Article
Biology
Hannah M. Oberle, Alexander N. Ford, Deepak Dileepkumar, Jordyn Czarny, Pierre F. Apostolides
Summary: Corticofugal projections from the neocortex to evolutionarily ancient subcortical structures are common in mammalian sensory systems, allowing the cortex to control ascending sensory representations predictively or in a feedback manner. This study focused on the projection from the mouse auditory cortex to the inferior colliculus (IC), revealing that although individual synapses were weak, IC neurons integrated inputs from multiple corticofugal axons to generate reliable depolarizations. Descending signals reached the IC within 30 ms of sound onset and were found to nonlinearly amplify IC neurons' acoustic responses.
Article
Neurosciences
Anna Schroeder, M. Belen Pardi, Joram Keijser, Tamas Dalmay, Ayelen I. Groisman, Erin M. Schuman, Henning Sprekeler, Johannes J. Letzkus
Summary: This study combines various techniques such as synaptic two-photon calcium imaging, circuit mapping, cortex-dependent learning, and chemogenetics in mice to investigate the role of inhibitory top-down projections. The results show that GABAergic afferents from the subthalamic zona incerta play a major role in transmitting top-down input to the neocortex. This transmission undergoes plasticity during learning and contributes to information transfer and behavioral memory.
Review
Neurosciences
M. Belen Pardi, Anna Schroeder, Johannes J. Letzkus
Summary: Accurate perception of the environment involves integrating sensory signals with internally generated information. Recent advances in brain imaging techniques allow for the study of how top-down information is encoded and integrated with bottom-up signals.
TRENDS IN NEUROSCIENCES
(2023)
Article
Neurosciences
Frhan I. Alanazi, Suneil K. Kalia, Mojgan Hodaie, Adriana Lopez L. Rios, Andres M. Lozano, Luka Milosevic, William D. Hutchison
Summary: The neurophysiology of selective attention in visual and auditory systems was studied in animal models and recorded neuronal activity in human patients with parkinsonian and non-parkinsonian tremors. The results showed that the firing rate of neurons decreased during the auditory oddball task, specifically related to auditory attention. The study also found that dopamine modulates thalamic beta oscillations for selective attention in Parkinson's disease patients.
NPJ PARKINSONS DISEASE
(2023)
Article
Multidisciplinary Sciences
Elisa N. Falk, Kevin J. Norman, Yury Garkun, Michael P. Demars, Susanna Im, Giulia Taccheri, Jenna Short, Keaven Caro, Sarah E. McCraney, Christina Cho, Milo R. Smith, Hung-Mo Lin, Hiroyuki Koike, Julia Bateh, Priscilla Maccario, Leah Waltrip, Meaghan Janis, Hirofumi Morishita
Summary: This study reveals that dynamic regulation of the nicotinic cholinergic system plays a key role in the maturation of attentional circuit, particularly in the development of top-down frontal neurons. Following adolescence, the decrease in nicotinic tone by upregulation of Lynxl promotes the establishment of attentional behavior in adulthood. Disruption of this key maturational process is observed in a mouse model of fragile X syndrome, but can be rescued by suppressing nicotinic tone through the introduction of Lynxl in top-down projections.
Article
Multidisciplinary Sciences
Marius Markmann, Melanie Lenz, Oliver Hoeffken, Agne Steponaviciute, Martin Bruene, Martin Tegenthoff, Hubert R. Dinse, Albert Newen
Summary: Through hypnosis suggestions, semantic content can instantly and systematically alter spatial discrimination of tactile perception, indicating that this change is a result of modified perceptual processes, rather than simply altered judgment based on perception.
SCIENTIFIC REPORTS
(2023)
Article
Neurosciences
Bingmin Luo, Jing Li, Jingpeng Liu, Funi Li, Miaoqing Gu, Haoran Xiao, Shujun Lei, Zhongju Xiao
Summary: The brain regions responsible for the formation of auditory threat memory and perceptual decisions remain uncertain. This study used chemogenetic and optogenetic manipulations to investigate the roles of different brain regions in threat memory learning. The results suggest that the temporal association cortex plays a crucial role in auditory threat memory formation, with inputs from A1, A2, and MGm.
JOURNAL OF NEUROSCIENCE
(2022)
Article
Audiology & Speech-Language Pathology
G. Graham, M. S. Chimenti, K. L. Knudtson, D. N. Grenard, L. Co, M. Sumner, T. Tchou, K. M. Bieszczad
Summary: This study identifies genome-wide changes in learning-induced gene expression within the auditory cortex, which may underlie the formation of sound discrimination memory. Bioinformatic analysis reveals several biological pathways that are likely to be important for auditory discrimination learning. These findings provide insights into the early stages of changes in cortical and behavioral function related to long-term discriminative auditory memory formation.
Review
Neurosciences
Alexander Asilador, Daniel A. Llano
Summary: The article discusses the widespread acceptance that humans use contextual information to infer the meaning of ambiguous acoustic signals, as well as the current theories and models used to explain this phenomenon. It also highlights the importance of the corticofugal pathways in the brain in this process, and the predictive coding mechanisms that modulate perception of complex sounds.
FRONTIERS IN NEURAL CIRCUITS
(2021)
Article
Multidisciplinary Sciences
Jafar Doostmohammadi, Marc Alwin Gieselmann, Jochem van Kempen, Reza Lashgari, Ali Yoonessi, Alexander Thiele
Summary: Sharp-wave ripples (SWRs) are observed in the hippocampus during offline states, but their association with awake conscious and goal-directed behavior is unknown. This study found that ripple activity also occurs in macaque visual areas V1 and V4 during focused spatial attention. The occurrence of ripples is influenced by stimulus characteristics and attentional focus. During attention cued to the receptive field, ripples reduced the monkey's reaction time in detecting behaviorally relevant events. These findings suggest that ripple activity is not limited to offline states but occurs in neocortex during active attentive states.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Computer Science, Artificial Intelligence
Ryan Burt, Nina N. Thigpen, Andreas Keil, Jose C. Principe
Summary: A unique deep learning architecture combining bottom-up saliency, top-down attention, and object recognition module is proposed for focusing on relevant data and learning important features through unsupervised learning. The Gamma saliency technique shows comparable performance to the best alternative algorithms in various databases, while significantly improving training speed.
Article
Neurosciences
Amanda Henton, Yanjun Zhao, Thanos Tzounopoulos
Summary: Damage to sensory organs triggers compensatory plasticity mechanisms in sensory cortices, resulting in restored cortical responses and recovery of perceptual detection thresholds. In this study, the authors investigated the changes in intrinsic properties and biophysical mechanisms following noise-induced peripheral damage. They found a specific reduction in the intrinsic excitability of parvalbumin-expressing neurons in the auditory cortex, associated with an increase in KCNQ potassium channel activity. These findings provide insights into the cell type and channel-specific plasticity mechanisms involved in hearing loss and related disorders.
JOURNAL OF NEUROSCIENCE
(2023)
Article
Multidisciplinary Sciences
Domenica Veniero, Joachim Gross, Stephanie Morand, Felix Duecker, Alexander T. Sack, Gregor Thut
Summary: The activation of the Frontal Eye Fields can shape visual cortex activity and perception through mechanisms of oscillatory realignment at the beta frequency.
NATURE COMMUNICATIONS
(2021)
Article
Neurosciences
Yuan Cheng, Ruru Chen, Bowen Su, Guimin Zhang, Yutian Sun, Pengying An, Yue Fang, Yifan Zhang, Ye Shan, Etienne de Villers-Sidani, Yunfeng Wang, Xiaoming Zhou
Summary: Antidepressants can have negative effects on auditory processing, worsening psychiatric symptoms. These drugs can affect auditory memory, cortical neuron response, and perineuronal nets. Pairing drug treatment with enriched sound exposure can help alleviate these effects. These findings are important for understanding the impact of antidepressants on hearing and developing new treatment strategies for psychiatric disorders.
JOURNAL OF NEUROSCIENCE
(2023)
Article
Neurosciences
Timothy Olsen, Andrea R. Hasenstaub
Summary: This study investigated the characteristics of different cell types and the differences between onset and offset responses. The results showed that offset responses are generally less depressive than onset responses, and the dynamics of onset responses do not predict the dynamics of offset responses. Different cell types exhibit variations in the dynamics of their onset responses and the prevalence of their offset responses. Response clusters are associated with cell type.
JOURNAL OF NEUROSCIENCE
(2022)