Biology subjects

Raoufy, M. R.

Publications and source records attributed to Raoufy, M. R..

3 recordsLinked to original sources

bioRxiv2025

Olfactory bulb-medial prefrontal cortex circuit slow oscillations encode working memory representations

Working memory (WM), the ability to maintain task-related information, is fundamental to animal behaviors. Despite significance, there is limited knowledge on how it is orchestrated by the neural activity in the brain. Here, we show that the olfactory bulb (OB) and medial prefrontal cortex (mPFC) slow oscillations (1-30 Hz) are augmented during WM, and furthermore, the pattern of these activities convey task-related information. Moreover, we find that the OB-mPFC delta and beta power-based connectivity is enhanced by WM. On the other hand, theta oscillations have the most prominent roles in phase coupling in this circuit. We also show bidirectional information transfer, stronger in the mPFC-to-OB direction, between the two brain areas. Furthermore, during WM, beta activity in both regions is tuned by the phase of local and long-range delta as well as theta oscillations. Together, our results suggest that the dynamics of OB-mPFC circuit slow band activities underlies WM, with possible implications for other cognitive functions in health and disease.

neuroscience↗

bioRxiv2024

Context-Dependent Modulations in Acoustic Features of Zebra Finch Distance Calls: Insights from a Novel Goal-Directed Vocalization Paradigm

Songbirds are renowned for their complex vocal communication abilities; among them, zebra finches (Taeniopygia guttata) are a key species for studying vocal learning and communication. Zebra finches use various calls with different meanings, including the distance call, which is used for long-distance contact. Whether these calls are static with fixed meanings or flexible remains an open question. In this study we aimed to answer this question by designing a novel behavioral paradigm, in which we trained food-restricted zebra finches to use distance calls for food request. Nine out of ten birds learned this association and used their distance calls to obtain food when they were hungry. We then introduced a visually-separated audience and compared the distance calls used for food requests with those used for communication between birds. Results revealed significant acoustic differences in power, pitch, and other spectral characteristics between the distance calls uttered in these two contexts. Our findings suggest that zebra finches can use their distance call for different goals and also acoustically modulate it based on the context. Therefore, it demonstrates a level of vocal control thought to be exclusive to songs. This study enhances our understanding of vocal flexibility and its role in vocal communication.

animal behavior and cognition↗

bioRxiv2024

Olfactory bulb stimulation mitigates Alzheimer-like disease progression

BackgroundDeep brain stimulation (DBS) has demonstrated potential in mitigating Alzheimers disease (AD). However, the invasive nature of DBS presents challenges for its application. The olfactory bulb (OB), showing early AD-related changes and extensive connections with memory regions, offers an attractive entry point for intervention, potentially restoring normal activity in deteriorating memory circuits. AimsOur study examined the impact of electrically stimulating the OB on working memory as well as pathological and electrophysiological alterations in the OB, medial prefrontal cortex, hippocampus, and entorhinal cortex in amyloid beta (A{beta}) AD model rats. MethodsMale Wistar rats underwent surgery for electrode implantation in brain regions, inducing Alzheimers-like disease. Bilateral olfactory bulb (OB) electrical stimulation was performed for 1 hour daily to the OB of stimulation group animals for 18 consecutive days, followed by evaluations of histological, behavioral, and local field potential signal processing. ResultsOB stimulation counteracted A{beta} plaque accumulation and prevented AD-induced working memory impairments. Furthermore, it prompted an increase in power across diverse frequency bands and enhanced functional connectivity, particularly in the gamma band, within the investigated regions during a working memory task. ConclusionThis preclinical investigation highlights the potential of olfactory pathway-based brain stimulation to modulate the activity of deep-seated memory networks for AD treatment. Importantly, the accessibility of this pathway via the nasal cavity lays the groundwork for the development of minimally invasive approaches targeting the olfactory pathway for brain modulation.

neuroscience↗