5:10 partial reinforcement schedule. The participants had no other task than attending to the stimuli and indicating the end of each trial by pressing a button. Results During unpaired visual presentations (preceding and following the paired presentation) we observed significant brain responses beyond primary visual cortex in the bilateral posterior auditory association cortex (planum temporale, planum parietale) and in the right superior temporal sulcus whereas the primary auditory regions were not involved. By contrast, the activity in auditory core regions was markedly larger when participants were presented with auditory stimuli. Conclusion These results demonstrate involvement of multisensory and auditory association areas in perception of unimodal visual stimulation which may reflect the instantaneous forming of multisensory associations and cannot be attributed to sensation of an auditory event. More importantly, we are able to show that brain

  18. Attention Modulates the Auditory Cortical Processing of Spatial and Category Cues in Naturalistic Auditory Scenes.

    PubMed

    Renvall, Hanna; Staeren, Noël; Barz, Claudia S; Ley, Anke; Formisano, Elia

    2016-01-01

    This combined fMRI and MEG study investigated brain activations during listening and attending to natural auditory scenes. We first recorded, using in-ear microphones, vocal non-speech sounds, and environmental sounds that were mixed to construct auditory scenes containing two concurrent sound streams. During the brain measurements, subjects attended to one of the streams while spatial acoustic information of the scene was either preserved (stereophonic sounds) or removed (monophonic sounds). Compared to monophonic sounds, stereophonic sounds evoked larger blood-oxygenation-level-dependent (BOLD) fMRI responses in the bilateral posterior superior temporal areas, independent of which stimulus attribute the subject was attending to. This finding is consistent with the functional role of these regions in the (automatic) processing of auditory spatial cues. Additionally, significant differences in the cortical activation patterns depending on the target of attention were observed. Bilateral planum temporale and inferior frontal gyrus were preferentially activated when attending to stereophonic environmental sounds, whereas when subjects attended to stereophonic voice sounds, the BOLD responses were larger at the bilateral middle superior temporal gyrus and sulcus, previously reported to show voice sensitivity. In contrast, the time-resolved MEG responses were stronger for mono- than stereophonic sounds in the bilateral auditory cortices at ~360 ms after the stimulus onset when attending to the voice excerpts within the combined sounds. The observed effects suggest that during the segregation of auditory objects from the auditory background, spatial sound cues together with other relevant temporal and spectral cues are processed in an attention-dependent manner at the cortical locations generally involved in sound recognition. More synchronous neuronal activation during monophonic than stereophonic sound processing, as well as (local) neuronal inhibitory mechanisms in

  19. Attention Modulates the Auditory Cortical Processing of Spatial and Category Cues in Naturalistic Auditory Scenes

    PubMed Central

    Renvall, Hanna; Staeren, Noël; Barz, Claudia S.; Ley, Anke; Formisano, Elia

    2016-01-01

    This combined fMRI and MEG study investigated brain activations during listening and attending to natural auditory scenes. We first recorded, using in-ear microphones, vocal non-speech sounds, and environmental sounds that were mixed to construct auditory scenes containing two concurrent sound streams. During the brain measurements, subjects attended to one of the streams while spatial acoustic information of the scene was either preserved (stereophonic sounds) or removed (monophonic sounds). Compared to monophonic sounds, stereophonic sounds evoked larger blood-oxygenation-level-dependent (BOLD) fMRI responses in the bilateral posterior superior temporal areas, independent of which stimulus attribute the subject was attending to. This finding is consistent with the functional role of these regions in the (automatic) processing of auditory spatial cues. Additionally, significant differences in the cortical activation patterns depending on the target of attention were observed. Bilateral planum temporale and inferior frontal gyrus were preferentially activated when attending to stereophonic environmental sounds, whereas when subjects attended to stereophonic voice sounds, the BOLD responses were larger at the bilateral middle superior temporal gyrus and sulcus, previously reported to show voice sensitivity. In contrast, the time-resolved MEG responses were stronger for mono- than stereophonic sounds in the bilateral auditory cortices at ~360 ms after the stimulus onset when attending to the voice excerpts within the combined sounds. The observed effects suggest that during the segregation of auditory objects from the auditory background, spatial sound cues together with other relevant temporal and spectral cues are processed in an attention-dependent manner at the cortical locations generally involved in sound recognition. More synchronous neuronal activation during monophonic than stereophonic sound processing, as well as (local) neuronal inhibitory mechanisms in

  20. Regional manifold learning for deformable registration of brain MR images.

    PubMed

    Ye, Dong Hye; Hamm, Jihun; Kwon, Dongjin; Davatzikos, Christos; Pohl, Kilian M

    2012-01-01

    We propose a method for deformable registration based on learning the manifolds of individual brain regions. Recent publications on registration of medical images advocate the use of manifold learning in order to confine the search space to anatomically plausible deformations. Existing methods construct manifolds based on a single metric over the entire image domain thus frequently miss regional brain variations. We address this issue by first learning manifolds for specific regions and then computing region-specific deformations from these manifolds. We then determine deformations for the entire image domain by learning the global manifold in such a way that it preserves the region-specific deformations. We evaluate the accuracy of our method by applying it to the LPBA40 dataset and measuring the overlap of the deformed segmentations. The result shows significant improvement in registration accuracy on cortex regions compared to other state of the art methods.

  1. Brain regionalization: of signaling centers and boundaries.

    PubMed

    Cavodeassi, Florencia; Houart, Corinne

    2012-03-01

    Our knowledge of the general mechanisms controlling the formation of the vertebrate central nervous system has advanced tremendously in the last decade. Here, we discuss the impact of the combined use of cell manipulation, in vivo imaging and genetics in the zebrafish on recent progress in understanding how signaling processes progressively control regionalization of the central nervous system. We highlight the unresolved issues and speculate upon the fundamental role the zebrafish will continue having in answering them.

  2. Specific regions of the brain are capable of fructose metabolism.

    PubMed

    Oppelt, Sarah A; Zhang, Wanming; Tolan, Dean R

    2017-02-15

    High fructose consumption in the Western diet correlates with disease states such as obesity and metabolic syndrome complications, including type II diabetes, chronic kidney disease, and non-alcoholic fatty acid liver disease. Liver and kidneys are responsible for metabolism of 40-60% of ingested fructose, while the physiological fate of the remaining fructose remains poorly understood. The primary metabolic pathway for fructose includes the fructose-transporting solute-like carrier transport proteins 2a (SLC2a or GLUT), including GLUT5 and GLUT9, ketohexokinase (KHK), and aldolase. Bioinformatic analysis of gene expression encoding these proteins (glut5, glut9, khk, and aldoC, respectively) identifies other organs capable of this fructose metabolism. This analysis predicts brain, lymphoreticular tissue, placenta, and reproductive tissues as possible additional organs for fructose metabolism. While expression of these genes is highest in liver, the brain is predicted to have expression levels of these genes similar to kidney. RNA in situ hybridization of coronal slices of adult mouse brains validate the in silico expression of glut5, glut9, khk, and aldoC, and show expression across many regions of the brain, with the most notable expression in the cerebellum, hippocampus, cortex, and olfactory bulb. Dissected samples of these brain regions show KHK and aldolase enzyme activity 5-10 times the concentration of that in liver. Furthermore, rates of fructose oxidation in these brain regions are 15-150 times that of liver slices, confirming the bioinformatics prediction and in situ hybridization data. This suggests that previously unappreciated regions across the brain can use fructose, in addition to glucose, for energy production.

  3. Regional brain glucose metabolism in patients with brain tumors before and after radiotherapy

    SciTech Connect

    Wang, G.J.; Volkow, N.D.; Lau, Y.H.

    1994-05-01

    This study was performed to measure regional glucose metabolism in nonaffected brain regions of patients with primary or metastatic brain tumors. Seven female and four male patients (mean age 51.5{plus_minus}14.0 years old) were compared with eleven age and sex matched normal subjects. None of the patients had hydrocephalus and/or increased intracranial pressure. Brain glucose metabolism was measured using FDG-PET scan. Five of the patients were reevaluated one week after receiving radiation treatment (RT) to the brain. Patients were on Decadron and/or Dilantin at the time of both scan. PET images were analyzed with a template of 115 nonoverlapping regions of interest and then grouped into eight gray matter regions on each hemisphere. Brain regions with tumors and edema shown in MR imaging were excluded. Z scores were used to compare individual patients` regional values with those of normal subjects. The number of regional values with Z scores of less than - 3.0 were considered abnormal and were quantified. The mean global glucose metabolic rate (mean of all regions) in nonaffected brain regions of patients was significantly lower than that of normal controls (32.1{plus_minus}9.0 versus 44.8{plus_minus}6.3 {mu}mol/100g/min, p<0.001). Analyses of individual subjects revealed that none of the controls and 8 of the 11 patients had at least one abnormal region. In these 8 patients the regions which were abnormal were most frequently localized in right (n=5) and left occipital (n=6) and right orbital frontal cortex (n=7) whereas the basal ganglia was not affected. Five of the patients who had repeated scans following RT showed decrements in tumor metabolism (41{plus_minus}20.5%) and a significant increase in whole brain metabolism (8.6{plus_minus}5.3%, p<0.001). The improvement in whole brain metabolism after RT suggests that the brain metabolic decrements in the patients were related to the presence of tumoral tissue and not just a medication effect.

  4. Region-specific growth restriction of brain following preterm birth

    PubMed Central

    Iwata, Sachiko; Katayama, Reiji; Kinoshita, Masahiro; Saikusa, Mamoru; Araki, Yuko; Takashima, Sachio; Abe, Toshi; Iwata, Osuke

    2016-01-01

    Regional brain sizes of very-preterm infants at term-equivalent age differ from those of term-born peers, which have been linked with later cognitive impairments. However, dependence of regional brain volume loss on gestational age has not been studied in detail. To investigate the spatial pattern of brain growth in neonates without destructive brain lesions, head MRI of 189 neonates with a wide range of gestational age (24–42 weeks gestation) was assessed using simple metrics measurements. Dependence of MRI findings on gestational age at birth (Agebirth) and the corrected age at MRI scan (AgeMRI) were assessed. The head circumference was positively correlated with AgeMRI, but not Agebirth. The bi-parietal width, deep grey matter area and the trans-cerebellar diameter were positively correlated with both Agebirth and AgeMRI. The callosal thickness (positive), atrial width of lateral ventricle (negative) and the inter-hemispheric distance (negative) were exclusively correlated with Agebirth. The callosal thickness and cerebral/cerebellar transverse diameters showed predominant dependence on Agebirth over AgeMRI, suggesting that brain growth after preterm-birth was considerably restricted or even became negligible compared with that in utero. Such growth restriction after preterm birth may extensively affect relatively more matured infants, considering the linear relationships observed between brain sizes and Agebirth. PMID:27658730

  5. Reproducibility of regional brain metabolic responses to lorazepam

    SciTech Connect

    Wang, G.J.; Volkow, N.D.; Overall, J. |

    1996-10-01

    Changes in regional brain glucose metabolism in response to benzodiazepine agonists have been used as indicators of benzodiazepine-GABA receptor function. The purpose of this study was to assess the reproducibility of these responses. Sixteen healthy right-handed men underwent scanning with PET and [{sup 18}F]fluorodeoxyglucose (FDG) twice: before placebo and before lorazepam (30 {mu}g/kg). The same double FDG procedure was repeated 6-8 wk later on the men to assess test-retest reproducibility. The regional absolute brain metabolic values obtained during the second evaluation were significantly lower than those obtained from the first evaluation regardless of condition (p {le} 0.001). Lorazepam significantly and consistently decreased both whole-brain metabolism and the magnitude. The regional pattern of the changes were comparable for both studies (12.3% {plus_minus} 6.9% and 13.7% {plus_minus} 7.4%). Lorazepam effects were the largest in the thalamus (22.2% {plus_minus} 8.6% and 22.4% {plus_minus} 6.9%) and occipital cortex (19% {plus_minus} 8.9% and 21.8% {plus_minus} 8.9%). Relative metabolic measures were highly reproducible both for pharmacolgic and replication condition. This study measured the test-retest reproducibility in regional brain metabolic responses, and although the global and regional metabolic values were significantly lower for the repeated evaluation, the response to lorazepam was highly reproducible. 1613 refs., 3 figs., 3 tabs.

  6. Expression of arginine decarboxylase in brain regions and neuronal cells

    PubMed Central

    Iyo, Abiye H.; Zhu, Meng-Yang; Ordway, Gregory A.; Regunathan, Soundar

    2010-01-01

    After our initial report of a mammalian gene for arginine decarboxylase, an enzyme for the synthesis of agmatine from arginine, we have determined the regional expression of ADC in rat. We have analyzed the expression of ADC in rat brain regions by activity, protein and mRNA levels, and the regulation of expression in neuronal cells by RNA interference. In rat brain, ADC was widely expressed in major brain regions, with a substantial amount in hypothalamus, followed by cortex, and with least amounts in locus coeruleus and medulla. ADC mRNA was detected in primary astrocytes and C6 glioma cells. While no ADC message was detected in fresh neurons (3 days old), significant message appeared in differentiated neurons (3 weeks old). PC12 cells, treated with nerve growth factor, had higher ADC mRNA compared with naive cells. The siRNA mixture directed towards the N-terminal regions of ADC cDNA down-regulated the levels of mRNA and protein in cultured neurons/C6 glioma cells and these cells produced lower agmatine. Thus, this study demonstrates that ADC message is expressed in rat brain regions, that it is regulated in neuronal cells and that the down-regulation of ADC activity by specific siRNA leads to lower agmatine production. PMID:16445852

  7. Conventional and cross-correlation brain-stem auditory evoked responses in the white leghorn chick: rate manipulations

    NASA Technical Reports Server (NTRS)

    Burkard, R.; Jones, S.; Jones, T.

    1994-01-01

    Rate-dependent changes in the chick brain-stem auditory evoked response (BAER) using conventional averaging and a cross-correlation technique were investigated. Five 15- to 19-day-old white leghorn chicks were anesthetized with Chloropent. In each chick, the left ear was acoustically stimulated. Electrical pulses of 0.1-ms duration were shaped, attenuated, and passed through a current driver to an Etymotic ER-2 which was sealed in the ear canal. Electrical activity from stainless-steel electrodes was amplified, filtered (300-3000 Hz) and digitized at 20 kHz. Click levels included 70 and 90 dB peSPL. In each animal, conventional BAERs were obtained at rates ranging from 5 to 90 Hz. BAERs were also obtained using a cross-correlation technique involving pseudorandom pulse sequences called maximum length sequences (MLSs). The minimum time between pulses, called the minimum pulse interval (MPI), ranged from 0.5 to 6 ms. Two BAERs were obtained for each condition. Dependent variables included the latency and amplitude of the cochlear microphonic (CM), wave 2 and wave 3. BAERs were observed in all chicks, for all level by rate combinations for both conventional and MLS BAERs. There was no effect of click level or rate on the latency of the CM. The latency of waves 2 and 3 increased with decreasing click level and increasing rate. CM amplitude decreased with decreasing click level, but was not influenced by click rate for the 70 dB peSPL condition. For the 90 dB peSPL click, CM amplitude was uninfluenced by click rate for conventional averaging. For MLS BAERs, CM amplitude was similar to conventional averaging for longer MPIs.(ABSTRACT TRUNCATED AT 250 WORDS).

  8. Central auditory disorders: toward a neuropsychology of auditory objects

    PubMed Central

    Goll, Johanna C.; Crutch, Sebastian J.; Warren, Jason D.

    2012-01-01

    Purpose of review Analysis of the auditory environment, source identification and vocal communication all require efficient brain mechanisms for disambiguating, representing and understanding complex natural sounds as ‘auditory objects’. Failure of these mechanisms leads to a diverse spectrum of clinical deficits. Here we review current evidence concerning the phenomenology, mechanisms and brain substrates of auditory agnosias and related disorders of auditory object processing. Recent findings Analysis of lesions causing auditory object deficits has revealed certain broad anatomical correlations: deficient parsing of the auditory scene is associated with lesions involving the parieto-temporal junction, while selective disorders of sound recognition occur with more anterior temporal lobe or extra-temporal damage. Distributed neural networks have been increasingly implicated in the pathogenesis of such disorders as developmental dyslexia, congenital amusia and tinnitus. Auditory category deficits may arise from defective interaction of spectrotemporal encoding and executive and mnestic processes. Dedicated brain mechanisms are likely to process specialised sound objects such as voices and melodies. Summary Emerging empirical evidence suggests a clinically relevant, hierarchical and fractionated neuropsychological model of auditory object processing that provides a framework for understanding auditory agnosias and makes specific predictions to direct future work. PMID:20975559

  9. Cognitive Abilities Independent of IQ Correlate with Regional Brain Structure

    ERIC Educational Resources Information Center

    Johnson, Wendy; Jung, Rex E.; Colom, Roberto; Haier, Richard J.

    2008-01-01

    There is increasing evidence relating psychometric measures of general intelligence and reasoning to regional brain structure and function assessed with a variety of neuroimaging techniques. Cognitive dimensions independent of general intelligence can also be identified psychometrically and studied for any neuroanatomical correlates. Here we…

  10. Early life stress affects limited regional brain activity in depression.

    PubMed

    Du, Lian; Wang, Jingjie; Meng, Ben; Yong, Na; Yang, Xiangying; Huang, Qingling; Zhang, Yan; Yang, Lingling; Qu, Yuan; Chen, Zhu; Li, Yongmei; Lv, Fajin; Hu, Hua

    2016-05-03

    Early life stress (ELS) can alter brain function and increases the risk of major depressive disorder (MDD) in later life. This study investigated whether ELS contributes to differences in regional brain activity between MDD patients and healthy controls (HC), as measured by amplitude of low-frequency fluctuation (ALFF)/fractional (f)ALFF. Eighteen first-episode, treatment-naïve MDD patients and HC were assessed with the Childhood Trauma Questionnaire and resting-state functional magnetic resonance imaging. We compared ALFF/fALFF between MDD patients and HC, with or without controlling for ELS, and determined whether ELS level was correlated with regional brain activity in each group. After regressing out ELS, we found that ALFF increased in bilateral amygdala and left orbital/cerebellum, while fALFF decreased in left inferior temporal and right middle frontal gyri in MDD patients relative to controls. ELS positively correlated with regional activity in the left cerebellum in MDD and in the right post-central/inferior temporal/superior frontal cingulate, inferior frontal gyrus and bilateral cerebellum in HC. Our findings indicate that there is only very limited region showing correlation between ELS and brain activity in MDD, while diverse areas in HC, suggesting ELS has few impacts on MDD patients.

  11. Brain Regions Underlying Word Finding Difficulties in Temporal Lobe Epilepsy

    ERIC Educational Resources Information Center

    Trebuchon-Da Fonseca, Agnes; Guedj, Eric; Alario, F-Xavier; Laguitton, Virginie; Mundler, Olivier; Chauvel, Patrick; Liegeois-Chauvel, Catherine

    2009-01-01

    Word finding difficulties are often reported by epileptic patients with seizures originating from the language dominant cerebral hemisphere, for example, in temporal lobe epilepsy. Evidence regarding the brain regions underlying this deficit comes from studies of peri-operative electro-cortical stimulation, as well as post-surgical performance.…

  12. Early life stress affects limited regional brain activity in depression

    PubMed Central

    Du, Lian; Wang, Jingjie; Meng, Ben; Yong, Na; Yang, Xiangying; Huang, Qingling; Zhang, Yan; Yang, Lingling; Qu, Yuan; Chen, Zhu; Li, Yongmei; Lv, Fajin; Hu, Hua

    2016-01-01

    Early life stress (ELS) can alter brain function and increases the risk of major depressive disorder (MDD) in later life. This study investigated whether ELS contributes to differences in regional brain activity between MDD patients and healthy controls (HC), as measured by amplitude of low-frequency fluctuation (ALFF)/fractional (f)ALFF. Eighteen first-episode, treatment-naïve MDD patients and HC were assessed with the Childhood Trauma Questionnaire and resting-state functional magnetic resonance imaging. We compared ALFF/fALFF between MDD patients and HC, with or without controlling for ELS, and determined whether ELS level was correlated with regional brain activity in each group. After regressing out ELS, we found that ALFF increased in bilateral amygdala and left orbital/cerebellum, while fALFF decreased in left inferior temporal and right middle frontal gyri in MDD patients relative to controls. ELS positively correlated with regional activity in the left cerebellum in MDD and in the right post-central/inferior temporal/superior frontal cingulate, inferior frontal gyrus and bilateral cerebellum in HC. Our findings indicate that there is only very limited region showing correlation between ELS and brain activity in MDD, while diverse areas in HC, suggesting ELS has few impacts on MDD patients. PMID:27138376

  13. Influence of ketamine on regional brain glucose use

    SciTech Connect

    Davis, D.W.; Mans, A.M.; Biebuyck, J.F.; Hawkins, R.A.

    1988-08-01

    The purpose of this study was to determine the effect of different doses of ketamine on cerebral function at the level of individual brain structures as reflected by glucose use. Rats received either 5 or 30 mg/kg ketamine intravenously as a loading dose, followed by an infusion to maintain a steady-state level of the drug. An additional group received 30 mg/kg as a single injection only, and was studied 20 min later, by which time they were recovering consciousness (withdrawal group). Regional brain energy metabolism was evaluated with (6-/sup 14/C)glucose and quantitative autoradiography during a 5-min experimental period. A subhypnotic, steady-state dose (5 mg/kg) of ketamine caused a stimulation of glucose use in most brain areas, with an average increase of 20%. At the larger steady-state dose (30 mg/kg, which is sufficient to cause anesthesia), there was no significant effect on most brain regions; some sensory nuclei were depressed (inferior colliculus, -29%; cerebellar dentate nucleus, -18%; vestibular nucleus, -16%), but glucose use in the ventral posterior hippocampus was increased by 33%. In contrast, during withdrawal from a 30-mg/kg bolus, there was a stimulation of glucose use throughout the brain (21-78%), at a time when plasma ketamine levels were similar to the levels in the 5 mg/kg group. At each steady-state dose, as well as during withdrawal, ketamine caused a notable stimulation of glucose use by the hippocampus.

  14. Auditory verbal hallucinations: neuroimaging and treatment.

    PubMed

    Bohlken, M M; Hugdahl, K; Sommer, I E C

    2017-01-01

    Auditory verbal hallucinations (AVH) are a frequently occurring phenomenon in the general population and are considered a psychotic symptom when presented in the context of a psychiatric disorder. Neuroimaging literature has shown that AVH are subserved by a variety of alterations in brain structure and function, which primarily concentrate around brain regions associated with the processing of auditory verbal stimuli and with executive control functions. However, the direction of association between AVH and brain function remains equivocal in certain research areas and needs to be carefully reviewed and interpreted. When AVH have significant impact on daily functioning, several efficacious treatments can be attempted such as antipsychotic medication, brain stimulation and cognitive-behavioural therapy. Interestingly, the neural correlates of these treatments largely overlap with brain regions involved in AVH. This suggests that the efficacy of treatment corresponds to a normalization of AVH-related brain activity. In this selected review, we give a compact yet comprehensive overview of the structural and functional neuroimaging literature on AVH, with a special focus on the neural correlates of efficacious treatment.

  15. Differential susceptibility of brain regions to tributyltin chloride toxicity.

    PubMed

    Mitra, Sumonto; Siddiqui, Waseem A; Khandelwal, Shashi

    2015-12-01

    Tributyltin (TBT), a well-known endocrine disruptor, is an omnipresent environmental pollutant and is explicitly used in many industrial applications. Previously we have shown its neurotoxic potential on cerebral cortex of male Wistar rats. As the effect of TBT on other brain regions is not known, we planned this study to evaluate its effect on four brain regions (cerebellum, hippocampus, hypothalamus, and striatum). Four-week-old male Wistar rats were gavaged with a single dose of TBT-chloride (TBTC) (10, 20, and 30 mg/kg) and sacrificed on days 3 and 7, respectively. Effect of TBTC on blood-brain barrier (BBB) permeability and tin (Sn) accumulation were measured. Oxidative stress indexes such as reactive oxygen species (ROS), reduced and oxidized glutathione (GSH/GSSG) ratio, lipid peroxidation, and protein carbonylation were analyzed as they play an imperative role in various neuropathological conditions. Since metal catalyzed reactions are a major source of oxidant generation, levels of essential metals like iron (Fe), zinc (Zn), and calcium (Ca) were estimated. We found that TBTC disrupted BBB and increased Sn accumulation, both of which appear significantly correlated. Altered metal homeostasis and ROS generation accompanied by elevated lipid peroxidation and protein carbonylation indicated oxidative damage which appeared more pronounced in the striatum than in cerebellum, hippocampus, and hypothalamus. This could be associated to the depleted GSH levels in striatum. These results suggest that striatum is more susceptible to TBTC induced oxidative damage as compared with other brain regions under study.

  16. Cross-Modal Plasticity in Higher-Order Auditory Cortex of Congenitally Deaf Cats Does Not Limit Auditory Responsiveness to Cochlear Implants

    PubMed Central

    Baumhoff, Peter; Tillein, Jochen; Lomber, Stephen G.; Hubka, Peter; Kral, Andrej

    2016-01-01

    Congenital sensory deprivation can lead to reorganization of the deprived cortical regions by another sensory system. Such cross-modal reorganization may either compete with or complement the “original“ inputs to the deprived area after sensory restoration and can thus be either adverse or beneficial for sensory restoration. In congenital deafness, a previous inactivation study documented that supranormal visual behavior was mediated by higher-order auditory fields in congenitally deaf cats (CDCs). However, both the auditory responsiveness of “deaf” higher-order fields and interactions between the reorganized and the original sensory input remain unknown. Here, we studied a higher-order auditory field responsible for the supranormal visual function in CDCs, the auditory dorsal zone (DZ). Hearing cats and visual cortical areas served as a control. Using mapping with microelectrode arrays, we demonstrate spatially scattered visual (cross-modal) responsiveness in the DZ, but show that this did not interfere substantially with robust auditory responsiveness elicited through cochlear implants. Visually responsive and auditory-responsive neurons in the deaf auditory cortex formed two distinct populations that did not show bimodal interactions. Therefore, cross-modal plasticity in the deaf higher-order auditory cortex had limited effects on auditory inputs. The moderate number of scattered cross-modally responsive neurons could be the consequence of exuberant connections formed during development that were not pruned postnatally in deaf cats. Although juvenile brain circuits are modified extensively by experience, the main driving input to the cross-modally (visually) reorganized higher-order auditory cortex remained auditory in congenital deafness. SIGNIFICANCE STATEMENT In a common view, the “unused” auditory cortex of deaf individuals is reorganized to a compensatory sensory function during development. According to this view, cross-modal plasticity takes

  17. The hippocampus may be more susceptible to environmental noise than the auditory cortex.

    PubMed

    Cheng, Liang; Wang, Shao-Hui; Huang, Yun; Liao, Xiao-Mei

    2016-03-01

    Noise exposure can cause structural and functional problem in the auditory cortex (AC) and hippocampus, the two brain regions in the auditory and non-auditory systems respectively. The aim of the present study was to explore which one of these two brain regions may be more susceptible to environmental noise. The AC and hippocampus of mice were separated following 1 or 3 weeks exposure to moderate noise (80 dB SPL, 2 h/day). The levels of oxidative stress and tau phosphorylation were then measured to evaluate the effects by noise. Results showed significant peroxidation and tau hyperphosphorylation in the hippocampus with 1 week of noise exposure. However, the AC did not show significant changes until exposure for 3 weeks. These data suggest that although the hippocampus and AC were affected by moderate noise exposure, the hippocampus in the non-auditory system may have been more vulnerable to environmental noise than the AC.

  18. Different Brain Regions are Infected with Fungi in Alzheimer's Disease.

    PubMed

    Pisa, Diana; Alonso, Ruth; Rábano, Alberto; Rodal, Izaskun; Carrasco, Luis

    2015-10-15

    The possibility that Alzheimer's disease (AD) has a microbial aetiology has been proposed by several researchers. Here, we provide evidence that tissue from the central nervous system (CNS) of AD patients contain fungal cells and hyphae. Fungal material can be detected both intra- and extracellularly using specific antibodies against several fungi. Different brain regions including external frontal cortex, cerebellar hemisphere, entorhinal cortex/hippocampus and choroid plexus contain fungal material, which is absent in brain tissue from control individuals. Analysis of brain sections from ten additional AD patients reveals that all are infected with fungi. Fungal infection is also observed in blood vessels, which may explain the vascular pathology frequently detected in AD patients. Sequencing of fungal DNA extracted from frozen CNS samples identifies several fungal species. Collectively, our findings provide compelling evidence for the existence of fungal infection in the CNS from AD patients, but not in control individuals.

  19. Cortical brain regions associated with color processing: an FMRI study.

    PubMed

    Bramão, Inês; Faísca, Luís; Forkstam, Christian; Reis, Alexandra; Petersson, Karl Magnus

    2010-11-05

    To clarify whether the neural pathways concerning color processing are the same for natural objects, for artifacts objects and for non-objects we examined brain responses measured with functional magnetic resonance imaging (FMRI) during a covert naming task including the factors color (color vs. black&white (B&W)) and stimulus type (natural vs. artifacts vs. non-objects). Our results indicate that the superior parietal lobule and precuneus (BA 7) bilaterally, the right hippocampus and the right fusifom gyrus (V4) make part of a network responsible for color processing both for natural objects and artifacts, but not for non-objects. When color objects (both natural and artifacts) were contrasted with color non-objects we observed activations in the right parahippocampal gyrus (BA 35/36), the superior parietal lobule (BA 7) bilaterally, the left inferior middle temporal region (BA 20/21) and the inferior and superior frontal regions (BA 10/11/47). These additional activations suggest that colored objects recruit brain regions that are related to visual semantic information/retrieval and brain regions related to visuo-spatial processing. Overall, the results suggest that color information is an attribute that can improve object recognition (behavioral results) and activate a specific neural network related to visual semantic information that is more extensive than for B&W objects during object recognition.

  20. Differences in Regional Brain Volumes Two Months and One Year after Mild Traumatic Brain Injury.

    PubMed

    Zagorchev, Lyubomir; Meyer, Carsten; Stehle, Thomas; Wenzel, Fabian; Young, Stewart; Peters, Jochen; Weese, Juergen; Paulsen, Keith; Garlinghouse, Matthew; Ford, James; Roth, Robert; Flashman, Laura; McAllister, Thomas

    2016-01-01

    Conventional structural imaging is often normal after mild traumatic brain injury (mTBI). There is a need for structural neuroimaging biomarkers that facilitate detection of milder injuries, allow recovery trajectory monitoring, and identify those at risk for poor functional outcome and disability. We present a novel approach to quantifying volumes of candidate brain regions at risk for injury. Compared to controls, patients with mTBI had significantly smaller volumes in several regions including the caudate, putamen, and thalamus when assessed 2 months after injury. These differences persisted but were reduced in magnitude 1 year after injury, suggesting the possibility of normalization over time in the affected regions. More pronounced differences, however, were found in the amygdala and hippocampus, suggesting the possibility of regionally specific responses to injury.

  1. Modulation of Auditory Spatial Attention by Angry Prosody: An fMRI Auditory Dot-Probe Study.

    PubMed

    Ceravolo, Leonardo; Frühholz, Sascha; Grandjean, Didier

    2016-01-01

    Emotional stimuli have been shown to modulate attentional orienting through signals sent by subcortical brain regions that modulate visual perception at early stages of processing. Fewer studies, however, have investigated a similar effect of emotional stimuli on attentional orienting in the auditory domain together with an investigation of brain regions underlying such attentional modulation, which is the general aim of the present study. Therefore, we used an original auditory dot-probe paradigm involving simultaneously presented neutral and angry non-speech vocal utterances lateralized to either the left or the right auditory space, immediately followed by a short and lateralized single sine wave tone presented in the same (valid trial) or in the opposite space as the preceding angry voice (invalid trial). Behavioral results showed an expected facilitation effect for target detection during valid trials while functional data showed greater activation in the middle and posterior superior temporal sulci (STS) and in the medial frontal cortex for valid vs. invalid trials. The use of reaction time facilitation [absolute value of the Z-score of valid-(invalid+neutral)] as a group covariate extended enhanced activity in the amygdalae, auditory thalamus, and visual cortex. Taken together, our results suggest the involvement of a large and distributed network of regions among which the STS, thalamus, and amygdala are crucial for the decoding of angry prosody, as well as for orienting and maintaining attention within an auditory space that was previously primed by a vocal emotional event.

  2. Modulation of Auditory Spatial Attention by Angry Prosody: An fMRI Auditory Dot-Probe Study

    PubMed Central

    Ceravolo, Leonardo; Frühholz, Sascha; Grandjean, Didier

    2016-01-01

    Emotional stimuli have been shown to modulate attentional orienting through signals sent by subcortical brain regions that modulate visual perception at early stages of processing. Fewer studies, however, have investigated a similar effect of emotional stimuli on attentional orienting in the auditory domain together with an investigation of brain regions underlying such attentional modulation, which is the general aim of the present study. Therefore, we used an original auditory dot-probe paradigm involving simultaneously presented neutral and angry non-speech vocal utterances lateralized to either the left or the right auditory space, immediately followed by a short and lateralized single sine wave tone presented in the same (valid trial) or in the opposite space as the preceding angry voice (invalid trial). Behavioral results showed an expected facilitation effect for target detection during valid trials while functional data showed greater activation in the middle and posterior superior temporal sulci (STS) and in the medial frontal cortex for valid vs. invalid trials. The use of reaction time facilitation [absolute value of the Z-score of valid-(invalid+neutral)] as a group covariate extended enhanced activity in the amygdalae, auditory thalamus, and visual cortex. Taken together, our results suggest the involvement of a large and distributed network of regions among which the STS, thalamus, and amygdala are crucial for the decoding of angry prosody, as well as for orienting and maintaining attention within an auditory space that was previously primed by a vocal emotional event. PMID:27242420

  3. The function of BDNF in the adult auditory system.

    PubMed

    Singer, Wibke; Panford-Walsh, Rama; Knipper, Marlies

    2014-01-01

    The inner ear of vertebrates is specialized to perceive sound, gravity and movements. Each of the specialized sensory organs within the cochlea (sound) and vestibular system (gravity, head movements) transmits information to specific areas of the brain. During development, brain-derived neurotrophic factor (BDNF) orchestrates the survival and outgrowth of afferent fibers connecting the vestibular organ and those regions in the cochlea that map information for low frequency sound to central auditory nuclei and higher-auditory centers. The role of BDNF in the mature inner ear is less understood. This is mainly due to the fact that constitutive BDNF mutant mice are postnatally lethal. Only in the last few years has the improved technology of performing conditional cell specific deletion of BDNF in vivo allowed the study of the function of BDNF in the mature developed organ. This review provides an overview of the current knowledge of the expression pattern and function of BDNF in the peripheral and central auditory system from just prior to the first auditory experience onwards. A special focus will be put on the differential mechanisms in which BDNF drives refinement of auditory circuitries during the onset of sensory experience and in the adult brain. This article is part of the Special Issue entitled 'BDNF Regulation of Synaptic Structure, Function, and Plasticity'.

  4. Comparison of air- and bone-conducted brain stem auditory evoked responses in young dogs and dogs with bilateral ear canal obstruction.

    PubMed

    Wolschrijn, C F; Venker-van Haagen, A J; van den Brom, W E

    1997-11-01

    Brain stem responses to air- and bone-conducted stimuli were analyzed in 11 young dogs, using an in-the-ear transducer and a vibrator designed for human hearing tests, respectively. The mean thresholds were 0 to 10 dB for air-conducted stimuli and 50 to 60 dB for bone-conducted stimuli. The wave forms and inter-peak latencies of the waves of the auditory evoked responses elicited by air-conducted and bone-conducted stimuli were similar. This indicated that the signals had the same origin and thus both the air-conducted and the bone-conducted responses could be considered to be auditory responses. Measurement of air-conducted and bone-conducted brain stem-evoked responses in five dogs with bilateral chronic obstructive ear disease revealed thresholds of 50 to 60 dB for air-conducted stimuli and 60 to 70 dB for bone-conducted stimuli. By comparison of these results with those in the 11 young dogs, it could be concluded that there was hearing loss other than that caused by obstruction of the ear canals.

  5. Spatiotemporal reconstruction of auditory steady-state responses to acoustic amplitude modulations: Potential sources beyond the auditory pathway.

    PubMed

    Farahani, Ehsan Darestani; Goossens, Tine; Wouters, Jan; van Wieringen, Astrid

    2017-03-01

    Investigating the neural generators of auditory steady-state responses (ASSRs), i.e., auditory evoked brain responses, with a wide range of screening and diagnostic applications, has been the focus of various studies for many years. Most of these studies employed a priori assumptions regarding the number and location of neural generators. The aim of this study is to reconstruct ASSR sources with minimal assumptions in order to gain in-depth insight into the number and location of brain regions that are activated in response to low- as well as high-frequency acoustically amplitude modulated signals. In order to reconstruct ASSR sources, we applied independent component analysis with subsequent equivalent dipole modeling to single-subject EEG data (young adults, 20-30 years of age). These data were based on white noise stimuli, amplitude modulated at 4, 20, 40, or 80Hz. The independent components that exhibited a significant ASSR were clustered among all participants by means of a probabilistic clustering method based on a Gaussian mixture model. Results suggest that a widely distributed network of sources, located in cortical as well as subcortical regions, is active in response to 4, 20, 40, and 80Hz amplitude modulated noises. Some of these sources are located beyond the central auditory pathway. Comparison of brain sources in response to different modulation frequencies suggested that the identified brain sources in the brainstem, the left and the right auditory cortex show a higher responsiveness to 40Hz than to the other modulation frequencies.

  6. Predicting regional neurodegeneration from the healthy brain functional connectome.

    PubMed

    Zhou, Juan; Gennatas, Efstathios D; Kramer, Joel H; Miller, Bruce L; Seeley, William W

    2012-03-22

    Neurodegenerative diseases target large-scale neural networks. Four competing mechanistic hypotheses have been proposed to explain network-based disease patterning: nodal stress, transneuronal spread, trophic failure, and shared vulnerability. Here, we used task-free fMRI to derive the healthy intrinsic connectivity patterns seeded by brain regions vulnerable to any of five distinct neurodegenerative diseases. These data enabled us to investigate how intrinsic connectivity in health predicts region-by-region vulnerability to disease. For each illness, specific regions emerged as critical network "epicenters" whose normal connectivity profiles most resembled the disease-associated atrophy pattern. Graph theoretical analyses in healthy subjects revealed that regions with higher total connectional flow and, more consistently, shorter functional paths to the epicenters, showed greater disease-related vulnerability. These findings best fit a transneuronal spread model of network-based vulnerability. Molecular pathological approaches may help clarify what makes each epicenter vulnerable to its targeting disease and how toxic protein species travel between networked brain structures.

  7. Multivariate sensitivity to voice during auditory categorization.

    PubMed

    Lee, Yune Sang; Peelle, Jonathan E; Kraemer, David; Lloyd, Samuel; Granger, Richard

    2015-09-01

    Past neuroimaging studies have documented discrete regions of human temporal cortex that are more strongly activated by conspecific voice sounds than by nonvoice sounds. However, the mechanisms underlying this voice sensitivity remain unclear. In the present functional MRI study, we took a novel approach to examining voice sensitivity, in which we applied a signal detection paradigm to the assessment of multivariate pattern classification among several living and nonliving categories of auditory stimuli. Within this framework, voice sensitivity can be interpreted as a distinct neural representation of brain activity that correctly distinguishes human vocalizations from other auditory object categories. Across a series of auditory categorization tests, we found that bilateral superior and middle temporal cortex consistently exhibited robust sensitivity to human vocal sounds. Although the strongest categorization was in distinguishing human voice from other categories, subsets of these regions were also able to distinguish reliably between nonhuman categories, suggesting a general role in auditory object categorization. Our findings complement the current evidence of cortical sensitivity to human vocal sounds by revealing that the greatest sensitivity during categorization tasks is devoted to distinguishing voice from nonvoice categories within human temporal cortex.

  8. Relationship of regional brain β-amyloid to gait speed

    PubMed Central

    Payoux, Pierre; Djilali, Adel; Delrieu, Julien; Hoogendijk, Emiel O.; Rolland, Yves; Cesari, Matteo; Weiner, Michael W.; Andrieu, Sandrine; Vellas, Bruno

    2016-01-01

    Objective: To investigate in vivo the relationship of regional brain β-amyloid (Aβ) to gait speed in a group of elderly individuals at high risk for dementia. Methods: Cross-sectional associations between brain Aβ as measured with [18F]florbetapir PET and gait speed were examined in 128 elderly participants. Subjects ranged from healthy to mildly cognitively impaired enrolled in the control arm of the multidomain intervention in the Multidomain Alzheimer Preventive Trial (MAPT). Nearly all participants presented spontaneous memory complaints. Regional [18F]florbetapir (AV45) standardized uptake volume ratios were obtained via semiautomated quantitative analysis using the cerebellum as reference region. Gait speed was measured by timing participants while they walked 4 meters. Associations were explored with linear regression, correcting for age, sex, education, body mass index (BMI), and APOE genotype. Results: We found a significant association between Aβ in the posterior and anterior putamen, occipital cortex, precuneus, and anterior cingulate and slow gait speed (all corrected p < 0.05). A multivariate model emphasized the locations of the posterior putamen and the precuneus. Aβ burden explained up to 9% of the variance in gait speed, and significantly improved regression models already containing demographic variables, BMI, and APOE status. Conclusions: The present PET study confirms, in vivo, previous postmortem evidence showing an association between Alzheimer disease (AD) pathology and gait speed, and provides additional evidence on potential regional effects of brain Aβ on motor function. More research is needed to elucidate the neural mechanisms underlying these regional associations, which may involve motor and sensorimotor circuits hitherto largely neglected in the pathophysiology of AD. PMID:26643548

  9. Abnormal regional brain function in Parkinson's disease: truth or fiction?

    PubMed

    Ma, Yilong; Tang, Chengke; Moeller, James R; Eidelberg, David

    2009-04-01

    Normalization of regional measurements by the global mean is commonly employed to minimize inter-subject variability in functional imaging studies. This practice is based on the assumption that global values do not substantially differ between patient and control groups. In this issue of NeuroImage, Borghammer and colleagues challenge the validity of this assumption. They focus on Parkinson's disease (PD) and use computer simulations to show that lower global values can produce spurious increases in subcortical brain regions. The authors speculate that the increased signal observed in these areas in PD is artefactual and unrelated to localized changes in brain function. In this commentary, we summarize what is currently known of the relationship between regional and global metabolic activity in PD and experimental parkinsonism. We found that early stage PD patients exhibit global values that are virtually identical to those of age-matched healthy subjects. SPM analysis revealed increased normalized metabolic activity in a discrete set of biologically relevant subcortical brain regions. Because of their higher variability, the corresponding absolute regional measures did not differ across the two groups. Longitudinal imaging studies in this population showed that the subcortical elevations in normalized metabolism appeared earlier and progressed faster than did focal cortical or global metabolic reductions. The observed increases in subcortical activity, but not the global changes, correlated with independent clinical measures of disease progression. Multivariate analysis with SSM/PCA further confirmed that the abnormal spatial covariance structure of early PD is dominated by these subcortical increases as opposed to network-related reductions in cortical metabolic activity or global changes. Thus, increased subcortical activity in PD cannot be regarded as a simple artefact of global normalization. Moreover, stability of the normalized measurements, particularly at

  10. Enhanced regional brain metabolic responses to benzodiazepines in cocaine abusers

    SciTech Connect

    Volkow, N.D.; Wang, G.J.; Fowler, J.S.

    1997-05-01

    While dopamine (DA) appears to be crucial for cocaine reinforcement, its involvement in cocaine addiction is much less clear. Using PET we have shown persistent reductions in striatal DA D2 receptors (which arc predominantly located on GABA cells) in cocaine abusers. This finding coupled to GABA`s role as an effector for DA led us to investigate if there were GABAergic abnormalities in cocaine abusers. In this study we measured regional brain metabolic responses to lorazepam, to indirectly assess GABA function (benzodiazepines facilitate GABAergic neurotransmission). Methods: The experimental subjects consisted of 12 active cocaine abusers and 32 age matched controls. Each subject underwent two PET FDG scans obtained within 1 week of each other. The first FDG scan was obtained after administration of placebo (3 cc of saline solution) given 40-50 minutes prior to FDG; and the second after administration of lorazepam (30 {mu}g/kg) given 40-50 minutes prior to FDG. The subjects were blind to the drugs received. Results: Lorazepam-induced sleepiness was significantly greater in abusers than in controls (p<0.001). Lorazepam-induced decreases in brain glucose metabolism were significantly larger in cocaine abusers than in controls. Whereas in controls whole brain metabolism decreased 13{+-}7 %, in cocaine abusers it decreased 21{+-}13 % (p < 0.05). Lorazepam-induced decrements in regional metabolism were significantly larger in striatum (p < 0.0 1), thalamus (p < 0.01) and cerebellum (p < 0.005) of cocaine abusers than of controls (ANOVA diagnosis by condition (placebo versus lorazepam) interaction effect). The only brain region for which the absolute metabolic changes-induced by lorazepam in cocaine abusers were equivalent to those in controls was the orbitofrontal cortex. These results document an accentuated sensitivity to benzodiazepines in cocaine abusers which is compatible with disrupted GABAergic function in these patients.

  11. Assessment of intermittent UMTS electromagnetic field effects on blood circulation in the human auditory region using a near-infrared system.

    PubMed

    Spichtig, Sonja; Scholkmann, Felix; Chin, Lydia; Lehmann, Hugo; Wolf, Martin

    2012-01-01

    The aim of the present study was to assess the potential effects of intermittent Universal Mobile Telecommunications System electromagnetic fields (UMTS-EMF) on blood circulation in the human head (auditory region) using near-infrared spectroscopy (NIRS) on two different timescales: short-term (effects occurring within 80 s) and medium-term (effects occurring within 80 s to 30 min). For the first time, we measured potential immediate effects of UMTS-EMF in real-time without any interference during exposure. Three different exposures (sham, 0.18 W/kg, and 1.8 W/kg) were applied in a controlled, randomized, crossover, and double-blind paradigm on 16 healthy volunteers. In addition to oxy-, deoxy-, and total haemoglobin concentrations ([O(2) Hb], [HHb], and [tHb], respectively), the heart rate (HR), subjective well-being, tiredness, and counting speed were recorded. During exposure to 0.18 W/kg, we found a significant short-term increase in Δ[O(2) Hb] and Δ[tHb], which is small (≈17%) compared to a functional brain activation. A significant decrease in the medium-term response of Δ[HHb] at 0.18 and 1.8 W/kg exposures was detected, which is in the range of physiological fluctuations. The medium-term ΔHR was significantly higher (+1.84 bpm) at 1.8 W/kg than for sham exposure. The other parameters showed no significant effects. Our results suggest that intermittent exposure to UMTS-EMF has small short- and medium-term effects on cerebral blood circulation and HR.

  12. Repetitive Transcranial Magnetic Stimulation Activates Specific Regions in Rat Brain

    NASA Astrophysics Data System (ADS)

    Ji, Ru-Rong; Schlaepfer, Thomas E.; Aizenman, Carlos D.; Epstein, Charles M.; Qiu, Dike; Huang, Justin C.; Rupp, Fabio

    1998-12-01

    Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique to induce electric currents in the brain. Although rTMS is being evaluated as a possible alternative to electroconvulsive therapy for the treatment of refractory depression, little is known about the pattern of activation induced in the brain by rTMS. We have compared immediate early gene expression in rat brain after rTMS and electroconvulsive stimulation, a well-established animal model for electroconvulsive therapy. Our result shows that rTMS applied in conditions effective in animal models of depression induces different patterns of immediate-early gene expression than does electroconvulsive stimulation. In particular, rTMS evokes strong neural responses in the paraventricular nucleus of the thalamus (PVT) and in other regions involved in the regulation of circadian rhythms. The response in PVT is independent of the orientation of the stimulation probe relative to the head. Part of this response is likely because of direct activation, as repetitive magnetic stimulation also activates PVT neurons in brain slices.

  13. Local awakening: regional reorganizations of brain oscillations after sleep.

    PubMed

    Tsai, Pei-Jung; Chen, Sharon Chia-Ju; Hsu, Chun-Yao; Wu, Changwei W; Wu, Yu-Chin; Hung, Ching-Sui; Yang, Albert C; Liu, Po-Yu; Biswal, Bharat; Lin, Ching-Po

    2014-11-15

    Brain functions express rhythmic fluctuations accompanied by sleep and wakefulness each day, but how sleep regulates brain rhythms remains unclear. Following the dose-dependent local sleep concept, two succeeding questions emerge: (1) is the sleep regulation a network-specific process; and (2) is the awakening state dependent on the previous sleep stages? To answer the questions, we conducted simultaneous EEG and fMRI recordings over 22 healthy male participants, along pre-sleep, nocturnal sleep and awakening. Using paired comparisons between awakening and pre-sleep conditions, three scenarios of the regional specificity were demonstrated on awakening: (1) the default-mode and hippocampal networks maintained similar connectivity and spectral power; (2) the sensorimotor network presented reduced connectivity and spectral power; and (3) the thalamus demonstrated substantially enhanced connectivity to the neo-cortex with decreased spectral power. With regard to the stage effect, the deep sleep group had significant changes in both functional connectivity and spectral power on awakening, whereas the indices of light sleep group remained relatively quiescent after sleep. The phenomena implied that slow-wave sleep could be key to rebooting the BOLD fluctuations after sleep. In conclusion, the regional specificity and the stage effect were verified in support of the local awakening concept, indicating that sleep regulation leads to the reorganization of brain networks upon awakening.

  14. Non-auditory Effect of Noise Pollution and Its Risk on Human Brain Activity in Different Audio Frequency Using Electroencephalogram Complexity

    PubMed Central

    ALLAHVERDY, Armin; JAFARI, Amir Homayoun

    2016-01-01

    Background: Noise pollution is one of the most harmful ambiance disturbances. It may cause many deficits in ability and activity of persons in the urban and industrial areas. It also may cause many kinds of psychopathies. Therefore, it is very important to measure the risk of this pollution in different area. Methods: This study was conducted in the Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences from June to September of 2015, in which, different frequencies of noise pollution were played for volunteers. 16-channel EEG signal was recorded synchronously, then by using fractal dimension and relative power of Beta sub-band of EEG, the complexity of EEG signals was measured. Results: As the results, it is observed that the average complexity of brain activity is increased in the middle of audio frequency range and the complexity map of brain activity changes in different frequencies, which can show the effects of frequency changes on human brain activity. Conclusion: The complexity of EEG is a good measure for ranking the annoyance and non-auditory risk of noise pollution on human brain activity. PMID:27957440

  15. Radioreceptor assay of opioid peptides in selected canine brain regions

    SciTech Connect

    Desiderio, D.M.; Takeshita, H.

    1985-09-01

    A radioreceptor assay using the opioid delta receptor-preferring ligand D-/sup 2/ala, D-/sup 5/leu leucine enkephalin (/sup 3/H-DADL) and the broader-specificity ligand /sup 3/H-etorphine was used to measure five HPLC-purified neuropeptide fractions derived from the peptide-rich fraction of tissue homogenates of nine anatomical regions of the canine brain. The receptoractive peptides studied were methionine enkephalin, alpha-neo-endorphin, dynorphin 1-8, methionine enkephalin-Arg-Phe, and leucine enkephalin. These peptides derive from two larger precursors: proenkephalin A, which contains methionine enkephalin, leucine enkephalin, methionine enkephalin-Arg-Phe; and proenkephalin B, which contains alpha-neo-endorphin and dynorphin 1-8. Receptoractive peptides were measured in the peptide-rich fraction derived from homogenates of canine hypothalamus, pituitary, caudate nucleus, amygdala, hippocampus, mid-brain, thalamus, pons-medulla, and cortex.

  16. Copper pathology in vulnerable brain regions in Parkinson's disease.

    PubMed

    Davies, Katherine M; Bohic, Sylvain; Carmona, Asunción; Ortega, Richard; Cottam, Veronica; Hare, Dominic J; Finberg, John P M; Reyes, Stefanie; Halliday, Glenda M; Mercer, Julian F B; Double, Kay L

    2014-04-01

    Synchrotron-based x-ray fluorescence microscopy, immunofluorescence, and Western blotting were used to investigate changes in copper (Cu) and Cu-associated pathways in the vulnerable substantia nigra (SN) and locus coeruleus (LC) and in nondegenerating brain regions in cases of Parkinson's disease (PD) and appropriate healthy and disease controls. In PD and incidental Lewy body disease, levels of Cu and Cu transporter protein 1, were significantly reduced in surviving neurons in the SN and LC. Specific activity of the cuproprotein superoxide dismutase 1 was unchanged in the SN in PD but was enhanced in the parkinsonian anterior cingulate cortex, a region with α-synuclein pathology, normal Cu, and limited cell loss. These data suggest that regions affected by α-synuclein pathology may display enhanced vulnerability and cell loss if Cu-dependent protective mechanisms are compromised. Additional investigation of copper pathology in PD may identify novel targets for the development of protective therapies for this disorder.

  17. Attention to natural auditory signals.

    PubMed

    Caporello Bluvas, Emily; Gentner, Timothy Q

    2013-11-01

    The challenge of understanding how the brain processes natural signals is compounded by the fact that such signals are often tied closely to specific natural behaviors and natural environments. This added complexity is especially true for auditory communication signals that can carry information at multiple hierarchical levels, and often occur in the context of other competing communication signals. Selective attention provides a mechanism to focus processing resources on specific components of auditory signals, and simultaneously suppress responses to unwanted signals or noise. Although selective auditory attention has been well-studied behaviorally, very little is known about how selective auditory attention shapes the processing on natural auditory signals, and how the mechanisms of auditory attention are implemented in single neurons or neural circuits. Here we review the role of selective attention in modulating auditory responses to complex natural stimuli in humans. We then suggest how the current understanding can be applied to the study of selective auditory attention in the context natural signal processing at the level of single neurons and populations in animal models amenable to invasive neuroscience techniques. This article is part of a Special Issue entitled "Communication Sounds and the Brain: New Directions and Perspectives".

  18. Severe and extensive neonatal hearing loss in cats results in auditory cortex plasticity that differentiates into two regions.

    PubMed

    Rajan, R; Irvine, D R F

    2010-06-01

    We examined the response characteristics of primary auditory cortex (A1) neurons in adult cats partially but extensively deafened by ototoxic drugs 2-8 days after birth. The damage evoked extensive A1 topographic map reorganization as also found by others, but a novel finding was that in the majority of cats with low-frequency edges to the cochlear lesion, the area of reorganization segregated into two areas expressing the same novel frequency inputs but differentiated by neuronal sensitivity and responsiveness. Immediately adjacent to normal A1 is an approximately 1.2-mm-wide area of reorganization in which sensitivity and responsiveness to sound are similar to that in normal A1 in the same animals and in unlesioned adult animals. Extending further into deprived A1 is a more extensive area of reorganization where neurons have poorer sensitivity and responsiveness to new inputs. These two areas did not differ in response-area bandwidth and response latency. We interpret these novel changes as the cortical consequences of severe receptor organ lesions extending to low-frequency cochlear regions. We speculate that the two areas of A1 reorganization may reflect differences in the transcortical spatial distribution of thalamo-cortical and horizontal intracortical connections. Qualitatively similar changes in response properties have been seen after retinal lesions producing large areas of visual cortical reorganization, suggesting they might be a general consequence of receptor lesions that deprive large regions of cortex of normal input. These effects may have perceptual implications for the use of cochlear implants in patients with residual low-frequency hearing.

  19. Dynamic pupillary exchange engages brain regions encoding social salience.

    PubMed

    Harrison, Neil A; Gray, Marcus A; Critchley, Hugo D

    2009-01-01

    Covert exchange of autonomic responses may shape social affective behavior, as observed in mirroring of pupillary responses during sadness processing. We examined how, independent of facial emotional expression, dynamic coherence between one's own and another's pupil size modulates regional brain activity. Fourteen subjects viewed pairs of eye stimuli while undergoing fMRI. Using continuous pupillometry biofeedback, the size of the observed pupils was varied, correlating positively or negatively with changes in participants' own pupils. Viewing both static and dynamic stimuli activated right fusiform gyrus. Observing dynamically changing pupils activated STS and amygdala, regions engaged by non-static and salient facial features. Discordance between observed and observer's pupillary changes enhanced activity within bilateral anterior insula, left amygdala and anterior cingulate. In contrast, processing positively correlated pupils enhanced activity within left frontal operculum. Our findings suggest pupillary signals are monitored continuously during social interactions and that incongruent changes activate brain regions involved in tracking motivational salience and attentionally meaningful information. Naturalistically, dynamic coherence in pupillary change follows fluctuations in ambient light. Correspondingly, in social contexts discordant pupil response is likely to reflect divergence of dispositional state. Our data provide empirical evidence for an autonomically mediated extension of forward models of motor control into social interaction.

  20. Regional brain metabolism in a murine systemic lupus erythematosus model.

    PubMed

    Vo, An; Volpe, Bruce T; Tang, Chris C; Schiffer, Wynne K; Kowal, Czeslawa; Huerta, Patricio T; Uluğ, Aziz M; Dewey, Stephen L; Eidelberg, David; Diamond, Betty

    2014-08-01

    Systemic lupus erythematosus (SLE) is characterized by multiorgan inflammation, neuropsychiatric disorders (NPSLE), and anti-nuclear antibodies. We previously identified a subset of anti-DNA antibodies (DNRAb) cross-reactive with the N-methyl-D-aspartate receptor, present in 30% to 40% of patients, able to enhance excitatory post-synaptic potentials and trigger neuronal apoptosis. DNRAb+ mice exhibit memory impairment or altered fear response, depending on whether the antibody penetrates the hippocampus or amygdala. Here, we used 18F-fluorodeoxyglucose (FDG) microPET to plot changes in brain metabolism after regional blood-brain barrier (BBB) breach. In DNRAb+ mice, metabolism declined at the site of BBB breach in the first 2 weeks and increased over the next 2 weeks. In contrast, DNRAb- mice exhibited metabolic increases in these regions over the 4 weeks after the insult. Memory impairment was present in DNRAb+ animals with hippocampal BBB breach and altered fear conditioning in DNRAb+ mice with amygdala BBB breach. In DNRAb+ mice, we observed an inverse relationship between neuron number and regional metabolism, while a positive correlation was observed in DNRAb- mice. These findings suggest that local metabolic alterations in this model take place through different mechanisms with distinct time courses, with important implications for the interpretation of imaging data in SLE subjects.

  1. Regional brain metabolism in a murine systemic lupus erythematosus model

    PubMed Central

    Vo, An; Volpe, Bruce T; Tang, Chris C; Schiffer, Wynne K; Kowal, Czeslawa; Huerta, Patricio T; Uluğ, Aziz M; Dewey, Stephen L; Eidelberg, David; Diamond, Betty

    2014-01-01

    Systemic lupus erythematosus (SLE) is characterized by multiorgan inflammation, neuropsychiatric disorders (NPSLE), and anti-nuclear antibodies. We previously identified a subset of anti-DNA antibodies (DNRAb) cross-reactive with the N-methyl-D-aspartate receptor, present in 30% to 40% of patients, able to enhance excitatory post-synaptic potentials and trigger neuronal apoptosis. DNRAb+ mice exhibit memory impairment or altered fear response, depending on whether the antibody penetrates the hippocampus or amygdala. Here, we used 18F-fluorodeoxyglucose (FDG) microPET to plot changes in brain metabolism after regional blood–brain barrier (BBB) breach. In DNRAb+ mice, metabolism declined at the site of BBB breach in the first 2 weeks and increased over the next 2 weeks. In contrast, DNRAb− mice exhibited metabolic increases in these regions over the 4 weeks after the insult. Memory impairment was present in DNRAb+ animals with hippocampal BBB breach and altered fear conditioning in DNRAb+ mice with amygdala BBB breach. In DNRAb+ mice, we observed an inverse relationship between neuron number and regional metabolism, while a positive correlation was observed in DNRAb− mice. These findings suggest that local metabolic alterations in this model take place through different mechanisms with distinct time courses, with important implications for the interpretation of imaging data in SLE subjects. PMID:24824914

  2. Representations of Pitch and Timbre Variation in Human Auditory Cortex.

    PubMed

    Allen, Emily J; Burton, Philip C; Olman, Cheryl A; Oxenham, Andrew J

    2017-02-01

    Pitch and timbre are two primary dimensions of auditory perception, but how they are represented in the human brain remains a matter of contention. Some animal studies of auditory cortical processing have suggested modular processing, with different brain regions preferentially coding for pitch or timbre, whereas other studies have suggested a distributed code for different attributes across the same population of neurons. This study tested whether variations in pitch and timbre elicit activity in distinct regions of the human temporal lobes. Listeners were presented with sequences of sounds that varied in either fundamental frequency (eliciting changes in pitch) or spectral centroid (eliciting changes in brightness, an important attribute of timbre), with the degree of pitch or timbre variation in each sequence parametrically manipulated. The BOLD responses from auditory cortex increased with increasing sequence variance along each perceptual dimension. The spatial extent, region, and laterality of the cortical regions most responsive to variations in pitch or timbre at the univariate level of analysis were largely overlapping. However, patterns of activation in response to pitch or timbre variations were discriminable in most subjects at an individual level using multivoxel pattern analysis, suggesting a distributed coding of the two dimensions bilaterally in human auditory cortex.

  3. Neurons derived from different brain regions are inherently different in vitro: a novel multiregional brain-on-a-chip.

    PubMed

    Dauth, Stephanie; Maoz, Ben M; Sheehy, Sean P; Hemphill, Matthew A; Murty, Tara; Macedonia, Mary Kate; Greer, Angie M; Budnik, Bogdan; Parker, Kevin Kit

    2017-03-01

    Brain in vitro models are critically important to developing our understanding of basic nervous system cellular physiology, potential neurotoxic effects of chemicals, and specific cellular mechanisms of many disease states. In this study, we sought to address key shortcomings of current brain in vitro models: the scarcity of comparative data for cells originating from distinct brain regions and the lack of multiregional brain in vitro models. We demonstrated that rat neurons from different brain regions exhibit unique profiles regarding their cell composition, protein expression, metabolism, and electrical activity in vitro. In vivo, the brain is unique in its structural and functional organization, and the interactions and communication between different brain areas are essential components of proper brain function. This fact and the observation that neurons from different areas of the brain exhibit unique behaviors in vitro underline the importance of establishing multiregional brain in vitro models. Therefore, we here developed a multiregional brain-on-a-chip and observed a reduction of overall firing activity, as well as altered amounts of astrocytes and specific neuronal cell types compared with separately cultured neurons. Furthermore, this multiregional model was used to study the effects of phencyclidine, a drug known to induce schizophrenia-like symptoms in vivo, on individual brain areas separately while monitoring downstream effects on interconnected regions. Overall, this work provides a comparison of cells from different brain regions in vitro and introduces a multiregional brain-on-a-chip that enables the development of unique disease models incorporating essential in vivo features.NEW & NOTEWORTHY Due to the scarcity of comparative data for cells from different brain regions in vitro, we demonstrated that neurons isolated from distinct brain areas exhibit unique behaviors in vitro. Moreover, in vivo proper brain function is dependent on the

  4. Isatin, regional distribution in rat brain and tissues.

    PubMed

    Watkins, P; Clow, A; Glover, V; Halket, J; Przyborowska, A; Sandler, M

    1990-01-01

    Isatin has recently been identified in rat tissues and normal human urine, where it forms the major proportion of the endogenous monoamine oxidase inhibitor, tribulin. In this paper, we show that isatin, measured by gas chromatography/mass spectrometry, has a distinct regional distribution in rat tissues, with highest concentrations in seminal vesicles (1.6 ?g/g) and vas deferens (3.4 ?g/g). There was also a discontinuous distribution within rat brain, concentrations being highest in the hippocampus (0.13 ?g/g).

  5. Auditory agnosia and auditory spatial deficits following left hemispheric lesions: evidence for distinct processing pathways.

    PubMed

    Clarke, S; Bellmann, A; Meuli, R A; Assal, G; Steck, A J

    2000-01-01

    Auditory recognition and auditory spatial functions were studied in four patients with circumscribed left hemispheric lesions. Patient FD was severely deficient in recognition of environmental sounds but normal in auditory localisation and auditory motion perception. The lesion included the left superior, middle and inferior temporal gyri and lateral auditory areas (as identified in previous anatomical studies), but spared Heschl's gyrus, the acoustic radiation and the thalamus. Patient SD had the same profile as FD, with deficient recognition of environmental sounds but normal auditory localisation and motion perception. The lesion comprised the postero-inferior part of the frontal convexity and the anterior third of the temporal lobe; data from non-human primates indicate that the latter are interconnected with lateral auditory areas. Patient MA was deficient in recognition of environmental sounds, auditory localisation and auditory motion perception, confirming that auditory spatial functions can be disturbed by left unilateral damage; the lesion involved the supratemporal region as well as the temporal, postero-inferior frontal and antero-inferior parietal convexities. Patient CZ was severely deficient in auditory motion perception and partially deficient in auditory localisation, but normal in recognition of environmental sounds; the lesion involved large parts of the parieto-frontal convexity and the supratemporal region. We propose that auditory information is processed in the human auditory cortex along two distinct pathways, one lateral devoted to auditory recognition and one medial and posterior devoted to auditory spatial functions.

  6. Speech motor brain regions are differentially recruited during perception of native and foreign-accented phonemes for first and second language listeners.

    PubMed

    Callan, Daniel; Callan, Akiko; Jones, Jeffery A

    2014-01-01

    Brain imaging studies indicate that speech motor areas are recruited for auditory speech perception, especially when intelligibility is low due to environmental noise or when speech is accented. The purpose of the present study was to determine the relative contribution of brain regions to the processing of speech containing phonetic categories from one's own language, speech with accented samples of one's native phonetic categories, and speech with unfamiliar phonetic categories. To that end, native English and Japanese speakers identified the speech sounds /r/ and /l/ that were produced by native English speakers (unaccented) and Japanese speakers (foreign-accented) while functional magnetic resonance imaging measured their brain activity. For native English speakers, the Japanese accented speech was more difficult to categorize than the unaccented English speech. In contrast, Japanese speakers have difficulty distinguishing between /r/ and /l/, so both the Japanese accented and English unaccented speech were difficult to categorize. Brain regions involved with listening to foreign-accented productions of a first language included primarily the right cerebellum, left ventral inferior premotor cortex PMvi, and Broca's area. Brain regions most involved with listening to a second-language phonetic contrast (foreign-accented and unaccented productions) also included the left PMvi and the right cerebellum. Additionally, increased activity was observed in the right PMvi, the left and right ventral superior premotor cortex PMvs, and the left cerebellum. These results support a role for speech motor regions during the perception of foreign-accented native speech and for perception of difficult second-language phonetic contrasts.

  7. Connectivity of epileptic brain regions in wake and sleep.

    PubMed

    Klimes, Petr; Duque, Juliano J; Jurak, Pavel; Halamek, Josef; Worrell, Gregory A

    2015-08-01

    Focal epileptic brain is characterized by a region of pathological tissue seizure onset zone (SOZ) - the pathologic tissue generating seizures. During the interictal period (nonseizure) the SOZ is characterized by epileptiform activity - interictal spikes & high-frequency oscillations (HFO). The SOZ also exhibits hyper-synchrony and functional disconnection from the surrounding areas. Recent studies have described the synchrony inside the SOZ and surrounding tissue for just small sets of patients (2-4) and without any distinction in behavioral states. Wake and sleep cycles can, however, have a significant influence on SOZ activity. Here we show the results of connectivity analysis in three fundamental areas of the epileptic brain - inside SOZ, outside SOZ and bridging areas in 7 patients during wake and sleep. We observed increased synchrony inside SOZ and decreased synchrony on its edges (bridging areas) in specific frequency bands. We also detected significant differences of synchrony levels between wake and sleep periods in HFO frequencies. Our results provide additional insight into the properties of SOZ connectivity. Knowledge of these principles may prove useful for SOZ localization and understanding epileptic brain function in general.

  8. Brain size and visual environment predict species differences in paper wasp sensory processing brain regions (hymenoptera: vespidae, polistinae).

    PubMed

    O'Donnell, Sean; Clifford, Marie R; DeLeon, Sara; Papa, Christopher; Zahedi, Nazaneen; Bulova, Susan J

    2013-01-01

    The mosaic brain evolution hypothesis predicts that the relative volumes of functionally distinct brain regions will vary independently and correlate with species' ecology. Paper wasp species (Hymenoptera: Vespidae, Polistinae) differ in light exposure: they construct open versus enclosed nests and one genus (Apoica) is nocturnal. We asked whether light environments were related to species differences in the size of antennal and optic processing brain tissues. Paper wasp brains have anatomically distinct peripheral and central regions that process antennal and optic sensory inputs. We measured the volumes of 4 sensory processing brain regions in paper wasp species from 13 Neotropical genera including open and enclosed nesters, and diurnal and nocturnal species. Species differed in sensory region volumes, but there was no evidence for trade-offs among sensory modalities. All sensory region volumes correlated with brain size. However, peripheral optic processing investment increased with brain size at a higher rate than peripheral antennal processing investment. Our data suggest that mosaic and concerted (size-constrained) brain evolution are not exclusive alternatives. When brain regions increase with brain size at different rates, these distinct allometries can allow for differential investment among sensory modalities. As predicted by mosaic evolution, species ecology was associated with some aspects of brain region investment. Nest architecture variation was not associated with brain investment differences, but the nocturnal genus Apoica had the largest antennal:optic volume ratio in its peripheral sensory lobes. Investment in central processing tissues was not related to nocturnality, a pattern also noted in mammals. The plasticity of neural connections in central regions may accommodate evolutionary shifts in input from the periphery with relatively minor changes in volume.

  9. Multimodal lexical processing in auditory cortex is literacy skill dependent.

    PubMed

    McNorgan, Chris; Awati, Neha; Desroches, Amy S; Booth, James R

    2014-09-01

    Literacy is a uniquely human cross-modal cognitive process wherein visual orthographic representations become associated with auditory phonological representations through experience. Developmental studies provide insight into how experience-dependent changes in brain organization influence phonological processing as a function of literacy. Previous investigations show a synchrony-dependent influence of letter presentation on individual phoneme processing in superior temporal sulcus; others demonstrate recruitment of primary and associative auditory cortex during cross-modal processing. We sought to determine whether brain regions supporting phonological processing of larger lexical units (monosyllabic words) over larger time windows is sensitive to cross-modal information, and whether such effects are literacy dependent. Twenty-two children (age 8-14 years) made rhyming judgments for sequentially presented word and pseudoword pairs presented either unimodally (auditory- or visual-only) or cross-modally (audiovisual). Regression analyses examined the relationship between literacy and congruency effects (overlapping orthography and phonology vs. overlapping phonology-only). We extend previous findings by showing that higher literacy is correlated with greater congruency effects in auditory cortex (i.e., planum temporale) only for cross-modal processing. These skill effects were specific to known words and occurred over a large time window, suggesting that multimodal integration in posterior auditory cortex is critical for fluent reading.

  10. The Drosophila Auditory System

    PubMed Central

    Boekhoff-Falk, Grace; Eberl, Daniel F.

    2013-01-01

    Development of a functional auditory system in Drosophila requires specification and differentiation of the chordotonal sensilla of Johnston’s organ (JO) in the antenna, correct axonal targeting to the antennal mechanosensory and motor center (AMMC) in the brain, and synaptic connections to neurons in the downstream circuit. Chordotonal development in JO is functionally complicated by structural, molecular and functional diversity that is not yet fully understood, and construction of the auditory neural circuitry is only beginning to unfold. Here we describe our current understanding of developmental and molecular mechanisms that generate the exquisite functions of the Drosophila auditory system, emphasizing recent progress and highlighting important new questions arising from research on this remarkable sensory system. PMID:24719289

  11. Central auditory imperception.

    PubMed

    Snow, J B; Rintelmann, W F; Miller, J M; Konkle, D F

    1977-09-01

    The development of clinically applicable techniques for the evaluation of hearing impairment caused by lesions of the central auditory pathways has increased clinical interest in the anatomy and physiology of these pathways. A conceptualization of present understanding of the anatomy and physiology of the central auditory pathways is presented. Clinical tests based on reduction of redundancy of the speech message, degradation of speech and binaural interations are presented. Specifically performance-intensity functions, filtered speech tests, competing message tests and time-compressed speech tests are presented with the emphasis on our experience with time-compressed speech tests. With proper use of these tests not only can central auditory impairments by detected, but brain stem lesions can be distinguished from cortical lesions.

  12. Origins of task-specific sensory-independent organization in the visual and auditory brain: neuroscience evidence, open questions and clinical implications.

    PubMed

    Heimler, Benedetta; Striem-Amit, Ella; Amedi, Amir

    2015-12-01

    Evidence of task-specific sensory-independent (TSSI) plasticity from blind and deaf populations has led to a better understanding of brain organization. However, the principles determining the origins of this plasticity remain unclear. We review recent data suggesting that a combination of the connectivity bias and sensitivity to task-distinctive features might account for TSSI plasticity in the sensory cortices as a whole, from the higher-order occipital/temporal cortices to the primary sensory cortices. We discuss current theories and evidence, open questions and related predictions. Finally, given the rapid progress in visual and auditory restoration techniques, we address the crucial need to develop effective rehabilitation approaches for sensory recovery.

  13. Microglial brain region-dependent diversity and selective regional sensitivities to ageing

    PubMed Central

    Grabert, Kathleen; Michoel, Tom; Karavolos, Michail H; Clohisey, Sara; Baillie, J Kenneth; Stevens, Mark P; Freeman, Tom C; Summers, Kim M; McColl, Barry W

    2015-01-01

    Microglia play critical roles in neural development, homeostasis and neuroinflammation and are increasingly implicated in age-related neurological dysfunction. Neurodegeneration often occurs in disease-specific spatially-restricted patterns, the origins of which are unknown. We performed the first genome-wide analysis of microglia from discrete brain regions across the adult lifespan of the mouse and reveal that microglia have distinct region-dependent transcriptional identities and age in a regionally variable manner. In the young adult brain, differences in bioenergetic and immunoregulatory pathways were the major sources of heterogeneity and suggested that cerebellar and hippocampal microglia exist in a more immune vigilant state. Immune function correlated with regional transcriptional patterns. Augmentation of the distinct cerebellar immunophenotype and a contrasting loss in distinction of the hippocampal phenotype among forebrain regions were key features during ageing. Microglial diversity may enable regionally localised homeostatic functions but could also underlie region-specific sensitivities to microglial dysregulation and involvement in age-related neurodegeneration. PMID:26780511

  14. Face processing in autism spectrum disorders: from brain regions to brain networks

    PubMed Central

    Nomi, Jason S.; Uddin, Lucina Q.

    2015-01-01

    Autism spectrum disorder (ASD) is characterized by reduced attention to social stimuli including the human face. This hypo-responsiveness to stimuli that are engaging to typically developing individuals may result from dysfunctioning motivation, reward, and attention systems in the brain. Here we review an emerging neuroimaging literature that emphasizes a shift from focusing on hypo-activation of isolated brain regions such as the fusiform gyrus, amygdala, and superior temporal sulcus in ASD to a more holistic approach to understanding face perception as a process supported by distributed cortical and subcortical brain networks. We summarize evidence for atypical activation patterns within brain networks that may contribute to social deficits characteristic of the disorder. We conclude by pointing to gaps in the literature and future directions that will continue to shed light on aspects of face processing in autism that are still under-examined. In particular, we highlight the need for more developmental studies and studies examining ecologically valid and naturalistic social stimuli. PMID:25829246

  15. Acetamiprid Accumulates in Different Amounts in Murine Brain Regions

    PubMed Central

    Terayama, Hayato; Endo, Hitoshi; Tsukamoto, Hideo; Matsumoto, Koichi; Umezu, Mai; Kanazawa, Teruhisa; Ito, Masatoshi; Sato, Tadayuki; Naito, Munekazu; Kawakami, Satoshi; Fujino, Yasuhiro; Tatemichi, Masayuki; Sakabe, Kou

    2016-01-01

    Neonicotinoids such as acetamiprid (ACE) belong to a new and widely used single class of pesticides. Neonicotinoids mimic the chemical structure of nicotine and share agonist activity with the nicotine acetylcholine receptor (nAchR). Neonicotinoids are widely considered to be safe in humans; however, they have recently been implicated in a number of human health disorders. A wide range of musculoskeletal and neuromuscular disorders associated with high doses of neonicotinoids administered to animals have also been reported. Consequently, we used a mouse model to investigate the response of the central nervous system to ACE treatment. Our results show that exposure to ACE-containing water for three or seven days (decuple and centuple of no observable adverse effect level (NOAEL)/day) caused a decrease in body weight in 10-week old A/JJmsSlc (A/J) mice. However, the treatments did not affect brain histology or expression of CD34. ACE concentrations were significantly higher in the midbrain of ACE-treated mice than that of the normal and vehicle groups. Expression levels of α7, α4, and β2 nAChRs were found to be low in the olfactory bulb and midbrain of normal mice. Furthermore, in the experimental group (centuple ACE-containing water for seven days), β2 nAChR expression decreased in many brain regions. Information regarding the amount of accumulated ACE and expression levels of the acetylcholine receptor in each region of the brain is important for understanding any clinical symptoms that may be associated with ACE exposure. PMID:27669271

  16. Aging Effects on Regional Brain Structural Changes in Schizophrenia

    PubMed Central

    Nenadić, Igor; Sauer, Heinrich; Smesny, Stefan; Gaser, Christian

    2012-01-01

    Background: Although mostly conceptualized as a neurodevelopmental disorder, there is an increasing interest in progressive changes of cognitive deficits and brain structure and function in schizophrenia across the life span. Methods: In this study, we investigated age-related changes in regional gray matter using voxel-based morphometry in a sample of 99 patients (age range 18–65 years) with Diagnostic and Statistical Manual of Mental Disorders-IV schizophrenia and 113 healthy controls (age range 19–59 years) using a cross-sectional design. Results: We found steeper age-related decline in gray matter in patients in a cluster comprising the left superior temporal cortex and adjacent inferior parietal lobule. We then divided the schizophrenia sample in 3 subgroups based on a 3-factor model of psychopathology ratings. Age-related changes were markedly different in each of the 3 subgroups (compared with healthy controls). While patients with predominantly paranoid symptoms showed stronger age-related progression in the left superior temporal cortex and right inferior frontal gyrus, those of the disorganized subgroup had stronger gray matter loss in the left lateral cerebellum, while the predominantly negative subgroup showed minor effects in the left superior temporal gyrus. Conclusions: Our findings show that differences in brain structural changes associated with aging diverge between schizophrenia patients and healthy subjects and that different subgroups within a patient sample might be at higher risk of age-related regional gray matter loss. PMID:21296908

  17. Auditory Imagination.

    ERIC Educational Resources Information Center

    Croft, Martyn

    Auditory imagination is used in this paper to describe a number of issues and activities related to sound and having to do with listening, thinking, recalling, imagining, reshaping, creating, and uttering sounds and words. Examples of auditory imagination in religious and literary works are cited that indicate a belief in an imagined, expected, or…

  18. Real-time fMRI brain computer interfaces: self-regulation of single brain regions to networks.

    PubMed

    Ruiz, Sergio; Buyukturkoglu, Korhan; Rana, Mohit; Birbaumer, Niels; Sitaram, Ranganatha

    2014-01-01

    With the advent of brain computer interfaces based on real-time fMRI (rtfMRI-BCI), the possibility of performing neurofeedback based on brain hemodynamics has become a reality. In the early stage of the development of this field, studies have focused on the volitional control of activity in circumscribed brain regions. However, based on the understanding that the brain functions by coordinated activity of spatially distributed regions, there have recently been further developments to incorporate real-time feedback of functional connectivity and spatio-temporal patterns of brain activity. The present article reviews the principles of rtfMRI neurofeedback, its applications, benefits and limitations. A special emphasis is given to the discussion of novel developments that have enabled the use of this methodology to achieve self-regulation of the functional connectivity between different brain areas and of distributed brain networks, anticipating new and exciting applications for cognitive neuroscience and for the potential alleviation of neuropsychiatric disorders.

  19. Premotor cortex is sensitive to auditory-visual congruence for biological motion.

    PubMed

    Wuerger, Sophie M; Parkes, Laura; Lewis, Penelope A; Crocker-Buque, Alex; Rutschmann, Roland; Meyer, Georg F

    2012-03-01

    The auditory and visual perception systems have developed special processing strategies for ecologically valid motion stimuli, utilizing some of the statistical properties of the real world. A well-known example is the perception of biological motion, for example, the perception of a human walker. The aim of the current study was to identify the cortical network involved in the integration of auditory and visual biological motion signals. We first determined the cortical regions of auditory and visual coactivation (Experiment 1); a conjunction analysis based on unimodal brain activations identified four regions: middle temporal area, inferior parietal lobule, ventral premotor cortex, and cerebellum. The brain activations arising from bimodal motion stimuli (Experiment 2) were then analyzed within these regions of coactivation. Auditory footsteps were presented concurrently with either an intact visual point-light walker (biological motion) or a scrambled point-light walker; auditory and visual motion in depth (walking direction) could either be congruent or incongruent. Our main finding is that motion incongruency (across modalities) increases the activity in the ventral premotor cortex, but only if the visual point-light walker is intact. Our results extend our current knowledge by providing new evidence consistent with the idea that the premotor area assimilates information across the auditory and visual modalities by comparing the incoming sensory input with an internal representation.

  20. Brain regions underlying word finding difficulties in temporal lobe epilepsy.

    PubMed

    Trebuchon-Da Fonseca, Agnes; Guedj, Eric; Alario, F-Xavier; Laguitton, Virginie; Mundler, Olivier; Chauvel, Patrick; Liegeois-Chauvel, Catherine

    2009-10-01

    Word finding difficulties are often reported by epileptic patients with seizures originating from the language dominant cerebral hemisphere, for example, in temporal lobe epilepsy. Evidence regarding the brain regions underlying this deficit comes from studies of peri-operative electro-cortical stimulation, as well as post-surgical performance. This evidence has highlighted a role for the anterior part of the dominant temporal lobe in oral word production. These conclusions contrast with findings from activation studies involving healthy speakers or acute ischaemic stroke patients, where the region most directly related to word retrieval appears to be the posterior part of the left temporal lobe. To clarify the neural basis of word retrieval in temporal lobe epilepsy, we tested forty-three drug-resistant temporal lobe epilepsy patients (28 left, 15 right). Comprehensive neuropsychological and language assessments were performed. Single spoken word production was elicited with picture or definition stimuli. Detailed analysis allowed the distinction of impaired word retrieval from other possible causes of naming failure. Finally, the neural substrate of the deficit was assessed by correlating word retrieval performance and resting-state brain metabolism in 18 fluoro-2-deoxy-d-glucose-Positron Emission Tomography. Naming difficulties often resulted from genuine word retrieval failures (anomic states), both in picture and in definition tasks. Left temporal lobe epilepsy patients showed considerably worse performance than right temporal lobe epilepsy patients. Performance was poorer in the definition than in the picture task. Across patients and the left temporal lobe epilepsy subgroup, frequency of anomic state was negatively correlated with resting-state brain metabolism in left posterior and basal temporal regions (Brodmann's area 20-37-39). These results show the involvement of posterior temporal regions, within a larger antero-posterior-basal temporal network, in

  1. Specific Regional Transcription of Apolipoprotein E in Human Brain Neurons

    PubMed Central

    Xu, Pu-Ting; Gilbert, John R.; Qiu, Hui-Ling; Ervin, John; Rothrock-Christian, Tracie R.; Hulette, Christine; Schmechel, Donald E.

    1999-01-01

    In central nervous system injury and disease, apolipoprotein E (APOE, gene; apoE, protein) might be involved in neuronal injury and death indirectly through extracellular effects and/or more directly through intracellular effects on neuronal metabolism. Although intracellular effects could clearly be mediated by neuronal uptake of extracellular apoE, recent experiments in injury models in normal rodents and in mice transgenic for the human APOE gene suggest the additional possibility of intraneuronal synthesis. To examine whether APOE might be synthesized by human neurons, we performed in situ hybridization on paraffin-embedded and frozen brain sections from three nondemented controls and five Alzheimer’s disease (AD) patients using digoxigenin-labeled antisense and sense cRNA probes to human APOE. Using the antisense APOE probes, we found the expected strong hybridization signal in glial cells as well as a generally fainter signal in selected neurons in cerebral cortex and hippocampus. In hippocampus, many APOE mRNA-containing neurons were observed in sectors CA1 to CA4 and the granule cell layer of the dentate gyrus. In these regions, APOE mRNA containing neurons could be observed adjacent to nonhybridizing neurons of the same cell class. APOE mRNA transcription in neurons is regionally specific. In cerebellar cortex, APOE mRNA was seen only in Bergmann glial cells and scattered astrocytes but not in Purkinje cells or granule cell neurons. ApoE immunocytochemical localization in semi-adjacent sections supported the selectivity of APOE transcription. These results demonstrate the expected result that APOE mRNA is transcribed and expressed in glial cells in human brain. The important new finding is that APOE mRNA is also transcribed and expressed in many neurons in frontal cortex and human hippocampus but not in neurons of cerebellar cortex from the same brains. This regionally specific human APOE gene expression suggests that synthesis of apoE might play a role

  2. Positron Emission Tomography Imaging Reveals Auditory and Frontal Cortical Regions Involved with Speech Perception and Loudness Adaptation.

    PubMed

    Berding, Georg; Wilke, Florian; Rode, Thilo; Haense, Cathleen; Joseph, Gert; Meyer, Geerd J; Mamach, Martin; Lenarz, Minoo; Geworski, Lilli; Bengel, Frank M; Lenarz, Thomas; Lim, Hubert H

    2015-01-01

    Considerable progress has been made in the treatment of hearing loss with auditory implants. However, there are still many implanted patients that experience hearing deficiencies, such as limited speech understanding or vanishing perception with continuous stimulation (i.e., abnormal loudness adaptation). The present study aims to identify specific patterns of cerebral cortex activity involved with such deficiencies. We performed O-15-water positron emission tomography (PET) in patients implanted with electrodes within the cochlea, brainstem, or midbrain to investigate the pattern of cortical activation in response to speech or continuous multi-tone stimuli directly inputted into the implant processor that then delivered electrical patterns through those electrodes. Statistical parametric mapping was performed on a single subject basis. Better speech understanding was correlated with a larger extent of bilateral auditory cortex activation. In contrast to speech, the continuous multi-tone stimulus elicited mainly unilateral auditory cortical activity in which greater loudness adaptation corresponded to weaker activation and even deactivation. Interestingly, greater loudness adaptation was correlated with stronger activity within the ventral prefrontal cortex, which could be up-regulated to suppress the irrelevant or aberrant signals into the auditory cortex. The ability to detect these specific cortical patterns and differences across patients and stimuli demonstrates the potential for using PET to diagnose auditory function or dysfunction in implant patients, which in turn could guide the development of appropriate stimulation strategies for improving hearing rehabilitation. Beyond hearing restoration, our study also reveals a potential role of the frontal cortex in suppressing irrelevant or aberrant activity within the auditory cortex, and thus may be relevant for understanding and treating tinnitus.

  3. Functional Imaging of Auditory Cortex in Adult Cats using High-field fMRI

    PubMed Central

    Brown, Trecia A.; Gati, Joseph S.; Hughes, Sarah M.; Nixon, Pam L.; Menon, Ravi S.; Lomber, Stephen G.

    2014-01-01

    Current knowledge of sensory processing in the mammalian auditory system is mainly derived from electrophysiological studies in a variety of animal models, including monkeys, ferrets, bats, rodents, and cats. In order to draw suitable parallels between human and animal models of auditory function, it is important to establish a bridge between human functional imaging studies and animal electrophysiological studies. Functional magnetic resonance imaging (fMRI) is an established, minimally invasive method of measuring broad patterns of hemodynamic activity across different regions of the cerebral cortex. This technique is widely used to probe sensory function in the human brain, is a useful tool in linking studies of auditory processing in both humans and animals and has been successfully used to investigate auditory function in monkeys and rodents. The following protocol describes an experimental procedure for investigating auditory function in anesthetized adult cats by measuring stimulus-evoked hemodynamic changes in auditory cortex using fMRI. This method facilitates comparison of the hemodynamic responses across different models of auditory function thus leading to a better understanding of species-independent features of the mammalian auditory cortex. PMID:24637937

  4. Sounds and beyond: multisensory and other non-auditory signals in the inferior colliculus

    PubMed Central

    Gruters, Kurtis G.; Groh, Jennifer M.

    2012-01-01

    The inferior colliculus (IC) is a major processing center situated mid-way along both the ascending and descending auditory pathways of the brain stem. Although it is fundamentally an auditory area, the IC also receives anatomical input from non-auditory sources. Neurophysiological studies corroborate that non-auditory stimuli can modulate auditory processing in the IC and even elicit responses independent of coincident auditory stimulation. In this article, we review anatomical and physiological evidence for multisensory and other non-auditory processing in the IC. Specifically, the contributions of signals related to vision, eye movements and position, somatosensation, and behavioral context to neural activity in the IC will be described. These signals are potentially important for localizing sound sources, attending to salient stimuli, distinguishing environmental from self-generated sounds, and perceiving and generating communication sounds. They suggest that the IC should be thought of as a node in a highly interconnected sensory, motor, and cognitive network dedicated to synthesizing a higher-order auditory percept rather than simply reporting patterns of air pressure detected by the cochlea. We highlight some of the potential pitfalls that can arise from experimental manipulations that may disrupt the normal function of this network, such as the use of anesthesia or the severing of connections from cortical structures that project to the IC. Finally, we note that the presence of these signals in the IC has implications for our understanding not just of the IC but also of the multitude of other regions within and beyond the auditory system that are dependent on signals that pass through the IC. Whatever the IC “hears” would seem to be passed both “upward” to thalamus and thence to auditory cortex and beyond, as well as “downward” via centrifugal connections to earlier areas of the auditory pathway such as the cochlear nucleus. PMID:23248584

  5. Brain Region-Specific Trafficking of the Dopamine Transporter

    PubMed Central

    Block, Ethan R.; Nuttle, Jacob; Balcita-Pedicino, Judith Joyce; Caltagarone, John; Watkins, Simon C.

    2015-01-01

    The dopamine (DA) transporter (DAT) controls dopaminergic neurotransmission by removing extracellular DA. Although DA reuptake is proposed to be regulated by DAT traffic to and from the cell surface, the membrane trafficking system involved in the endocytic cycling of DAT in the intact mammalian brain has not been characterized. Hence, we performed immunolabeling and quantitative analysis of the subcellular and regional distribution of DAT using the transgenic knock-in mouse expressing hemagglutinin (HA) epitope-tagged DAT (HA-DAT) and by using a combination of electron microscopy and a novel method for immunofluorescence labeling of HA-DAT in acute sagittal brain slices. Both approaches demonstrated that, in midbrain somatodendritic regions, HA-DAT was present in the plasma membrane, endoplasmic reticulum, and Golgi complex, with a small fraction in early and recycling endosomes and an even smaller fraction in late endosomes and lysosomes. In the striatum and in axonal tracts between the midbrain and striatum, HA-DAT was detected predominantly in the plasma membrane, and quantitative analysis revealed increased DAT density in striatal compared with midbrain plasma membranes. Endosomes were strikingly rare and lysosomes were absent in striatal axons, in which there was little intracellular HA-DAT. Acute administration of amphetamine in vivo (60 min) or to slices ex vivo (10–60 min) did not result in detectable changes in DAT distribution. Altogether, these data provide evidence for regional differences in DAT plasma membrane targeting and retention and suggest a surprisingly low level of endocytic trafficking of DAT in the striatum along with limited DAT endocytic activity in somatodendritic areas. SIGNIFICANCE STATEMENT The dopamine transporter (DAT) is the key regulator of the dopamine neurotransmission in the CNS. In the present study, we developed a new approach for studying DAT localization and dynamics in intact neurons in acute sagittal brain slices from

  6. Aerobic exercise reduces neuronal responses in food reward brain regions.

    PubMed

    Evero, Nero; Hackett, Laura C; Clark, Robert D; Phelan, Suzanne; Hagobian, Todd A

    2012-05-01

    Acute exercise suppresses ad libitum energy intake, but little is known about the effects of exercise on food reward brain regions. After an overnight fast, 30 (17 men, 13 women), healthy, habitually active (age = 22.2 ± 0.7 yr, body mass index = 23.6 ± 0.4 kg/m(2), Vo(2peak) = 44.2 ± 1.5 ml·kg(-1)·min(-1)) individuals completed 60 min of exercise on a cycle ergometer or 60 min of rest (no-exercise) in a counterbalanced, crossover fashion. After each condition, blood oxygen level-dependent responses to high-energy food, low-energy food, and control visual cues, were measured by functional magnetic resonance imaging. Exercise, compared with no-exercise, significantly (P < 0.005) reduced the neuronal response to food (high and low food) cues vs. control cues in the insula (-0.37 ± 0.13 vs. +0.07 ± 0.18%), putamen (-0.39 ± 0.10 vs. -0.10 ± 0.09%), and rolandic operculum (-0.37 ± 0.17 vs. 0.17 ± 0.12%). Exercise alone significantly (P < 0.005) reduced the neuronal response to high food vs. control and low food vs. control cues in the inferior orbitofrontal cortex (-0.94 ± 0.33%), insula (-0.37 ± 0.13%), and putamen (-0.41 ± 0.10%). No-exercise alone significantly (P < 0.005) reduced the neuronal response to high vs. control and low vs. control cues in the middle (-0.47 ± 0.15%) and inferior occipital gyrus (-1.00 ± 0.23%). Exercise reduced neuronal responses in brain regions consistent with reduced pleasure of food, reduced incentive motivation to eat, and reduced anticipation and consumption of food. Reduced neuronal response in these food reward brain regions after exercise is in line with the paradigm that acute exercise suppresses subsequent energy intake.

  7. Sex, acceleration, brain imaging, and rhesus monkeys: Converging evidence for an evolutionary bias for looming auditory motion

    NASA Astrophysics Data System (ADS)

    Neuhoff, John G.

    2003-04-01

    Increasing acoustic intensity is a primary cue to looming auditory motion. Perceptual overestimation of increasing intensity could provide an evolutionary selective advantage by specifying that an approaching sound source is closer than actual, thus affording advanced warning and more time than expected to prepare for the arrival of the source. Here, multiple lines of converging evidence for this evolutionary hypothesis are presented. First, it is shown that intensity change specifying accelerating source approach changes in loudness more than equivalent intensity change specifying decelerating source approach. Second, consistent with evolutionary hunter-gatherer theories of sex-specific spatial abilities, it is shown that females have a significantly larger bias for rising intensity than males. Third, using functional magnetic resonance imaging in conjunction with approaching and receding auditory motion, it is shown that approaching sources preferentially activate a specific neural network responsible for attention allocation, motor planning, and translating perception into action. Finally, it is shown that rhesus monkeys also exhibit a rising intensity bias by orienting longer to looming tones than to receding tones. Together these results illustrate an adaptive perceptual bias that has evolved because it provides a selective advantage in processing looming acoustic sources. [Work supported by NSF and CDC.

  8. The cortical language circuit: from auditory perception to sentence comprehension.

    PubMed

    Friederici, Angela D

    2012-05-01

    Over the years, a large body of work on the brain basis of language comprehension has accumulated, paving the way for the formulation of a comprehensive model. The model proposed here describes the functional neuroanatomy of the different processing steps from auditory perception to comprehension as located in different gray matter brain regions. It also specifies the information flow between these regions, taking into account white matter fiber tract connections. Bottom-up, input-driven processes proceeding from the auditory cortex to the anterior superior temporal cortex and from there to the prefrontal cortex, as well as top-down, controlled and predictive processes from the prefrontal cortex back to the temporal cortex are proposed to constitute the cortical language circuit.

  9. Nonrigid brain MR image registration using uniform spherical region descriptor.

    PubMed

    Liao, Shu; Chung, Albert C S

    2012-01-01

    There are two main issues that make nonrigid image registration a challenging task. First, voxel intensity similarity may not be necessarily equivalent to anatomical similarity in the image correspondence searching process. Second, during the imaging process, some interferences such as unexpected rotations of input volumes and monotonic gray-level bias fields can adversely affect the registration quality. In this paper, a new feature-based nonrigid image registration method is proposed. The proposed method is based on a new type of image feature, namely, uniform spherical region descriptor (USRD), as signatures for each voxel. The USRD is rotation and monotonic gray-level transformation invariant and can be efficiently calculated. The registration process is therefore formulated as a feature matching problem. The USRD feature is integrated with the Markov random field labeling framework in which energy function is defined for registration. The energy function is then optimized by the α-expansion algorithm. The proposed method has been compared with five state-of-the-art registration approaches on both the simulated and real 3-D databases obtained from the BrainWeb and Internet Brain Segmentation Repository, respectively. Experimental results demonstrate that the proposed method can achieve high registration accuracy and reliable robustness behavior.

  10. Determining hierarchical functional networks from auditory stimuli fMRI.

    PubMed

    Patel, Rajan S; Bowman, F Dubois; Rilling, James K

    2006-05-01

    We determined connectivity of the human brain using functional magnetic resonance imaging (fMRI) while subjects experienced auditory stimuli in a 2-by-2 factorial design. The two factors in this study were "speaker" (same or different speaker) and "sentence" (same or different sentences). Connectivity studies allow us to ask how spatially remote brain regions are neurophysiologically related given these stimuli. In the context of this study, we examined how the "speaker" effect and "sentence" effect influenced these relationships. We applied a Bayesian connectivity method that determines hierarchical functional networks of functionally connected brain regions. Hierarchy in these functional networks is determined by conditional probabilities of elevated activity. For example, a brain region that becomes active a superset of the time of another region is considered ascendant to that brain region in the hierarchical network. For each factor level, we found a baseline functional network connecting the primary auditory cortex (Brodmann's Area [BA] 41) with the BA 42 and BA 22 of the superior temporal gyrus (STG). We also found a baseline functional network that includes Wernicke's Area (BA 22 posterior), STG, and BA 44 for each factor level. However, we additionally observed a strong ascendant connection from BA 41 to the posterior cingulate (BA 30) and Broca's Area and a stronger connection from Wernicke's Area to STG and the posterior cingulate while passively listening to different sentences rather than the same sentence repeatedly. Finally, our results revealed no significant "speaker" effect or interaction between "speaker" and "sentence."

  11. Early experience and domestication affect auditory discrimination learning, open field behaviour and brain size in wild Mongolian gerbils and domesticated laboratory gerbils (Meriones unguiculatus forma domestica).

    PubMed

    Stuermer, Ingo W; Wetzel, Wolfram

    2006-10-02

    The influence of early experience and strain differences on auditory discrimination learning, open field behaviour and brain size was investigated in wild-type Mongolian gerbils (strain Ugoe:MU95) raised in the wild (wild F-0) or in the laboratory (wild F-1) and in domesticated Laboratory Gerbils (LAB). Adult males were conditioned for 10 days in a shuttle box go/no-go paradigm to discriminate two frequency-modulated tones. Significant learning was established within 5 days in wild F-0 and within 3 days in wild F-1 and LAB. Spontaneous jumps in the shuttle box (inter-trial crossings) were frequently seen in wild F-0 and F-1, but rarely in LAB. All groups exhibited nearly the same ability to remember after 2 weeks without training. In the open field test applied on 5 consecutive days, no differences in locomotion patterns and inner field preferences were found. Rearing frequency decreased over 5 days in wild gerbils. Running distances (4-6m/min) were similar in wild F-0 and LAB, but higher in wild F-1. The ratio of brain size to body weight did not differ between wild F-0 and F-1, but was 17.1% lower in LAB. Correspondingly high brain weights in wild F-1 and F-0 support our domestication hypothesis and negate any serious effect of early experience or captivity on brain size in Mongolian gerbils. In contrast, wild F-1 raised in the laboratory show a rapid improvement in learning performance, indicating that early experience rather that genetic differences between strains affect shuttle box discrimination learning in gerbils.

  12. Developmental pattern of CB1 cannabinoid receptor immunoreactivity in brain regions important to zebra finch (Taeniopygia guttata) song learning and control.

    PubMed

    Soderstrom, Ken; Tian, Qiyu

    2006-06-10

    Zebra finches learn song during distinct developmental stages, making them an important species for studying mechanisms underlying vocal development. Distinct interconnected forebrain regions have been identified as important to specific features of zebra finch vocal learning and production. Because prior experiments have demonstrated that late postnatal exposure to cannabinoid agonists alters zebra finch song learning, we have sought to identify brain regions likely involved in it. By using an affinity-purified polyclonal antibody directed against the zebra finch CB(1) cannabinoid receptor, we have studied staining patterns in groups of males at 25, 50, 75, and >100 days of age (adults). A general waxing and waning of staining intensity were observed over this developmental period. Distinct staining of song-related brain regions was also noted. Early establishment of staining patterns within rostral telencephalic song regions [area X and lateral magnocellular nucleus of the anterior nidopallium (lMAN)] suggests a role in auditory learning. Later establishment and maintenance in adulthood of small somata and neuropil staining within regions of rostral telencephalon [HVC and robust nucleus of the arcopallium (RA)] are consistent with a vocal motor role for cannabinoid signaling. Our results provide insight into brain regions likely responsible for cannabinoid-altered vocal learning and add to accumulating evidence supporting an important role for cannabinoid signaling in CNS development.

  13. Bilingualism alters brain functional connectivity between "control" regions and "language" regions: Evidence from bimodal bilinguals.

    PubMed

    Li, Le; Abutalebi, Jubin; Zou, Lijuan; Yan, Xin; Liu, Lanfang; Feng, Xiaoxia; Wang, Ruiming; Guo, Taomei; Ding, Guosheng

    2015-05-01

    Previous neuroimaging studies have revealed that bilingualism induces both structural and functional neuroplasticity in the dorsal anterior cingulate cortex (dACC) and the left caudate nucleus (LCN), both of which are associated with cognitive control. Since these "control" regions should work together with other language regions during language processing, we hypothesized that bilingualism may also alter the functional interaction between the dACC/LCN and language regions. Here we tested this hypothesis by exploring the functional connectivity (FC) in bimodal bilinguals and monolinguals using functional MRI when they either performed a picture naming task with spoken language or were in resting state. We found that for bimodal bilinguals who use spoken and sign languages, the FC of the dACC with regions involved in spoken language (e.g. the left superior temporal gyrus) was stronger in performing the task, but weaker in the resting state as compared to monolinguals. For the LCN, its intrinsic FC with sign language regions including the left inferior temporo-occipital part and right inferior and superior parietal lobules was increased in the bilinguals. These results demonstrate that bilingual experience may alter the brain functional interaction between "control" regions and "language" regions. For different control regions, the FC alters in different ways. The findings also deepen our understanding of the functional roles of the dACC and LCN in language processing.

  14. Diminished Auditory Responses during NREM Sleep Correlate with the Hierarchy of Language Processing

    PubMed Central

    Furman-Haran, Edna; Arzi, Anat; Levkovitz, Yechiel; Malach, Rafael

    2016-01-01

    Natural sleep provides a powerful model system for studying the neuronal correlates of awareness and state changes in the human brain. To quantitatively map the nature of sleep-induced modulations in sensory responses we presented participants with auditory stimuli possessing different levels of linguistic complexity. Ten participants were scanned using functional magnetic resonance imaging (fMRI) during the waking state and after falling asleep. Sleep staging was based on heart rate measures validated independently on 20 participants using concurrent EEG and heart rate measurements and the results were confirmed using permutation analysis. Participants were exposed to three types of auditory stimuli: scrambled sounds, meaningless word sentences and comprehensible sentences. During non-rapid eye movement (NREM) sleep, we found diminishing brain activation along the hierarchy of language processing, more pronounced in higher processing regions. Specifically, the auditory thalamus showed similar activation levels during sleep and waking states, primary auditory cortex remained activated but showed a significant reduction in auditory responses during sleep, and the high order language-related representation in inferior frontal gyrus (IFG) cortex showed a complete abolishment of responses during NREM sleep. In addition to an overall activation decrease in language processing regions in superior temporal gyrus and IFG, those areas manifested a loss of semantic selectivity during NREM sleep. Our results suggest that the decreased awareness to linguistic auditory stimuli during NREM sleep is linked to diminished activity in high order processing stations. PMID:27310812

  15. Nonlinear Auditory Modeling as a Basis for Speaker Recognition

    DTIC Science & Technology

    2010-08-26

    development of new "common modulation" features based on modeling a more central region of auditory processing in the brain’s inferior colliculus...performance improvements have been achieved by estimating the onset times of secondary excitation pulses within glottal cycles . Here we had assumed...secondary excitations (per glottal cycle ) were associated with a nonlinear production model, e.g., multiple vocal fold vibrations or sound generation by

  16. Reduced Regional Brain Cortical Thickness in Patients with Heart Failure

    PubMed Central

    Kumar, Rajesh; Yadav, Santosh K.; Palomares, Jose A.; Park, Bumhee; Joshi, Shantanu H.; Ogren, Jennifer A.; Macey, Paul M.; Fonarow, Gregg C.; Harper, Ronald M.; Woo, Mary A.

    2015-01-01

    Aims Autonomic, cognitive, and neuropsychologic deficits appear in heart failure (HF) subjects, and these compromised functions depend on cerebral cortex integrity in addition to that of subcortical and brainstem sites. Impaired autoregulation, low cardiac output, sleep-disordered-breathing, hypertension, and diabetic conditions in HF offer considerable potential to affect cortical areas by loss of neurons and glia, which would be expressed as reduced cortical thicknesses. However, except for gross descriptions of cortical volume loss/injury, regional cortical thickness integrity in HF is unknown. Our goal was to assess regional cortical thicknesses across the brain in HF, compared to control subjects. Methods and Results We examined localized cortical thicknesses in 35 HF and 61 control subjects with high-resolution T1-weighted images (3.0-Tesla MRI) using FreeSurfer software, and assessed group differences with analysis-of-covariance (covariates; age, gender; p<0.05; FDR). Significantly-reduced cortical thicknesses appeared in HF over controls in multiple areas, including the frontal, parietal, temporal, and occipital lobes, more markedly on the left side, within areas that control autonomic, cognitive, affective, language, and visual functions. Conclusion Heart failure subjects show reduced regional cortical thicknesses in sites that control autonomic, cognitive, affective, language, and visual functions that are deficient in the condition. The findings suggest chronic tissue alterations, with regional changes reflecting loss of neurons and glia, and presumably are related to earlier-described axonal changes. The pathological mechanisms contributing to reduced cortical thicknesses likely include hypoxia/ischemia, accompanying impaired cerebral perfusion from reduced cardiac output and sleep-disordered-breathing and other comorbidities in HF. PMID:25962164

  17. Longer storage of auditory than of visual information in the rabbit brain: evidence from dorsal hippocampal electrophysiology.

    PubMed

    Astikainen, Piia; Ruusuvirta, Timo; Korhonen, Tapani

    2005-01-01

    Whereas sensory memory in humans has been found to store auditory information for a longer time than visual information, it is unclear whether this is the case also in other species. We recorded hippocampal event-related potentials (ERPs) in awake rabbits exposed to occasional changes in a repeated 50-ms acoustic (1000 versus 2000 Hz) and visual (vertical versus horizontal orientation) stimulus. Three intervals (500, 1500, or 3000 ms) between stimulus repetitions were applied. Whereas acoustic changes significantly affected ERPs with the repetition intervals of 500 and 1500 ms, visual changes did so only with the repetition interval of 500 ms. Our finding, thus, suggests a similarity in sensory processing abilities between human and non-human mammals.

  18. New protein extraction/solubilization protocol for gel-based proteomics of rat (female) whole brain and brain regions.

    PubMed

    Hirano, Misato; Rakwal, Randeep; Shibato, Junko; Agrawal, Ganesh Kumar; Jwa, Nam-Soo; Iwahashi, Hitoshi; Masuo, Yoshinori

    2006-08-31

    The rat is an accepted model for studying human psychiatric/neurological disorders. We provide a protocol for total soluble protein extraction using trichloroacetic acid/acetone (TCA/A) from rat (female) whole brain, 10 brain regions and the pituitary gland, and show that two-dimensional gel electrophoresis (2-DGE) using pre-cast immobilized pH (4-7) gradient (IPG) strip gels (13 cm) in the first dimension yields clean silver nitrate stained protein profiles. Though TCA/A precipitation may not be "ideal", the important choice here is the selection of an appropriate lysis buffer (LB) for solubilizing precipitated proteins. Our results reveal enrichment of protein spots by use of individual brain regions rather than whole brain, as well as the presence of differentially expressed spots in their proteomes. Thus individual brain regions provide improved protein coverage and are better suited for differential protein detection. Moreover, using a phosphoprotein-specific dye, in-gel detection of phosphoproteins was demonstrated. Representative high-resolution silver nitrate stained proteome profiles of rat whole brain total soluble protein are presented. Shortcomings apart (failure to separate membrane proteins), gel-based proteomics remains a viable option, and 2-DGE is the method of choice for generating high-resolution proteome maps of rat brain and brain regions.

  19. Effect Of Electromagnetic Waves Emitted From Mobile Phone On Brain Stem Auditory Evoked Potential In Adult Males.

    PubMed

    Singh, K

    2015-01-01

    Mobile phone (MP) is commonly used communication tool. Electromagnetic waves (EMWs) emitted from MP may have potential health hazards. So, it was planned to study the effect of electromagnetic waves (EMWs) emitted from the mobile phone on brainstem auditory evoked potential (BAEP) in male subjects in the age group of 20-40 years. BAEPs were recorded using standard method of 10-20 system of electrode placement and sound click stimuli of specified intensity, duration and frequency.Right ear was exposed to EMW emitted from MP for about 10 min. On comparison of before and after exposure to MP in right ear (found to be dominating ear), there was significant increase in latency of II, III (p < 0.05) and V (p < 0.001) wave, amplitude of I-Ia wave (p < 0.05) and decrease in IPL of III-V wave (P < 0.05) after exposure to MP. But no significant change was found in waves of BAEP in left ear before vs after MP. On comparison of right (having exposure routinely as found to be dominating ear) and left ears (not exposed to MP), before exposure to MP, IPL of IIl-V wave and amplitude of V-Va is more (< 0.001) in right ear compared to more latency of III and IV wave (< 0.001) in left ear. After exposure to MP, the amplitude of V-Va was (p < 0.05) more in right ear compared to left ear. In conclusion, EMWs emitted from MP affects the auditory potential.

  20. Stroke bricks - spatial brain regions to assess ischemic stroke localization.

    PubMed

    Ciszek, Bogdan; Jóźwiak, Rafał; Sobieszczuk, Ewa; Przelaskowski, Artur; Skadorwa, Tymon

    2017-03-29

    Computer-aided analysis of non-contrast CT (NCCT) images for rapid diagnosis of ischemic stroke is based on the augmented visualization of evolving ischemic lesions. Computerized support of NCCT often leads to overinterpretation of ischemic areas, thus it is of great interest to provide neurologically verified regions in order to improve accuracy of subsequent radiological assessment. We propose Stroke Bricks (StBr) as an arbitrary spatial division of brain tissue into the regions associated with specific clinical symptoms of ischemic stroke. Neurological stroke deficit is formally translated into respective areas of possible ischemic lesions. StBr were designed according to formalized mapping of neurological symptoms and were attributed to the uniquely defined areas of impaired blood supply. StBr concept may be useful for an integrated radiological CT-based assessment of suspected stroke cases or can be included into computer-aided tools to optimize the evaluation of stroke site and its extent. These data in turn are appropriable for further diagnosis, predicting the therapeutic outcome as well as for patients' qualification for an appropriate form of reperfusion therapy. The usefulness of Stroke Bricks was illustrated in the case studies.

  1. Weight Perturbation Alters Leptin Signal Transduction in a Region-Specific Manner throughout the Brain.

    PubMed

    Morabito, Michael V; Ravussin, Yann; Mueller, Bridget R; Skowronski, Alicja A; Watanabe, Kazuhisa; Foo, Kylie S; Lee, Samuel X; Lehmann, Anders; Hjorth, Stephan; Zeltser, Lori M; LeDuc, Charles A; Leibel, Rudolph L

    2017-01-01

    Diet-induced obesity (DIO) resulting from consumption of a high fat diet (HFD) attenuates normal neuronal responses to leptin and may contribute to the metabolic defense of an acquired higher body weight in humans; the molecular bases for the persistence of this defense are unknown. We measured the responses of 23 brain regions to exogenous leptin in 4 different groups of weight- and/or diet-perturbed mice. Responses to leptin were assessed by quantifying pSTAT3 levels in brain nuclei 30 minutes following 3 mg/kg intraperitoneal leptin. HFD attenuated leptin sensing throughout the brain, but weight loss did not restore central leptin signaling to control levels in several brain regions important in energy homeostasis, including the arcuate and dorsomedial hypothalamic nuclei. Effects of diet on leptin signaling varied by brain region, with results dependent on the method of weight loss (restriction of calories of HFD, ad lib intake of standard mouse chow). High fat diet attenuates leptin signaling throughout the brain, but some brain regions maintain their ability to sense leptin. Weight loss restores leptin sensing to some degree in most (but not all) brain regions, while other brain regions display hypersensitivity to leptin following weight loss. Normal leptin sensing was restored in several brain regions, with the pattern of restoration dependent on the method of weight loss.

  2. Weight Perturbation Alters Leptin Signal Transduction in a Region-Specific Manner throughout the Brain

    PubMed Central

    Morabito, Michael V.; Ravussin, Yann; Mueller, Bridget R.; Skowronski, Alicja A.; Watanabe, Kazuhisa; Foo, Kylie S.; Lee, Samuel X.; Lehmann, Anders; Hjorth, Stephan; Zeltser, Lori M.; LeDuc, Charles A.; Leibel, Rudolph L.

    2017-01-01

    Diet-induced obesity (DIO) resulting from consumption of a high fat diet (HFD) attenuates normal neuronal responses to leptin and may contribute to the metabolic defense of an acquired higher body weight in humans; the molecular bases for the persistence of this defense are unknown. We measured the responses of 23 brain regions to exogenous leptin in 4 different groups of weight- and/or diet-perturbed mice. Responses to leptin were assessed by quantifying pSTAT3 levels in brain nuclei 30 minutes following 3 mg/kg intraperitoneal leptin. HFD attenuated leptin sensing throughout the brain, but weight loss did not restore central leptin signaling to control levels in several brain regions important in energy homeostasis, including the arcuate and dorsomedial hypothalamic nuclei. Effects of diet on leptin signaling varied by brain region, with results dependent on the method of weight loss (restriction of calories of HFD, ad lib intake of standard mouse chow). High fat diet attenuates leptin signaling throughout the brain, but some brain regions maintain their ability to sense leptin. Weight loss restores leptin sensing to some degree in most (but not all) brain regions, while other brain regions display hypersensitivity to leptin following weight loss. Normal leptin sensing was restored in several brain regions, with the pattern of restoration dependent on the method of weight loss. PMID:28107353

  3. Preferred EEG brain states at stimulus onset in a fixed interstimulus interval equiprobable auditory Go/NoGo task: a definitive study.

    PubMed

    Barry, Robert J; De Blasio, Frances M; De Pascalis, Vilfredo; Karamacoska, Diana

    2014-10-01

    This study examined the occurrence of preferred EEG phase states at stimulus onset in an equiprobable auditory Go/NoGo task with a fixed interstimulus interval, and their effects on the resultant event-related potentials (ERPs). We used a sliding short-time FFT decomposition of the EEG at Cz for each trial to assess prestimulus EEG activity in the delta, theta, alpha and beta bands. We determined the phase of each 2 Hz narrow-band contributing to these four broad bands at 125 ms before each stimulus onset, and for the first time, avoided contamination from poststimulus EEG activity. This phase value was extrapolated 125 ms to obtain the phase at stimulus onset, combined into the broad-band phase, and used to sort trials into four phase groups for each of the four broad bands. For each band, ERPs were derived for each phase from the raw EEG activity at 19 sites. Data sets from each band were separately decomposed using temporal Principal Components Analyses with unrestricted VARIMAX rotation to extract N1-1, PN, P2, P3, SW and LP components. Each component was analysed as a function of EEG phase at stimulus onset in the context of a simple conceptualisation of orthogonal phase effects (cortical negativity vs. positivity, negative driving vs. positive driving, waxing vs. waning). The predicted non-random occurrence of phase-defined brain states was confirmed. The preferred states of negativity, negative driving, and waxing were each associated with more efficient stimulus processing, as reflected in amplitude differences of the components. The present results confirm the existence of preferred brain states and their impact on the efficiency of brain dynamics in perceptual and cognitive processing.

  4. Gender and environmental effects on regional brain-derived neurotrophic factor expression after experimental traumatic brain injury.

    PubMed

    Chen, X; Li, Y; Kline, A E; Dixon, C E; Zafonte, R D; Wagner, A K

    2005-01-01

    Alterations in brain-derived neurotrophic factor expression have been reported in multiple brain regions acutely after traumatic brain injury, however neither injury nor post-injury environmental enrichment has been shown to affect hippocampal brain-derived neurotrophic factor gene expression in male rats chronically post-injury. Studies have demonstrated hormone-related neuroprotection for female rats after traumatic brain injury, and estrogen and exercise both influence brain-derived neurotrophic factor levels. Despite recent studies suggesting that exposure post-traumatic brain injury to environmental enrichment improves cognitive recovery in male rats, we have shown that environmental enrichment mediated improvements with spatial learning are gender specific and only positively affect males. Therefore the purpose of this study was to evaluate the effect of gender and environmental enrichment on chronic post-injury cortical and hippocampal brain-derived neurotrophic factor protein expression. Sprague-Dawley male and cycling female rats were placed into environmental enrichment or standard housing after controlled cortical impact or sham surgery. Four weeks post-surgery, hippocampal and frontal cortex brain-derived neurotrophic factor expression were examined using Western blot. Results revealed significant increases in brain-derived neurotrophic factor expression in the frontal cortex ipsilateral to injury for males (P=0.03). Environmental enrichment did not augment this effect. Neither environmental enrichment nor injury significantly affected cortical brain-derived neurotrophic factor expression for females. In the hippocampus ipsilateral to injury brain-derived neurotrophic factor expression for both males and females was half (49% and 51% respectively) of that observed in shams housed in the standard environment. For injured males, there was a trend in this region for environmental enrichment to restore brain-derived neurotrophic factor levels to sham values

  5. Analysis of gene expression in mouse brain regions after exposure to 1.9 GHz radiofrequency fields

    PubMed Central

    McNamee, James P.; Bellier, Pascale V.; Konkle, Anne T. M.; Thomas, Reuben; Wasoontarajaroen, Siriwat; Lemay, Eric; Gajda, Greg B.

    2016-01-01

    Abstract Purpose: To assess 1.9 GHz radiofrequency (RF) field exposure on gene expression within a variety of discrete mouse brain regions using whole genome microarray analysis. Materials and methods: Adult male C57BL/6 mice were exposed to 1.9 GHz pulse-modulated or continuous-wave RF fields for 4 h/day for 5 consecutive days at whole body average (WBA) specific absorption rates of 0 (sham), ∼0.2 W/kg and ∼1.4 W/kg. Total RNA was isolated from the auditory cortex, amygdala, caudate, cerebellum, hippocampus, hypothalamus, and medial prefrontal cortex and differential gene expression was assessed using Illumina MouseWG-6 (v2) BeadChip arrays. Validation of potentially responding genes was conducted by RT-PCR. Results: When analysis of gene expression was conducted within individual brain regions when controlling the false discovery rate (FDR), no differentially expressed genes were identified relative to the sham control. However, it must be noted that most fold changes among groups were observed to be less than 1.5-fold and this study had limited ability to detect such small changes. While some genes were differentially expressed without correction for multiple-comparisons testing, no consistent pattern of response was observed among different RF-exposure levels or among different RF-modulations. Conclusions: The current study provides the most comprehensive analysis of potential gene expression changes in the rodent brain in response to RF field exposure conducted to date. Within the exposure conditions and limitations of this study, no convincing evidence of consistent changes in gene expression was found in response to 1.9 GHz RF field exposure. PMID:27028625

  6. Modulation of auditory processing during speech movement planning is limited in adults who stutter

    PubMed Central

    Daliri, Ayoub; Max, Ludo

    2015-01-01

    Stuttering is associated with atypical structural and functional connectivity in sensorimotor brain areas, in particular premotor, motor, and auditory regions. It remains unknown, however, which specific mechanisms of speech planning and execution are affected by these neurological abnormalities. To investigate pre-movement sensory modulation, we recorded 12 stuttering and 12 nonstuttering adults’ auditory evoked potentials in response to probe tones presented prior to speech onset in a delayed-response speaking condition vs. no-speaking control conditions (silent reading; seeing nonlinguistic symbols). Findings indicate that, during speech movement planning, the nonstuttering group showed a statistically significant modulation of auditory processing (reduced N1 amplitude) that was not observed in the stuttering group. Thus, the obtained results provide electrophysiological evidence in support of the hypothesis that stuttering is associated with deficiencies in modulating the cortical auditory system during speech movement planning. This specific sensorimotor integration deficiency may contribute to inefficient feedback monitoring and, consequently, speech dysfluencies. PMID:25796060

  7. Molecular cloning of the gene encoding the bovine brain ribonuclease and its expression in different regions of the brain.

    PubMed Central

    Sasso, M P; Carsana, A; Confalone, E; Cosi, C; Sorrentino, S; Viola, M; Palmieri, M; Russo, E; Furia, A

    1991-01-01

    In this paper we report the molecular cloning of the gene encoding the bovine brain ribonuclease. The nucleotide sequence determined in this work shows a high degree of identity to the homologous gene encoding the bovine pancreatic ribonuclease. Processing of the primary transcripts of these genes also follows a similar pathway, splicing of the unique intron in the 5' untranslated region occurs at corresponding positions. Expression of the bovine brain ribonuclease gene can be detected both at the transcriptional and translational levels in all the regions of the brain examined. Images PMID:1754384

  8. Insult-induced adaptive plasticity of the auditory system

    PubMed Central

    Gold, Joshua R.; Bajo, Victoria M.

    2014-01-01

    The brain displays a remarkable capacity for both widespread and region-specific modifications in response to environmental challenges, with adaptive processes bringing about the reweighing of connections in neural networks putatively required for optimizing performance and behavior. As an avenue for investigation, studies centered around changes in the mammalian auditory system, extending from the brainstem to the cortex, have revealed a plethora of mechanisms that operate in the context of sensory disruption after insult, be it lesion-, noise trauma, drug-, or age-related. Of particular interest in recent work are those aspects of auditory processing which, after sensory disruption, change at multiple—if not all—levels of the auditory hierarchy. These include changes in excitatory, inhibitory and neuromodulatory networks, consistent with theories of homeostatic plasticity; functional alterations in gene expression and in protein levels; as well as broader network processing effects with cognitive and behavioral implications. Nevertheless, there abounds substantial debate regarding which of these processes may only be sequelae of the original insult, and which may, in fact, be maladaptively compelling further degradation of the organism's competence to cope with its disrupted sensory context. In this review, we aim to examine how the mammalian auditory system responds in the wake of particular insults, and to disambiguate how the changes that develop might underlie a correlated class of phantom disorders, including tinnitus and hyperacusis, which putatively are brought about through maladaptive neuroplastic disruptions to auditory networks governing the spatial and temporal processing of acoustic sensory information. PMID:24904256

  9. Automated selection of brain regions for real-time fMRI brain-computer interfaces

    NASA Astrophysics Data System (ADS)

    Lührs, Michael; Sorger, Bettina; Goebel, Rainer; Esposito, Fabrizio

    2017-02-01

    Objective. Brain-computer interfaces (BCIs) implemented with real-time functional magnetic resonance imaging (rt-fMRI) use fMRI time-courses from predefined regions of interest (ROIs). To reach best performances, localizer experiments and on-site expert supervision are required for ROI definition. To automate this step, we developed two unsupervised computational techniques based on the general linear model (GLM) and independent component analysis (ICA) of rt-fMRI data, and compared their performances on a communication BCI. Approach. 3 T fMRI data of six volunteers were re-analyzed in simulated real-time. During a localizer run, participants performed three mental tasks following visual cues. During two communication runs, a letter-spelling display guided the subjects to freely encode letters by performing one of the mental tasks with a specific timing. GLM- and ICA-based procedures were used to decode each letter, respectively using compact ROIs and whole-brain distributed spatio-temporal patterns of fMRI activity, automatically defined from subject-specific or group-level maps. Main results. Letter-decoding performances were comparable to supervised methods. In combination with a similarity-based criterion, GLM- and ICA-based approaches successfully decoded more than 80% (average) of the letters. Subject-specific maps yielded optimal performances. Significance. Automated solutions for ROI selection may help accelerating the translation of rt-fMRI BCIs from research to clinical applications.

  10. Cross-modal recruitment of primary visual cortex by auditory stimuli in the nonhuman primate brain: a molecular mapping study.

    PubMed

    Hirst, Priscilla; Javadi Khomami, Pasha; Gharat, Amol; Zangenehpour, Shahin

    2012-01-01

    Recent studies suggest that exposure to only one component of audiovisual events can lead to cross-modal cortical activation. However, it is not certain whether such crossmodal recruitment can occur in the absence of explicit conditioning, semantic factors, or long-term associations. A recent study demonstrated that crossmodal cortical recruitment can occur even after a brief exposure to bimodal stimuli without semantic association. In addition, the authors showed that the primary visual cortex is under such crossmodal influence. In the present study, we used molecular activity mapping of the immediate early gene zif268. We found that animals, which had previously been exposed to a combination of auditory and visual stimuli, showed increased number of active neurons in the primary visual cortex when presented with sounds alone. As previously implied, this crossmodal activation appears to be the result of implicit associations of the two stimuli, likely driven by their spatiotemporal characteristics; it was observed after a relatively short period of exposure (~45 min) and lasted for a relatively long period after the initial exposure (~1 day). These results suggest that the previously reported findings may be directly rooted in the increased activity of the neurons occupying the primary visual cortex.

  11. Functional Connectivity of Multiple Brain Regions Required for the Consolidation of Social Recognition Memory.

    PubMed

    Tanimizu, Toshiyuki; Kenney, Justin W; Okano, Emiko; Kadoma, Kazune; Frankland, Paul W; Kida, Satoshi

    2017-04-12

    Social recognition memory is an essential and basic component of social behavior that is used to discriminate familiar and novel animals/humans. Previous studies have shown the importance of several brain regions for social recognition memories; however, the mechanisms underlying the consolidation of social recognition memory at the molecular and anatomic levels remain unknown. Here, we show a brain network necessary for the generation of social recognition memory in mice. A mouse genetic study showed that cAMP-responsive element-binding protein (CREB)-mediated transcription is required for the formation of social recognition memory. Importantly, significant inductions of the CREB target immediate-early genes c-fos and Arc were observed in the hippocampus (CA1 and CA3 regions), medial prefrontal cortex (mPFC), anterior cingulate cortex (ACC), and amygdala (basolateral region) when social recognition memory was generated. Pharmacological experiments using a microinfusion of the protein synthesis inhibitor anisomycin showed that protein synthesis in these brain regions is required for the consolidation of social recognition memory. These findings suggested that social recognition memory is consolidated through the activation of CREB-mediated gene expression in the hippocampus/mPFC/ACC/amygdala. Network analyses suggested that these four brain regions show functional connectivity with other brain regions and, more importantly, that the hippocampus functions as a hub to integrate brain networks and generate social recognition memory, whereas the ACC and amygdala are important for coordinating brain activity when social interaction is initiated by connecting with other brain regions. We have found that a brain network composed of the hippocampus/mPFC/ACC/amygdala is required for the consolidation of social recognition memory.SIGNIFICANCE STATEMENT Here, we identify brain networks composed of multiple brain regions for the consolidation of social recognition memory. We

  12. Nonverbal auditory agnosia with lesion to Wernicke’s area

    PubMed Central

    Saygin, Ayse Pinar; Leech, Robert; Dick, Frederic

    2009-01-01

    We report the case of patient M, who suffered unilateral left posterior temporal and parietal damage, brain regions typically associated with language processing. Language function largely recovered since the infarct, with no measurable speech comprehension impairments. However, the patient exhibited a severe impairment in nonverbal auditory comprehension. We carried out extensive audiological and behavioral testing in order to characterize M’s unusual neuropsychological profile. We also examined the patient’s and controls’ neural responses to verbal and nonverbal auditory stimuli using functional magnetic resonance imaging (fMRI). We verified that the patient exhibited persistent and severe auditory agnosia for nonverbal sounds in the absence of verbal comprehension deficits or peripheral hearing problems. Acoustical analyses suggested that his residual processing of a minority of environmental sounds might rely on his speech processing abilities. In the patient’s brain, contralateral (right) temporal cortex as well as perilesional (left) anterior temporal cortex were strongly responsive to verbal, but not to nonverbal sounds, a pattern that stands in marked contrast to the controls’ data. This substantial reorganization of auditory processing likely supported the recovery of M’s speech processing. PMID:19698727

  13. Nonverbal auditory agnosia with lesion to Wernicke's area.

    PubMed

    Saygin, Ayse Pinar; Leech, Robert; Dick, Frederic

    2010-01-01

    We report the case of patient M, who suffered unilateral left posterior temporal and parietal damage, brain regions typically associated with language processing. Language function largely recovered since the infarct, with no measurable speech comprehension impairments. However, the patient exhibited a severe impairment in nonverbal auditory comprehension. We carried out extensive audiological and behavioral testing in order to characterize M's unusual neuropsychological profile. We also examined the patient's and controls' neural responses to verbal and nonverbal auditory stimuli using functional magnetic resonance imaging (fMRI). We verified that the patient exhibited persistent and severe auditory agnosia for nonverbal sounds in the absence of verbal comprehension deficits or peripheral hearing problems. Acoustical analyses suggested that his residual processing of a minority of environmental sounds might rely on his speech processing abilities. In the patient's brain, contralateral (right) temporal cortex as well as perilesional (left) anterior temporal cortex were strongly responsive to verbal, but not to nonverbal sounds, a pattern that stands in marked contrast to the controls' data. This substantial reorganization of auditory processing likely supported the recovery of M's speech processing.

  14. Demonstration of prosthetic activation of central auditory pathways using ( sup 14 C)-2-deoxyglucose

    SciTech Connect

    Evans, D.A.; Niparko, J.K.; Altschuler, R.A.; Frey, K.A.; Miller, J.M. )

    1990-02-01

    The cochlear prosthesis is not applicable to patients who lack an implantable cochlea or an intact vestibulocochlear nerve. Direct electrical stimulation of the cochlear nucleus (CN) of the brain stem might provide a method for auditory rehabilitation of these patients. A penetrating CN electrode has been developed and tissue tolerance to this device demonstrated. This study was undertaken to evaluate metabolic activation of central nervous system (CNS) auditory tracts produced by such implants. Regional cerebral glucose use resulting from CN stimulation was estimated in a series of chronically implanted guinea pigs with the use of ({sup 14}C)-2-deoxyglucose (2-DG). Enhanced 2-DG uptake was observed in structures of the auditory tract. The activation of central auditory structures achieved with CN stimulation was similar to that produced by acoustic stimulation and by electrical stimulation of the modiolar portion of the auditory nerve in control groups. An interesting banding pattern was observed in the inferior colliculus following CN stimulation, as previously described with acoustic stimulation. This study demonstrates that functional metabolic activation of central auditory pathways can be achieved with a penetrating CNS auditory prosthesis.

  15. Adaptation to vocal expressions reveals multistep perception of auditory emotion.

    PubMed

    Bestelmeyer, Patricia E G; Maurage, Pierre; Rouger, Julien; Latinus, Marianne; Belin, Pascal

    2014-06-11

    The human voice carries speech as well as important nonlinguistic signals that influence our social interactions. Among these cues that impact our behavior and communication with other people is the perceived emotional state of the speaker. A theoretical framework for the neural processing stages of emotional prosody has suggested that auditory emotion is perceived in multiple steps (Schirmer and Kotz, 2006) involving low-level auditory analysis and integration of the acoustic information followed by higher-level cognition. Empirical evidence for this multistep processing chain, however, is still sparse. We examined this question using functional magnetic resonance imaging and a continuous carry-over design (Aguirre, 2007) to measure brain activity while volunteers listened to non-speech-affective vocalizations morphed on a continuum between anger and fear. Analyses dissociated neuronal adaptation effects induced by similarity in perceived emotional content between consecutive stimuli from those induced by their acoustic similarity. We found that bilateral voice-sensitive auditory regions as well as right amygdala coded the physical difference between consecutive stimuli. In contrast, activity in bilateral anterior insulae, medial superior frontal cortex, precuneus, and subcortical regions such as bilateral hippocampi depended predominantly on the perceptual difference between morphs. Our results suggest that the processing of vocal affect recognition is a multistep process involving largely distinct neural networks. Amygdala and auditory areas predominantly code emotion-related acoustic information while more anterior insular and prefrontal regions respond to the abstract, cognitive representation of vocal affect.

  16. Auditory and audio-visual processing in patients with cochlear, auditory brainstem, and auditory midbrain implants: An EEG study.

    PubMed

    Schierholz, Irina; Finke, Mareike; Kral, Andrej; Büchner, Andreas; Rach, Stefan; Lenarz, Thomas; Dengler, Reinhard; Sandmann, Pascale

    2017-04-01

    There is substantial variability in speech recognition ability across patients with cochlear implants (CIs), auditory brainstem implants (ABIs), and auditory midbrain implants (AMIs). To better understand how this variability is related to central processing differences, the current electroencephalography (EEG) study compared hearing abilities and auditory-cortex activation in patients with electrical stimulation at different sites of the auditory pathway. Three different groups of patients with auditory implants (Hannover Medical School; ABI: n = 6, CI: n = 6; AMI: n = 2) performed a speeded response task and a speech recognition test with auditory, visual, and audio-visual stimuli. Behavioral performance and cortical processing of auditory and audio-visual stimuli were compared between groups. ABI and AMI patients showed prolonged response times on auditory and audio-visual stimuli compared with NH listeners and CI patients. This was confirmed by prolonged N1 latencies and reduced N1 amplitudes in ABI and AMI patients. However, patients with central auditory implants showed a remarkable gain in performance when visual and auditory input was combined, in both speech and non-speech conditions, which was reflected by a strong visual modulation of auditory-cortex activation in these individuals. In sum, the results suggest that the behavioral improvement for audio-visual conditions in central auditory implant patients is based on enhanced audio-visual interactions in the auditory cortex. Their findings may provide important implications for the optimization of electrical stimulation and rehabilitation strategies in patients with central auditory prostheses. Hum Brain Mapp 38:2206-2225, 2017. © 2017 Wiley Periodicals, Inc.

  17. Auditory and visual impairments in patients with blast-related traumatic brain injury: Effect of dual sensory impairment on Functional Independence Measure.

    PubMed

    Lew, Henry L; Garvert, Donn W; Pogoda, Terri K; Hsu, Pei-Te; Devine, Jennifer M; White, Daniel K; Myers, Paula J; Goodrich, Gregory L

    2009-01-01

    The frequencies of hearing impairment (HI), vision impairment (VI), or dual (hearing and vision) sensory impairment (DSI) in patients with blast-related traumatic brain injury (TBI) and their effects on functional recovery are not well documented. In this preliminary study of 175 patients admitted to a Polytrauma Rehabilitation Center, we completed hearing and vision examinations and obtained Functional Independence Measure (FIM) scores at admission and discharge for 62 patients with blast-related TBI. We diagnosed HI only, VI only, and DSI in 19%, 34%, and 32% of patients, respectively. Only 15% of the patients had no sensory impairment in either auditory or visual modality. An analysis of variance showed a group difference for the total and motor FIM scores at discharge (p < 0.04). Regression model analyses demonstrated that DSI significantly contributed to reduced gain in total ( t = -2.25) and motor ( t = -2.50) FIM scores ( p < 0.05). Understanding the long-term consequences of sensory impairments in the functional recovery of patients with blast-related TBI requires further research.

  18. Perineuronal nets in the auditory system.

    PubMed

    Sonntag, Mandy; Blosa, Maren; Schmidt, Sophie; Rübsamen, Rudolf; Morawski, Markus

    2015-11-01

    Perineuronal nets (PNs) are a unique and complex meshwork of specific extracellular matrix molecules that ensheath a subset of neurons in many regions of the central nervous system (CNS). PNs appear late in development and are supposed to restrict synaptic plasticity and to stabilize functional neuronal connections. PNs were further hypothesized to create a charged milieu around the neurons and thus, might directly modulate synaptic activity. Although PNs were first described more than 120 years ago, their exact functions still remain elusive. The purpose of the present review is to propose the nuclei of the auditory system, which are highly enriched in PN-wearing neurons, as particularly suitable structures to study the functional significance of PNs. We provide a detailed description of the distribution of PNs from the cochlear nucleus to the auditory cortex considering distinct markers for detection of PNs. We further point to the suitability of specific auditory neurons to serve as promising model systems to study in detail the contribution of PNs to synaptic physiology and also more generally to the functionality of the brain.

  19. Brain Dynamics of Aging: Multiscale Variability of EEG Signals at Rest and during an Auditory Oddball Task1,2,3

    PubMed Central

    Sleimen-Malkoun, Rita; Perdikis, Dionysios; Müller, Viktor; Blanc, Jean-Luc; Huys, Raoul; Temprado, Jean-Jacques

    2015-01-01

    Abstract The present work focused on the study of fluctuations of cortical activity across time scales in young and older healthy adults. The main objective was to offer a comprehensive characterization of the changes of brain (cortical) signal variability during aging, and to make the link with known underlying structural, neurophysiological, and functional modifications, as well as aging theories. We analyzed electroencephalogram (EEG) data of young and elderly adults, which were collected at resting state and during an auditory oddball task. We used a wide battery of metrics that typically are separately applied in the literature, and we compared them with more specific ones that address their limits. Our procedure aimed to overcome some of the methodological limitations of earlier studies and verify whether previous findings can be reproduced and extended to different experimental conditions. In both rest and task conditions, our results mainly revealed that EEG signals presented systematic age-related changes that were time-scale-dependent with regard to the structure of fluctuations (complexity) but not with regard to their magnitude. Namely, compared with young adults, the cortical fluctuations of the elderly were more complex at shorter time scales, but less complex at longer scales, although always showing a lower variance. Additionally, the elderly showed signs of spatial, as well as between, experimental conditions dedifferentiation. By integrating these so far isolated findings across time scales, metrics, and conditions, the present study offers an overview of age-related changes in the fluctuation electrocortical activity while making the link with underlying brain dynamics. PMID:26464983

  20. Sleep-Disordered Breathing Affects Auditory Processing in 5–7 Year-Old Children: Evidence From Brain Recordings

    PubMed Central

    Key, Alexandra P.F.; Molfese, Dennis L.; O’Brien, Louise; Gozal, David

    2010-01-01

    Poor sleep in children is associated with lower neurocognitive functioning and increased maladaptive behaviors. The current study examined the impact of snoring (the most common manifestation of sleep-disordered breathing) on cognitive and brain functioning in a sample of 35 asymptomatic children ages 5–7 years identified in the community as having habitual snoring (SDB). All participants completed polysomnographic, neurocognitive (NEPSY) and psychophysiological (ERPs to speech sounds) assessments. The results indicated that sub-clinical levels of SDB may not necessarily lead to reduced performance on standardized behavioral measures of attention and memory. However, brain indices of speech perception and discrimination (N1/P2) are sensitive to individual differences in the quality of sleep. We postulate that addition of ERPs to the standard clinical measures of sleep problems could lead to early identification of children who may be more cognitively vulnerable because of chronic sleep disturbances. PMID:20183723

  1. Emotion modulates activity in the 'what' but not 'where' auditory processing pathway.

    PubMed

    Kryklywy, James H; Macpherson, Ewan A; Greening, Steven G; Mitchell, Derek G V

    2013-11-15

    Auditory cortices can be separated into dissociable processing pathways similar to those observed in the visual domain. Emotional stimuli elicit enhanced neural activation within sensory cortices when compared to neutral stimuli. This effect is particularly notable in the ventral visual stream. Little is known, however, about how emotion interacts with dorsal processing streams, and essentially nothing is known about the impact of emotion on auditory stimulus localization. In the current study, we used fMRI in concert with individualized auditory virtual environments to investigate the effect of emotion during an auditory stimulus localization task. Surprisingly, participants were significantly slower to localize emotional relative to neutral sounds. A separate localizer scan was performed to isolate neural regions sensitive to stimulus location independent of emotion. When applied to the main experimental task, a significant main effect of location, but not emotion, was found in this ROI. A whole-brain analysis of the data revealed that posterior-medial regions of auditory cortex were modulated by sound location; however, additional anterior-lateral areas of auditory cortex demonstrated enhanced neural activity to emotional compared to neutral stimuli. The latter region resembled areas described in dual pathway models of auditory processing as the 'what' processing stream, prompting a follow-up task to generate an identity-sensitive ROI (the 'what' pathway) independent of location and emotion. Within this region, significant main effects of location and emotion were identified, as well as a significant interaction. These results suggest that emotion modulates activity in the 'what,' but not the 'where,' auditory processing pathway.

  2. Developmental and regional patterns of GAP-43 immunoreactivity in a metamorphosing brain.

    PubMed

    Simmons, Andrea Megela; Tanyu, Leslie H; Horowitz, Seth S; Chapman, Judith A; Brown, Rebecca A

    2008-01-01

    Growth-associated protein-43 is typically expressed at high levels in the nervous system during development. In adult animals, its expression is lower, but still observable in brain areas showing structural or functional plasticity. We examined patterns of GAP-43 immunoreactivity in the brain of the bullfrog, an animal whose nervous system undergoes considerable reorganization across metamorphic development and retains a strong capacity for plasticity in adulthood. Immunolabeling was mostly diffuse in hatchling tadpoles, but became progressively more discrete as larval development proceeded. In many brain areas, intensity of immunolabel peaked at metamorphic climax, the time of final transition from aquatic to semi-terrestrial life. Changes in intensity of GAP-43 expression in the medial vestibular nucleus, superior olivary nucleus, and torus semicircularis appeared correlated with stage-dependent functional changes in processing auditory stimuli. Immunolabeling in the Purkinje cell layer of the cerebellum and in the cerebellar nucleus was detectable at most developmental time points. Heavy immunolabel was present from early larval stages through the end of climax in the thalamus (ventromedial, anterior, posterior, central nuclei). Immunolabel in the tadpole telencephalon was observed around the lateral ventricles, and in the medial septum and ventral striatum. In postmetamorphic animals, immunoreactivity was confined mainly to the ventricular zones and immediately adjacent cell layers. GAP-43 expression was present in olfactory, auditory and optic cranial nerves throughout larval and postmetamorphic life. The continued expression of GAP-43 in brain nuclei and in cranial nerves throughout development and into adulthood reflects the high regenerative potential of the bullfrog's central nervous system.

  3. Children with reading difficulties show differences in brain regions associated with orthographic processing during spoken language processing.

    PubMed

    Desroches, Amy S; Cone, Nadia E; Bolger, Donald J; Bitan, Tali; Burman, Douglas D; Booth, James R

    2010-10-14

    We explored the neural basis of spoken language deficits in children with reading difficulty, specifically focusing on the role of orthography during spoken language processing. We used functional magnetic resonance imaging (fMRI) to examine differences in brain activation between children with reading difficulties (aged 9-to-15 years) and age-matched children with typical achievement during an auditory rhyming task. Both groups showed activation in bilateral superior temporal gyri (BA 42 and 22), a region associated with phonological processing, with no significant between-group differences. Interestingly, typically achieving children, but not children with reading difficulties, showed activation of left fusiform cortex (BA 37), a region implicated in orthographic processing. Furthermore, this activation was significantly greater for typically achieving children compared to those with reading difficulties. These findings suggest that typical children automatically activate orthographic representations during spoken language processing, while those with reading difficulties do not. Follow-up analyses revealed that the intensity of the activation in the fusiform gyrus was associated with significantly stronger behavioral conflict effects in typically achieving children only (i.e., longer latencies to rhyming pairs with orthographically dissimilar endings than to those with identical orthographic endings; jazz-has vs. cat-hat). Finally, for reading disabled children, a positive correlation between left fusiform activation and nonword reading was observed, such that greater access to orthography was related to decoding ability. Taken together, the results suggest that the integration of orthographic and phonological processing is directly related to reading ability.

  4. The Brain Tourniquet: Physiological Isolation of Brain Regions Damaged by Traumatic Head Injury

    DTIC Science & Technology

    2008-06-19

    brain slices were treated after injury with either a nootropic agent (aniracetam, cyclothiazide, IDRA 21, or 1-BCP) or the antiepileptic drug...pharmacological approach. 15. SUBJECT TERMS traumatic brain injury, cell necrosis, neuroprotection, nootropics , epilepsy, long-term potentiation...render their use problematic in an effective brain tourniquet system. We chose to focus our investigations on the nootropic (cognition enhancing) drugs

  5. Auditory system

    NASA Technical Reports Server (NTRS)

    Ades, H. W.

    1973-01-01

    The physical correlations of hearing, i.e. the acoustic stimuli, are reported. The auditory system, consisting of external ear, middle ear, inner ear, organ of Corti, basilar membrane, hair cells, inner hair cells, outer hair cells, innervation of hair cells, and transducer mechanisms, is discussed. Both conductive and sensorineural hearing losses are also examined.

  6. Pre-target axon sorting in the avian auditory brainstem

    PubMed Central

    Kashima, Daniel T.; Rubel, Edwin W; Seidl, Armin H.

    2012-01-01

    Topographic organization of neurons is a hallmark of brain structure. The establishment of the connections between topographically organized brain regions has attracted much experimental attention and it is widely accepted that molecular cues guide outgrowing axons to their targets in order to construct topographic maps. In a number of systems afferent axons are organized topographically along their trajectory as well and it has been suggested that this pre-target sorting contributes to map formation. Neurons in auditory regions of the brain are arranged according to their best frequency (BF), the sound frequency they respond to optimally. This BF changes predictably with position along the so-called tonotopic axis. In the avian auditory brainstem, the tonotopic organization of the second- and third-order auditory neurons in nucleus magnocellularis (NM) and nucleus laminaris (NL) has been well described. In this study we examine whether the decussating NM axons forming the crossed dorsal cochlear tract (XDCT) and innervating the contralateral NL are arranged in a systematic manner. We electroporated dye into cells in different frequency regions of NM to anterogradely label their axons in the XDCT. The placement of dye in NM was compared to the location of labeled axons in XDCT. Our results show that NM axons in XDCT are organized in a precise tonotopic manner along the rostrocaudal axis, spanning over the entire rostrocaudal extent of both the origin and target nuclei. We propose that in the avian auditory brainstem, this pre-target axon sorting contributes to tonotopic map formation in NL. PMID:23239056

  7. Functional Organization of the Ventral Auditory Pathway.

    PubMed

    Cohen, Yale E; Bennur, Sharath; Christison-Lagay, Kate; Gifford, Adam M; Tsunada, Joji

    2016-01-01

    The fundamental problem in audition is determining the mechanisms required by the brain to transform an unlabelled mixture of auditory stimuli into coherent perceptual representations. This process is called auditory-scene analysis. The perceptual representations that result from auditory-scene analysis are formed through a complex interaction of perceptual grouping, attention, categorization and decision-making. Despite a great deal of scientific energy devoted to understanding these aspects of hearing, we still do not understand (1) how sound perception arises from neural activity and (2) the causal relationship between neural activity and sound perception. Here, we review the role of the "ventral" auditory pathway in sound perception. We hypothesize that, in the early parts of the auditory cortex, neural activity reflects the auditory properties of a stimulus. However, in latter parts of the auditory cortex, neurons encode the sensory evidence that forms an auditory decision and are causally involved in the decision process. Finally, in the prefrontal cortex, which receives input from the auditory cortex, neural activity reflects the actual perceptual decision. Together, these studies indicate that the ventral pathway contains hierarchical circuits that are specialized for auditory perception and scene analysis.

  8. The representation of level and loudness in the central auditory system for unilateral stimulation.

    PubMed

    Behler, Oliver; Uppenkamp, Stefan

    2016-06-16

    Loudness is the perceptual correlate of the physical intensity of a sound. However, loudness judgments depend on a variety of other variables and can vary considerably between individual listeners. While functional magnetic resonance imaging (fMRI) has been extensively used to characterize the neural representation of physical sound intensity in the human auditory system, only few studies have also investigated brain activity in relation to individual loudness. The physiological correlate of loudness perception is not yet fully understood. The present study systematically explored the interrelation of sound pressure level, ear of entry, individual loudness judgments, and fMRI activation along different stages of the central auditory system and across hemispheres for a group of normal hearing listeners. 4-kHz-bandpass filtered noise stimuli were presented monaurally to each ear at levels from 37 to 97dB SPL. One diotic condition and a silence condition were included as control conditions. The participants completed a categorical loudness scaling procedure with similar stimuli before auditory fMRI was performed. The relationship between brain activity, as inferred from blood oxygenation level dependent (BOLD) contrasts, and both sound level and loudness estimates were analyzed by means of functional activation maps and linear mixed effects models for various anatomically defined regions of interest in the ascending auditory pathway and in the cortex. Our findings are overall in line with the notion that fMRI activation in several regions within auditory cortex as well as in certain stages of the ascending auditory pathway might be more a direct linear reflection of perceived loudness rather than of sound pressure level. The results indicate distinct functional differences between midbrain and cortical areas as well as between specific regions within auditory cortex, suggesting a systematic hierarchy in terms of lateralization and the representation of level and

  9. Regional infant brain development: an MRI-based morphometric analysis in 3 to 13 month olds.

    PubMed

    Choe, Myong-Sun; Ortiz-Mantilla, Silvia; Makris, Nikos; Gregas, Matt; Bacic, Janine; Haehn, Daniel; Kennedy, David; Pienaar, Rudolph; Caviness, Verne S; Benasich, April A; Grant, P Ellen

    2013-09-01

    Elucidation of infant brain development is a critically important goal given the enduring impact of these early processes on various domains including later cognition and language. Although infants' whole-brain growth rates have long been available, regional growth rates have not been reported systematically. Accordingly, relatively less is known about the dynamics and organization of typically developing infant brains. Here we report global and regional volumetric growth of cerebrum, cerebellum, and brainstem with gender dimorphism, in 33 cross-sectional scans, over 3 to 13 months, using T1-weighted 3-dimensional spoiled gradient echo images and detailed semi-automated brain segmentation. Except for the midbrain and lateral ventricles, all absolute volumes of brain regions showed significant growth, with 6 different patterns of volumetric change. When normalized to the whole brain, the regional increase was characterized by 5 differential patterns. The putamen, cerebellar hemispheres, and total cerebellum were the only regions that showed positive growth in the normalized brain. Our results show region-specific patterns of volumetric change and contribute to the systematic understanding of infant brain development. This study greatly expands our knowledge of normal development and in future may provide a basis for identifying early deviation above and beyond normative variation that might signal higher risk for neurological disorders.

  10. Identification of a set of genes showing regionally enriched expression in the mouse brain

    PubMed Central

    D'Souza, Cletus A; Chopra, Vikramjit; Varhol, Richard; Xie, Yuan-Yun; Bohacec, Slavita; Zhao, Yongjun; Lee, Lisa LC; Bilenky, Mikhail; Portales-Casamar, Elodie; He, An; Wasserman, Wyeth W; Goldowitz, Daniel; Marra, Marco A; Holt, Robert A; Simpson, Elizabeth M; Jones, Steven JM

    2008-01-01

    Background The Pleiades Promoter Project aims to improve gene therapy by designing human mini-promoters (< 4 kb) that drive gene expression in specific brain regions or cell-types of therapeutic interest. Our goal was to first identify genes displaying regionally enriched expression in the mouse brain so that promoters designed from orthologous human genes can then be tested to drive reporter expression in a similar pattern in the mouse brain. Results We have utilized LongSAGE to identify regionally enriched transcripts in the adult mouse brain. As supplemental strategies, we also performed a meta-analysis of published literature and inspected the Allen Brain Atlas in situ hybridization data. From a set of approximately 30,000 mouse genes, 237 were identified as showing specific or enriched expression in 30 target regions of the mouse brain. GO term over-representation among these genes revealed co-involvement in various aspects of central nervous system development and physiology. Conclusion Using a multi-faceted expression validation approach, we have identified mouse genes whose human orthologs are good candidates for design of mini-promoters. These mouse genes represent molecular markers in several discrete brain regions/cell-types, which could potentially provide a mechanistic explanation of unique functions performed by each region. This set of markers may also serve as a resource for further studies of gene regulatory elements influencing brain expression. PMID:18625066

  11. Auditory and visual connectivity gradients in frontoparietal cortex.

    PubMed

    Braga, Rodrigo M; Hellyer, Peter J; Wise, Richard J S; Leech, Robert

    2017-01-01

    A frontoparietal network of brain regions is often implicated in both auditory and visual information processing. Although it is possible that the same set of multimodal regions subserves both modalities, there is increasing evidence that there is a differentiation of sensory function within frontoparietal cortex. Magnetic resonance imaging (MRI) in humans was used to investigate whether different frontoparietal regions showed intrinsic biases in connectivity with visual or auditory modalities. Structural connectivity was assessed with diffusion tractography and functional connectivity was tested using functional MRI. A dorsal-ventral gradient of function was observed, where connectivity with visual cortex dominates dorsal frontal and parietal connections, while connectivity with auditory cortex dominates ventral frontal and parietal regions. A gradient was also observed along the posterior-anterior axis, although in opposite directions in prefrontal and parietal cortices. The results suggest that the location of neural activity within frontoparietal cortex may be influenced by these intrinsic biases toward visual and auditory processing. Thus, the location of activity in frontoparietal cortex may be influenced as much by stimulus modality as the cognitive demands of a task. It was concluded that stimulus modality was spatially encoded throughout frontal and parietal cortices, and was speculated that such an arrangement allows for top-down modulation of modality-specific information to occur within higher-order cortex. This could provide a potentially faster and more efficient pathway by which top-down selection between sensory modalities could occur, by constraining modulations to within frontal and parietal regions, rather than long-range connections to sensory cortices. Hum Brain Mapp 38:255-270, 2017. © 2016 Wiley Periodicals, Inc.

  12. Auditory and visual connectivity gradients in frontoparietal cortex

    PubMed Central

    Hellyer, Peter J.; Wise, Richard J. S.; Leech, Robert

    2016-01-01

    Abstract A frontoparietal network of brain regions is often implicated in both auditory and visual information processing. Although it is possible that the same set of multimodal regions subserves both modalities, there is increasing evidence that there is a differentiation of sensory function within frontoparietal cortex. Magnetic resonance imaging (MRI) in humans was used to investigate whether different frontoparietal regions showed intrinsic biases in connectivity with visual or auditory modalities. Structural connectivity was assessed with diffusion tractography and functional connectivity was tested using functional MRI. A dorsal–ventral gradient of function was observed, where connectivity with visual cortex dominates dorsal frontal and parietal connections, while connectivity with auditory cortex dominates ventral frontal and parietal regions. A gradient was also observed along the posterior–anterior axis, although in opposite directions in prefrontal and parietal cortices. The results suggest that the location of neural activity within frontoparietal cortex may be influenced by these intrinsic biases toward visual and auditory processing. Thus, the location of activity in frontoparietal cortex may be influenced as much by stimulus modality as the cognitive demands of a task. It was concluded that stimulus modality was spatially encoded throughout frontal and parietal cortices, and was speculated that such an arrangement allows for top–down modulation of modality‐specific information to occur within higher‐order cortex. This could provide a potentially faster and more efficient pathway by which top–down selection between sensory modalities could occur, by constraining modulations to within frontal and parietal regions, rather than long‐range connections to sensory cortices. Hum Brain Mapp 38:255–270, 2017. © 2016 Wiley Periodicals, Inc. PMID:27571304

  13. Distortion product otoacoustic emissions and auditory evoked potentials in the hedgehog tenrec, Echinops telfairi.

    PubMed

    Drexl, Markus; Faulstich, Michael; Von Stebut, Boris; Radtke-Schuller, Susanne; Kössl, Manfred

    2003-12-01

    The hedgehog tenrec, Echinops telfairi, has certain basal mammalian features, like a cloaca and a sparsely differentiated brain with smooth cerebral hemispheres. The peripheral auditory capabilities of this species were investigated by means of distortion product otoacoustic emissions (DPOAE). For comparison, we determined auditory evoked potentials (AEP) in the inferior colliculus and the auditory cortex. Both methods show that the auditory range of E. telfairi extends well into ultrasonic frequencies, with a region of highest sensitivity at around 16 kHz. The total auditory range spans about 4 octaves at 40 dB SPL. The low-frequency limit of auditory processing is found at frequencies of about 2-3 kHz. The DPOAE and the AEP thresholds of E. telfairi do not run fully parallel in the high-frequency range. For a threshold value of 40 dB SPL, cochlear mechanical thresholds as measured with DPOAE extend up to 50 kHz, whereas neuronal thresholds reach the high-frequency limit at about 30 kHz. Frequency tuning, as assessed from DPOAE suppression tuning curves, was low to moderate with Q(10 dB) values ranging from 1.7 to 8. The lack of discontinuity in the group delay (derived from DPOAE measurements) reveals that cochlear frequency representation is tonotopic without any region of specialized mechanical tuning.

  14. Tonotopic maps in human auditory cortex using arterial spin labeling

    PubMed Central

    Ivanov, Dimo; Havlicek, Martin; Formisano, Elia; Uludağ, Kâmil

    2016-01-01

    Abstract A tonotopic organization of the human auditory cortex (AC) has been reliably found by neuroimaging studies. However, a full characterization and parcellation of the AC is still lacking. In this study, we employed pseudo‐continuous arterial spin labeling (pCASL) to map tonotopy and voice selective regions using, for the first time, cerebral blood flow (CBF). We demonstrated the feasibility of CBF‐based tonotopy and found a good agreement with BOLD signal‐based tonotopy, despite the lower contrast‐to‐noise ratio of CBF. Quantitative perfusion mapping of baseline CBF showed a region of high perfusion centered on Heschl's gyrus and corresponding to the main high‐low‐high frequency gradients, co‐located to the presumed primary auditory core and suggesting baseline CBF as a novel marker for AC parcellation. Furthermore, susceptibility weighted imaging was employed to investigate the tissue specificity of CBF and BOLD signal and the possible venous bias of BOLD‐based tonotopy. For BOLD only active voxels, we found a higher percentage of vein contamination than for CBF only active voxels. Taken together, we demonstrated that both baseline and stimulus‐induced CBF is an alternative fMRI approach to the standard BOLD signal to study auditory processing and delineate the functional organization of the auditory cortex. Hum Brain Mapp 38:1140–1154, 2017. © 2016 Wiley Periodicals, Inc. PMID:27790786

  15. Tonotopic maps in human auditory cortex using arterial spin labeling.

    PubMed

    Gardumi, Anna; Ivanov, Dimo; Havlicek, Martin; Formisano, Elia; Uludağ, Kâmil

    2017-03-01

    A tonotopic organization of the human auditory cortex (AC) has been reliably found by neuroimaging studies. However, a full characterization and parcellation of the AC is still lacking. In this study, we employed pseudo-continuous arterial spin labeling (pCASL) to map tonotopy and voice selective regions using, for the first time, cerebral blood flow (CBF). We demonstrated the feasibility of CBF-based tonotopy and found a good agreement with BOLD signal-based tonotopy, despite the lower contrast-to-noise ratio of CBF. Quantitative perfusion mapping of baseline CBF showed a region of high perfusion centered on Heschl's gyrus and corresponding to the main high-low-high frequency gradients, co-located to the presumed primary auditory core and suggesting baseline CBF as a novel marker for AC parcellation. Furthermore, susceptibility weighted imaging was employed to investigate the tissue specificity of CBF and BOLD signal and the possible venous bias of BOLD-based tonotopy. For BOLD only active voxels, we found a higher percentage of vein contamination than for CBF only active voxels. Taken together, we demonstrated that both baseline and stimulus-induced CBF is an alternative fMRI approach to the standard BOLD signal to study auditory processing and delineate the functional organization of the auditory cortex. Hum Brain Mapp 38:1140-1154, 2017. © 2016 Wiley Periodicals, Inc.

  16. Auditory short-term memory in the primate auditory cortex.

    PubMed

    Scott, Brian H; Mishkin, Mortimer

    2016-06-01

    Sounds are fleeting, and assembling the sequence of inputs at the ear into a coherent percept requires auditory memory across various time scales. Auditory short-term memory comprises at least two components: an active ׳working memory' bolstered by rehearsal, and a sensory trace that may be passively retained. Working memory relies on representations recalled from long-term memory, and their rehearsal may require phonological mechanisms unique to humans. The sensory component, passive short-term memory (pSTM), is tractable to study in nonhuman primates, whose brain architecture and behavioral repertoire are comparable to our own. This review discusses recent advances in the behavioral and neurophysiological study of auditory memory with a focus on single-unit recordings from macaque monkeys performing delayed-match-to-sample (DMS) tasks. Monkeys appear to employ pSTM to solve these tasks, as evidenced by the impact of interfering stimuli on memory performance. In several regards, pSTM in monkeys resembles pitch memory in humans, and may engage similar neural mechanisms. Neural correlates of DMS performance have been observed throughout the auditory and prefrontal cortex, defining a network of areas supporting auditory STM with parallels to that supporting visual STM. These correlates include persistent neural firing, or a suppression of firing, during the delay period of the memory task, as well as suppression or (less commonly) enhancement of sensory responses when a sound is repeated as a ׳match' stimulus. Auditory STM is supported by a distributed temporo-frontal network in which sensitivity to stimulus history is an intrinsic feature of auditory processing. This article is part of a Special Issue entitled SI: Auditory working memory.

  17. Balance or imbalance: inhibitory circuits for direction selectivity in the auditory system.

    PubMed

    Rabang, Cal F; Lin, Jeff; Wu, Guangying K

    2015-05-01

    The auditory system detects and processes dynamic sound information transmitted in the environment. Other than the basic acoustic parameters, such as frequency, amplitude and phase, the time-varying changes of these parameters must also be encoded in our brain. Frequency-modulated (FM) sound is socially and environmentally significant, and the direction of FM sweeps is essential for animal communication and human speech. Many auditory neurons selectively respond to the directional change of such FM signals. In the past half century, our knowledge of auditory representation and processing has been updated frequently, due to technological advancement. Recently, in vivo whole-cell voltage clamp recordings have been applied to different brain regions in sensory systems. These recordings illustrate the synaptic mechanisms underlying basic sensory information processing and provide profound insights toward our understanding of neural circuits for complex signal analysis. In this review, we summarize the major findings of direction selectivity at several key auditory regions and emphasize on the recent discoveries on the synaptic mechanisms for direction selectivity in the auditory system. We conclude this review by describing promising technical developments in dissecting neural circuits and future directions in the study of complex sound analysis.

  18. Mapping Individual Brain Networks Using Statistical Similarity in Regional Morphology from MRI.

    PubMed

    Kong, Xiang-zhen; Liu, Zhaoguo; Huang, Lijie; Wang, Xu; Yang, Zetian; Zhou, Guangfu; Zhen, Zonglei; Liu, Jia

    2015-01-01

    Representing brain morphology as a network has the advantage that the regional morphology of 'isolated' structures can be described statistically based on graph theory. However, very few studies have investigated brain morphology from the holistic perspective of complex networks, particularly in individual brains. We proposed a new network framework for individual brain morphology. Technically, in the new network, nodes are defined as regions based on a brain atlas, and edges are estimated using our newly-developed inter-regional relation measure based on regional morphological distributions. This implementation allows nodes in the brain network to be functionally/anatomically homogeneous but different with respect to shape and size. We first demonstrated the new network framework in a healthy sample. Thereafter, we studied the graph-theoretical properties of the networks obtained and compared the results with previous morphological, anatomical, and functional networks. The robustness of the method was assessed via measurement of the reliability of the network metrics using a test-retest dataset. Finally, to illustrate potential applications, the networks were used to measure age-related changes in commonly used network metrics. Results suggest that the proposed method could provide a concise description of brain organization at a network level and be used to investigate interindividual variability in brain morphology from the perspective of complex networks. Furthermore, the method could open a new window into modeling the complexly distributed brain and facilitate the emerging field of human connectomics.

  19. Automatic detection of the hippocampal region associated with Alzheimer's disease from microscopic images of mice brain

    NASA Astrophysics Data System (ADS)

    Albaidhani, Tahseen; Hawkes, Cheryl; Jassim, Sabah; Al-Assam, Hisham

    2016-05-01

    The hippocampus is the region of the brain that is primarily associated with memory and spatial navigation. It is one of the first brain regions to be damaged when a person suffers from Alzheimer's disease. Recent research in this field has focussed on the assessment of damage to different blood vessels within the hippocampal region from a high throughput brain microscopic images. The ultimate aim of our research is the creation of an automatic system to count and classify different blood vessels such as capillaries, veins, and arteries in the hippocampus region. This work should provide biologists with efficient and accurate tools in their investigation of the causes of Alzheimer's disease. Locating the boundary of the Region of Interest in the hippocampus from microscopic images of mice brain is the first essential stage towards developing such a system. This task benefits from the variation in colour channels and texture between the two sides of the hippocampus and the boundary region. Accordingly, the developed initial step of our research to locating the hippocampus edge uses a colour-based segmentation of the brain image followed by Hough transforms on the colour channel that isolate the hippocampus region. The output is then used to split the brain image into two sides of the detected section of the boundary: the inside region and the outside region. Experimental results on a sufficiently number of microscopic images demonstrate the effectiveness of the developed solution.

  20. A higher sensory brain region is involved in reversing reinforcement-induced vocal changes in a songbird.

    PubMed

    Canopoli, Alessandro; Herbst, Joshua A; Hahnloser, Richard H R

    2014-05-14

    Many animals exhibit flexible behaviors that they can adjust to increase reward or avoid harm (learning by positive or aversive reinforcement). But what neural mechanisms allow them to restore their original behavior (motor program) after reinforcement is withdrawn? One possibility is that motor restoration relies on brain areas that have a role in memorization but no role in either motor production or in sensory processing relevant for expressing the behavior and its refinement. We investigated the role of a higher auditory brain area in the songbird for modifying and restoring the stereotyped adult song. We exposed zebra finches to aversively reinforcing white noise stimuli contingent on the pitch of one of their stereotyped song syllables. In response, birds significantly changed the pitch of that syllable to avoid the aversive reinforcer. After we withdrew reinforcement, birds recovered their original song within a few days. However, we found that large bilateral lesions in the caudal medial nidopallium (NCM, a high auditory area) impaired recovery of the original pitch even several weeks after withdrawal of the reinforcing stimuli. Because NCM lesions spared both successful noise-avoidance behavior and birds' auditory discrimination ability, our results show that NCM is not needed for directed motor changes or for auditory discriminative processing, but is implied in memorizing or recalling the memory of the recent song target.

  1. Spatiotemporal properties of the BOLD response in the songbirds' auditory circuit during a variety of listening tasks.

    PubMed

    Van Meir, Vincent; Boumans, Tiny; De Groof, Geert; Van Audekerke, Johan; Smolders, Alain; Scheunders, Paul; Sijbers, Jan; Verhoye, Marleen; Balthazart, Jacques; Van der Linden, Annemie

    2005-05-01

    Auditory fMRI in humans has recently received increasing attention from cognitive neuroscientists as a tool to understand mental processing of learned acoustic sequences and analyzing speech recognition and development of musical skills. The present study introduces this tool in a well-documented animal model for vocal learning, the songbird, and provides fundamental insight in the main technical issues associated with auditory fMRI in these songbirds. Stimulation protocols with various listening tasks lead to appropriate activation of successive relays in the songbirds' auditory pathway. The elicited BOLD response is also region and stimulus specific, and its temporal aspects provide accurate measures of the changes in brain physiology induced by the acoustic stimuli. Extensive repetition of an identical stimulus does not lead to habituation of the response in the primary or secondary telencephalic auditory regions of anesthetized subjects. The BOLD signal intensity changes during a stimulation and subsequent rest period have a very specific time course which shows a remarkable resemblance to auditory evoked BOLD responses commonly observed in human subjects. This observation indicates that auditory fMRI in the songbird may establish a link between auditory related neuro-imaging studies done in humans and the large body of neuro-ethological research on song learning and neuro-plasticity performed in songbirds.

  2. Harmonic Training and the Formation of Pitch Representation in a Neural Network Model of the Auditory Brain

    PubMed Central

    Ahmad, Nasir; Higgins, Irina; Walker, Kerry M. M.; Stringer, Simon M.

    2016-01-01

    Attempting to explain the perceptual qualities of pitch has proven to be, and remains, a difficult problem. The wide range of sounds which elicit pitch and a lack of agreement across neurophysiological studies on how pitch is encoded by the brain have made this attempt more difficult. In describing the potential neural mechanisms by which pitch may be processed, a number of neural networks have been proposed and implemented. However, no unsupervised neural networks with biologically accurate cochlear inputs have yet been demonstrated. This paper proposes a simple system in which pitch representing neurons are produced in a biologically plausible setting. Purely unsupervised regimes of neural network learning are implemented and these prove to be sufficient in identifying the pitch of sounds with a variety of spectral profiles, including sounds with missing fundamental frequencies and iterated rippled noises. PMID:27047368

  3. The robo-pigeon based on the multiple brain regions synchronization implanted microelectrodes.

    PubMed

    Huai, Rui-Tuo; Yang, Jun-Qing; Wang, Hui

    2016-07-03

    Almost all multichannel microelectrodes are only applied to the same nucleus. The multiple brain regions synchronization implanted microelectrodes can be implanted in the several brain regions at the same time, when used in the robo-animal, which can reduce the operation process, shorten animals operation time. Due to electrode position relatively fixed, errors caused by each separately implanted electrode were reduced and the animal control effect was greatly increased compared to the original electrodes. The electrode fixed time was also extended. This microelectrode provided beneficial reference function for the study of the free state of small animals in different brain regions.

  4. Long-term recovery from hippocampal-related behavioral and biochemical abnormalities induced by noise exposure during brain development. Evaluation of auditory pathway integrity.

    PubMed

    Uran, S L; Gómez-Casati, M E; Guelman, L R

    2014-10-01

    Sound is an important part of man's contact with the environment and has served as critical means for survival throughout his evolution. As a result of exposure to noise, physiological functions such as those involving structures of the auditory and non-auditory systems might be damaged. We have previously reported that noise-exposed developing rats elicited hippocampal-related histological, biochemical and behavioral changes. However, no data about the time lapse of these changes were reported. Moreover, measurements of auditory pathway function were not performed in exposed animals. Therefore, with the present work, we aim to test the onset and the persistence of the different extra-auditory abnormalities observed in noise-exposed rats and to evaluate auditory pathway integrity. Male Wistar rats of 15 days were exposed to moderate noise levels (95-97 dB SPL, 2 h a day) during one day (acute noise exposure, ANE) or during 15 days (sub-acute noise exposure, SANE). Hippocampal biochemical determinations as well as short (ST) and long term (LT) behavioral assessments were performed. In addition, histological and functional evaluations of the auditory pathway were carried out in exposed animals. Our results show that hippocampal-related behavioral and biochemical changes (impairments in habituation, recognition and associative memories as well as distortion of anxiety-related behavior, decreases in reactive oxygen species (ROS) levels and increases in antioxidant enzymes activities) induced by noise exposure were almost completely restored by PND 90. In addition, auditory evaluation shows that increased cochlear thresholds observed in exposed rats were re-established at PND 90, although with a remarkable supra-threshold amplitude reduction. These data suggest that noise-induced hippocampal and auditory-related alterations are mostly transient and that the effects of noise on the hippocampus might be, at least in part, mediated by the damage on the auditory pathway

  5. Auditory neuroplasticity, hearing loss and cochlear implants.

    PubMed

    Ryugo, David

    2015-07-01

    Data from our laboratory show that the auditory brain is highly malleable by experience. We establish a base of knowledge that describes the normal structure and workings at the initial stages of the central auditory system. This research is expanded to include the associated pathology in the auditory brain stem created by hearing loss. Utilizing the congenitally deaf white cat, we demonstrate the way that cells, synapses, and circuits are pathologically affected by sound deprivation. We further show that the restoration of auditory nerve activity via electrical stimulation through cochlear implants serves to correct key features of brain pathology caused by hearing loss. The data suggest that rigorous training with cochlear implants and/or hearing aids offers the promise of heretofore unattained benefits.

  6. Regional selection of the brain size regulating gene CASC5 provides new insight into human brain evolution.

    PubMed

    Shi, Lei; Hu, Enzhi; Wang, Zhenbo; Liu, Jiewei; Li, Jin; Li, Ming; Chen, Hua; Yu, Chunshui; Jiang, Tianzi; Su, Bing

    2017-02-01

    Human evolution is marked by a continued enlargement of the brain. Previous studies on human brain evolution focused on identifying sequence divergences of brain size regulating genes between humans and nonhuman primates. However, the evolutionary pattern of the brain size regulating genes during recent human evolution is largely unknown. We conducted a comprehensive analysis of the brain size regulating gene CASC5 and found that in recent human evolution, CASC5 has accumulated many modern human specific amino acid changes, including two fixed changes and six polymorphic changes. Among human populations, 4 of the 6 amino acid polymorphic sites have high frequencies of derived alleles in East Asians, but are rare in Europeans and Africans. We proved that this between-population allelic divergence was caused by regional Darwinian positive selection in East Asians. Further analysis of brain image data of Han Chinese showed significant associations of the amino acid polymorphic sites with gray matter volume. Hence, CASC5 may contribute to the morphological and structural changes of the human brain during recent evolution. The observed between-population divergence of CASC5 variants was driven by natural selection that tends to favor a larger gray matter volume in East Asians.

  7. Comparison of tactile, auditory, and visual modality for brain-computer interface use: a case study with a patient in the locked-in state.

    PubMed

    Kaufmann, Tobias; Holz, Elisa M; Kübler, Andrea

    2013-01-01

    This paper describes a case study with a patient in the classic locked-in state, who currently has no means of independent communication. Following a user-centered approach, we investigated event-related potentials (ERP) elicited in different modalities for use in brain-computer interface (BCI) systems. Such systems could provide her with an alternative communication channel. To investigate the most viable modality for achieving BCI based communication, classic oddball paradigms (1 rare and 1 frequent stimulus, ratio 1:5) in the visual, auditory and tactile modality were conducted (2 runs per modality). Classifiers were built on one run and tested offline on another run (and vice versa). In these paradigms, the tactile modality was clearly superior to other modalities, displaying high offline accuracy even when classification was performed on single trials only. Consequently, we tested the tactile paradigm online and the patient successfully selected targets without any error. Furthermore, we investigated use of the visual or tactile modality for different BCI systems with more than two selection options. In the visual modality, several BCI paradigms were tested offline. Neither matrix-based nor so-called gaze-independent paradigms constituted a means of control. These results may thus question the gaze-independence of current gaze-independent approaches to BCI. A tactile four-choice BCI resulted in high offline classification accuracies. Yet, online use raised various issues. Although performance was clearly above chance, practical daily life use appeared unlikely when compared to other communication approaches (e.g., partner scanning). Our results emphasize the need for user-centered design in BCI development including identification of the best stimulus modality for a particular user. Finally, the paper discusses feasibility of EEG-based BCI systems for patients in classic locked-in state and compares BCI to other AT solutions that we also tested during the

  8. Brain dynamics of distractibility: interaction between top-down and bottom-up mechanisms of auditory attention.

    PubMed

    Bidet-Caulet, Aurélie; Bottemanne, Laure; Fonteneau, Clara; Giard, Marie-Hélène; Bertrand, Olivier

    2015-05-01

    Attention improves the processing of specific information while other stimuli are disregarded. A good balance between bottom-up (attentional capture by unexpected salient stimuli) and top-down (selection of relevant information) mechanisms is crucial to be both task-efficient and aware of our environment. Only few studies have explored how an isolated unexpected task-irrelevant stimulus outside the attention focus can disturb the top-down attention mechanisms necessary to the good performance of the ongoing task, and how these top-down mechanisms can modulate the bottom-up mechanisms of attentional capture triggered by an unexpected event. We recorded scalp electroencephalography in 18 young adults performing a new paradigm measuring distractibility and assessing both bottom-up and top-down attention mechanisms, at the same time. Increasing task load in top-down attention was found to reduce early processing of the distracting sound, but not bottom-up attentional capture mechanisms nor the behavioral distraction cost in reaction time. Moreover, the impact of bottom-up attentional capture by distracting sounds on target processing was revealed as a delayed latency of the N100 sensory response to target sounds mirroring increased reaction times. These results provide crucial information into how bottom-up and top-down mechanisms dynamically interact and compete in the human brain, i.e. on the precarious balance between voluntary attention and distraction.

  9. Multiple Determinants of Whole and Regional Brain Volume among Terrestrial Carnivorans

    PubMed Central

    Swanson, Eli M.; Holekamp, Kay E.; Lundrigan, Barbara L.; Arsznov, Bradley M.; Sakai, Sharleen T.

    2012-01-01

    Mammalian brain volumes vary considerably, even after controlling for body size. Although several hypotheses have been proposed to explain this variation, most research in mammals on the evolution of encephalization has focused on primates, leaving the generality of these explanations uncertain. Furthermore, much research still addresses only one hypothesis at a time, despite the demonstrated importance of considering multiple factors simultaneously. We used phylogenetic comparative methods to investigate simultaneously the importance of several factors previously hypothesized to be important in neural evolution among mammalian carnivores, including social complexity, forelimb use, home range size, diet, life history, phylogeny, and recent evolutionary changes in body size. We also tested hypotheses suggesting roles for these variables in determining the relative volume of four brain regions measured using computed tomography. Our data suggest that, in contrast to brain size in primates, carnivoran brain size may lag behind body size over evolutionary time. Moreover, carnivore species that primarily consume vertebrates have the largest brains. Although we found no support for a role of social complexity in overall encephalization, relative cerebrum volume correlated positively with sociality. Finally, our results support negative relationships among different brain regions after accounting for overall endocranial volume, suggesting that increased size of one brain regions is often accompanied by reduced size in other regions rather than overall brain expansion. PMID:22719890

  10. Multi-sensory integration in brainstem and auditory cortex.

    PubMed

    Basura, Gregory J; Koehler, Seth D; Shore, Susan E

    2012-11-16

    Tinnitus is the perception of sound in the absence of a physical sound stimulus. It is thought to arise from aberrant neural activity within central auditory pathways that may be influenced by multiple brain centers, including the somatosensory system. Auditory-somatosensory (bimodal) integration occurs in the dorsal cochlear nucleus (DCN), where electrical activation of somatosensory regions alters pyramidal cell spike timing and rates of sound stimuli. Moreover, in conditions of tinnitus, bimodal integration in DCN is enhanced, producing greater spontaneous and sound-driven neural activity, which are neural correlates of tinnitus. In primary auditory cortex (A1), a similar auditory-somatosensory integration has been described in the normal system (Lakatos et al., 2007), where sub-threshold multisensory modulation may be a direct reflection of subcortical multisensory responses (Tyll et al., 2011). The present work utilized simultaneous recordings from both DCN and A1 to directly compare bimodal integration across these separate brain stations of the intact auditory pathway. Four-shank, 32-channel electrodes were placed in DCN and A1 to simultaneously record tone-evoked unit activity in the presence and absence of spinal trigeminal nucleus (Sp5) electrical activation. Bimodal stimulation led to long-lasting facilitation or suppression of single and multi-unit responses to subsequent sound in both DCN and A1. Immediate (bimodal response) and long-lasting (bimodal plasticity) effects of Sp5-tone stimulation were facilitation or suppression of tone-evoked firing rates in DCN and A1 at all Sp5-tone pairing intervals (10, 20, and 40 ms), and greater suppression at 20 ms pairing-intervals for single unit responses. Understanding the complex relationships between DCN and A1 bimodal processing in the normal animal provides the basis for studying its disruption in hearing loss and tinnitus models. This article is part of a Special Issue entitled: Tinnitus Neuroscience.

  11. Neural Representations Used by Brain Regions Underlying Speech Production

    ERIC Educational Resources Information Center

    Segawa, Jennifer Anne

    2013-01-01

    Speech utterances are phoneme sequences but may not always be represented as such in the brain. For instance, electropalatography evidence indicates that as speaking rate increases, gestures within syllables are manipulated separately but those within consonant clusters act as one motor unit. Moreover, speech error data suggest that a syllable's…

  12. Bilateral Brain Regions Associated with Naming in Older Adults

    ERIC Educational Resources Information Center

    Obler, Loraine K.; Rykhlevskaia, Elena; Schnyer, David; Clark-Cotton, Manuella R.; Spiro, Avron, III; Hyun, JungMoon; Kim, Dae-Shik; Goral, Mira; Albert, Martin L.

    2010-01-01

    To determine structural brain correlates of naming abilities in older adults, we tested 24 individuals aged 56-79 on two confrontation-naming tests (the Boston Naming Test (BNT) and the Action Naming Test (ANT)), then collected from these individuals structural Magnetic-Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI) data. Overall,…

  13. Brain stem auditory potentials evoked by clicks in the presence of high-pass filtered noise in dogs.

    PubMed

    Poncelet, L; Deltenre, P; Coppens, A; Michaux, C; Coussart, E

    2006-04-01

    This study evaluates the effects of a high-frequency hearing loss simulated by the high-pass-noise masking method, on the click-evoked brain stem-evoked potentials (BAEP) characteristics in dogs. BAEP were obtained in response to rarefaction and condensation click stimuli from 60 dB normal hearing level (NHL, corresponding to 89 dB sound pressure level) to wave V threshold, using steps of 5 dB in eleven 58 to 80-day-old Beagle puppies. Responses were added, providing an equivalent to alternate polarity clicks, and subtracted, providing the rarefaction-condensation potential (RCDP). The procedure was repeated while constant level, high-pass filtered (HPF) noise was superposed to the click. Cut-off frequencies of the successively used filters were 8, 4, 2 and 1 kHz. For each condition, wave V and RCDP thresholds, and slope of the wave V latency-intensity curve (LIC) were collected. The intensity range at which RCDP could not be recorded (pre-RCDP range) was calculated. Compared with the no noise condition, the pre-RCDP range significantly diminished and the wave V threshold significantly increased when the superposed HPF noise reached the 4 kHz area. Wave V LIC slope became significantly steeper with the 2 kHz HPF noise. In this non-invasive model of high-frequency hearing loss, impaired hearing of frequencies from 8 kHz and above escaped detection through click BAEP study in dogs. Frequencies above 13 kHz were however not specifically addressed in this study.

  14. Right-Left Asymmetries in the Brain

    ERIC Educational Resources Information Center

    Galaburda, Albert M.; And Others

    1978-01-01

    Reports on structural asymmetrics between the hemispheres which are found in the human brain. Auditory region and Sylvian Fissure asymmetry have also been observed in the fetus and in other primates. Describes research which has correlated asymmetries with hand preference, certain childhood learning disabilities and some dementing illnesses of…

  15. Central auditory function of deafness genes.

    PubMed

    Willaredt, Marc A; Ebbers, Lena; Nothwang, Hans Gerd

    2014-06-01

    The highly variable benefit of hearing devices is a serious challenge in auditory rehabilitation. Various factors contribute to this phenomenon such as the diversity in ear defects, the different extent of auditory nerve hypoplasia, the age of intervention, and cognitive abilities. Recent analyses indicate that, in addition, central auditory functions of deafness genes have to be considered in this context. Since reduced neuronal activity acts as the common denominator in deafness, it is widely assumed that peripheral deafness influences development and function of the central auditory system in a stereotypical manner. However, functional characterization of transgenic mice with mutated deafness genes demonstrated gene-specific abnormalities in the central auditory system as well. A frequent function of deafness genes in the central auditory system is supported by a genome-wide expression study that revealed significant enrichment of these genes in the transcriptome of the auditory brainstem compared to the entire brain. Here, we will summarize current knowledge of the diverse central auditory functions of deafness genes. We furthermore propose the intimately interwoven gene regulatory networks governing development of the otic placode and the hindbrain as a mechanistic explanation for the widespread expression of these genes beyond the cochlea. We conclude that better knowledge of central auditory dysfunction caused by genetic alterations in deafness genes is required. In combination with improved genetic diagnostics becoming currently available through novel sequencing technologies, this information will likely contribute to better outcome prediction of hearing devices.

  16. Age- and Brain Region-Specific Differences in Mitochondrial Bioenergetics in Brown Norway Rats

    EPA Pesticide Factsheets

    Differences in various mitochondrial bioenergetics parameters in different brain regions in different age groups.This dataset is associated with the following publication:Pandya, J.D., J. Royland , R.C. McPhail, P.G. Sullivan, and P. Kodavanti. Age-and Brain Region-Specific Differences in Mitochondrial Bioenergetics in Brown Norway Rats. NEUROBIOLOGY OF AGING. Elsevier Science Ltd, New York, NY, USA, 42: 25-34, (2016).

  17. Temporary inactivation of NCM, an auditory region, increases social interaction and decreases song perception in female zebra finches.

    PubMed

    Tomaszycki, Michelle L; Blaine, Sara K

    2014-10-01

    The caudomedial nidopallium (NCM) is an important site for the storage of auditory memories, particularly song, in passerines. In zebra finches, males sing and females do not, but females use song to choose mates. The extent to which the NCM is necessary for female mate choice is not well understood. To investigate the role of NCM in partner preferences, adult female zebra finches were bilaterally implanted with chronic cannulae directed at the NCM. Lidocaine, a sodium channel blocker, or saline (control) was infused into the NCM of females using a repeated measures design. Females were then tested in 3 separate paradigms: song preference, sexual partner preference, and pairing behavior/partner preference. We hypothesized that lidocaine would increase interactions with males by decreasing song discrimination and that this would be further evident in the song discrimination task. Indeed, females, when treated with lidocaine, had no preference for males singing unaltered song over males singing distorted song. These same females, when treated with saline, demonstrated a significant preference for males singing normal song. Furthermore, females affiliated with males more after receiving lidocaine than after receiving saline in the pairing paradigm, although neither treatment led to the formation of a partner preference. Our results support the hypothesis that NCM plays an important role not only in song discrimination, but also affiliation with a male.

  18. Eye Movements during Auditory Attention Predict Individual Differences in Dorsal Attention Network Activity

    PubMed Central

    Braga, Rodrigo M.; Fu, Richard Z.; Seemungal, Barry M.; Wise, Richard J. S.; Leech, Robert

    2016-01-01

    The neural mechanisms supporting auditory attention are not fully understood. A dorsal frontoparietal network of brain regions is thought to mediate the spatial orienting of attention across all sensory modalities. Key parts of this network, the frontal eye fields (FEF) and the superior parietal lobes (SPL), contain retinotopic maps and elicit saccades when stimulated. This suggests that their recruitment during auditory attention might reflect crossmodal oculomotor processes; however this has not been confirmed experimentally. Here we investigate whether task-evoked eye movements during an auditory task can predict the magnitude of activity within the dorsal frontoparietal network. A spatial and non-spatial listening task was used with on-line eye-tracking and functional magnetic resonance imaging (fMRI). No visual stimuli or cues were used. The auditory task elicited systematic eye movements, with saccade rate and gaze position predicting attentional engagement and the cued sound location, respectively. Activity associated with these separate aspects of evoked eye-movements dissociated between the SPL and FEF. However these observed eye movements could not account for all the activation in the frontoparietal network. Our results suggest that the recruitment of the SPL and FEF during attentive listening reflects, at least partly, overt crossmodal oculomotor processes during non-visual attention. Further work is needed to establish whether the network’s remaining contribution to auditory attention is through covert crossmodal processes, or is directly involved in the manipulation of auditory information. PMID:27242465

  19. Gene expression in the rodent brain is associated with its regional connectivity.

    PubMed

    Wolf, Lior; Goldberg, Chen; Manor, Nathan; Sharan, Roded; Ruppin, Eytan

    2011-05-01

    The putative link between gene expression of brain regions and their neural connectivity patterns is a fundamental question in neuroscience. Here this question is addressed in the first large scale study of a prototypical mammalian rodent brain, using a combination of rat brain regional connectivity data with gene expression of the mouse brain. Remarkably, even though this study uses data from two different rodent species (due to the data limitations), we still find that the connectivity of the majority of brain regions is highly predictable from their gene expression levels-the outgoing (incoming) connectivity is successfully predicted for 73% (56%) of brain regions, with an overall fairly marked accuracy level of 0.79 (0.83). Many genes are found to play a part in predicting both the incoming and outgoing connectivity (241 out of the 500 top selected genes, p-value<1e-5). Reassuringly, the genes previously known from the literature to be involved in axon guidance do carry significant information about regional brain connectivity. Surveying the genes known to be associated with the pathogenesis of several brain disorders, we find that those associated with schizophrenia, autism and attention deficit disorder are the most highly enriched in the connectivity-related genes identified here. Finally, we find that the profile of functional annotation groups that are associated with regional connectivity in the rodent is significantly correlated with the annotation profile of genes previously found to determine neural connectivity in C. elegans (Pearson correlation of 0.24, p<1e-6 for the outgoing connections and 0.27, p<1e-5 for the incoming). Overall, the association between connectivity and gene expression in a specific extant rodent species' brain is likely to be even stronger than found here, given the limitations of current data.

  20. Differential auditory signal processing in an animal model

    NASA Astrophysics Data System (ADS)

    Lim, Dukhwan; Kim, Chongsun; Chang, Sun O.

    2002-05-01

    Auditory evoked responses were collected in male zebra finches (Poephila guttata) to objectively determine differential frequency selectivity. First, the mating call of the animal was recorded and analyzed for its frequency components through the customized program. Then, auditory brainstem responses and cortical responses of each anesthetized animal were routinely recorded in response to tone bursts of 1-8 kHz derived from the corresponding mating call spectrum. From the results, most mating calls showed relatively consistent spectral structures. The upper limit of the spectrum was well under 10 kHz. The peak energy bands were concentrated in the region less than 5 kHz. The assessment of auditory brainstem responses and cortical evoked potentials showed differential selectivity with a series of characteristic scales. This system appears to be an excellent model to investigate complex sound processing and related language behaviors. These data could also be used in designing effective signal processing strategies in auditory rehabilitation devices such as hearing aids and cochlear implants. [Work supported by Brain Science & Engineering Program from Korean Ministry of Science and Technology.

  1. Better Glasgow outcome score, cerebral perfusion pressure and focal brain oxygenation in severely traumatized brain following direct regional brain hypothermia therapy: A prospective randomized study

    PubMed Central

    Idris, Zamzuri; Zenian, Mohd Sofan; Muzaimi, Mustapha; Hamid, Wan Zuraida Wan Abdul

    2014-01-01

    Background: Induced hypothermia for treatment of traumatic brain injury is controversial. Since many pathways involved in the pathophysiology of secondary brain injury are temperature dependent, regional brain hypothermia is thought capable to mitigate those processes. The objectives of this study are to assess the therapeutic effects and complications of regional brain cooling in severe head injury with Glasgow coma scale (GCS) 6-7. Materials and Methods: A prospective randomized controlled pilot study involving patients with severe traumatic brain injury with GCS 6 and 7 who required decompressive craniectomy. Patients were randomized into two groups: Cooling and no cooling. For the cooling group, analysis was made by dividing the group into mild and deep cooling. Brain was cooled by irrigating the brain continuously with cold Hartmann solution for 24-48 h. Main outcome assessments were a dichotomized Glasgow outcome score (GOS) at 6 months posttrauma. Results: A total of 32 patients were recruited. The cooling-treated patients did better than no cooling. There were 63.2% of patients in cooling group attained good GOS at 6 months compared to only 15.4% in noncooling group (P = 0.007). Interestingly, the analysis at 6 months post-trauma disclosed mild-cooling-treated patients did better than no cooling (70% vs. 15.4% attained good GOS, P = 0.013) and apparently, the deep-cooling-treated patients failed to be better than either no cooling (P = 0.074) or mild cooling group (P = 0.650). Conclusion: Data from this pilot study imply direct regional brain hypothermia appears safe, feasible and maybe beneficial in treating severely head-injured patients. PMID:25685201

  2. Effects of physical exercise on central nervous system functions: a review of brain region specific adaptations.

    PubMed

    Morgan, Julie A; Corrigan, Frances; Baune, Bernhard T

    2015-01-01

    Pathologies of central nervous system (CNS) functions are involved in prevalent conditions such as Alzheimer's disease, depression, and Parkinson's disease. Notable pathologies include dysfunctions of circadian rhythm, central metabolism, cardiovascular function, central stress responses, and movement mediated by the basal ganglia. Although evidence suggests exercise may benefit these conditions, the neurobiological mechanisms of exercise in specific brain regions involved in these important CNS functions have yet to be clarified. Here we review murine evidence about the effects of exercise on discrete brain regions involved in important CNS functions. Exercise effects on circadian rhythm, central metabolism, cardiovascular function, stress responses in the brain stem and hypothalamic pituitary axis, and movement are examined. The databases Pubmed, Web of Science, and Embase were searched for articles investigating regional brain adaptations to exercise. Brain regions examined included the brain stem, hypothalamus, and basal ganglia. We found evidence of multiple regional adaptations to both forced and voluntary exercise. Exercise can induce molecular adaptations in neuronal function in many instances. Taken together, these findings suggest that the regional physiological adaptations that occur with exercise could constitute a promising field for elucidating molecular and cellular mechanisms of recovery in psychiatric and neurological health conditions.

  3. Studies on Auditory and Vestibular End Organs and Brain Stem Nuclei. [inner ear damage and hearing defects

    NASA Technical Reports Server (NTRS)

    Ades, H. W.

    1974-01-01

    Cats were exposed to tones of 125, 1000, 2000, and 4000 Hz at sound pressure levels in the range 120 to 157.5 db, and for durations of one hour (1000, 2000, 4000 Hz) or four hours (125 Hz). Pure tone audiograms were obtained for each animal before and after exposure. Cochleas of animals were examined by phase-contrast microscopy. Extent of inner ear damage and range of frequencies for which hearing loss occurred increased as exposure tone was decreased in frequency. For example, exposure to 4000 Hz produced damage in a restricted region of the cochlea and hearing loss for a relatively narrow range of frequencies; exposure to 125 Hz produced wide-spread inner ear damage and hearing loss throughout the frequency range 125 to 6000 Hz.

  4. The Regional Variability of Enzymes in the Brain.

    DTIC Science & Technology

    1986-08-01

    modifications of some enzyme activities, including those of cytochrome c oxidase and MDH (10). Head injury which results in brain damage also causes...represents a lysosomal marker enzyme and cytochrome c oxidase , bound to the inner mitochondrial membrane, as well as fumarase, GDH, NAD- and NADP... Cytochrome c Oxidase (EC 1.9.3.1) Assay : Cytochrome c oxidase was assayed by the method of DeDuve (44). The reaction is as follows: Cytochrome c

  5. Kainic acid inhibits protein amino acid incorporation in select rat brain regions.

    PubMed

    Planas, A M; Soriano, M A; Ferrer, I; Rodríguez-Farré, E

    1994-11-21

    Regional incorporation of labelled methionine into proteins was studied with quantitative autoradiography in different regions of the rat brain 2.5 h following systemic kainic acid administration. Labelled protein concentration was found reduced to approximately 40% of control values in the pyramidal cell layer of hippocampus, piriform, entorhinal and perirhinal cortices, ventral lateral septum and mediodorsal thalamic nucleus. These regions showed increased levels of label not incorporated into proteins, indicating that free labelled methionine was available for protein synthesis. Reduction of protein amino acid incorporation in those brain regions selectively affected by kainic acid may be involved in subsequent tissue damage.

  6. Global differential expression of genes located in the Down Syndrome Critical Region in normal human brain

    PubMed Central

    Montoya, Julio Cesar; Fajardo, Dianora; Peña, Angela; Sánchez, Adalberto; Domínguez, Martha C; Satizábal, José María

    2014-01-01

    Background: The information of gene expression obtained from databases, have made possible the extraction and analysis of data related with several molecular processes involving not only in brain homeostasis but its disruption in some neuropathologies; principally in Down syndrome and the Alzheimer disease. Objective: To correlate the levels of transcription of 19 genes located in the Down Syndrome Critical Region (DSCR) with their expression in several substructures of normal human brain. Methods: There were obtained expression profiles of 19 DSCR genes in 42 brain substructures, from gene expression values available at the database of the human brain of the Brain Atlas of the Allen Institute for Brain Sciences", (http://human.brain-map.org/). The co-expression patterns of DSCR genes in brain were calculated by using multivariate statistical methods. Results: Highest levels of gene expression were registered at caudate nucleus, nucleus accumbens and putamen among central areas of cerebral cortex. Increased expression levels of RCAN1 that encode by a protein involved in signal transduction process of the CNS were recorded for PCP4 that participates in the binding to calmodulin and TTC3; a protein that is associated with differentiation of neurons. That previously identified brain structures play a crucial role in the learning process, in different class of memory and in motor skills. Conclusion: The precise regulation of DSCR gene expression is crucial to maintain the brain homeostasis, especially in those areas with high levels of gene expression associated with a remarkable process of learning and cognition. PMID:25767303

  7. Mapping brain region activity during chewing: a functional magnetic resonance imaging study.

    PubMed

    Onozuka, M; Fujita, M; Watanabe, K; Hirano, Y; Niwa, M; Nishiyama, K; Saito, S

    2002-11-01

    Mastication has been suggested to increase neuronal activities in various regions of the human brain. However, because of technical difficulties, the fine anatomical and physiological regions linked to mastication have not been fully elucidated. Using functional magnetic resonance imaging during cycles of rhythmic gum-chewing and no chewing, we therefore examined the interaction between chewing and brain regional activity in 17 subjects (aged 20-31 years). In all subjects, chewing resulted in a bilateral increase in blood oxygenation level-dependent (BOLD) signals in the sensorimotor cortex, supplementary motor area, insula, thalamus, and cerebellum. In addition, in the first three regions, chewing of moderately hard gum produced stronger BOLD signals than the chewing of hard gum. However, the signal was higher in the cerebellum and not significant in the thalamus, respectively. These results suggest that chewing causes regional increases in brain neuronal activities which are related to biting force.

  8. Hormone replacement therapy and age-related brain shrinkage: regional effects.

    PubMed

    Raz, Naftali; Rodrigue, Karen M; Kennedy, Kristen M; Acker, James D

    2004-11-15

    Neuroprotective properties of estrogen have been established in animal models, but clinical trials of hormone replacement therapy (HRT) produced contradictory results. We examined the impact of HRT on age-related regional changes in human brain volume. Six brain regions were measured twice, five years apart, in 12 healthy women who took HRT and in matched controls who did not. The controls showed a typical pattern of differential brain shrinkage in the association cortices and the hippocampus with no change in the primary visual cortex. In contrast, women who took HRT showed comparable shrinkage of the hippocampus but no significant shrinkage of the neocortex. Future large scale studies may benefit from applying regional rather than global measures in assessment of brain integrity.

  9. The construction of common and specific significance subnetworks of Alzheimer's disease from multiple brain regions.

    PubMed

    Kong, Wei; Mou, Xiaoyang; Zhang, Na; Zeng, Weiming; Li, Shasha; Yang, Yang

    2015-01-01

    Alzheimer's disease (AD) is a progressively and fatally neurodegenerative disorder and leads to irreversibly cognitive and memorial damage in different brain regions. The identification and analysis of the dysregulated pathways and subnetworks among affected brain regions will provide deep insights for the pathogenetic mechanism of AD. In this paper, commonly and specifically significant subnetworks were identified from six AD brain regions. Protein-protein interaction (PPI) data were integrated to add molecular biological information to construct the functional modules of six AD brain regions by Heinz algorithm. Then, the simulated annealing algorithm based on edge weight is applied to predicting and optimizing the maximal scoring networks for common and specific genes, respectively, which can remove the weak interactions and add the prediction of strong interactions to increase the accuracy of the networks. The identified common subnetworks showed that inflammation of the brain nerves is one of the critical factors of AD and calcium imbalance may be a link among several causative factors in AD pathogenesis. In addition, the extracted specific subnetworks for each brain region revealed many biologically functional mechanisms to understand AD pathogenesis.

  10. Multivoxel patterns reveal functionally differentiated networks underlying auditory feedback processing of speech.

    PubMed

    Zheng, Zane Z; Vicente-Grabovetsky, Alejandro; MacDonald, Ewen N; Munhall, Kevin G; Cusack, Rhodri; Johnsrude, Ingrid S

    2013-03-06

    The everyday act of speaking involves the complex processes of speech motor control. An important component of control is monitoring, detection, and processing of errors when auditory feedback does not correspond to the intended motor gesture. Here we show, using fMRI and converging operations within a multivoxel pattern analysis framework, that this sensorimotor process is supported by functionally differentiated brain networks. During scanning, a real-time speech-tracking system was used to deliver two acoustically different types of distorted auditory feedback or unaltered feedback while human participants were vocalizing monosyllabic words, and to present the same auditory stimuli while participants were passively listening. Whole-brain analysis of neural-pattern similarity revealed three functional networks that were differentially sensitive to distorted auditory feedback during vocalization, compared with during passive listening. One network of regions appears to encode an "error signal" regardless of acoustic features of the error: this network, including right angular gyrus, right supplementary motor area, and bilateral cerebellum, yielded consistent neural patterns across acoustically different, distorted feedback types, only during articulation (not during passive listening). In contrast, a frontotemporal network appears sensitive to the speech features of auditory stimuli during passive listening; this preference for speech features was diminished when the same stimuli were presented as auditory concomitants of vocalization. A third network, showing a distinct functional pattern from the other two, appears to capture aspects of both neural response profiles. Together, our findings suggest that auditory feedback processing during speech motor control may rely on multiple, interactive, functionally differentiated neural systems.

  11. Temporal and regional changes after focal traumatic brain injury.

    PubMed

    Lescot, Thomas; Fulla-Oller, Laurence; Fulla-Oller, Lawrence; Po, Chrystelle; Chen, Xiao Ru; Puybasset, Louis; Gillet, Brigitte; Plotkine, Michel; Meric, Philippe; Marchand-Leroux, Catherine

    2010-01-01

    Magnetic resonance imaging (MRI) is widely used to evaluate the consequences of traumatic brain injury (TBI) in both experimental and clinical studies. Improved assessment of experimental TBI using the same methods as those used in clinical investigations would help to translate laboratory research into clinical advances. Here our goal was to characterize lateral fluid percussion-induced TBI, with special emphasis on differentiating the contused cortex from the pericontusional subcortical tissue. We used both in vivo MRI and proton magnetic resonance spectroscopy ((1)H-MRS) to evaluate adult male Sprague-Dawley rats 24 h and 48 h and 7 days after TBI. T2 and apparent diffusion coefficient (ADC) maps were derived from T2-weighted and diffusion-weighted images, respectively. Ratios of N-acetylaspartate (NAA), choline compounds (Cho), and lactate (Lac) over creatine (Cr) were estimated by (1)H-MRS. T2 values were high in the contused cortex 24 h after TBI, suggesting edema development; ADC was low, consistent with cytotoxic edema. At the same site, NAA/Cr was decreased and Lac/Cr elevated during the first week after TBI. In the ipsilateral subcortical area, NAA/Cr was markedly decreased and Lac/Cr was elevated during the first week, although MRI showed no evidence of edema, suggesting that (1)H-MRS detected "invisible" damage. (1)H-MRS combined with MRI may improve the detection of brain injury. Extensive assessments of animal models may increase the chances of developing successful neuroprotective strategies.

  12. An integrative analysis of regional gene expression profiles in the human brain.

    PubMed

    Myers, Emma M; Bartlett, Christopher W; Machiraju, Raghu; Bohland, Jason W

    2015-02-01

    Studies of the brain's transcriptome have become prominent in recent years, resulting in an accumulation of datasets with somewhat distinct attributes. These datasets, which are often analyzed only in isolation, also are often collected with divergent goals, which are reflected in their sampling properties. While many researchers have been interested in sampling gene expression in one or a few brain areas in a large number of subjects, recent efforts from the Allen Institute for Brain Sciences and others have focused instead on dense neuroanatomical sampling, necessarily limiting the number of individual donor brains studied. The purpose of the present work is to develop methods that draw on the complementary strengths of these two types of datasets for study of the human brain, and to characterize the anatomical specificity of gene expression profiles and gene co-expression networks derived from human brains using different specific technologies. The approach is applied using two publicly accessible datasets: (1) the high anatomical resolution Allen Human Brain Atlas (AHBA, Hawrylycz et al., 2012) and (2) a relatively large sample size, but comparatively coarse neuroanatomical dataset described previously by Gibbs et al. (2010). We found a relatively high degree of correspondence in differentially expressed genes and regional gene expression profiles across the two datasets. Gene co-expression networks defined in individual brain regions were less congruent, but also showed modest anatomical specificity. Using gene modules derived from the Gibbs dataset and from curated gene lists, we demonstrated varying degrees of anatomical specificity based on two classes of methods, one focused on network modularity and the other focused on enrichment of expression levels. Two approaches to assessing the statistical significance of a gene set's modularity in a given brain region were studied, which provide complementary information about the anatomical specificity of a gene

  13. Longitudinal regional brain volume loss in schizophrenia: Relationship to antipsychotic medication and change in social function

    PubMed Central

    Guo, Joyce Y.; Huhtaniska, Sanna; Miettunen, Jouko; Jääskeläinen, Erika; Kiviniemi, Vesa; Nikkinen, Juha; Moilanen, Jani; Haapea, Marianne; Mäki, Pirjo; Jones, Peter B.; Veijola, Juha; Isohanni, Matti; Murray, Graham K.

    2015-01-01

    Background Progressive brain volume loss in schizophrenia has been reported in previous studies but its cause and regional distribution remains unclear. We investigated progressive regional brain reductions in schizophrenia and correlations with potential mediators. Method Participants were drawn from the Northern Finland Birth Cohort 1966. A total of 33 schizophrenia individuals and 71 controls were MRI scanned at baseline (mean age = 34.7, SD = 0.77) and at follow-up (mean age = 43.4, SD = 0.44). Regional brain change differences and associations with clinical mediators were examined using FSL voxelwise SIENA. Results Schizophrenia cases exhibited greater progressive brain reductions than controls, mainly in the frontal and temporal lobes. The degree of periventricular brain volume reductions were predicted by antipsychotic medication exposure at the fourth ventricular edge and by the number of days in hospital between the scans (a proxy measure of relapse duration) at the thalamic ventricular border. Decline in social and occupational functioning was associated with right supramarginal gyrus reduction. Conclusion Our findings are consistent with the possibility that antipsychotic medication exposure and time spent in relapse partially explain progressive brain reductions in schizophrenia. However, residual confounding could also account for the findings and caution must be applied before drawing causal inferences from associations demonstrated in observational studies of modest size. Less progressive brain volume loss in schizophrenia may indicate better preserved social and occupational functions. PMID:26189075

  14. Dual role of cerebral blood flow in regional brain temperature control in the healthy newborn infant.

    PubMed

    Iwata, Sachiko; Tachtsidis, Ilias; Takashima, Sachio; Matsuishi, Toyojiro; Robertson, Nicola J; Iwata, Osuke

    2014-10-01

    Small shifts in brain temperature after hypoxia-ischaemia affect cell viability. The main determinants of brain temperature are cerebral metabolism, which contributes to local heat production, and brain perfusion, which removes heat. However, few studies have addressed the effect of cerebral metabolism and perfusion on regional brain temperature in human neonates because of the lack of non-invasive cot-side monitors. This study aimed (i) to determine non-invasive monitoring tools of cerebral metabolism and perfusion by combining near-infrared spectroscopy and echocardiography, and (ii) to investigate the dependence of brain temperature on cerebral metabolism and perfusion in unsedated newborn infants. Thirty-two healthy newborn infants were recruited. They were studied with cerebral near-infrared spectroscopy, echocardiography, and a zero-heat flux tissue thermometer. A surrogate of cerebral blood flow (CBF) was measured using superior vena cava flow adjusted for cerebral volume (rSVC flow). The tissue oxygenation index, fractional oxygen extraction (FOE), and the cerebral metabolic rate of oxygen relative to rSVC flow (CMRO₂ index) were also estimated. A greater rSVC flow was positively associated with higher brain temperatures, particularly for superficial structures. The CMRO₂ index and rSVC flow were positively coupled. However, brain temperature was independent of FOE and the CMRO₂ index. A cooler ambient temperature was associated with a greater temperature gradient between the scalp surface and the body core. Cerebral oxygen metabolism and perfusion were monitored in newborn infants without using tracers. In these healthy newborn infants, cerebral perfusion and ambient temperature were significant independent variables of brain temperature. CBF has primarily been associated with heat removal from the brain. However, our results suggest that CBF is likely to deliver heat specifically to the superficial brain. Further studies are required to assess the

  15. Parameters of diffusional kurtosis imaging for the diagnosis of acute cerebral infarction in different brain regions.

    PubMed

    Guo, Yue-Lin; Li, Su-Juan; Zhang, Zhong-Ping; Shen, Zhi-Wei; Zhang, Gui-Shan; Yan, Gen; Wang, Yan-Ting; Rao, Hai-Bing; Zheng, Wen-Bin; Wu, Ren-Hua

    2016-08-01

    Diffusional kurtosis imaging (DKI) is a new type diffusion-weighted sequence which measures the non-Gaussianity of water diffusion. The present study aimed to investigate whether the parameters of DKI could distinguish between differences in water molecule diffusion in various brain regions under the conditions of acute infarction and to identify the optimal DKI parameter for locating ischemic lesions in each brain region. A total of 28 patients with acute ischemic stroke in different brain regions were recruited for the present study. The relative values of DKI parameters were selected as major assessment indices, and the homogeneity of background image and contrast of adjacent structures were used as minor assessment indices. According to the brain region involved in three DKI parametric maps, including mean kurtosis (MK), axial kurtosis (Ka) and radial kurtosis (Kr), 112 groups of regions of interest were outlined in the following regions: Corpus callosum (n=17); corona radiata (n=26); thalamus (n=21); subcortical white matter (n=24); and cerebral cortex (n=24). For ischemic lesions in the corpus callosum and corona radiata, significant increases in relative Ka were detected, as compared with the other parameters (P<0.05). For ischemic lesions in the thalamus, subcortical white matter and cerebral cortices, an increase in the three parameters was detected, however this difference was not significant. Minor assessment indices demonstrated that Ka lacked tissue contrast and the background of Kr was heterogeneous; thus, MK was the superior assessment parameter for ischemic lesions in these regions. In conclusion, Ka is better suited for the diagnosis of acute ischemic lesions in highly anisotropic brain regions, such as the corpus callosum and corona radiate. MK may be appropriate for the lesions in low anisotropic or isotropic brain regions, such as the thalamus, subcortical white matter and cerebral cortices.

  16. Test-retest reproducibility for regional brain metabolic responses to lorazepam

    SciTech Connect

    Wang, G.J.; Volkow, N.D.; Overall, J. |||

    1996-05-01

    Changes in regional brain glucose metabolism as assessed with PET and FDG in response to acute administration of benzodiazepine agonists have been used as indicators of benzodiazepine-GABA receptor function. The purpose of this study was to assess the reproducibility of these responses. Sixteen healthy right-handed men were scanned with positron emission tomography (PET) and [F-18] fluorodeoxyglucose (FDG) twice: prior to placebo and prior to lorazepam (30 {mu}g/kg). The same double FDG procedure was repeated 6-8 weeks later to assess test-retest reproducibility. The regional absolute brain metabolic values obtained during the second evaluation were significantly lower than those obtained for the first evaluation regardless of condition (p {le} 0.001). Lorazepam significantly and consistently decreased whole brain metabolism and the magnitude as well as the regional pattern of the changes was comparable for both studies (12.3 {plus_minus} 6.9% and 13.7 {plus_minus} 7.4%). Lorazepam effects were largest in thalamus (22.2 {plus_minus} 8.9%). Relative metabolic measures ROI/global were highly reproducible both for drug as well as replication condition. This is the first study to measure test-retest reproducibility in regional brain metabolic response to a pharmacological challenge. While the global and regional absolute metabolic values were significantly lower for the repeated evaluation, the regional brain metabolic response to lorazepam was highly reproducible.

  17. Regional volumes in brain stem and cerebellum are associated with postural impairments in young brain-injured patients.

    PubMed

    Drijkoningen, David; Leunissen, Inge; Caeyenberghs, Karen; Hoogkamer, Wouter; Sunaert, Stefan; Duysens, Jacques; Swinnen, Stephan P

    2015-12-01

    Many patients with traumatic brain injury (TBI) suffer from postural control impairments that can profoundly affect daily life. The cerebellum and brain stem are crucial for the neural control of posture and have been shown to be vulnerable to primary and secondary structural consequences of TBI. The aim of this study was to investigate whether morphometric differences in the brain stem and cerebellum can account for impairments in static and dynamic postural control in TBI. TBI patients (n = 18) and healthy controls (n = 30) completed three challenging postural control tasks on the EquiTest® system (Neurocom). Infratentorial grey matter (GM) and white matter (WM) volumes were analyzed with cerebellum-optimized voxel-based morphometry using the spatially unbiased infratentorial toolbox. Volume loss in TBI patients was revealed in global cerebellar GM, global infratentorial WM, middle cerebellar peduncles, pons and midbrain. In the TBI group and across both groups, lower postural control performance was associated with reduced GM volume in the vermal/paravermal regions of lobules I-IV, V and VI. Moreover, across all participants, worse postural control performance was associated with lower WM volume in the pons, medulla, midbrain, superior and middle cerebellar peduncles and cerebellum. This is the first study in TBI patients to demonstrate an association between postural impairments and reduced volume in specific infratentorial brain areas. Volumetric measures of the brain stem and cerebellum may be valuable prognostic markers of the chronic neural pathology, which complicates rehabilitation of postural control in TBI.

  18. Anatomical study of the auditory region of Arctotherium tarijense (Ursidae, Tremarctinae), an extinct short-faced bear from the Pleistocene of South America.

    PubMed

    Arnaudo, Maria Eugenia; Bona, Paula; Soibelzon, Leopoldo Hector; Schubert, Blaine W

    2016-12-01

    Here we present the most detailed morphological study of the auditory region of a tremarctinae bear, Arctotherium tarijense Ameghino. In addition, we provide new anatomical information of the Tremarctinae inner ear, such as coplanarity and deviation from orthogonality of the semicircular canals, as an approach to infer the head movements which encountered the extinct forms in locomotion. Based on morphological comparisons, A. tarijense exhibits the following particular features: the cavum tympani presents the highest relative volume compared with other ursids; the processus paraoccipitalis has a foramen that is absent in other tremarctines; there is only one (ventral) recess in the anterior region of the cavum tympani; and the recessus epytimpanicus is the smallest for all ursids studied. In relation to the inner ear, A. tarijense shows the lowest values of orthogonality deviation and highest scores of locomotor agility. Based on this, is possible to make a preliminary proposal that this species had a relative high vestibular sensibility and therefore a better ability to explore different kind of habitats. However, this hypothesis might be contrasted among bears taking into account the orientation of each semicircular canal in a phylogenetic framework.

  19. A new neonatal cortical and subcortical brain atlas: the Melbourne Children's Regional Infant Brain (M-CRIB) atlas.

    PubMed

    Alexander, Bonnie; Murray, Andrea L; Loh, Wai Yen; Matthews, Lillian G; Adamson, Chris; Beare, Richard; Chen, Jian; Kelly, Claire E; Rees, Sandra; Warfield, Simon K; Anderson, Peter J; Doyle, Lex W; Spittle, Alicia J; Cheong, Jeanie L Y; Seal, Marc L; Thompson, Deanne K

    2017-02-15

    Investigating neonatal brain structure and function can offer valuable insights into behaviour and cognition in healthy and clinical populations; both at term age, and longitudinally in comparison with later time points. Parcellated brain atlases for adult populations are readily available, however warping infant data to adult template space is not ideal due to morphological and tissue differences between these groups. Several parcellated neonatal atlases have been developed, although there remains strong demand for manually parcellated ground truth data with detailed cortical definition. Additionally, compatibility with existing adult atlases is favourable for use in longitudinal investigations. We aimed to address these needs by replicating the widely-used Desikan-Killiany (2006) adult cortical atlas in neonates. We also aimed to extend brain coverage by complementing this cortical scheme with basal ganglia, thalamus, cerebellum and other subcortical segmentations. Thus, we have manually parcellated these areas volumetrically using high-resolution neonatal T2-weighted MRI scans, and initial automated and manually edited tissue classification, providing 100 regions in all. Linear and nonlinear T2-weighted structural templates were also generated. In this paper we provide manual parcellation protocols, and present the parcellated probability maps and structural templates together as the Melbourne Children's Regional Infant Brain (M-CRIB) atlas.

  20. Perinatal Risk Factors Altering Regional Brain Structure in the Preterm Infant

    ERIC Educational Resources Information Center

    Thompson, Deanne K.; Warfield, Simon K.; Carlin, John B.; Pavlovic, Masa; Wang, Hong X.; Bear, Merilyn; Kean, Michael J.; Doyle, Lex W.; Egan, Gary F.; Inder, Terrie E.

    2007-01-01

    Neuroanatomical structure appears to be altered in preterm infants, but there has been little insight into the major perinatal risk factors associated with regional cerebral structural alterations. MR images were taken to quantitatively compare regional brain tissue volumes between term and preterm infants and to investigate associations between…

  1. Differences in resting state regional cerebral blood flow assessed with 99mTc-HMPAO SPECT and brain atlas matching between depressed patients with and without tinnitus.

    PubMed

    Gardner, A; Pagani, M; Jacobsson, H; Lindberg, G; Larsson, S A; Wägner, A; Hällstrom, T

    2002-05-01

    An increased occurrence of major depressive disorder has been reported in tinnitus patients, and of tinnitus in depressive patients. Involvement of several Brodmann areas (BAs) has been reported in tinnitus perception. The aim of this study was to assess the regional cerebral blood flow (rCBF) changes in depressed patients with and without tinnitus. The rCBF distribution at rest was compared among 45 patients with a lifetime prevalence of major depressive disorder, of whom 27 had severe tinnitus, and 26 normal healthy subjects. 99mTc-hexamethylenepropylene amine oxime (99mTc-HMPAO) single photon emission computed tomography (SPECT), using a three-headed gamma camera, was performed and the uptake in 34 functional sub-volumes of the brain bilaterally was assessed by a computerized brain atlas. Decreased rCBF in right frontal lobe BA 45 (P<0.05), the left parietal lobe BA 39 (P<0.00) and the left visual association cortex BA 18 (P<0.05) was found in tinnitus patients compared with non-tinnitus patients. The proportion of tinnitus patients with pronounced rCBF alterations in one or more of the temporal lobe BAs 41+21+22 was increased compared to gender matched controls (P<0.00) and patients without tinnitus (P<0.05). Positive correlations were found between trait anxiety scales from the Karolinska Scales of Personality and rCBF in tinnitus patients only in three limbic BAs (P<0.01), and inverse correlations in non-tinnitus patients only in five BAs subserving auditory perception and processing (P<0.05). rCBF differences between healthy controls and depressed patients with and without tinnitus were found in this study. The rCBF alterations were distributed in the cortex and were particularly specific in the auditory cortex. These findings suggest that taking audiological symptoms into account may yield more consistent results between rCBF studies of depression.

  2. Neuroestrogen signaling in the songbird auditory cortex propagates into a sensorimotor network via an 'interface' nucleus.

    PubMed

    Pawlisch, B A; Remage-Healey, L

    2015-01-22

    Neuromodulators rapidly alter activity of neural circuits and can therefore shape higher order functions, such as sensorimotor integration. Increasing evidence suggests that brain-derived estrogens, such as 17-β-estradiol, can act rapidly to modulate sensory processing. However, less is known about how rapid estrogen signaling can impact downstream circuits. Past studies have demonstrated that estradiol levels increase within the songbird auditory cortex (the caudomedial nidopallium, NCM) during social interactions. Local estradiol signaling enhances the auditory-evoked firing rate of neurons in NCM to a variety of stimuli, while also enhancing the selectivity of auditory-evoked responses of neurons in a downstream sensorimotor brain region, HVC (proper name). Since these two brain regions are not directly connected, we employed dual extracellular recordings in HVC and the upstream nucleus interfacialis of the nidopallium (NIf) during manipulations of estradiol within NCM to better understand the pathway by which estradiol signaling propagates to downstream circuits. NIf has direct input into HVC, passing auditory information into the vocal motor output pathway, and is a possible source of the neural selectivity within HVC. Here, during acute estradiol administration in NCM, NIf neurons showed increases in baseline firing rates and auditory-evoked firing rates to all stimuli. Furthermore, when estradiol synthesis was blocked in NCM, we observed simultaneous decreases in the selectivity of NIf and HVC neurons. These effects were not due to direct estradiol actions because NIf has little to no capability for local estrogen synthesis or estrogen receptors, and these effects were specific to NIf because other neurons immediately surrounding NIf did not show these changes. Our results demonstrate that transsynaptic, rapid fluctuations in neuroestrogens are transmitted into NIf and subsequently HVC, both regions important for sensorimotor integration. Overall, these

  3. Neuroestrogen signaling in the songbird auditory cortex propagates into a sensorimotor network via an `interface' nucleus

    PubMed Central

    Pawlisch, Benjamin A.; Remage-Healey, Luke

    2014-01-01

    Neuromodulators rapidly alter activity of neural circuits and can therefore shape higher-order functions, such as sensorimotor integration. Increasing evidence suggests that brain-derived estrogens, such as 17-β-estradiol, can act rapidly to modulate sensory processing. However, less is known about how rapid estrogen signaling can impact downstream circuits. Past studies have demonstrated that estradiol levels increase within the songbird auditory cortex (the caudomedial nidopallium, NCM) during social interactions. Local estradiol signaling enhances the auditory-evoked firing rate of neurons in NCM to a variety of stimuli, while also enhancing the selectivity of auditory-evoked responses of neurons in a downstream sensorimotor brain region, HVC (proper name). Since these two brain regions are not directly connected, we employed dual extracellular recordings in HVC and the upstream nucleus interfacialis of the nidopallium (NIf) during manipulations of estradiol within NCM to better understand the pathway by which estradiol signaling propagates to downstream circuits. NIf has direct input into HVC, passing auditory information into the vocal motor output pathway, and is a possible source of the neural selectivity within HVC. Here, during acute estradiol administration in NCM, NIf neurons showed increases in baseline firing rates and auditory-evoked firing rates to all stimuli. Furthermore, when estradiol synthesis was blocked in NCM, we observed simultaneous decreases in the selectivity of NIf and HVC neurons. These effects were not due to direct estradiol actions because NIf has little to no capability for local estrogen synthesis or estrogen receptors, and these effects were specific to NIf because other neurons immediately surrounding NIf did not show these changes. Our results demonstrate that transsynaptic, rapid fluctuations in neuroestrogens are transmitted into NIf and subsequently HVC, both regions important for sensorimotor integration. Overall, these

  4. Brain regions associated with visual cues are important for bird migration.

    PubMed

    Vincze, Orsolya; Vágási, Csongor I; Pap, Péter L; Osváth, Gergely; Møller, Anders Pape

    2015-11-01

    Long-distance migratory birds have relatively smaller brains than short-distance migrants or residents. Here, we test whether reduction in brain size with migration distance can be generalized across the different brain regions suggested to play key roles in orientation during migration. Based on 152 bird species, belonging to 61 avian families from six continents, we show that the sizes of both the telencephalon and the whole brain decrease, and the relative size of the optic lobe increases, while cerebellum size does not change with increasing migration distance. Body mass, whole brain size, optic lobe size and wing aspect ratio together account for a remarkable 46% of interspecific variation in average migration distance across bird species. These results indicate that visual acuity might be a primary neural adaptation to the ecological challenge of migration.

  5. Brain regions associated with visual cues are important for bird migration

    PubMed Central

    Vincze, Orsolya; Vágási, Csongor I.; Pap, Péter L.; Osváth, Gergely; Møller, Anders Pape

    2015-01-01

    Long-distance migratory birds have relatively smaller brains than short-distance migrants or residents. Here, we test whether reduction in brain size with migration distance can be generalized across the different brain regions suggested to play key roles in orientation during migration. Based on 152 bird species, belonging to 61 avian families from six continents, we show that the sizes of both the telencephalon and the whole brain decrease, and the relative size of the optic lobe increases, while cerebellum size does not change with increasing migration distance. Body mass, whole brain size, optic lobe size and wing aspect ratio together account for a remarkable 46% of interspecific variation in average migration distance across bird species. These results indicate that visual acuity might be a primary neural adaptation to the ecological challenge of migration. PMID:26538538

  6. Detecting Epileptic Regions Based on Global Brain Connectivity Patterns

    PubMed Central

    Sweet, Andrew; Venkataraman, Archana; Stufflebeam, Steven M.; Liu, Hesheng; Tanaka, Naoro; Madsen, Joseph; Golland, Polina

    2014-01-01

    We present a method to detect epileptic regions based on functional connectivity differences between individual epilepsy patients and a healthy population. Our model assumes that the global functional characteristics of these differences are shared across patients, but it allows for the epileptic regions to vary between individuals. We evaluate the detection performance against intracranial EEG observations and compare our approach with two baseline methods that use standard statistics. The baseline techniques are sensitive to the choice of thresholds, whereas our algorithm automatically estimates the appropriate model parameters and compares favorably with the best baseline results. This suggests the promise of our approach for pre-surgical planning in epilepsy. PMID:24505654

  7. Detecting epileptic regions based on global brain connectivity patterns.

    PubMed

    Sweet, Andrew; Venkataraman, Archana; Stufflebeam, Steven M; Liu, Hesheng; Tanaka, Naoro; Madsen, Joseph; Golland, Polina

    2013-01-01

    We present a method to detect epileptic regions based on functional connectivity differences between individual epilepsy patients and a healthy population. Our model assumes that the global functional characteristics of these differences are shared across patients, but it allows for the epileptic regions to vary between individuals. We evaluate the detection performance against intracranial EEG observations and compare our approach with two baseline methods that use standard statistics. The baseline techniques are sensitive to the choice of thresholds, whereas our algorithm automatically estimates the appropriate model parameters and compares favorably with the best baseline results. This suggests the promise of our approach for pre-surgical planning in epilepsy.

  8. Efficient regeneration by activation of neurogenesis in homeostatically quiescent regions of the adult vertebrate brain.

    PubMed

    Berg, Daniel A; Kirkham, Matthew; Beljajeva, Anna; Knapp, Dunja; Habermann, Bianca; Ryge, Jesper; Tanaka, Elly M; Simon, András

    2010-12-01

    In contrast to mammals, salamanders and teleost fishes can efficiently repair the adult brain. It has been hypothesised that constitutively active neurogenic niches are a prerequisite for extensive neuronal regeneration capacity. Here, we show that the highly regenerative salamander, the red spotted newt, displays an unexpectedly similar distribution of active germinal niches with mammals under normal physiological conditions. Proliferation zones in the adult newt brain are restricted to the forebrain, whereas all other regions are essentially quiescent. However, ablation of midbrain dopamine neurons in newts induced ependymoglia cells in the normally quiescent midbrain to proliferate and to undertake full dopamine neuron regeneration. Using oligonucleotide microarrays, we have catalogued a set of differentially expressed genes in these activated ependymoglia cells. This strategy identified hedgehog signalling as a key component of adult dopamine neuron regeneration. These data show that brain regeneration can occur by activation of neurogenesis in quiescent brain regions.

  9. Determination of regional brain temperature using proton magnetic resonance spectroscopy to assess brain-body temperature differences in healthy human subjects.

    PubMed

    Childs, Charmaine; Hiltunen, Yrjö; Vidyasagar, Rishma; Kauppinen, Risto A

    2007-01-01

    Proton magnetic resonance spectroscopy ((1)H MRS) was used to determine brain temperature in healthy volunteers. Partially water-suppressed (1)H MRS data sets were acquired at 3T from four different gray matter (GM)/white matter (WM) volumes. Brain temperatures were determined from the chemical-shift difference between the CH(3) of N-acetyl aspartate (NAA) at 2.01 ppm and water. Brain temperatures in (1)H MRS voxels of 2 x 2 x 2 cm(3) showed no substantial heterogeneity. The volume-averaged temperature from single-voxel spectroscopy was compared with body temperatures obtained from the oral cavity, tympanum, and temporal artery regions. The mean brain parenchyma temperature was 0.5 degrees C cooler than readings obtained from three extra-brain sites (P < 0.01). (1)H MRS imaging (MRSI) data were acquired from a slice encompassing the single-voxel volumes to assess the ability of spectroscopic imaging to determine regional brain temperature within the imaging slice. Brain temperature away from the center of the brain determined by MRSI differed from that obtained by single-voxel MRS in the same brain region, possibly due to a poor line width (LW) in MRSI. The data are discussed in the light of proposed brain-body temperature gradients and the use of (1)H MRSI to monitor brain temperature in pathologies, such as brain trauma.

  10. Effect of whole-brain irradiation on the specific brain regions in a rat model: Metabolic and histopathological changes.

    PubMed

    Bálentová, Soňa; Hnilicová, Petra; Kalenská, Dagmar; Murín, Peter; Hajtmanová, Eva; Lehotský, Ján; Adamkov, Marian

    2017-03-19

    Effect of ionizing radiation on the brain affects neuronal, glial, and endothelial cell population and lead to significant morphological, metabolic, and functional deficits. In the present study we investigated a dose- and time-dependent correlation between radiation-induced metabolic and histopathological changes. Adult male Wistar rats received a total dose of 35Gy delivered in 7 fractions (dose 5Gy per fraction) once per week in the same weekday during 7 consecutive weeks. Proton magnetic resonance spectroscopy ((1)H MRS), histochemistry, immunohistochemistry and confocal microscopy were used to determine whether radiation-induced alteration of the brain metabolites correlates with appropriate histopathological changes of neurogenesis and glial cell response in 2 neurogenic regions: the hippocampal dentate gyrus (DG) and the subventricular zone-olfactory bulb axis (SVZ-OB axis). Evaluation of the brain metabolites 18-19 weeks after irradiation performed by (1)H MRS revealed a significant decrease in the total N-acetylaspartate to total creatine (tNAA/tCr) ratio in the striatum and OB. A significant decline of gamma-aminobutyric acid to tCr (GABA/tCr) ratio was seen in the OB and hippocampus. MR revealed absence of gross inflammatory or necrotic lesions in these regions. Image analysis of the brain sections 18-21 weeks after the exposure showed a radiation-induced increase of neurodegeneration, inhibition of neurogenesis and strong resemblance to the reactive astrogliosis. Results showed that fractionated whole-brain irradiation led to the changes in neurotransmission and to the loss of neuronal viability in vivo. Metabolic changes were closely associated with histopathological findings, i.e. initiation of neuronal cell death, inhibition of neurogenesis and strong response of astrocytes indicated development of late radiation-induced changes.

  11. Auditory processing under cross-modal visual load investigated with simultaneous EEG-fMRI.

    PubMed

    Regenbogen, Christina; De Vos, Maarten; Debener, Stefan; Turetsky, Bruce I; Mössnang, Carolin; Finkelmeyer, Andreas; Habel, Ute; Neuner, Irene; Kellermann, Thilo

    2012-01-01

    Cognitive task demands in one sensory modality (T1) can have beneficial effects on a secondary task (T2) in a different modality, due to reduced top-down control needed to inhibit the secondary task, as well as crossmodal spread of attention. This contrasts findings of cognitive load compromising a secondary modality's processing. We manipulated cognitive load within one modality (visual) and studied the consequences of cognitive demands on secondary (auditory) processing. 15 healthy participants underwent a simultaneous EEG-fMRI experiment. Data from 8 participants were obtained outside the scanner for validation purposes. The primary task (T1) was to respond to a visual working memory (WM) task with four conditions, while the secondary task (T2) consisted of an auditory oddball stream, which participants were asked to ignore. The fMRI results revealed fronto-parietal WM network activations in response to T1 task manipulation. This was accompanied by significantly higher reaction times and lower hit rates with increasing task difficulty which confirmed successful manipulation of WM load. Amplitudes of auditory evoked potentials, representing fundamental auditory processing showed a continuous augmentation which demonstrated a systematic relation to cross-modal cognitive load. With increasing WM load, primary auditory cortices were increasingly deactivated while psychophysiological interaction results suggested the emergence of auditory cortices connectivity with visual WM regions. These results suggest differential effects of crossmodal attention on fundamental auditory processing. We suggest a continuous allocation of resources to brain regions processing primary tasks when challenging the central executive under high cognitive load.

  12. Toward Epileptic Brain Region Detection Based on Magnetic Nanoparticle Patterning

    PubMed Central

    Pedram, Maysam Z.; Shamloo, Amir; Alasty, Aria; Ghafar-Zadeh, Ebrahim

    2015-01-01

    Resection of the epilepsy foci is the best treatment for more than 15% of epileptic patients or 50% of patients who are refractory to all forms of medical treatment. Accurate mapping of the locations of epileptic neuronal networks can result in the complete resection of epileptic foci. Even though currently electroencephalography is the best technique for mapping the epileptic focus, it cannot define the boundary of epilepsy that accurately. Herein we put forward a new accurate brain mapping technique using superparamagnetic nanoparticles (SPMNs). The main hypothesis in this new approach is the creation of super-paramagnetic aggregates in the epileptic foci due to high electrical and magnetic activities. These aggregates may improve tissue contrast of magnetic resonance imaging (MRI) that results in improving the resection of epileptic foci. In this paper, we present the mathematical models before discussing the simulation results. Furthermore, we mimic the aggregation of SPMNs in a weak magnetic field using a low-cost microfabricated device. Based on these results, the SPMNs may play a crucial role in diagnostic epilepsy and the subsequent treatment of this disease. PMID:26402686

  13. Auditory fMRI of Sound Intensity and Loudness for Unilateral Stimulation.

    PubMed

    Behler, Oliver; Uppenkamp, Stefan

    2016-01-01

    We report a systematic exploration of the interrelation of sound intensity, ear of entry, individual loudness judgments, and brain activity across hemispheres, using auditory functional magnetic resonance imaging (fMRI). The stimuli employed were 4 kHz-bandpass filtered noise stimuli, presented monaurally to each ear at levels from 37 to 97 dB SPL. One diotic condition and a silence condition were included as control conditions. Normal hearing listeners completed a categorical loudness scaling procedure with similar stimuli before auditory fMRI was performed. The relationship between brain activity, as inferred from blood oxygenation level dependent (BOLD) contrasts, and both sound intensity and loudness estimates were analyzed by means of linear mixed effects models for various anatomically defined regions of interest in the ascending auditory pathway and in the cortex. The results indicate distinct functional differences between midbrain and cortical areas as well as between specific regions within auditory cortex, suggesting a systematic hierarchy in terms of lateralization and the representation of sensory stimulation and perception.

  14. Developmental stress impairs performance on an association task in male and female songbirds, but impairs auditory learning in females only.

    PubMed

    Farrell, Tara M; Morgan, Amanda; MacDougall-Shackleton, Scott A

    2016-01-01

    In songbirds, early-life environments critically shape song development. Many studies have demonstrated that developmental stress impairs song learning and the development of song-control regions of the brain in males. However, song has evolved through signaller-receiver networks and the effect stress has on the ability to receive auditory signals is equally important, especially for females who use song as an indicator of mate quality. Female song preferences have been the metric used to evaluate how developmental stress affects auditory learning, but preferences are shaped by many non-cognitive factors and preclude the evaluation of auditory learning abilities in males. To determine whether developmental stress specifically affects auditory learning in both sexes, we subjected juvenile European starlings, Sturnus vulgaris, to either an ad libitum or an unpredictable food supply treatment from 35 to 115 days of age. In adulthood, we assessed learning of both auditory and visual discrimination tasks. Females reared in the experimental group were slower than females in the control group to acquire a relative frequency auditory task, and slower than their male counterparts to acquire an absolute frequency auditory task. There was no difference in auditory performance between treatment groups for males. However, on the colour association task, birds from the experimental group committed more errors per trial than control birds. There was no correlation in performance across the cognitive tasks. Developmental stress did not affect all cognitive processes equally across the sexes. Our results suggest that the male auditory system may be more robust to developmental stress than that of females.

  15. Electrostimulation mapping of comprehension of auditory and visual words.

    PubMed

    Roux, Franck-Emmanuel; Miskin, Krasimir; Durand, Jean-Baptiste; Sacko, Oumar; Réhault, Emilie; Tanova, Rositsa; Démonet, Jean-François

    2015-10-01

    In order to spare functional areas during the removal of brain tumours, electrical stimulation mapping was used in 90 patients (77 in the left hemisphere and 13 in the right; 2754 cortical sites tested). Language functions were studied with a special focus on comprehension of auditory and visual words and the semantic system. In addition to naming, patients were asked to perform pointing tasks from auditory and visual stimuli (using sets of 4 different images controlled for familiarity), and also auditory object (sound recognition) and Token test tasks. Ninety-two auditory comprehension interference sites were observed. We found that the process of auditory comprehension involved a few, fine-grained, sub-centimetre cortical territories. Early stages of speech comprehension seem to relate to two posterior regions in the left superior temporal gyrus. Downstream lexical-semantic speech processing and sound analysis involved 2 pathways, along the anterior part of the left superior temporal gyrus, and posteriorly around the supramarginal and middle temporal gyri. Electrostimulation experimentally dissociated perceptual consciousness attached to speech comprehension. The initial word discrimination process can be considered as an "automatic" stage, the attention feedback not being impaired by stimulation as would be the case at the lexical-semantic stage. Multimodal organization of the superior temporal gyrus was also detected since some neurones could be involved in comprehension of visual material and naming. These findings demonstrate a fine graded, sub-centimetre, cortical representation of speech comprehension processing mainly in the left superior temporal gyrus and are in line with those described in dual stream models of language comprehension processing.

  16. Regional Blood-Brain Barrier Responses to Central Cholinergic Activity

    DTIC Science & Technology

    1989-07-30

    regions were of particular interest because they show the largest decreases in glucose metabolism following limbic seizures ( Ben - Ari et al., 1981). It is...following seizures ( Ben - Ari et. al., 1981). The piriform cortex-amygdala also appears to be a generator of epileptiform activity in a variety of seizure...produced by PTZ. Such studies are ongoing and the results will be given in subsequent reports. 11 REFERENCES Ben - Ari , Y., D. Richie, E. Tremblay and G

  17. Changes in Regional Brain Perfusion During Functional Brain Activation: Comparison of [64Cu]-PTSM with [14C]-Iodoantipyrine

    PubMed Central

    Holschneider, DP; Yang, J; Sadler, TR; Galifianakis, NB; Bozorgzadeh, MH; Bading, JR; Conti, PS; Maarek, J-M I

    2008-01-01

    A dilemma in behavioral brain mapping is that conventional techniques immobilize the subject, extinguishing all but the simplest behaviors. This is avoided if brain activation is imaged after completion of the behavior and tissue capture of the tracer. A single-pass flow tracer proposed for positron emission tomography (PET) is a radiolabeled copper(II) complex of pyruvaldehyde bis(N4-methylthiosemicarbazone), [Cu64]-PTSM. [Cu64]-PTSM reaches steady-state cerebral distribution more rapidly than the metabolic tracer [18F]-fluorodeoxyglucose, allowing imaging with substantially greater temporal resolution. Using dual-label autoradiography, this study compares the relative regional cerebral blood flow tracer distribution (CBF-TR) of [64Cu]-PTSM to that of the classic perfusion tracer [14C]-iodoantipyrine in a rat model during treadmill walking. Rats were exposed to continuous walking on a treadmill and compared to quiescent controls. [64Cu]-PTSM was bolus injected (iv) after 1 minute, followed by a 5 minute uptake and subsequent bolus injection of [14C]-iodoantipyrine. CBF-TR was quantified by autoradiography and analyzed in the three-dimensionally reconstructed brain by statistical parametric mapping, as well as by region-of-interest analysis. A high homology was found between the [64Cu]-PTSM and [14C]-iodoantipyrine patterns of cerebral activation in cortical and subcortical regions. For white matter, however, [64Cu]-PTSM showed lower perfusion than [14Cu]-iodoantipyrine. [64Cu]-PTSM is a useful tracer for functional brain mapping in freely-moving subjects. Its application in conjunction with PET promises to increase our understanding of the neural circuitry of behaviors dependent on locomotion. PMID:18687316

  18. Influence of high deformation rate, brain region, transverse compression, and specimen size on rat brain shear stress morphology and magnitude.

    PubMed

    Haslach, Henry W; Gipple, Jenna M; Leahy, Lauren N

    2017-01-26

    An external mechanical insult to the brain, such as a blast, may create internal stress and deformation waves, which have shear and longitudinal components that can induce combined shear and compression of the brain tissue. To isolate the consequences of such interactions for the shear stress and to investigate the role of the extracellular fluid in the mechanical response, translational shear stretch at 10/s, 60/s, and 100/s translational shear rates under either 0% or 33% fixed transverse compression is applied without preconditioning to rat brain specimens. The specimens from the cerebrum, the cerebellum grey matter, and the brainstem white matter are nearly the full length of their respective regions. The translational shear stress response to translational shear deformation is characterized by the effect that each of four factors, high deformation rate, brain region, transverse compression, and specimen size, have on the shear stress magnitude averaged over ten specimens for each combination of factors. Increasing the deformation rate increases the magnitude of the shear stress at a given translational shear stretch, and as tested by ANOVAs so does applying transverse fixed compression of 33% of the thickness. The stress magnitude differs by the region that is the specimen source: cerebrum, cerebellum or brainstem. The magnitude of the shear stress response at a given deformation rate and stretch depends on the specimen length, called a specimen size effect. Surprisingly, under no compression a shorter length specimen requires more shear stress, but under 33% compression a shorter length specimen requires less shear stress, to meet a required shear deformation rate. The shear specimen size effect calls into question the applicability of the classical shear stress definition to hydrated soft biological tissue.

  19. Functional photoacoustic imaging to observe regional brain activation induced by cocaine hydrochloride

    NASA Astrophysics Data System (ADS)

    Jo, Janggun; Yang, Xinmai

    2011-09-01

    Photoacoustic microscopy (PAM) was used to detect small animal brain activation in response to drug abuse. Cocaine hydrochloride in saline solution was injected into the blood stream of Sprague Dawley rats through tail veins. The rat brain functional change in response to the injection of drug was then monitored by the PAM technique. Images in the coronal view of the rat brain at the locations of 1.2 and 3.4 mm posterior to bregma were obtained. The resulted photoacoustic (PA) images showed the regional changes in the blood volume. Additionally, the regional changes in blood oxygenation were also presented. The results demonstrated that PA imaging is capable of monitoring regional hemodynamic changes induced by drug abuse.

  20. On-Line Statistical Segmentation of a Non-Speech Auditory Stream in Neonates as Demonstrated by Event-Related Brain Potentials

    ERIC Educational Resources Information Center

    Kudo, Noriko; Nonaka, Yulri; Mizuno, Noriko; Mizuno, Katsumi; Okanoya, Kazuo

    2011-01-01

    The ability to statistically segment a continuous auditory stream is one of the most important preparations for initiating language learning. Such ability is available to human infants at 8 months of age, as shown by a behavioral measurement. However, behavioral study alone cannot determine how early this ability is available. A recent study using…

  1. Differential production of reactive oxygen species in distinct brain regions of hypoglycemic mice.

    PubMed

    Amador-Alvarado, Leticia; Montiel, Teresa; Massieu, Lourdes

    2014-09-01

    Hypoglycemia is a serious complication of insulin therapy in patients suffering from type 1 Diabetes Mellitus. Severe hypoglycemia leading to coma (isoelectricity) induces massive neuronal death in vulnerable brain regions such as the hippocampus, the striatum and the cerebral cortex. It has been suggested that the production of reactive oxygen species (ROS) and oxidative stress is involved in hypoglycemic brain damage, and that ROS generation is stimulated by glucose reintroduction (GR) after the hypoglycemic coma. However, the distribution of ROS in discrete brain regions has not been studied in detail. Using the oxidation sensitive marker dihydroethidium (DHE) we have investigated the distribution of ROS in different regions of the mouse brain during prolonged severe hypoglycemia without isoelectricity, as well as the effect of GR on ROS levels. Results show that ROS generation increases in the hippocampus, the cerebral cortex and the striatum after prolonged severe hypoglycemia before the coma. The hippocampus showed the largest increases in ROS levels. GR further stimulated ROS production in the hippocampus and the striatum while in the cerebral cortex, only the somatosensory and parietal areas were significantly affected by GR. Results suggest that ROS are differentially produced during the hypoglycemic insult and that a different response to GR is present among distinct brain regions.

  2. Regional Gray Matter Growth, Sexual Dimorphism, and Cerebral Asymmetry in the Neonatal Brain

    PubMed Central

    Gilmore, John H.; Lin, Weili; Prastawa, Marcel W.; Looney, Christopher B.; Vetsa, Y. Sampath K.; Knickmeyer, Rebecca C.; Evans, Dianne D.; Smith, J. Keith; Hamer, Robert M.; Lieberman, Jeffrey A.; Gerig, Guido

    2010-01-01

    Although there has been recent interest in the study of childhood and adolescent brain development, very little is known about normal brain development in the first few months of life. In older children, there are regional differences in cortical gray matter development, whereas cortical gray and white matter growth after birth has not been studied to a great extent. The adult human brain is also characterized by cerebral asymmetries and sexual dimorphisms, although very little is known about how these asymmetries and dimorphisms develop. We used magnetic resonance imaging and an automatic segmentation methodology to study brain structure in 74 neonates in the first few weeks after birth. We found robust cortical gray matter growth compared with white matter growth, with occipital regions growing much faster than prefrontal regions. Sexual dimorphism is present at birth, with males having larger total brain cortical gray and white matter volumes than females. In contrast to adults and older children, the left hemisphere is larger than the right hemisphere, and the normal pattern of fronto-occipital asymmetry described in older children and adults is not present. Regional differences in cortical gray matter growth are likely related to differential maturation of sensory and motor systems compared with prefrontal executive function after birth. These findings also indicate that whereas some adult patterns of sexual dimorphism and cerebral asymmetries are present at birth, others develop after birth. PMID:17287499

  3. Classification of Alzheimer's disease using regional saliency maps from brain MR volumes

    NASA Astrophysics Data System (ADS)

    Pulido, Andrea; Rueda, Andrea; Romero, Eduardo

    2013-02-01

    Accurate diagnosis of Alzheimer's disease (AD) from structural Magnetic Resonance (MR) images is difficult due to the complex alteration of patterns in brain anatomy that could indicate the presence or absence of the pathology. Currently, an effective approach that allows to interpret the disease in terms of global and local changes is not available in the clinical practice. In this paper, we propose an approach for classification of brain MR images, based on finding pathology-related patterns through the identification of regional structural changes. The approach combines a probabilistic Latent Semantic Analysis (pLSA) technique, which allows to identify image regions through latent topics inferred from the brain MR slices, with a bottom-up Graph-Based Visual Saliency (GBVS) model, which calculates maps of relevant information per region. Regional saliency maps are finally combined into a single map on each slice, obtaining a master saliency map of each brain volume. The proposed approach includes a one-to-one comparison of the saliency maps which feeds a Support Vector Machine (SVM) classifier, to group test subjects into normal or probable AD subjects. A set of 156 brain MR images from healthy (76) and pathological (80) subjects, splitted into a training set (10 non-demented and 10 demented subjects) and one testing set (136 subjects), was used to evaluate the performance of the proposed approach. Preliminary results show that the proposed method reaches a maximum classification accuracy of 87.21%.

  4. Sodium tungstate induced neurological alterations in rat brain regions and their response to antioxidants.

    PubMed

    Sachdeva, Sherry; Pant, Satish C; Kushwaha, Pramod; Bhargava, Rakesh; Flora, Swaran J S

    2015-08-01

    Tungsten, recognized recently as an environmental contaminant, is being used in arms and ammunitions as substitute to depleted uranium. We studied the effects of sodium tungstate on oxidative stress, few selected neurological variables like acetylcholinesterase, biogenic amines in rat brain regions (cerebral cortex, hippocampus and cerebellum) and their prevention following co-administration of N-acetylcysteine (NAC), naringenin and quercetin. Animals were sub-chronically exposed to sodium tungstate (100 ppm in drinking water) and orally co-supplemented with different antioxidants (0.30 mM) for three months. Sodium tungstate significantly decreased the activity of acetylcholinesterase, dopamine, nor-epinephrine and 5-hydroxytryptamine levels while it increased monoamine oxidase activity in different brain regions. Tungstate exposure produced a significant increase in biochemical variables indicative of oxidative stress while, neurological alterations were more pronounced in the cerebral cortex compared to other regions. Co-administration of NAC and flavonoids with sodium tungstate significantly restored glutathione, prevented changes in the brain biogenic amines, reactive oxygen species (ROS) and TBARS levels in the different brain regions. The protection was more prominent in the animals co-administered with NAC. We can thus conclude that sodium tungstate induced brain oxidative stress and the alterations in some neurological variables can effectively be reduced by co-supplementation of NAC.

  5. Regional gray matter growth, sexual dimorphism, and cerebral asymmetry in the neonatal brain.

    PubMed

    Gilmore, John H; Lin, Weili; Prastawa, Marcel W; Looney, Christopher B; Vetsa, Y Sampath K; Knickmeyer, Rebecca C; Evans, Dianne D; Smith, J Keith; Hamer, Robert M; Lieberman, Jeffrey A; Gerig, Guido

    2007-02-07

    Although there has been recent interest in the study of childhood and adolescent brain development, very little is known about normal brain development in the first few months of life. In older children, there are regional differences in cortical gray matter development, whereas cortical gray and white matter growth after birth has not been studied to a great extent. The adult human brain is also characterized by cerebral asymmetries and sexual dimorphisms, although very little is known about how these asymmetries and dimorphisms develop. We used magnetic resonance imaging and an automatic segmentation methodology to study brain structure in 74 neonates in the first few weeks after birth. We found robust cortical gray matter growth compared with white matter growth, with occipital regions growing much faster than prefrontal regions. Sexual dimorphism is present at birth, with males having larger total brain cortical gray and white matter volumes than females. In contrast to adults and older children, the left hemisphere is larger than the right hemisphere, and the normal pattern of fronto-occipital asymmetry described in older children and adults is not present. Regional differences in cortical gray matter growth are likely related to differential maturation of sensory and motor systems compared with prefrontal executive function after birth. These findings also indicate that whereas some adult patterns of sexual dimorphism and cerebral asymmetries are present at birth, others develop after birth.

  6. Longitudinal change in regional brain volumes in prodromal Huntington disease

    PubMed Central

    Aylward, Elizabeth H.; Nopoulos, Peggy C.; Ross, Christopher A.; Langbehn, Douglas R.; Pierson, Ronald K.; Mills, James A.; Johnson, Hans J.; Magnotta, Vincent A.; Juhl, Andrew R.; Paulsen, Jane S.

    2011-01-01

    Objective As therapeutics are being developed to target the underlying neuropathology of Huntington disease (HD), interest is increasing in methodologies for conducting clinical trials in the prodromal phase. This study was designed to examine the potential utility of structural MRI measures as outcome measures for such trials. Methods Data are presented from 211 prodromal individuals and 60 controls, scanned both at baseline and two-year follow-up. Prodromal participants were divided into groups based on proximity to estimated onset of diagnosable clinical disease: Far (>15 years from estimated onset); Mid (9–15 years); and Near (<9 years). Volumetric measurements of caudate, putamen, total striatum, globus pallidus, thalamus, total gray and white matter, and CSF were performed. Results All prodromal groups showed a faster rate of atrophy than Controls in striatum, total brain, and cerebral white matter (especially in the frontal lobe). Neither prodromal participants nor Controls showed significant longitudinal change in cortex (either total cortical gray or within individual lobes). When normal age-related atrophy (i.e., change observed in the Control group) was taken into account, there was more statistically significant disease-related atrophy in white matter than in striatum. Conclusion Measures of volume change in striatum and white matter volume, particularly in the frontal lobe, may serve as excellent outcome measures for future clinical trials in prodromal HD. Clinical trials using white matter or striatal volume change as an outcome measure will be most efficient if the sample is restricted to individuals who are within 15 years of estimated onset of diagnosable disease. PMID:20884680

  7. Magnetoencephalographic accuracy profiles for the detection of auditory pathway sources.

    PubMed

    Bauer, Martin; Trahms, Lutz; Sander, Tilmann

    2015-04-01

    The detection limits for cortical and brain stem sources associated with the auditory pathway are examined in order to analyse brain responses at the limits of the audible frequency range. The results obtained from this study are also relevant to other issues of auditory brain research. A complementary approach consisting of recordings of magnetoencephalographic (MEG) data and simulations of magnetic field distributions is presented in this work. A biomagnetic phantom consisting of a spherical volume filled with a saline solution and four current dipoles is built. The magnetic fields outside of the phantom generated by the current dipoles are then measured for a range of applied electric dipole moments with a planar multichannel SQUID magnetometer device and a helmet MEG gradiometer device. The inclusion of a magnetometer system is expected to be more sensitive to brain stem sources compared with a gradiometer system. The same electrical and geometrical configuration is simulated in a forward calculation. From both the measured and the simulated data, the dipole positions are estimated using an inverse calculation. Results are obtained for the reconstruction accuracy as a function of applied electric dipole moment and depth of the current dipole. We found that both systems can localize cortical and subcortical sources at physiological dipole strength even for brain stem sources. Further, we found that a planar magnetometer system is more suitable if the position of the brain source can be restricted in a limited region of the brain. If this is not the case, a helmet-shaped sensor system offers more accurate source estimation.

  8. Electrophysiological measurement of human auditory function

    NASA Technical Reports Server (NTRS)

    Galambos, R.

    1975-01-01

    Contingent negative variations in the presence and amplitudes of brain potentials evoked by sound are considered. Evidence is produced that the evoked brain stem response to auditory stimuli is clearly related to brain events associated with cognitive processing of acoustic signals since their properties depend upon where the listener directs his attention, whether the signal is an expected event or a surprise, and when sound that is listened-for is heard at last.

  9. Genetic contributions to regional variability in human brain structure: methods and preliminary results.

    PubMed

    Wright, I C; Sham, P; Murray, R M; Weinberger, D R; Bullmore, E T

    2002-09-01

    Twin studies provide one approach for investigating and partitioning genetic and environmental contributions to phenotypic variability in human brain structure. Previous twin studies have found that cerebral volume, hemispheric volume, ventricular volume, and cortical gyral pattern variability were heritable. We investigated the contributions of genetic and environmental factors to both global (brain volume and lateral ventricular volume) and regional (parcellated gray matter) variability in brain structure. We examined MR images from 10 pairs of healthy monozygotic and 10 pairs of same-sex dizygotic twins. Regional gray matter volume was estimated by automated image segmentation, transformation to standard space, and parcellation using a digital atlas. Heritability was estimated by path analysis. Estimated heritability for brain volume variability was high (0.66; 95% confidence interval 0.17, 1.0) but the major effects on lateral ventricular volume variability were common and unique environmental factors. We constructed a map of regional brain heritability and found large genetic effects shared in common between several bilateral brain regions, particularly paralimbic structures and temporal-parietal neocortex. We tested three specific hypotheses with regard to the genetic control of brain variability: (i) that the strength of the genetic effect is related to gyral ontogenesis, (ii) that there is greater genetic control of left than of right hemisphere variability, and (iii) that random or fluctuating asymmetry in bilateral structures is not heritable. We found no evidence in support of the first two hypotheses, but our results were consistent with the third hypothesis. Finally, we used principal component (PC) analysis of the genetic correlation matrix, to identify systems of anatomically distributed gray matter regions which shared major genetic effects in common. Frontal and parietal neocortical areas loaded positively on the first PC; some paralimbic and

  10. Rheological regional properties of brain tissue studied under cyclic creep/ recovery shear stresses

    NASA Astrophysics Data System (ADS)

    Boudjema, F.; Lounis, M.; Khelidj, B.; Bessai, N.

    2015-04-01

    The rheological properties of brain tissue were studied by repeated creep-recovery shear tests under static conditions for different regions. Corpus callosum CC, Thalamus Th and Corona radiata CR. Non-linear viscoelastic model was also proposed to characterize the transient/steady states of shear creep results. From the creep-recovery data it was obvious that the brain tissues show high regional anisotropy. However. the both samples exhibit fluid viscoelastic properties in the first shear stress cycle of 100 Pa, while this behaviour evolutes to solid viscoelastic with cyclic effect.

  11. Big Cat Coalitions: A Comparative Analysis of Regional Brain Volumes in Felidae.

    PubMed

    Sakai, Sharleen T; Arsznov, Bradley M; Hristova, Ani E; Yoon, Elise J; Lundrigan, Barbara L

    2016-01-01

    Broad-based species comparisons across mammalian orders suggest a number of factors that might influence the evolution of large brains. However, the relationship between these factors and total and regional brain size remains unclear. This study investigated the relationship between relative brain size and regional brain volumes and sociality in 13 felid species in hopes of revealing relationships that are not detected in more inclusive comparative studies. In addition, a more detailed analysis was conducted of four focal species: lions (Panthera leo), leopards (Panthera pardus), cougars (Puma concolor), and cheetahs (Acinonyx jubatus). These species differ markedly in sociality and behavioral flexibility, factors hypothesized to contribute to increased relative brain size and/or frontal cortex size. Lions are the only truly social species, living in prides. Although cheetahs are largely solitary, males often form small groups. Both leopards and cougars are solitary. Of the four species, leopards exhibit the most behavioral flexibility, readily adapting to changing circumstances. Regional brain volumes were analyzed using computed tomography. Skulls (n = 75) were scanned to create three-dimensional virtual endocasts, and regional brain volumes were measured using either sulcal or bony landmarks obtained from the endocasts or skulls. Phylogenetic least squares regression analyses found that sociality does not correspond with larger relative brain size in these species. However, the sociality/solitary variable significantly predicted anterior cerebrum (AC) volume, a region that includes frontal cortex. This latter finding is despite the fact that the two social species in our sample, lions and cheetahs, possess the largest and smallest relative AC volumes, respectively. Additionally, an ANOVA comparing regional brain volumes in four focal species revealed that lions and leopards, while not significantly different from one another, have relatively larger AC volumes

  12. Big Cat Coalitions: A Comparative Analysis of Regional Brain Volumes in Felidae

    PubMed Central

    Sakai, Sharleen T.; Arsznov, Bradley M.; Hristova, Ani E.; Yoon, Elise J.; Lundrigan, Barbara L.

    2016-01-01

    Broad-based species comparisons across mammalian orders suggest a number of factors that might influence the evolution of large brains. However, the relationship between these factors and total and regional brain size remains unclear. This study investigated the relationship between relative brain size and regional brain volumes and sociality in 13 felid species in hopes of revealing relationships that are not detected in more inclusive comparative studies. In addition, a more detailed analysis was conducted of four focal species: lions (Panthera leo), leopards (Panthera pardus), cougars (Puma concolor), and cheetahs (Acinonyx jubatus). These species differ markedly in sociality and behavioral flexibility, factors hypothesized to contribute to increased relative brain size and/or frontal cortex size. Lions are the only truly social species, living in prides. Although cheetahs are largely solitary, males often form small groups. Both leopards and cougars are solitary. Of the four species, leopards exhibit the most behavioral flexibility, readily adapting to changing circumstances. Regional brain volumes were analyzed using computed tomography. Skulls (n = 75) were scanned to create three-dimensional virtual endocasts, and regional brain volumes were measured using either sulcal or bony landmarks obtained from the endocasts or skulls. Phylogenetic least squares regression analyses found that sociality does not correspond with larger relative brain size in these species. However, the sociality/solitary variable significantly predicted anterior cerebrum (AC) volume, a region that includes frontal cortex. This latter finding is despite the fact that the two social species in our sample, lions and cheetahs, possess the largest and smallest relative AC volumes, respectively. Additionally, an ANOVA comparing regional brain volumes in four focal species revealed that lions and leopards, while not significantly different from one another, have relatively larger AC volumes

  13. Simian virus 40 regulatory region structural diversity and the association of viral archetypal regulatory regions with human brain tumors.

    PubMed

    Lednicky, J A; Butel, J S

    2001-02-01

    The regulatory region (RR) of simian virus 40 (SV40) contains enhancer/promoter elements and an origin of DNA replication. Natural SV40 isolates from simian brain or kidney tissues typically have an archetypal RR arrangement with a single 72-basepair enhancer element. A rare simpler, shorter SV40 RR exists that lacks a duplicated sequence in the G/C-rich region and is termed protoarchetypal. Occasionally, SV40 strain variants arise de novo that have complex RRs, which typically contain sequence reiterations, rearrangements, and/or deletions. These variants replicate faster and to higher titers in tissue culture; we speculate that such faster-growing variants were selected when laboratory strains of SV40 were initially recovered. SV40 strains with archetypal RRs have been found in some human brain tumors. The possible implications of these findings and a brief review of the SV40 RR structure are presented.

  14. Analysis of spatial-temporal gene expression patterns reveals dynamics and regionalization in developing mouse brain.

    PubMed

    Chou, Shen-Ju; Wang, Chindi; Sintupisut, Nardnisa; Niou, Zhen-Xian; Lin, Chih-Hsu; Li, Ker-Chau; Yeang, Chen-Hsiang

    2016-01-20

    Allen Brain Atlas (ABA) provides a valuable resource of spatial/temporal gene expressions in mammalian brains. Despite rich information extracted from this database, current analyses suffer from several limitations. First, most studies are either gene-centric or region-centric, thus are inadequate to capture the superposition of multiple spatial-temporal patterns. Second, standard tools of expression analysis such as matrix factorization can capture those patterns but do not explicitly incorporate spatial dependency. To overcome those limitations, we proposed a computational method to detect recurrent patterns in the spatial-temporal gene expression data of developing mouse brains. We demonstrated that regional distinction in brain development could be revealed by localized gene expression patterns. The patterns expressed in the forebrain, medullary and pontomedullary, and basal ganglia are enriched with genes involved in forebrain development, locomotory behavior, and dopamine metabolism respectively. In addition, the timing of global gene expression patterns reflects the general trends of molecular events in mouse brain development. Furthermore, we validated functional implications of the inferred patterns by showing genes sharing similar spatial-temporal expression patterns with Lhx2 exhibited differential expression in the embryonic forebrains of Lhx2 mutant mice. These analysis outcomes confirm the utility of recurrent expression patterns in studying brain development.

  15. Brain-Region Specific Apoptosis Triggered by Eph/ephrin Signaling.

    PubMed

    Park, Soochul

    2013-09-01

    Eph receptors and their ligands, ephrins, are abundantly expressed in neuroepithelial cells of the early embryonic brain. Overstimulation of Eph signaling in vivo increases apoptotic cell death of neuroepithelial cells, whereas null mutation of the Eph gene leads to the development of a larger brain during embryogenesis. Thus, it appears that Eph-ephrin signaling plays a role in regulating apoptotic cell death of neuroepithelial cells, thereby influencing brain size during embryonic development. Interestingly, Eph-ephrin signaling is bi-directional, with forward signaling from ephrin- to Eph-expressing cells and reverse signaling from Eph- to ephrin-expressing cells. However, it is not clear whether this forward or reverse signaling plays a role in regulating the size of the neuroepithelial cell population during early brain development. Also, Eph receptors and their corresponding ligands are mutually exclusive in their expression domains, and they encounter each other only at interfaces between their expression domains. This expression pattern may be a critical mechanism for preventing overstimulation of Eph-ephrin signaling. Nevertheless, Eph receptors are co-expressed with their corresponding ligands in certain brain regions. Recently, two studies demonstrated that brain region-specific apoptosis may be triggered by the overlapping expression of Eph and ephrin, a theme that will be explored in this mini-review.

  16. Chronic ethanol exposure produces time- and brain region-dependent changes in gene coexpression networks.

    PubMed

    Osterndorff-Kahanek, Elizabeth A; Becker, Howard C; Lopez, Marcelo F; Farris, Sean P; Tiwari, Gayatri R; Nunez, Yury O; Harris, R Adron; Mayfield, R Dayne

    2015-01-01

    Repeated ethanol exposure and withdrawal in mice increases voluntary drinking and represents an animal model of physical dependence. We examined time- and brain region-dependent changes in gene coexpression networks in amygdala (AMY), nucleus accumbens (NAC), prefrontal cortex (PFC), and liver after four weekly cycles of chronic intermittent ethanol (CIE) vapor exposure in C57BL/6J mice. Microarrays were used to compare gene expression profiles at 0-, 8-, and 120-hours following the last ethanol exposure. Each brain region exhibited a large number of differentially expressed genes (2,000-3,000) at the 0- and 8-hour time points, but fewer changes were detected at the 120-hour time point (400-600). Within each region, there was little gene overlap across time (~20%). All brain regions were significantly enriched with differentially expressed immune-related genes at the 8-hour time point. Weighted gene correlation network analysis identified modules that were highly enriched with differentially expressed genes at the 0- and 8-hour time points with virtually no enrichment at 120 hours. Modules enriched for both ethanol-responsive and cell-specific genes were identified in each brain region. These results indicate that chronic alcohol exposure causes global 'rewiring' of coexpression systems involving glial and immune signaling as well as neuronal genes.

  17. Chronic ethanol consumption profoundly alters regional brain ceramide and sphingomyelin content in rodents.

    PubMed

    Roux, Aurelie; Muller, Ludovic; Jackson, Shelley N; Baldwin, Katherine; Womack, Virginia; Pagiazitis, John G; O'Rourke, Joseph R; Thanos, Panayotis K; Balaban, Carey; Schultz, J Albert; Volkow, Nora D; Woods, Amina S

    2015-02-18

    Ceramides (CER) are involved in alcohol-induced neuroinflammation. In a mouse model of chronic alcohol exposure, 16 CER and 18 sphingomyelin (SM) concentrations from whole brain lipid extracts were measured using electrospray mass spectrometry. All 18 CER concentrations in alcohol exposed adults increased significantly (range: 25-607%); in juveniles, 6 CER decreased (range: -9 to -37%). In contrast, only three SM decreased in adult and one increased significantly in juvenile. Next, regional identification at 50 μm spatial resolution from coronal sections was obtained with matrix implanted laser desorption/ionization mass spectrometry imaging (MILDI-MSI) by implanting silver nanoparticulate matrices followed by focused laser desorption. Most of the CER and SM quantified in whole brain extracts were detected in MILDI images. Coronal sections from three brain levels show qualitative regional changes in CER-SM ion intensities, as a function of group and brain region, in cortex, striatum, accumbens, habenula, and hippocampus. Highly correlated changes in certain white matter CER-SM pairs occur in regions across all groups, including the hippocampus and the lateral (but not medial) cerebellar cortex of adult mice. Our data provide the first microscale MS evidence of regional lipid intensity variations induced by alcohol.

  18. Chronic Ethanol Consumption Profoundly Alters Regional Brain Ceramide and Sphingomyelin Content in Rodents

    PubMed Central

    2015-01-01

    Ceramides (CER) are involved in alcohol-induced neuroinflammation. In a mouse model of chronic alcohol exposure, 16 CER and 18 sphingomyelin (SM) concentrations from whole brain lipid extracts were measured using electrospray mass spectrometry. All 18 CER concentrations in alcohol exposed adults increased significantly (range: 25–607%); in juveniles, 6 CER decreased (range: −9 to −37%). In contrast, only three SM decreased in adult and one increased significantly in juvenile. Next, regional identification at 50 μm spatial resolution from coronal sections was obtained with matrix implanted laser desorption/ionization mass spectrometry imaging (MILDI-MSI) by implanting silver nanoparticulate matrices followed by focused laser desorption. Most of the CER and SM quantified in whole brain extracts were detected in MILDI images. Coronal sections from three brain levels show qualitative regional changes in CER-SM ion intensities, as a function of group and brain region, in cortex, striatum, accumbens, habenula, and hippocampus. Highly correlated changes in certain white matter CER-SM pairs occur in regions across all groups, including the hippocampus and the lateral (but not medial) cerebellar cortex of adult mice. Our data provide the first microscale MS evidence of regional lipid intensity variations induced by alcohol. PMID:25387107

  19. Region-Specific Defects of Respiratory Capacities in the Ndufs4(KO) Mouse Brain

    PubMed Central

    Kayser, Ernst-Bernhard; Sedensky, Margaret M.; Morgan, Philip G.

    2016-01-01

    Background Lack of NDUFS4, a subunit of mitochondrial complex I (NADH:ubiquinone oxidoreductase), causes Leigh syndrome (LS), a progressive encephalomyopathy. Knocking out Ndufs4, either systemically or in brain only, elicits LS in mice. In patients as well as in KO mice distinct regions of the brain degenerate while surrounding tissue survives despite systemic complex I dysfunction. For the understanding of disease etiology and ultimately for the development of rationale treatments for LS, it appears important to uncover the mechanisms that govern focal neurodegeneration. Results Here we used the Ndufs4(KO) mouse to investigate whether regional and temporal differences in respiratory capacity of the brain could be correlated with neurodegeneration. In the KO the respiratory capacity of synaptosomes from the degeneration prone regions olfactory bulb, brainstem and cerebellum was significantly decreased. The difference was measurable even before the onset of neurological symptoms. Furthermore, neither compensating nor exacerbating changes in glycolytic capacity of the synaptosomes were found. By contrast, the KO retained near normal levels of synaptosomal respiration in the degeneration-resistant/resilient “rest” of the brain. We also investigated non-synaptic mitochondria. The KO expectedly had diminished capacity for oxidative phosphorylation (state 3 respiration) with complex I dependent substrate combinations pyruvate/malate and glutamate/malate but surprisingly had normal activity with α-ketoglutarate/malate. No correlation between oxidative phosphorylation (pyruvate/malate driven state 3 respiration) and neurodegeneration was found: Notably, state 3 remained constant in the KO while in controls it tended to increase with time leading to significant differences between the genotypes in older mice in both vulnerable and resilient brain regions. Neither regional ROS damage, measured as HNE-modified protein, nor regional complex I stability, assessed by blue

  20. Auditory spatial attention representations in the human cerebral cortex.

    PubMed

    Kong, Lingqiang; Michalka, Samantha W; Rosen, Maya L; Sheremata, Summer L; Swisher, Jascha D; Shinn-Cunningham, Barbara G; Somers, David C

    2014-03-01

    Auditory spatial attention serves important functions in auditory source separation and selection. Although auditory spatial attention mechanisms have been generally investigated, the neural substrates encoding spatial information acted on by attention have not been identified in the human neocortex. We performed functional magnetic resonance imaging experiments to identify cortical regions that support auditory spatial attention and to test 2 hypotheses regarding the coding of auditory spatial attention: 1) auditory spatial attention might recruit the visuospatial maps of the intraparietal sulcus (IPS) to create multimodal spatial attention maps; 2) auditory spatial information might be encoded without explicit cortical maps. We mapped visuotopic IPS regions in individual subjects and measured auditory spatial attention effects within these regions of interest. Contrary to the multimodal map hypothesis, we observed that auditory spatial attentional modulations spared the visuotopic maps of IPS; the parietal regions activated by auditory attention lacked map structure. However, multivoxel pattern analysis revealed that the superior temporal gyrus and the supramarginal gyrus contained significant information about the direction of spatial attention. These findings support the hypothesis that auditory spatial information is coded without a cortical map representation. Our findings suggest that audiospatial and visuospatial attention utilize distinctly different spatial coding schemes.

  1. Systematically characterizing dysfunctional long intergenic non-coding RNAs in multiple brain regions of major psychosis

    PubMed Central

    Zhao, Hongying; Li, Feng; Deng, Yulan; Liu, Ling; Lan, Yujia; Zhang, Xinxin; Zhao, Tingting; Xu, Chaohan; Xu, Chun; Xiao, Yun; Li, Xia

    2016-01-01

    Schizophrenia (SZ) and bipolar disorder (BD) are severe neuropsychiatric disorders with serious impact on patients, together termed “major psychosis”. Recently, long intergenic non-coding RNAs (lincRNAs) were reported to play important roles in mental diseases. However, little was known about their molecular mechanism in pathogenesis of SZ and BD. Here, we performed RNA sequencing on 82 post-mortem brain tissues from three brain regions (orbitofrontal cortex (BA11), anterior cingulate cortex (BA24) and dorsolateral prefrontal cortex (BA9)) of patients with SZ and BD and control subjects, generating over one billion reads. We characterized lincRNA transcriptome in the three brain regions and identified 20 differentially expressed lincRNAs (DELincRNAs) in BA11 for BD, 34 and 1 in BA24 and BA9 for SZ, respectively. Our results showed that these DELincRNAs exhibited brain region-specific patterns. Applying weighted gene co-expression network analysis, we revealed that DELincRNAs together with other genes can function as modules to perform different functions in different brain regions, such as immune system development in BA24 and oligodendrocyte differentiation in BA9. Additionally, we found that DNA methylation alteration could partly explain the dysregulation of lincRNAs, some of which could function as enhancers in the pathogenesis of major psychosis. Together, we performed systematical characterization of dysfunctional lincRNAs in multiple brain regions of major psychosis, which provided a valuable resource to understand their roles in SZ and BD pathology and helped to discover novel biomarkers. PMID:27661005

  2. Selenotranscriptomic Analyses Identify Signature Selenoproteins in Brain Regions in a Mouse Model of Parkinson's Disease.

    PubMed

    Zhang, Xiong; Ye, Yang-Lie; Zhu, Hui; Sun, Sheng-Nan; Zheng, Jing; Fan, Hui-Hui; Wu, Hong-Mei; Chen, Song-Fang; Cheng, Wen-Hsing; Zhu, Jian-Hong

    Genes of selenoproteome have been increasingly implicated in various aspects of neurobiology and neurological disorders, but remain largely elusive in Parkinson's disease (PD). In this study, we investigated the selenotranscriptome (24 selenoproteins in total) in five brain regions (cerebellum, substantia nigra, cortex, pons and hippocampus) by real time qPCR in a two-phase manner using a mouse model of chronic PD. A wide range of changes in selenotranscriptome was observed in a manner depending on selenoproteins and brain regions. While Selv mRNA was not detectable and Dio1& 3 mRNA levels were not affected, 1, 11 and 9 selenoproteins displayed patterns of increase only, decrease only, and mixed response, respectively, in these brain regions of PD mice. In particular, the mRNA expression of Gpx1-4 showed only a decreased trend in the PD mouse brains. In substantia nigra, levels of 17 selenoprotein mRNAs were significantly decreased whereas no selenoprotein was up-regulated in the PD mice. In contrast, the majority of selenotranscriptome did not change and a few selenoprotein mRNAs that respond displayed a mixed pattern of up- and down-regulation in cerebellum, cortex, hippocampus, and/or pons of the PD mice. Gpx4, Sep15, Selm, Sepw1, and Sepp1 mRNAs were most abundant across all these five brain regions. Our results showed differential responses of selenoproteins in various brain regions of the PD mouse model, providing critical selenotranscriptomic profiling for future functional investigation of individual selenoprotein in PD etiology.

  3. Regional differences in actomyosin contraction shape the primary vesicles in the embryonic chicken brain

    NASA Astrophysics Data System (ADS)

    Filas, Benjamen A.; Oltean, Alina; Majidi, Shabnam; Bayly, Philip V.; Beebe, David C.; Taber, Larry A.

    2012-12-01

    In the early embryo, the brain initially forms as a relatively straight, cylindrical epithelial tube composed of neural stem cells. The brain tube then divides into three primary vesicles (forebrain, midbrain, hindbrain), as well as a series of bulges (rhombomeres) in the hindbrain. The boundaries between these subdivisions have been well studied as regions of differential gene expression, but the morphogenetic mechanisms that generate these constrictions are not well understood. Here, we show that regional variations in actomyosin-based contractility play a major role in vesicle formation in the embryonic chicken brain. In particular, boundaries did not form in brains exposed to the nonmuscle myosin II inhibitor blebbistatin, whereas increasing contractile force using calyculin or ATP deepened boundaries considerably. Tissue staining showed that contraction likely occurs at the inner part of the wall, as F-actin and phosphorylated myosin are concentrated at the apical side. However, relatively little actin and myosin was found in rhombomere boundaries. To determine the specific physical mechanisms that drive vesicle formation, we developed a finite-element model for the brain tube. Regional apical contraction was simulated in the model, with contractile anisotropy and strength estimated from contractile protein distributions and measurements of cell shapes. The model shows that a combination of circumferential contraction in the boundary regions and relatively isotropic contraction between boundaries can generate realistic morphologies for the primary vesicles. In contrast, rhombomere formation likely involves longitudinal contraction between boundaries. Further simulations suggest that these different mechanisms are dictated by regional differences in initial morphology and the need to withstand cerebrospinal fluid pressure. This study provides a new understanding of early brain morphogenesis.

  4. Peak I of the human auditory brainstem response results from the somatic regions of type I spiral ganglion cells: Evidence from computer modeling

    PubMed Central

    Rattay, Frank; Danner, Simon M.

    2014-01-01

    Early neural responses to acoustic signals can be electrically recorded as a series of waves, termed the auditory brainstem response (ABR). The latencies of the ABR waves are important for clinical and neurophysiological evaluations. Using a biophysical model of transmembrane currents along spiral ganglion cells, we show that in human (i) the non-myelinated somatic regions of type I cells, which innervate inner hair cells, predominantly contribute to peak I, (ii) the supra-strong postsynaptic stimulating current (400 pA) and transmembrane currents of the myelinated peripheral axons of type I cells are an order smaller; such postsynaptic currents correspond to the short latencies of a small recordable ABR peak I’, (iii) the ABR signal involvement of the central axon of bipolar type I cells is more effective than their peripheral counterpart as the doubled diameter causes larger transmembrane currents and a larger spike dipole-length, (iv) non-myelinated fibers of type II cells which innervate the outer hair cells generate essentially larger transmembrane currents but their ABR contribution is small because of the small ratio type II/type I cells, low firing rates and a short dipole length of spikes propagating slowly in non-myelinated fibers. Using a finite element model of a simplified head, peaks In and II (where In is the negative peak after peak I) are found to be stationary potentials when volleys of spikes cross the external electrical conductivity barrier at the bone&dura/CSF and at the CSF/brainstem interface whereas peaks I’ and I may be generated by strong local transmembrane currents as postsynaptic events at the distal ending and the soma region of type I cells, respectively. All simulated human inter-peak times (I–I′, II–I, In–I) are close to published data. PMID:25019355

  5. Bivariate Heritability of Total and Regional Brain Volumes: the Framingham Study

    PubMed Central

    DeStefano, Anita L.; Seshadri, Sudha; Beiser, Alexa; Atwood, Larry D.; Massaro, Joe M.; Au, Rhoda; Wolf, Philip A.; DeCarli, Charles

    2009-01-01

    Heritability and genetic and environmental correlations of total and regional brain volumes were estimated from a large, generally healthy, community-based sample, to determine if there are common elements to the genetic influence of brain volumes and white matter hyperintensity volume. There were 1538 Framingham Heart Study participants with brain volume measures from quantitative magnetic resonance imaging (MRI) who were free of stroke and other neurological disorders that might influence brain volumes and who were members of families with at least two Framingham Heart Study participants. Heritability was estimated using variance component methodology and adjusting for the components of the Framingham stroke risk profile. Genetic and environmental correlations between traits were obtained from bivariate analysis. Heritability estimates ranging from 0.46 to 0.60, were observed for total brain, white matter hyperintensity, hippocampal, temporal lobe, and lateral ventricular volumes. Moderate, yet significant, heritability was observed for the other measures. Bivariate analyses demonstrated that relationships between brain volume measures, except for white matter hyperintensity, reflected both moderate to strong shared genetic and shared environmental influences. This study confirms strong genetic effects on brain and white matter hyperintensity volumes. These data extend current knowledge by showing that these two different types of MRI measures do not share underlying genetic or environmental influences. PMID:19812462

  6. Role of Prion Replication in the Strain-dependent Brain Regional Distribution of Prions.

    PubMed

    Hu, Ping Ping; Morales, Rodrigo; Duran-Aniotz, Claudia; Moreno-Gonzalez, Ines; Khan, Uffaf; Soto, Claudio

    2016-06-10

    One intriguing feature of prion diseases is their strain variation. Prion strains are differentiated by the clinical consequences they generate in the host, their biochemical properties, and their potential to infect other animal species. The selective targeting of these agents to specific brain structures have been extensively used to characterize prion strains. However, the molecular basis dictating strain-specific neurotropism are still elusive. In this study, isolated brain structures from animals infected with four hamster prion strains (HY, DY, 139H, and SSLOW) were analyzed for their content of protease-resistant PrP(Sc) Our data show that these strains have different profiles of PrP deposition along the brain. These patterns of accumulation, which were independent of regional PrP(C) production, were not reproduced by in vitro replication when different brain regions were used as substrate for the misfolding-amplification reaction. On the contrary, our results show that in vitro replication efficiency depended exclusively on the amount of PrP(C) present in each part of the brain. Our results suggest that the variable regional distribution of PrP(Sc) in distinct strains is not determined by differences on prion formation, but on other factors or cellular pathways. Our findings may contribute to understand the molecular mechanisms of prion pathogenesis and strain diversity.

  7. Altered regional homogeneity of spontaneous brain activity in idiopathic trigeminal neuralgia

    PubMed Central

    Wang, Yanping; Zhang, Xiaoling; Guan, Qiaobing; Wan, Lihong; Yi, Yahui; Liu, Chun-Feng

    2015-01-01

    The pathophysiology of idiopathic trigeminal neuralgia (ITN) has conventionally been thought to be induced by neurovascular compression theory. Recent structural brain imaging evidence has suggested an additional central component for ITN pathophysiology. However, far less attention has been given to investigations of the basis of abnormal resting-state brain activity in these patients. The objective of this study was to investigate local brain activity in patients with ITN and its correlation with clinical variables of pain. Resting-state functional magnetic resonance imaging data from 17 patients with ITN and 19 age- and sex-matched healthy controls were analyzed using regional homogeneity (ReHo) analysis, which is a data-driven approach used to measure the regional synchronization of spontaneous brain activity. Patients with ITN had decreased ReHo in the left amygdala, right parahippocampal gyrus, and left cerebellum and increased ReHo in the right inferior temporal gyrus, right thalamus, right inferior parietal lobule, and left postcentral gyrus (corrected). Furthermore, the increase in ReHo in the left precentral gyrus was positively correlated with visual analog scale (r=0.54; P=0.002). Our study found abnormal functional homogeneity of intrinsic brain activity in several regions in ITN, suggesting the maladaptivity of the process of daily pain attacks and a central role for the pathophysiology of ITN. PMID:26508861

  8. Octave effect in auditory attention.

    PubMed

    Borra, Tobias; Versnel, Huib; Kemner, Chantal; van Opstal, A John; van Ee, Raymond

    2013-09-17

    After hearing a tone, the human auditory system becomes more sensitive to similar tones than to other tones. Current auditory models explain this phenomenon by a simple bandpass attention filter. Here, we demonstrate that auditory attention involves multiple pass-bands around octave-related frequencies above and below the cued tone. Intriguingly, this "octave effect" not only occurs for physically presented tones, but even persists for the missing fundamental in complex tones, and for imagined tones. Our results suggest neural interactions combining octave-related frequencies, likely located in nonprimary cortical regions. We speculate that this connectivity scheme evolved from exposure to natural vibrations containing octave-related spectral peaks, e.g., as produced by vocal cords.

  9. Fluoxetine pretreatment promotes neuronal survival and maturation after auditory fear conditioning in the rat amygdala.

    PubMed

    Jiang, Lizhu; Liu, Chen; Tong, Jianbin; Mao, Rongrong; Chen, Dan; Wang, Hui; Huang, Jufang; Li, Lingjiang

    2014-01-01

    The amygdala is a critical brain region for auditory fear conditioning, which is a stressful condition for experimental rats. Adult neurogenesis in the dentate gyrus (DG) of the hippocampus, known to be sensitive to behavioral stress and treatment of the antidepressant fluoxetine (FLX), is involved in the formation of hippocampus-dependent memories. Here, we investigated whether neurogenesis also occurs in the amygdala and contributes to auditory fear memory. In rats showing persistent auditory fear memory following fear conditioning, we found that the survival of new-born cells and the number of new-born cells that differentiated into mature neurons labeled by BrdU and NeuN decreased in the amygdala, but the number of cells that developed into astrocytes labeled by BrdU and GFAP increased. Chronic pretreatment with FLX partially rescued the reduction in neurogenesis in the amygdala and slightly suppressed the maintenance of the long-lasting auditory fear memory 30 days after the fear conditioning. The present results suggest that adult neurogenesis in the amygdala is sensitive to antidepressant treatment and may weaken long-lasting auditory fear memory.

  10. Music training relates to the development of neural mechanisms of selective auditory attention.

    PubMed

    Strait, Dana L; Slater, Jessica; O'Connell, Samantha; Kraus, Nina

    2015-04-01

    Selective attention decreases trial-to-trial variability in cortical auditory-evoked activity. This effect increases over the course of maturation, potentially reflecting the gradual development of selective attention and inhibitory control. Work in adults indicates that music training may alter the development of this neural response characteristic, especially over brain regions associated with executive control: in adult musicians, attention decreases variability in auditory-evoked responses recorded over prefrontal cortex to a greater extent than in nonmusicians. We aimed to determine whether this musician-associated effect emerges during childhood, when selective attention and inhibitory control are under development. We compared cortical auditory-evoked variability to attended and ignored speech streams in musicians and nonmusicians across three age groups: preschoolers, school-aged children and young adults. Results reveal that childhood music training is associated with reduced auditory-evoked response variability recorded over prefrontal cortex during selective auditory attention in school-aged child and adult musicians. Preschoolers, on the other hand, demonstrate no impact of selective attention on cortical response variability and no musician distinctions. This finding is consistent with the gradual emergence of attention during this period and may suggest no pre-existing differences in this attention-related cortical metric between children who undergo music training and those who do not.

  11. Reduction of variance in measurements of average metabolite concentration in anatomically-defined brain regions

    NASA Astrophysics Data System (ADS)

    Larsen, Ryan J.; Newman, Michael; Nikolaidis, Aki

    2016-11-01

    Multiple methods have been proposed for using Magnetic Resonance Spectroscopy Imaging (MRSI) to measure representative metabolite concentrations of anatomically-defined brain regions. Generally these methods require spectral analysis, quantitation of the signal, and reconciliation with anatomical brain regions. However, to simplify processing pipelines, it is practical to only include those corrections that significantly improve data quality. Of particular importance for cross-sectional studies is knowledge about how much each correction lowers the inter-subject variance of the measurement, thereby increasing statistical power. Here we use a data set of 72 subjects to calculate the reduction in inter-subject variance produced by several corrections that are commonly used to process MRSI data. Our results demonstrate that significant reductions of variance can be achieved by performing water scaling, accounting for tissue type, and integrating MRSI data over anatomical regions rather than simply assigning MRSI voxels with anatomical region labels.

  12. Regional anatomy of the pedunculopontine nucleus: relevance for deep brain stimulation.

    PubMed

    Fournier-Gosselin, Marie-Pierre; Lipsman, Nir; Saint-Cyr, Jean A; Hamani, Clement; Lozano, Andres M

    2013-09-01

    The pedunculopontine nucleus (PPN) is currently being investigated as a potential deep brain stimulation target to improve gait and posture in Parkinson's disease. This review examines the complex anatomy of the PPN region and suggests a functional mapping of the surrounding nuclei and fiber tracts that may serve as a guide to a more accurate placement of electrodes while avoiding potentially adverse effects. The relationships of the PPN were examined in different human brain atlases. Schematic representations of those structures in the vicinity of the PPN were generated and correlated with their potential stimulation effects. By providing a functional map and representative schematics of the PPN region, we hope to optimize the placement of deep brain stimulation electrodes, thereby maximizing safety and clinical efficacy.

  13. Visual influences on auditory spatial learning

    PubMed Central

    King, Andrew J.

    2008-01-01

    The visual and auditory systems frequently work together to facilitate the identification and localization of objects and events in the external world. Experience plays a critical role in establishing and maintaining congruent visual–auditory associations, so that the different sensory cues associated with targets that can be both seen and heard are synthesized appropriately. For stimulus location, visual information is normally more accurate and reliable and provides a reference for calibrating the perception of auditory space. During development, vision plays a key role in aligning neural representations of space in the brain, as revealed by the dramatic changes produced in auditory responses when visual inputs are altered, and is used throughout life to resolve short-term spatial conflicts between these modalities. However, accurate, and even supra-normal, auditory localization abilities can be achieved in the absence of vision, and the capacity of the mature brain to relearn to localize sound in the presence of substantially altered auditory spatial cues does not require visuomotor feedback. Thus, while vision is normally used to coordinate information across the senses, the neural circuits responsible for spatial hearing can be recalibrated in a vision-independent fashion. Nevertheless, early multisensory experience appears to be crucial for the emergence of an ability to match signals from different sensory modalities and therefore for the outcome of audiovisual-based rehabilitation of deaf patients in whom hearing has been restored by cochlear implantation. PMID:18986967

  14. McGurk illusion recalibrates subsequent auditory perception.

    PubMed

    Lüttke, Claudia S; Ekman, Matthias; van Gerven, Marcel A J; de Lange, Floris P

    2016-09-09

    Visual information can alter auditory perception. This is clearly illustrated by the well-known McGurk illusion, where an auditory/aba/ and a visual /aga/ are merged to the percept of 'ada'. It is less clear however whether such a change in perception may recalibrate subsequent perception. Here we asked whether the altered auditory perception due to the McGurk illusion affects subsequent auditory perception, i.e. whether this process of fusion may cause a recalibration of the auditory boundaries between phonemes. Participants categorized auditory and audiovisual speech stimuli as /aba/, /ada/ or /aga/ while activity patterns in their auditory cortices were recorded using fMRI. Interestingly, following a McGurk illusion, an auditory /aba/ was more often misperceived as 'ada'. Furthermore, we observed a neural counterpart of this recalibration in the early auditory cortex. When the auditory input /aba/ was perceived as 'ada', activity patterns bore stronger resemblance to activity patterns elicited by /ada/ sounds than when they were correctly perceived as /aba/. Our results suggest that upon experiencing the McGurk illusion, the brain shifts the neural representation of an /aba/ sound towards /ada/, culminating in a recalibration in perception of subsequent auditory input.

  15. McGurk illusion recalibrates subsequent auditory perception

    PubMed Central

    Lüttke, Claudia S.; Ekman, Matthias; van Gerven, Marcel A. J.; de Lange, Floris P.

    2016-01-01

    Visual information can alter auditory perception. This is clearly illustrated by the well-known McGurk illusion, where an auditory/aba/ and a visual /aga/ are merged to the percept of ‘ada’. It is less clear however whether such a change in perception may recalibrate subsequent perception. Here we asked whether the altered auditory perception due to the McGurk illusion affects subsequent auditory perception, i.e. whether this process of fusion may cause a recalibration of the auditory boundaries between phonemes. Participants categorized auditory and audiovisual speech stimuli as /aba/, /ada/ or /aga/ while activity patterns in their auditory cortices were recorded using fMRI. Interestingly, following a McGurk illusion, an auditory /aba/ was more often misperceived as ‘ada’. Furthermore, we observed a neural counterpart of this recalibration in the early auditory cortex. When the auditory input /aba/ was perceived as ‘ada’, activity patterns bore stronger resemblance to activity patterns elicited by /ada/ sounds than when they were correctly perceived as /aba/. Our results suggest that upon experiencing the McGurk illusion, the brain shifts the neural representation of an /aba/ sound towards /ada/, culminating in a recalibration in perception of subsequent auditory input. PMID:27611960

  16. Human auditory neuroimaging of intensity and loudness.

    PubMed

    Uppenkamp, Stefan; Röhl, Markus

    2014-01-01

    The physical intensity of a sound, usually expressed in dB on a logarithmic ratio scale, can easily be measured using technical equipment. Loudness is the perceptual correlate of sound intensity, and is usually determined by means of some sort of psychophysical scaling procedure. The interrelation of sound intensity and perceived loudness is still a matter of debate, and the physiological correlate of loudness perception in the human auditory pathway is not completely understood. Various studies indicate that the activation in human auditory cortex is more a representation of loudness sensation rather than of physical sound pressure level. This raises the questions (1), at what stage or stages in the ascending auditory pathway is the transformation of the physical stimulus into its perceptual correlate completed, and (2), to what extent other factors affecting individual loudness judgements might modulate the brain activation as registered by auditory neuroimaging. An overview is given about recent studies on the effects of sound intensity, duration, bandwidth and individual hearing status on the activation in the human auditory system, as measured by various approaches in auditory neuroimaging. This article is part of a Special Issue entitled Human Auditory Neuroimaging.

  17. Cognitive control of drug craving inhibits brain reward regions in cocaine abusers

    SciTech Connect

    Volkow, N.D.; Fowler, J.; Wang, G.J.; Telang, F.; Logan, J.; Jayne, M.; Ma, Y.; Pradhan, K.; Wong, C.T.; Swanson, J.M.

    2010-01-01

    Loss of control over drug taking is considered a hallmark of addiction and is critical in relapse. Dysfunction of frontal brain regions involved with inhibitory control may underlie this behavior. We evaluated whether addicted subjects when instructed to purposefully control their craving responses to drug-conditioned stimuli can inhibit limbic brain regions implicated in drug craving. We used PET and 2-deoxy-2[18F]fluoro-D-glucose to measure brain glucose metabolism (marker of brain function) in 24 cocaine abusers who watched a cocaine-cue video and compared brain activation with and without instructions to cognitively inhibit craving. A third scan was obtained at baseline (without video). Statistical parametric mapping was used for analysis and corroborated with regions of interest. The cocaine-cue video increased craving during the no-inhibition condition (pre 3 {+-} 3, post 6 {+-} 3; p < 0.001) but not when subjects were instructed to inhibit craving (pre 3 {+-} 2, post 3 {+-} 3). Comparisons with baseline showed visual activation for both cocaine-cue conditions and limbic inhibition (accumbens, orbitofrontal, insula, cingulate) when subjects purposefully inhibited craving (p < 0.001). Comparison between cocaine-cue conditions showed lower metabolism with cognitive inhibition in right orbitofrontal cortex and right accumbens (p < 0.005), which was associated with right inferior frontal activation (r = -0.62, p < 0.005). Decreases in metabolism in brain regions that process the predictive (nucleus accumbens) and motivational value (orbitofrontal cortex) of drug-conditioned stimuli were elicited by instruction to inhibit cue-induced craving. This suggests that cocaine abusers may retain some ability to inhibit craving and that strengthening fronto-accumbal regulation may be therapeutically beneficial in addiction.

  18. Decreased auditory GABA+ concentrations in presbycusis demonstrated by edited magnetic resonance spectroscopy.

    PubMed

    Gao, Fei; Wang, Guangbin; Ma, Wen; Ren, Fuxin; Li, Muwei; Dong, Yuling; Liu, Cheng; Liu, Bo; Bai, Xue; Zhao, Bin; Edden, Richard A E

    2015-02-01

    Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the central auditory system. Altered GABAergic neurotransmission has been found in both the inferior colliculus and the auditory cortex in animal models of presbycusis. Edited magnetic resonance spectroscopy (MRS), using the MEGA-PRESS sequence, is the most widely used technique for detecting GABA in the human brain. However, to date there has been a paucity of studies exploring changes to the GABA concentrations in the auditory region of patients with presbycusis. In this study, sixteen patients with presbycusis (5 males/11 females, mean age 63.1 ± 2.6 years) and twenty healthy controls (6 males/14 females, mean age 62.5 ± 2.3 years) underwent audiological and MRS examinations. Pure tone audiometry from 0.125 to 8 kHz and tympanometry were used to assess the hearing abilities of all subjects. The pure tone average (PTA; the average of hearing thresholds at 0.5, 1, 2 and 4 kHz) was calculated. The MEGA-PRESS sequence was used to measure GABA+ concentrations in 4 × 3 × 3 cm(3) volumes centered on the left and right Heschl's gyri. GABA+ concentrations were significantly lower in the presbycusis group compared to the control group (left auditory regions: p = 0.002, right auditory regions: p = 0.008). Significant negative correlations were observed between PTA and GABA+ concentrations in the presbycusis group (r = -0.57, p = 0.02), while a similar trend was found in the control group (r = -0.40, p = 0.08). These results are consistent with a hypothesis of dysfunctional GABAergic neurotransmission in the central auditory system in presbycusis and suggest a potential treatment target for presbycusis.

  19. Age-and Brain Region-Specific Differences in Mitochondrial Bioenergetics in Brown Norway Rats

    EPA Science Inventory

    Mitochondria are central regulators of energy homeostasis and play a pivotal role in mechanisms of cellular senescence. The objective of the present study was to evaluate mitochondrial bio­-energetic parameters in five brain regions [brainstem (BS), frontal cortex (FC), cereb...

  20. Comparison of Regional Brain Perfusion Levels in Chronically Smoking and Non-Smoking Adults

    PubMed Central

    Durazzo, Timothy C.; Meyerhoff, Dieter J.; Murray, Donna E.

    2015-01-01

    Chronic cigarette smoking is associated with numerous abnormalities in brain neurobiology, but few studies specifically investigated the chronic effects of smoking (compared to the acute effects of smoking, nicotine administration, or nicotine withdrawal) on cerebral perfusion (i.e., blood flow). Predominately middle-aged male (47 ± 11 years of age) smokers (n = 34) and non-smokers (n = 27) were compared on regional cortical perfusion measured by continuous arterial spin labeling magnetic resonance studies at 4 Tesla. Smokers showed significantly lower perfusion than non-smokers in the bilateral medial and lateral orbitofrontal cortices, bilateral inferior parietal lobules, bilateral superior temporal gyri, left posterior cingulate, right isthmus of cingulate, and right supramarginal gyrus. Greater lifetime duration of smoking (adjusted for age) was related to lower perfusion in multiple brain regions. The results indicated smokers showed significant perfusion deficits in anterior cortical regions implicated in the development, progression, and maintenance of all addictive disorders. Smokers concurrently demonstrated reduced blood flow in posterior brain regions that show morphological and metabolic aberrations as well as elevated beta amyloid deposition demonstrated by those with early stage Alzheimer disease. The findings provide additional novel evidence of the adverse effects of cigarette smoking on the human brain. PMID:26193290

  1. Identifying dysfunctional crosstalk of pathways in various regions of Alzheimer's disease brains

    PubMed Central

    2010-01-01

    Background Alzheimer's disease (AD) is a major neurodegenerative disorder leading to amnesia, cognitive impairment and dementia in the elderly. Usually this type of lesions results from dysfunctional protein cooperations in the biological pathways. In addition, AD progression is known to occur in different brain regions with particular features. Thus identification and analysis of crosstalk among dysregulated pathways as well as identification of their clusters in various diseased brain regions are expected to provide deep insights into the pathogenetic mechanism. Results Here we propose a network-based systems biology approach to detect the crosstalks among AD related pathways, as well as their dysfunctions in the six brain regions of AD patients. Through constructing a network of pathways, the relationships among AD pathway and its neighbor pathways are systematically investigated and visually presented by their intersections. We found that the significance degree of pathways related to the fatal disorders and the pathway overlapping strength can indicate the impacts of these neighbored pathways to AD development. Furthermore, the crosstalks among pathways reveal some evidence that the neighbor pathways of AD pathway closely cooperate and play important tasks in the AD progression. Conclusions Our study identifies the common and distinct features of the dysfunctional crosstalk of pathways in various AD brain regions. The global pathway crosstalk network and the clusters of relevant pathways of AD provide evidence of cooperativity among pathways for potential pathogenesis of the neuron complex disease. PMID:20840725

  2. Functional Connectivity between Brain Regions Involved in Learning Words of a New Language

    ERIC Educational Resources Information Center

    Veroude, Kim; Norris, David G.; Shumskaya, Elena; Gullberg, Marianne; Indefrey, Peter

    2010-01-01

    Previous studies have identified several brain regions that appear to be involved in the acquisition of novel word forms. Standard word-by-word presentation is often used although exposure to a new language normally occurs in a natural, real world situation. In the current experiment we investigated naturalistic language exposure and applied a…

  3. Delineation of separate brain regions used for scientific versus engineering modes of thinking

    NASA Astrophysics Data System (ADS)

    Patterson, Clair C.

    1994-08-01

    Powerful, latent abilities for extreme sophistication in abstract rationalization as potential biological adaptive behavioral responses were installed entirely through accident and inadvertence by biological evolution in the Homo sapiens sapiens species of brain. These potentials were never used, either in precursor species as factors in evolutionary increase in hominid brain mass, nor in less sophisticated forms within social environments characterized by Hss tribal brain population densities. Those latent abilities for unnatural biological adaptive behavior were forced to become manifest in various ways by growths in sophistication of communication interactions engendered by large growths in brain population densities brought on by developments in agriculture at the onset of the Holocene. It is proposed that differences probably exist between regions of the Hss brain involved in utilitarian, engineering types of problem conceptualization-solving versus regions of the brain involved in nonutilitarian, artistic-scientific types of problem conceptualization-solving. Populations isolated on separate continents from diffusive contact and influence on cultural developments, and selected for comparison of developments during equivalent stages of technological and social sophistication in matching 4000 year periods, show, at the ends of those periods, marked differences in aesthetic attributes expressed in cosmogonies, music, and writing (nonutilitarian thinking related to science and art). On the other hand the two cultures show virtually identical developments in three major stages of metallurgical technologies (utilitarian thinking related to engineering). Such archaeological data suggest that utilitarian modes of thought may utilize combinations of neuronal circuits in brain regions that are conserved among tribal populations territorially separated from each other for tens of thousands of years. Such conservation may not be true for neuronal circuits involved in

  4. Preserved pontine glucose metabolism in Alzheimer disease: A reference region for functional brain image (PET) analysis

    SciTech Connect

    Minoshima, Satoshi; Frey, K.A.; Foster, N.L.; Kuhl, D.W.

    1995-07-01

    Our goal was to examine regional preservation of energy metabolism in Alzheimer disease (AD) and to evaluate effects of PET data normalization to reference regions. Regional metabolic rates in the pons, thalamus, putamen, sensorimotor cortex, visual cortex, and cerebellum (reference regions) were determined stereotaxically and examined in 37 patients with probable AD and 22 normal controls based on quantitative {sup 18}FDG-PET measurements. Following normalization of metabolic rates of the parietotemporal association cortex and whole brain to each reference region, distinctions of the two groups were assessed. The pons showed the best preservation of glucose metabolism in AD. Other reference regions showed relatively preserved metabolism compared with the parietotemporal association cortex and whole brain, but had significant metabolic reduction. Data normalization to the pons not only enhanced statistical significance of metabolic reduction in the parietotemporal association cortex, but also preserved the presence of global cerebral metabolic reduction indicated in analysis of the quantitative data. Energy metabolism in the pons in probable AD is well preserved. The pons is a reliable reference for data normalization and will enhance diagnostic accuracy and efficiency of quantitative and nonquantitative functional brain imaging. 39 refs., 2 figs., 3 tabs.

  5. Auditory and visual cortex of primates: a comparison of two sensory systems

    PubMed Central

    Rauschecker, Josef P.

    2014-01-01

    A comparative view of the brain, comparing related functions across species and sensory systems, offers a number of advantages. In particular, it allows separating the formal purpose of a model structure from its implementation in specific brains. Models of auditory cortical processing can be conceived by analogy to the visual cortex, incorporating neural mechanisms that are found in both the visual and auditory systems. Examples of such canonical features on the columnar level are direction selectivity, size/bandwidth selectivity, as well as receptive fields with segregated versus overlapping on- and off-sub-regions. On a larger scale, parallel processing pathways have been envisioned that represent the two main facets of sensory perception: 1) identification of objects and 2) processing of space. Expanding this model in terms of sensorimotor integration and control offers an overarching view of cortical function independent of sensory modality. PMID:25728177

  6. Common and specific brain regions in high- versus low-confidence recognition memory.

    PubMed

    Kim, Hongkeun; Cabeza, Roberto

    2009-07-28

    The goal of the present functional magnetic resonance imaging (fMRI) study was to investigate whether and to what extent brain regions involved in high-confidence recognition (HCR) versus low-confidence recognition (LCR) overlap or separate from each other. To this end, we performed conjunction analyses involving activations elicited during high-confidence hit, low-confidence hit, and high-confidence correct rejection responses. The analyses yielded 3 main findings. First, sensory/perceptual and associated posterior regions were common to HCR and LCR, indicating contribution of these regions to both HCR and LCR activity. This finding may help explain why these regions are among the most common in functional neuroimaging studies of episodic retrieval. Second, medial temporal lobe (MTL) and associated midline regions were associated with HCR, possibly reflecting recollection-related processes, whereas specific prefrontal cortex (PFC) regions were associated with LCR, possibly reflecting executive control processes. This finding is consistent with the notion that the MTL and PFC networks play complementary roles during episodic retrieval. Finally, within posterior parietal cortex, a dorsal region was associated with LCR, possibly reflecting top-down attentional processes, whereas a ventral region was associated with HCR, possibly reflecting bottom-up attentional processes. This finding may help explain why functional neuroimaging studies have found diverse parietal effects during episodic retrieval. Taken together, our findings provide strong evidence that HCR versus LCR, and by implication, recollection versus familiarity processes, are represented in common as well as specific brain regions.

  7. Serotonin regulates brain-derived neurotrophic factor expression in select brain regions during acute psychological stress

    PubMed Central

    Jiang, De-guo; Jin, Shi-li; Li, Gong-ying; Li, Qing-qing; Li, Zhi-ruo; Ma, Hong-xia; Zhuo, Chuan-jun; Jiang, Rong-huan; Ye, Min-jie

    2016-01-01

    Previous studies suggest that serotonin (5-HT) might interact with brain-derived neurotrophic factor (BDNF) during the stress response. However, the relationship between 5-HT and BDNF expression under purely psychological stress is unclear. In this study, one hour before psychological stress exposure, the 5-HT1A receptor agonist 8-OH-DPAT or antagonist MDL73005, or the 5-HT2A receptor agonist DOI or antagonist ketanserin were administered to rats exposed to psychological stress. Immunohistochemistry and in situ hybridization revealed that after psychological stress, with the exception of the ventral tegmental area, BDNF protein and mRNA expression levels were higher in the 5-HT1A and the 5-HT2A receptor agonist groups compared with the solvent control no-stress or psychological stress group in the CA1 and CA3 of the hippocampus, prefrontal cortex, central amygdaloid nucleus, dorsomedial hypothalamic nucleus, dentate gyrus, shell of the nucleus accumbens and the midbrain periaqueductal gray. There was no significant difference between the two agonist groups. In contrast, after stress exposure, BDNF protein and mRNA expression levels were lower in the 5-HT1A and 5-HT2A receptor antagonist groups than in the solvent control non-stress group, with the exception of the ventral tegmental area. Our findings suggest that 5-HT regulates BDNF expression in a rat model of acute psychological stress. PMID:27857753

  8. Serotonin regulates brain-derived neurotrophic factor expression in select brain regions during acute psychological stress.

    PubMed

    Jiang, De-Guo; Jin, Shi-Li; Li, Gong-Ying; Li, Qing-Qing; Li, Zhi-Ruo; Ma, Hong-Xia; Zhuo, Chuan-Jun; Jiang, Rong-Huan; Ye, Min-Jie

    2016-09-01

    Previous studies suggest that serotonin (5-HT) might interact with brain-derived neurotrophic factor (BDNF) during the stress response. However, the relationship between 5-HT and BDNF expression under purely psychological stress is unclear. In this study, one hour before psychological stress exposure, the 5-HT1A receptor agonist 8-OH-DPAT or antagonist MDL73005, or the 5-HT2A receptor agonist DOI or antagonist ketanserin were administered to rats exposed to psychological stress. Immunohistochemistry and in situ hybridization revealed that after psychological stress, with the exception of the ventral tegmental area, BDNF protein and mRNA expression levels were higher in the 5-HT1A and the 5-HT2A receptor agonist groups compared with the solvent control no-stress or psychological stress group in the CA1 and CA3 of the hippocampus, prefrontal cortex, central amygdaloid nucleus, dorsomedial hypothalamic nucleus, dentate gyrus, shell of the nucleus accumbens and the midbrain periaqueductal gray. There was no significant difference between the two agonist groups. In contrast, after stress exposure, BDNF protein and mRNA expression levels were lower in the 5-HT1A and 5-HT2A receptor antagonist groups than in the solvent control non-stress group, with the exception of the ventral tegmental area. Our findings suggest that 5-HT regulates BDNF expression in a rat model of acute psychological stress.

  9. Neuromodulatory Effects of Auditory Training and Hearing Aid Use on Audiovisual Speech Perception in Elderly Individuals

    PubMed Central

    Yu, Luodi; Rao, Aparna; Zhang, Yang; Burton, Philip C.; Rishiq, Dania; Abrams, Harvey

    2017-01-01

    Although audiovisual (AV) training has been shown to improve overall speech perception in hearing-impaired listeners, there has been a lack of direct brain imaging data to help elucidate the neural networks and neural plasticity associated with hearing aid (HA) use and auditory training targeting speechreading. For this purpose, the current clinical case study reports functional magnetic resonance imaging (fMRI) data from two hearing-impaired patients who were first-time HA users. During the study period, both patients used HAs for 8 weeks; only one received a training program named ReadMyQuipsTM (RMQ) targeting speechreading during the second half of the study period for 4 weeks. Identical fMRI tests were administered at pre-fitting and at the end of the 8 weeks. Regions of interest (ROI) including auditory cortex and visual cortex for uni-sensory processing, and superior temporal sulcus (STS) for AV integration, were identified for each person through independent functional localizer task. The results showed experience-dependent changes involving ROIs of auditory cortex, STS and functional connectivity between uni-sensory ROIs and STS from pretest to posttest in both cases. These data provide initial evidence for the malleable experience-driven cortical functionality for AV speech perception in elderly hearing-impaired people and call for further studies with a much larger subject sample and systematic control to fill in the knowledge gap to understand brain plasticity associated with auditory rehabilitation in the aging population. PMID:28270763

  10. Functional approach using intraoperative brain mapping and neurophysiological monitoring for the surgical treatment of brain metastases in the central region.

    PubMed

    Sanmillan, Jose L; Fernández-Coello, Alejandro; Fernández-Conejero, Isabel; Plans, Gerard; Gabarrós, Andreu

    2017-03-01

    OBJECTIVE Brain metastases are the most frequent intracranial malignant tumor in adults. Surgical intervention for metastases in eloquent areas remains controversial and challenging. Even when metastases are not infiltrating intra-parenchymal tumors, eloquent areas can be affected. Therefore, this study aimed to describe the role of a functional guided approach for the resection of brain metastases in the central region. METHODS Thirty-three patients (19 men and 14 women) with perirolandic metastases who were treated at the authors' institution were reviewed. All participants underwent resection using a functional guided approach, which consisted of using intraoperative brain mapping and/or neurophysiological monitoring to aid in the resection, depending on the functionality of the brain parenchyma surrounding each metastasis. Motor and sensory functions were monitored in all patients, and supplementary motor and language area functions were assessed in 5 and 4 patients, respectively. Clinical data were analyzed at presentation, discharge, and the 6-month follow-up. RESULTS The most frequent presenting symptom was seizure, followed by paresis. Gross-total removal of the metastasis was achieved in 31 patients (93.9%). There were 6 deaths during the follow-up period. After the removal of the metastasis, 6 patients (18.2%) presented with transient neurological worsening, of whom 4 had worsening of motor function impairment and 2 had acquired new sensory disturbances. Total recovery was achieved before the 3rd month of follow-up in all cases. Excluding those patients who died due to the progression of systemic illness, 88.9% of patients had a Karnofsky Performance Scale score greater than 80% at the 6-month follow-up. The mean survival time was 24.4 months after surgery. CONCLUSIONS The implementation of intraoperative electrical brain stimulation techniques in the resection of central region metastases may improve surgical planning and resection and may spare eloquent

  11. The oscillatory activities and its synchronization in auditory-visual integration as revealed by event-related potentials to bimodal stimuli

    NASA Astrophysics Data System (ADS)

    Guo, Jia; Xu, Peng; Yao, Li; Shu, Hua; Zhao, Xiaojie

    2012-03-01

    Neural mechanism of auditory-visual speech integration is always a hot study of multi-modal perception. The articulation conveys speech information that helps detect and disambiguate the auditory speech. As important characteristic of EEG, oscillations and its synchronization have been applied to cognition research more and more. This study analyzed the EEG data acquired by unimodal and bimodal stimuli using time frequency and phase synchrony approach, investigated the oscillatory activities and its synchrony modes behind evoked potential during auditory-visual integration, in order to reveal the inherent neural integration mechanism under these modes. It was found that beta activity and its synchronization differences had relationship with gesture N1-P2, which happened in the earlier stage of speech coding to pronouncing action. Alpha oscillation and its synchronization related with auditory N1-P2 might be mainly responsible for auditory speech process caused by anticipation from gesture to sound feature. The visual gesture changing enhanced the interaction of auditory brain regions. These results provided explanations to the power and connectivity change of event-evoked oscillatory activities which matched ERPs during auditory-visual speech integration.

  12. Altered regional connectivity reflecting effects of different anaesthesia protocols in the mouse brain.

    PubMed

    Wu, Tong; Grandjean, Joanes; Bosshard, Simone C; Rudin, Markus; Reutens, David; Jiang, Tianzi

    2017-04-01

    Studies in mice using resting-state functional magnetic resonance imaging (rs-fMRI) have provided opportunities to investigate the effects of pharmacological manipulations on brain function and map the phenotypes of mouse models of human brain disorders. Mouse rs-fMRI is typically performed under anaesthesia, which induces both regional suppression of brain activity and disruption of large-scale neural networks. Previous comparative studies using rodents investigating various drug effects on long-distance functional connectivity (FC) have reported agent-specific FC patterns, however, effects of regional suppression are sparsely explored. Here we examined changes in regional connectivity under six different anaesthesia conditions using mouse rs-fMRI with the goal of refining the framework of understanding the brain activation under anaesthesia at a local level. Regional homogeneity (ReHo) was used to map local synchronization in the brain, followed by analysis of several brain areas based on ReHo maps. The results revealed high local coherence in most brain areas. The primary somatosensory cortex and caudate-putamen showed agent-specific properties. Lower local coherence in the cingulate cortex was observed under medetomidine, particularly when compared to the combination of medetomidine and isoflurane. The thalamus was associated with retained local coherence across anaesthetic levels and multiple nuclei. These results show that anaesthesia induced by the investigated anaesthetics through different molecular targets promote agent-specific regional connectivity. In addition, ReHo is a data-driven method with minimum user interaction, easy to use and fast to compute. Given that examination of the brain at a local level is widely applied in human rs-fMRI studies, our results show its sensitivity to extract information on varied neuronal activity under six different regimens relevant to mouse functional imaging. These results, therefore, will inform future rs

  13. Areas activated during naturalistic reading comprehension overlap topological visual, auditory, and somatotomotor maps

    PubMed Central

    2016-01-01

    Abstract Cortical mapping techniques using fMRI have been instrumental in identifying the boundaries of topological (neighbor‐preserving) maps in early sensory areas. The presence of topological maps beyond early sensory areas raises the possibility that they might play a significant role in other cognitive systems, and that topological mapping might help to delineate areas involved in higher cognitive processes. In this study, we combine surface‐based visual, auditory, and somatomotor mapping methods with a naturalistic reading comprehension task in the same group of subjects to provide a qualitative and quantitative assessment of the cortical overlap between sensory‐motor maps in all major sensory modalities, and reading processing regions. Our results suggest that cortical activation during naturalistic reading comprehension overlaps more extensively with topological sensory‐motor maps than has been heretofore appreciated. Reading activation in regions adjacent to occipital lobe and inferior parietal lobe almost completely overlaps visual maps, whereas a significant portion of frontal activation for reading in dorsolateral and ventral prefrontal cortex overlaps both visual and auditory maps. Even classical language regions in superior temporal cortex are partially overlapped by topological visual and auditory maps. By contrast, the main overlap with somatomotor maps is restricted to a small region on the anterior bank of the central sulcus near the border between the face and hand representations of M‐I. Hum Brain Mapp 37:2784–2810, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. PMID:27061771

  14. Areas activated during naturalistic reading comprehension overlap topological visual, auditory, and somatotomotor maps.

    PubMed

    Sood, Mariam R; Sereno, Martin I

    2016-08-01

    Cortical mapping techniques using fMRI have been instrumental in identifying the boundaries of topological (neighbor-preserving) maps in early sensory areas. The presence of topological maps beyond early sensory areas raises the possibility that they might play a significant role in other cognitive systems, and that topological mapping might help to delineate areas involved in higher cognitive processes. In this study, we combine surface-based visual, auditory, and somatomotor mapping methods with a naturalistic reading comprehension task in the same group of subjects to provide a qualitative and quantitative assessment of the cortical overlap between sensory-motor maps in all major sensory modalities, and reading processing regions. Our results suggest that cortical activation during naturalistic reading comprehension overlaps more extensively with topological sensory-motor maps than has been heretofore appreciated. Reading activation in regions adjacent to occipital lobe and inferior parietal lobe almost completely overlaps visual maps, whereas a significant portion of frontal activation for reading in dorsolateral and ventral prefrontal cortex overlaps both visual and auditory maps. Even classical language regions in superior temporal cortex are partially overlapped by topological visual and auditory maps. By contrast, the main overlap with somatomotor maps is restricted to a small region on the anterior bank of the central sulcus near the border between the face and hand representations of M-I. Hum Brain Mapp 37:2784-2810, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  15. Motion sickness increases functional connectivity between visual motion and nausea-associated brain regions.

    PubMed

    Toschi, Nicola; Kim, Jieun; Sclocco, Roberta; Duggento, Andrea; Barbieri, Riccardo; Kuo, Braden; Napadow, Vitaly

    2017-01-01

    The