scholarly journals Auditory Corticothalamic Neurons are Recruited by Motor Preparatory Inputs

2020 ◽  
Author(s):  
Kameron K. Clayton ◽  
Ross S. Williamson ◽  
Kenneth E. Hancock ◽  
Troy Hackett ◽  
Daniel B Polley

SUMMARYOptogenetic activation of Ntsr1+ layer 6 corticothalamic (L6 CT) neurons modulates thalamocortical sensory processing and perception for hundreds of milliseconds following laser offset. Naturally occurring sources of extrasensory inputs that could recruit L6 CTs prior to upcoming sensory stimuli have not been identified. Here, we found that 100% of L6 CTs in mouse primary auditory cortex (A1) expressed FoxP2, a protein marker found in brain areas that coordinate sensory inputs with movement. To test the idea that motor preparatory inputs could be a natural extrasensory activator of L6 CTs, we combined quantitative videography, optogenetically targeted single unit recordings, and two-photon imaging during self-initiated behavior. We found that A1 L6 CTs were activated hundreds of milliseconds prior to orofacial movements, but not whole-body movements associated with locomotion. These findings identify new local circuit arrangements for routing motor corollary discharge into A1 and suggest new roles for CT neurons in active sensing.

2019 ◽  
Author(s):  
Alexandra Libby ◽  
Timothy J. Buschman

AbstractSensory stimuli arrive in a continuous stream. By learning statistical regularities in the sequence of stimuli, the brain can predict future stimuli (Xu et al. 2012; Gavornik and Bear 2014; Maniscalco et al. 2018; J. Fiser and Aslin 2002). Such learning requires associating immediate sensory information with the memory of recently encountered stimuli (Ostojic and Fusi 2013; Kiyonaga et al. 2017). However, new sensory information can also interfere with short-term memories (Parthasarathy et al. 2017). How the brain prevents such interference is unknown. Here, we show that sensory representations rotate in neural space over time, to form an independent memory representation, thus reducing interference with future sensory inputs. We used an implicit learning paradigm in mice to study how statistical regularities in a sequence of stimuli are learned and represented in primary auditory cortex. Mice experienced both common sequences of stimuli (e.g. ABCD) and uncommon sequences (e.g. XYCD). Over four days of learning, the neural population representation of commonly associated stimuli (e.g. A and C) converged. This facilitated the prediction of upcoming stimuli, but also led unexpected sensory inputs to overwrite the sensory representation of previous stimuli (postdiction). Surprisingly, we found the memory of previous stimuli persisted in a second, orthogonal dimension. Unsupervised clustering of functional cell types revealed that the emergence of this second memory dimension is supported by two separate types of neurons; a ‘stable’ population that maintained its selectivity throughout the sequence and a ‘switching’ population that dynamically inverted its selectivity. This combination of sustained and dynamic representations produces a rotation of the encoding dimension in the neural population. This rotational dynamic may be a general principle, by which the cortex protects memories of prior events from interference by incoming stimuli.


Author(s):  
Ana Gentil-Gutiérrez ◽  
José Luis Cuesta-Gómez ◽  
Paula Rodríguez-Fernández ◽  
Jerónimo Javier González-Bernal

(1) Background: Children with Autism Spectrum Disorder (ASD) frequently have difficulties in processing sensory information, which is a limitation when participating in different contexts, such as school. The objective of the present study was to compare the sensory processing characteristics of children with ASD in the natural context of school through the perception of professionals in the field of education, in comparison with neurodevelopmental children (2) Methods: A cross-sectional descriptive study as conducted with study population consisting of children between three and ten years old, 36 of whom were diagnosed with ASD and attended the Autismo Burgos association; the remaining 24 had neurotypical development. The degree of response of the children to sensory stimuli at school was evaluated using the Sensory Profile-2 (SP-2) questionnaire in its school version, answered by the teachers. (3) Results: Statistically significant differences were found in sensory processing patterns (p = 0.001), in sensory systems (p = 0.001) and in school factors (p = 0.001). Children with ASD who obtained worse results. (4) Conclusions: Children with ASD are prone to present sensory alterations in different contexts, giving nonadapted behavioral and learning responses.


2009 ◽  
Vol 297 (1) ◽  
pp. E134-E141 ◽  
Author(s):  
Ichiro Sakata ◽  
Jing Yang ◽  
Charlotte E. Lee ◽  
Sherri Osborne-Lawrence ◽  
Sherry A. Rovinsky ◽  
...  

Ghrelin is a peptide hormone with many known functions, including orexigenic, blood glucose-regulatory, and antidepressant actions, among others. Mature ghrelin is unique in that it is the only known naturally occurring peptide to be posttranslationally modified by O-acylation with octanoate. This acylation is required for many of ghrelin's actions, including its effects on promoting increases in food intake and body weight. GOAT (ghrelin O-acyltransferase), one of 16 members of the MBOAT family of membrane-bound O-acyltransferases, has recently been identified as the enzyme responsible for catalyzing the addition of the octanoyl group to ghrelin. Although the initial reports of GOAT have localized its encoding mRNA to tissues known to contain ghrelin, it is as yet unclear whether the octanoylation occurs within ghrelin-producing cells or in neighboring cells. Here, we have performed dual-label histochemical analysis on mouse stomach sections and quantitative PCR on mRNAs from highly enriched pools of mouse gastric ghrelin cells to demonstrate a high degree of GOAT mRNA expression within ghrelin-producing cells of the gastric oxyntic mucosa. We also demonstrate that GOAT is the only member of the MBOAT family whose expression is highly enriched within gastric ghrelin cells and whose whole body distribution mirrors that of ghrelin.


2021 ◽  
Author(s):  
Yuanqing Zhang ◽  
Xiaohui Wang ◽  
Lin Zhu ◽  
Siyi Bai ◽  
Rui Li ◽  
...  

Cortical feedback has long been considered crucial for modulation of sensory processing. In the mammalian auditory system, studies have suggested that corticofugal feedback can have excitatory, inhibitory, or both effects on the response of subcortical neurons, leading to controversies regarding the role of corticothalamic influence. This has been further complicated by studies conducted under different brain states. In the current study, we used cryo-inactivation in the primary auditory cortex (A1) to examine the role of corticothalamic feedback on medial geniculate body (MGB) neurons in awake marmosets. The primary effects of A1 inactivation were a frequency-specific decrease in the auditory response of MGB neurons coupled with an increased spontaneous firing rate, which together resulted in a decrease in the signal-to-noise ratio. In addition, we report for the first-time that A1 robustly modulated the long-lasting sustained response of MGB neurons which changed the frequency tuning after A1 inactivation, e.g., neurons with sharp tuning increased tuning bandwidth whereas those with broad tuning decreased tuning bandwidth. Taken together, our results demonstrate that corticothalamic modulation in awake marmosets serves to enhance sensory processing in a way similar to center-surround models proposed in visual and somatosensory systems, a finding which supports common principles of corticothalamic processing across sensory systems.


2012 ◽  
Vol 92 (1) ◽  
pp. 193-235 ◽  
Author(s):  
Hanns Ulrich Zeilhofer ◽  
Hendrik Wildner ◽  
Gonzalo E. Yévenes

The two amino acids GABA and glycine mediate fast inhibitory neurotransmission in different CNS areas and serve pivotal roles in the spinal sensory processing. Under healthy conditions, they limit the excitability of spinal terminals of primary sensory nerve fibers and of intrinsic dorsal horn neurons through pre- and postsynaptic mechanisms, and thereby facilitate the spatial and temporal discrimination of sensory stimuli. Removal of fast inhibition not only reduces the fidelity of normal sensory processing but also provokes symptoms very much reminiscent of pathological and chronic pain syndromes. This review summarizes our knowledge of the molecular bases of spinal inhibitory neurotransmission and its organization in dorsal horn sensory circuits. Particular emphasis is placed on the role and mechanisms of spinal inhibitory malfunction in inflammatory and neuropathic chronic pain syndromes.


Author(s):  
Silvia-Raluca Matei ◽  
Damian Mircea Totolan ◽  
Claudia Salceanu

Occupational therapy focuses on children's sensory processing and modulation. This chapter approaches specific interventions on children with ASD from several perspectives. OT is based on sensory integrative approach when working with children with ASD: helping parents understand their child's behavior, helping children organize responses to sensory input. The sensory integrative approach is a formulated activity plan that helps people who haven't been able to develop their own sensory recognition program. This plan allows a child to integrate all sorts of different sensory activities in their day so they can engage in and begin to work with a wide variety of sensory inputs. This provides a wide number of benefits. Their focus and attention span increases because they won't have meltdowns from trying to process too much information; sensory integrative approach helps to rebuild/reform the child's nervous system. This allows them to physically handle more sensory input. As a result, OT has been proven effective in working with children with ASD.


2012 ◽  
Vol 25 (0) ◽  
pp. 107
Author(s):  
Nai-Yuan Nicholas Chang ◽  
Alex K. Malone ◽  
Timothy E. Hullar

Imbalance among patients with vestibular hypofunction has been related to inadequate compensatory eye movements in response to head movements. However, symptoms of imbalance might also occur due a temporal mismatch between vestibular and other balance-related sensory cues. This temporal mismatch could be reflected in a widened temporal binding window (TBW), or the length of time over which simultaneous sensory stimuli may be offset and still perceived as simultaneous. We hypothesized that decreased vestibular input would lead to a widening of the temporal binding window. We performed whole-body rotations about the earth-vertical axis following a sinusoidal trajectory at 0.5 Hz with a peak velocity of 60°/s in four normal subjects. Dichotic auditory clicks were presented through headphones at various phases relative to the rotations. Subjects were asked to indicate whether the cues were synchronous or asynchronous and the TBW was calculated. We then simulated decreased vestibular input by rotating at diminished peak velocities of 48, 24 and 12°/s in four normal subjects. TBW was calculated between ±1 SD away from the mean on the psychometric curve. We found that the TBW increases as amplitude of rotation decreases. Average TBW of 251 ms at 60°/s increased to 309 ms at 12°/s. This result leads to the novel conclusion that changes in temporal processing may be a mechanism for imbalance in patients with vestibular hypofunction.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Liang Ye ◽  
Murat Orynbayev ◽  
Xiangyu Zhu ◽  
Eunice Y. Lim ◽  
Ram R. Dereddi ◽  
...  

AbstractNorepinephrine adjusts sensory processing in cortical networks and gates plasticity enabling adaptive behavior. The actions of norepinephrine are profoundly altered by recreational drugs like ethanol, but the consequences of these changes on distinct targets such as astrocytes, which exhibit norepinephrine-dependent Ca2+ elevations during vigilance, are not well understood. Using in vivo two-photon imaging, we show that locomotion-induced Ca2+ elevations in mouse astroglia are profoundly inhibited by ethanol, an effect that can be reversed by enhancing norepinephrine release. Vigilance-dependent astroglial activation is abolished by deletion of α1A-adrenergic receptor from astroglia, indicating that norepinephrine acts directly on these ubiquitous glial cells. Ethanol reduces vigilance-dependent Ca2+ transients in noradrenergic terminals, but has little effect on astroglial responsiveness to norepinephrine, suggesting that ethanol suppresses their activation by inhibiting norepinephrine release. Since abolition of astroglia Ca2+ activation does not affect motor coordination, global suppression of astroglial networks may contribute to the cognitive effects of alcohol intoxication.


2016 ◽  
Vol 116 (2) ◽  
pp. 431-437 ◽  
Author(s):  
Charles G. Frye ◽  
Jason N. MacLean

Spontaneous propagation of spiking within the local neocortical circuits of mature primary sensory areas is highly nonrandom, engaging specific sets of interconnected and functionally related neurons. These spontaneous activations promise insight into neocortical structure and function, but their properties in the first 2 wk of perinatal development are incompletely characterized. Previously, we have found that there is a minimal numerical sample, on the order of 400 cells, necessary to fully capture mature neocortical circuit dynamics. Therefore we maximized our numerical sample by using two-photon calcium imaging to observe spontaneous activity in populations of up to 1,062 neurons spanning multiple columns and layers in 52 acute coronal slices of mouse neocortex at each day from postnatal day (PND) 3 to PND 15. Slices contained either primary auditory cortex (A1) or somatosensory barrel field (S1BF), which allowed us to compare sensory modalities with markedly different developmental timelines. Between PND 3 and PND 8, populations in both areas exhibited activations of anatomically compact subgroups on the order of dozens of cells. Between PND 9 and PND 13, the spatiotemporal structure of the activity diversified to include spatially distributed activations encompassing hundreds of cells. Sparse activations covering the entire field of view dominated in slices taken on or after PND 14. These and other findings demonstrate that the developmental progression of spontaneous activations from active local modules in the first postnatal week to sparse, intermingled groups of neurons at the beginning of the third postnatal week generalizes across primary sensory areas, consistent with an intrinsic developmental trajectory independent of sensory input.


Author(s):  
Riitta Hari

This chapter introduces magnetoencephalography (MEG), a tool to study brain dynamics in basic and clinical neuroscience. MEG picks up brain signals with millisecond resolution, as does electroencephalography, but without distortion by skull and scalp. The chapter describes current instrumentation based on superconducting quantum interference devices (SQUIDs). It delineates basic characteristics of measured signals: (1) brain rhythms and their reactivity during sensory processing and various tasks and (2) evoked responses elicited by sensory stimuli, and the dependence of these responses on various stimulus characteristics. Signals are described from healthy and diseased brains. The chapter presents studies of the brain basis of cognition and social interaction studied in dual-MEG setups and describes how MEG applications can be broadened by innovative setups, including frequency tagging. Progress in the field is predicted regarding sensor technology, data analysis, and multimodal brain imaging, all of which could strengthen MEG’s role in the study of brain dynamics.


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