Biology subjects

Dudchenko, P. A.

Publications and source records attributed to Dudchenko, P. A..

3 recordsLinked to original sources

bioRxiv2026

Visual capture of the head-direction signal in a rat model of Fragile X Syndrome

Fragile X Syndrome (FXS) is a common inherited monogenic cause of autism spectrum disorder and intellectual disability (ASD/ID), conditions frequently associated with altered sensory processing and multisensory integration. However, the circuit mechanisms underlying these alterations remain poorly understood. Here, we investigate the integration of visual and self-motion information in the head-direction (HD) system in a rat model of FXS (Fmr1-/y rats). Using high-density silicon probes, we recorded neuronal activity in the postsubiculum (PoSub), a cortical hub of the HD system, while adult Fmr1-/y and wild-type (WT) rats experienced repeated rotations of a visual landmark. In WT rats, the HD signal only partially followed landmark rotations, consistent with weighted integration of visual and self-motion information, and visual landmark control progressively weakened across repeated cue conflicts. In contrast, the HD signal in Fmr1-/y rats closely followed landmark rotations and failed to show experience-dependent recalibration. This enhanced visual capture was accompanied by reduced angular head velocity tuning in PoSub neurons, indicating weakened representation of self-motion information. Together, these findings reveal an altered balance between visual and self-motion inputs to the HD system in a rat model of FXS and identify a possible circuit-level mechanism through which sensory integration of vision and self-motion may be disrupted in ASD/ID.

neuroscience↗

bioRxiv2025

Age-dependent alterations in the head-direction signal in a rat model of Fragile X Syndrome

Fragile X Syndrome (FXS) is a common inherited monogenic cause of autism spectrum disorder and intellectual disability (ASD/ID), but the neural mechanisms underlying its symptoms remain unclear. Here, we investigate the development of the head-direction (HD) system in a rat model of FXS (Fmr1-/y rats) and its role in spatial cognition. Using high-density silicon probes, we recorded neuronal activity in the postsubiculum (PoSub), a cortical hub of the HD system, during exploration and sleep in juvenile and adult Fmr1-/y and wild-type (WT) rats. Surprisingly, juvenile Fmr1-/y rats exhibited enhanced HD tuning characterized by sharper directional tuning curves and improved stability of the HD signal in relation to the external environment. This enhancement was intrinsic to the HD circuit and persisted across behavioral and sleep states. However, by adulthood, HD tuning in Fmr1-/y rats became unstable, with increased drift in the allocentric reference frame despite intact intrinsic HD dynamics. These findings reveal a transient enhancement of spatial coding in the HD system of juvenile Fmr1-/y rats, followed by a degradation in adulthood, mirroring the developmental regression often observed in autism. Overall, our work reveals network-level dysfunctions in FXS and their developmental trajectories.

neuroscience↗

bioRxiv2022

The medial entorhinal cortex is necessary for the stimulus control over hippocampal place fields by distal, but not proximal, landmarks

A fundamental property of place cells in the hippocampus is the anchoring of their firing fields to salient landmarks within the environment. However, it is unclear how such information reaches the hippocampus. In the current experiment, we tested the hypothesis that the stimulus control exerted by distal visual landmarks requires input from the medial entorhinal cortex (MEC). Place cells were recorded from mice with ibotenic acid lesions of the MEC (n = 7) and from sham-lesioned mice (n = 6) following 90{degrees} rotations of either distal landmarks or proximal cues in a cue controlled environment. We found that lesions of the MEC impaired the anchoring of place fields to distal landmarks, but not proximal cues. We also observed that, relative to sham-lesioned mice, place cells in animals with MEC lesions exhibited significantly reduced spatial information and increased sparsity. These results support the view that distal landmark information reaches the hippocampus via the MEC, but that proximal cue information can do so via an alternative neural pathway.

neuroscience↗