Octopus cells in the posteroventral cochlear nucleus provide the main excitatory input to the superior paraolivary nucleus

[EN]Auditory streaming enables perception and interpretation of complex acoustic environments that contain competing sound sources. At early stages of central processing, sounds are segregated into separate streams representing attributes that later merge into acoustic objects. Streaming of temporal cues is critical for perceiving vocal communication, such as human speech, but our understanding of circuits that underlie this process is lacking, particularly at subcortical levels. The superior paraolivary nucleus (SPON), a prominent group of inhibitory neurons in the mammalian brainstem, has been implicated in processing temporal information needed for the segmentation of ongoing complex sounds into discrete events. The SPON requires temporally precise and robust excitatory input(s) to convey information about the steep rise in sound amplitude that marks the onset of voiced sound elements. Unfortunately, the sources of excitation to the SPON and the impact of these inputs on the behavior of SPON neurons have yet to be resolved. Using anatomical tract tracing and immunohistochemistry, we identified octopus cells in the contralateral cochlear nucleus (CN) as the primary source of excitatory input to the SPON. Cluster analysis of miniature excitatory events also indicated that the majority of SPON neurons receive one type of excitatory input. Precise octopus cell-driven onset spiking coupled with transient offset spiking make SPON responses well-suited to signal transitions in sound energy contained in vocalizations. Targets of octopus cell projections, including the SPON, are strongly implicated in the processing of temporal sound features, which suggests a common pathway that conveys information critical for perception of complex natural sounds.Swedish Research Council (proyecto 80326601) Hörselskadades Riksförbund, Tysta Skolan, Karolinska Institutets fonder. The Wenner-Gren Foundations. French National Research Agency (ptoyecto ANR-15-CE37-0007-01). Consejo Nacional de Ciencia y Tecnología de México (proyecto 665699). Instituto de Salud Carlos III (proyecto PI10/01803). Ministerio de Economía y Competitividad (proyectos BFU2013-43608-P y SAF2016-75803-P). Junta de Castilla y León (proyecto SA343U14)

Age-related Changes in Auditory Cortex Without Detectable Peripheral Alterations: A Multi-level Study in Sprague–Dawley Rats

International audienceAging is often considered to affect both the peripheral (i.e. the cochlea) and central (brainstem and thalamus-cortex) auditory systems. We investigated the effects of aging on the cochlea, brainstem and cortex of female Sprague-Dawley rats. The auditory nerve threshold remained stable between the ages of nine and 21 months, as did distortion product otoa-coustic emissions and the number of ribbon synapses between inner hair cells and nerve fibers. The first clear signs of aging appeared in the brainstem, in which response amplitude decreased, with thresholds remaining stable until the age of 15 months, and increasing slightly thereafter. The responses of primary auditory cortex neurons revealed specific effects of aging: at 21 months, receptive fields were spectrally narrower and the temporal reliability of responses to communication sounds was lower. However, aging had a null or even positive effect on neuronal responses in the presence of background noise, responses to amplitude-modulated sounds, and responses in gap-detection protocols. Overall, inter-animal variability remained high relative to the variability across groups of different ages, for all parameters tested. Beha-vioral performance for the modulation depth of amplitude modulation noise was worse in 21-month old animals than in other animals. Age-related alterations of cortical and behavioral responses were thus observed in animals displaying no signs of aging at the peripheral level. These results suggest that intrinsic, central aging effects can affect the perception of acoustic stimuli independently of the effects of aging on peripheral receptors

Billboard 200: The Lessons of Musical Success in the U.S.

International audienceThere has been little quantitative analysis of the successful careers of music artists in the literature given the importance of music in world culture. The Billboard 200 database in the U.S. (BB200, 200 best-selling weekly albums) is freely available for the period 1963–2019, a long period encompassing the entire careers of many musicians. An analysis of this database enabled us to establish some rules of musical success for artists, which are examined in this article. Our results show that the time distribution of success for artists reaching high chart positions follows a Frechet-like distribution, with a decline principally due to the progressively shorter lifespan of successive charted albums from the same artist. We then show that the surmised difficulty of the second album exists. Our findings also confirm that success is more diverse than it was a few decades ago, in the sense that more artists reach the charts every year. Finally, we analyze and model the lifespan of albums in the charts, facilitating the isolation of the contribution of marketing to success and failure and comparisons between albums. The BB200 database provides an interesting point of entry to music data science, music marketing, but also to the more complex related notions of musical quality and creativity

Comment le cerveau décode-t-il la musique ?

International audienc

Correlates of Network-level Regulatory Function Along the Ventral Respiratory Column in Rat Medulla.

International audienc

Age-related changes in the guinea pig auditory cortex : relationship with peripheral changes and comparison with tone-induced hearing loss.

International audienceElderly people often show degraded hearing performance and have difficulties in understanding speech, particularly in noisy environments. Although loss in peripheral hearing sensitivity is an important factor in explaining these low performances, central alterations also have an impact but their exact contributions remained unclear. In this study, we focus on the functional effects of aging on auditory cortex responses. Neuronal discharges and local field potentials were recorded in the auditory cortex of aged guinea pigs (> 3 years), and several parameters characterizing the processing of auditory information were quantified: the acoustic thresholds, response strength, latency and duration of the response, and breadth of tuning. Several of these parameters were also quantified from auditory brainstem responses collected from the same animals, and recordings obtained from a population of animals with trauma-induced hearing loss were also included in this study. The results showed that aging and acoustic trauma reduced the response strength at both brainstem and cortical levels, and increased the response latencies more at the cortical level than at the brainstem level. In addition to the brainstem hearing loss, aging induced a 'cortical hearing loss' as judged by additive changes in the threshold and frequency response seen in the cortex. It also increased the duration of neural responses and reduced the receptive field bandwidth, effects that were not found in traumatized animals. These effects substantiate the notion that presbycusis involves both peripheral hearing loss and biological aging in the central auditory system

Spatial representation of neural responses to natural and altered conspecific vocalizations in cat auditory cortex

International audienc

Maximum decoding abilities of temporal patterns and synchronized firings: application to auditory neurons responding to click trains and amplitude modulated white noise

International audienc