P181 The processing of auditory rhythms in the thalamocortical network throughout the development
Sepideh Sadat Malekjafarian*1, Maryam Ghorbani1,2, Sahar Moghimi3,Fabrice Wallois3,4
1 Electrical Engineering Department, Ferdowsi University of Mashhad, Iran
2Rayan Center for Neuroscience and Behavior, Ferdowsi University of Mashhad, Iran
3Inserm UMR1105, Groupe de Recherches sur l’Analyse Multimodale de la Fonction Cérébrale, CURS, Amiens Cedex 80036, France
4Inserm UMR1105, EFSN Pédiatriques, CHU Amiens sud, Amiens Cedex 80054, France
*Email:s.malekjafarian92@gmail.com
Introduction
In early neural development, thalamocortical network exhibits unique characteristics, especially in preterm infants whose brain is not yet fully developed. These include specific patterns of neural oscillations, which is crucial for development of cortical circuitry and formation of neural networks. Evidence suggests thatthe ability to perceive rhythm and synchronize with periodic patterns play a critical role in neurodevelopment, particularly in language, musicand social interaction. Here, we first developed a computational model of thalamocortical neural network which is capable of generating brain rhythms associated with preterm infants. Using this model, we then investigate the early development of neural response to external rhythm.
Methods
The model consists of (i) two recurrent excitatory-inhibitory neuron groups representingcortex-subplate network with adaptationand (ii) one excitatory-inhibitory group with burst representingthalamus. All parameters remain constant exceptI-E synaptic strength in cortex-subplate networkand thalamocortical connections to generate brain rhythms. We depict neurodevelopmental trajectories in our model using EEG recordings in 46 neonates (27-35 wGA) during rest and stimulation with specific auditory stimulus [1]. The same stimulus was applied to validate auditory processing.Asynchronization indexassesses the network’s alignment with stimulus oscillations.Developmental trajectories are compared between model and premature EEG recordings.
Results
Based on free parameters,the model was developed to achieve the best age matching with the age of EEGrecordings[1]. Additionally, we were able to extract two key features of premature signals, slope and burst-interburst intervals,at different ages from the model, which are consistent with experimental results.Exploiting the developmental regime that best fitted the evolution of the spontaneous neural activity,we then show how the nonlinear interaction of auditorystimuli with endogenous brain rhythms of the model can result in different responses at different ages. Our computational model can explain the mechanism underlying the process of auditory rhythms as neural synchronization to beat and meter frequencies strengthens with age.
Discussion
Our model with its free parameters can explain the age-related changes in neural response and the increasing ability of infants to process rhythms with increasing gestational age at birth previously observed in electrophysiological data. Utilizing E-I synaptic strengths and thalamocortical connections, the model can generate preterm spontaneous brain oscillations and effectively describe the neural response to auditory stimuli with different frequencies.This enables the model to explain the observation that neural synchronization to faster rhythm is present at all ages, while neural synchronization to slower, metric rhythms emerges only athigher ages.
Acknowledgements
No specific acknowledgments are applicable for this study
References
● Saadatmehr, B., Edalati, M., Wallois, F., Ghostine, G., Kongolo, G., Flaten, E., Tillmann, B., Trainor, L., & Moghimi, S., (2025). Auditory Rhythm Encoding during the last trimester of human gestation: from tracking the basic beat to tracking hierarchical nested temporal structures. The Journal of Neuroscience, 45(4), 1-10. https://doi.org/10.1523/JNEUROSCI.0398-24.2024
