scholarly journals Development of neural responsivity to vocal sounds in higher level auditory cortex of songbirds

2014 ◽  
Vol 112 (1) ◽  
pp. 81-94 ◽  
Author(s):  
Vanessa C. Miller-Sims ◽  
Sarah W. Bottjer
Keyword(s):  
Auditory Cortex ◽  
Vocal Learning ◽  
Response Strength ◽  
Neural Mechanisms ◽  
Sensitive Period ◽  
Unexpected Result ◽  
Salient Stimulus ◽  
Evoked Activity ◽  
High Level ◽  
Persistent Response

Like humans, songbirds learn vocal sounds from “tutors” during a sensitive period of development. Vocal learning in songbirds therefore provides a powerful model system for investigating neural mechanisms by which memories of learned vocal sounds are stored. This study examined whether NCM (caudo-medial nidopallium), a region of higher level auditory cortex in songbirds, serves as a locus where a neural memory of tutor sounds is acquired during early stages of vocal learning. NCM neurons respond well to complex auditory stimuli, and evoked activity in many NCM neurons habituates such that the response to a stimulus that is heard repeatedly decreases to approximately one-half its original level (stimulus-specific adaptation). The rate of neural habituation serves as an index of familiarity, being low for familiar sounds, but high for novel sounds. We found that response strength across different song stimuli was higher in NCM neurons of adult zebra finches than in juveniles, and that only adult NCM responded selectively to tutor song. The rate of habituation across both tutor song and novel conspecific songs was lower in adult than in juvenile NCM, indicating higher familiarity and a more persistent response to song stimuli in adults. In juvenile birds that have memorized tutor vocal sounds, neural habituation was higher for tutor song than for a familiar conspecific song. This unexpected result suggests that the response to tutor song in NCM at this age may be subject to top-down influences that maintain the tutor song as a salient stimulus, despite its high level of familiarity.

scholarly journals Deficits in monitoring self-produced speech in Parkinson’s disease

2019 ◽  
Author(s):  
Henry Railo ◽  
Niklas Nokelainen ◽  
Saara Savolainen ◽  
Valtteri Kaasinen
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neural Mechanisms ◽  
Speech Impairment ◽  
Self Monitoring ◽  
Evoked Activity ◽  
And Control ◽  
N1 Wave ◽  
Electrophysiological Correlate

AbstractObjectiveSpeech deficits are common in Parkinson’s disease, and behavioural findings suggest that the deficits may be due to impaired monitoring of self-produced speech. The neural mechanisms of speech deficits are not well understood. We examined a well-documented electrophysiological correlate of speech self-monitoring in patients with Parkinson’s disease and control participants.MethodsWe measured evoked electroencephalographic responses to self-produced and passively heard sounds (/a/ phonemes) in age-matched controls (N=18), and Parkinson’s disease patients who had minor speech impairment, but reported subjectively experiencing no speech deficits (N=17).ResultsDuring speaking, auditory evoked activity 100 ms after phonation (N1 wave) was less suppressed in Parkinson’s disease than controls when compared to the activity evoked by passively heard phonemes. This difference between the groups was driven by increased amplitudes to self-produced phonemes, and reduced amplitudes passively heard phonemes in Parkinson’s disease.ConclusionsThe finding indicates that auditory evoked activity is abnormally modulated during speech in Parkinson’s patients who do not subjectively notice speech impairment. This mechanism could play a role in producing speech deficits in as the disease progresses.

Mental Mechanisms

Mind-Society ◽  
2019 ◽  
pp. 22-47
Author(s):  
Paul Thagard
Keyword(s):  
Cognitive Appraisal ◽  
Mental Representations ◽  
Special Kind ◽  
Neural Mechanisms ◽  
Emotional Information ◽  
Sensory Inputs ◽  
The World ◽  
Sensory Motor ◽  
Human Thinking ◽  
High Level

Psychological explanations based on representations and procedures can be deepened by showing how they emerge from neural mechanisms. Neurons represent aspects of the world by collective patterns of firing. These patterns can be bound into more complicated patterns that can transcend the limitations of sensory inputs. Semantic pointers are a special kind of representation that operates by binding neural patterns encompassing sensory, motor, verbal, and emotional information. The semantic pointer theory applies not only to the ordinary operations of mental representations like concepts and rules but also to the most high-level kinds of human thinking, including language, creativity, and consciousness. Semantic pointers also encompass emotions, construed as bindings that combine cognitive appraisal with physiological perception.

Spontaneous activity resembling tone-evoked activity in the primary auditory cortex of guinea pigs

2010 ◽  
Vol 68 (2) ◽  
pp. 107-113 ◽  
Author(s):  
Kazuya Saitoh ◽  
Shinji Inagaki ◽  
Masataka Nishimura ◽  
Hideo Kawaguchi ◽  
Wen-Jie Song
Keyword(s):  
Auditory Cortex ◽  
Spontaneous Activity ◽  
Guinea Pigs ◽  
Primary Auditory Cortex ◽  
Evoked Activity

Predictable tones elicit stimulus-specific suppression of evoked activity in auditory cortex

NeuroImage ◽  
2019 ◽  
Vol 200 ◽  
pp. 242-249 ◽  
Author(s):  
Biao Han ◽  
Pim Mostert ◽  
Floris P. de Lange
Keyword(s):  
Auditory Cortex ◽  
Specific Suppression ◽  
Evoked Activity

scholarly journals Level Dependence of Contextual Modulation in Auditory Cortex

2008 ◽  
Vol 99 (4) ◽  
pp. 1616-1627 ◽  
Author(s):  
Ben Scholl ◽  
Xiang Gao ◽  
Michael Wehr
Keyword(s):  
Auditory Cortex ◽  
Cortical Neurons ◽  
Receptive Fields ◽  
Stimulus Context ◽  
Contextual Modulation ◽  
Sensory Stimuli ◽  
Low Contrast ◽  
Low Level ◽  
High Level ◽  
Contextual Interactions

Responses of cortical neurons to sensory stimuli within their receptive fields can be profoundly altered by the stimulus context. In visual and somatosensory cortex, contextual interactions have been shown to change sign from facilitation to suppression depending on stimulus strength. Contextual modulation of high-contrast stimuli tends to be suppressive, but for low-contrast stimuli tends to be facilitative. This trade-off may optimize contextual integration by cortical cells and has been suggested to be a general feature of cortical processing, but it remains unknown whether a similar phenomenon occurs in auditory cortex. Here we used whole cell and single-unit recordings to investigate how contextual interactions in auditory cortical neurons depend on the relative intensity of masker and probe stimuli in a two-tone stimulus paradigm. We tested the hypothesis that relatively low-level probes should show facilitation, whereas relatively high-level probes should show suppression. We found that contextual interactions were primarily suppressive across all probe levels, and that relatively low-level probes were subject to stronger suppression than high-level probes. These results were virtually identical for spiking and subthreshold responses. This suggests that, unlike visual cortical neurons, auditory cortical neurons show maximal suppression rather than facilitation for relatively weak stimuli.

scholarly journals A Live, AttenuatedBordetella pertussisVaccine Provides Long-Term Protection against Virulent Challenge in a Murine Model

2010 ◽  
Vol 18 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Ciaran M. Skerry ◽  
Bernard P. Mahon
Keyword(s):  
Whooping Cough ◽  
Interleukin 17 ◽  
Vaccination Programs ◽  
Virulent Challenge ◽  
One Year ◽  
High Level ◽  
New Generation ◽  
Prior Infection ◽  
Persistent Response

ABSTRACTDespite successful mass vaccination programs, whooping cough remains a significant cause of neonatal mortality. Immunity induced by current vaccines wanes in adolescence, requiring additional immunizations to prevent resurgence. There is a need for a new generation of vaccines capable of conferring long-lasting immunity from birth. Recently, a live, attenuated whooping cough vaccine, BPZE1, has been developed. Here, an established murine immunization model was used to examine the induction and longevity of immunological memory. In this predictive model, BPZE1 conferred a level of protection against virulent bacterial challenge comparable to that conferred by recovery from prior infection, up to 1 year after immunization. One year after immunization with BPZE1, a pertussis-specific persistent response, with high levels of gamma interferon (IFN-γ), could be detected from spleen cells restimulated with inactivatedBordetella pertussis. BPZE1 induced low levels of interleukin-17 (IL-17) and no IL-10 or IL-5. BPZE1 immunization induced long-lasting, efficacious memory B-cell and specific antibody responses dominated by IgG2a, which were boosted by subsequent challenge. Finally, the antibody induced by BPZE1 was functionally relevant and could clear a virulentB. pertussisinfection in antibody-deficient mice following passive transfer. This study suggests that BPZE1 is capable of conferring a high level of long-lived effective protection against virulentB. pertussis.

Synopses from the poster exhibition organized by R. H. Pain 1. New very efficient antibiotics in the field of cephalosporin derivatives

1980 ◽  
Vol 289 (1036) ◽  
pp. 361-376 ◽  
Keyword(s):  
Antimicrobial Activity ◽  
Structural Features ◽  
Side Chain ◽  
Unexpected Result ◽  
Reaction Sequence ◽  
General Reaction ◽  
Gram Negative ◽  
High Level ◽  
Very High

The semi-synthetic cephalosporin derivatives containing a 2-(2-amino-4-thiazolyl)-2- syn -oxyiminoacetyl side chain are obtained according to the general reaction sequence outlined in figure 1. They are characterized by a very high level of antimicrobial activity, especially against Gram-negative species. This unexpected result is due to the conjunction of two structural features: the aminothiazolyl moiety and the syn -oxyimino substituent.

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