Biology subjects

Garcia Garrido, M.

Publications and source records attributed to Garcia Garrido, M..

3 recordsLinked to original sources

bioRxiv2025

Temporal Interference Stimulation Enhances Neural Regeneration

Neural regeneration therapies aim to treat neurodegeneration by promoting the proliferation and maturation of exogenous or endogenous neural progenitor cells (NPCs). However, their efficacy has been limited. Deep brain stimulation (DBS) via implanted electrodes has been shown to promote neurogenesis. However, its invasiveness precludes deployment in research and widespread clinical use. Temporal interference (TI) has emerged as a strategy for non-invasive, high-precision DBS using multiple kHz-range electric fields, with a frequency difference within the range of neural activity. Here, we validate the potential of TI stimulation for neural regeneration augmentation. We demonstrate that TI stimulation with a theta-band frequency difference enhances the maturation of embryonic neural progenitor cells in vitro. We then demonstrate that theta-band TI stimulation targeting the hippocampus enhances endogenous hippocampal neurogenesis in an in vivo mouse model of Alzheimers disease. By uncovering frequency-specific control of stem cell fate, we propose a clinically relevant regeneration strategy which avoids pharmacological or genetic manipulation. Our results demonstrate focal, non-invasive augmentation of deep-brain neural regeneration. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=197 SRC="FIGDIR/small/670811v1_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@984165org.highwire.dtl.DTLVardef@1ed8bbdorg.highwire.dtl.DTLVardef@715057org.highwire.dtl.DTLVardef@151882f_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2024

Transient cortical Beta-frequency oscillations associated with contextual novelty in high density mouse EEG

Beta-frequency oscillations (20-30 Hz) are prominent in both human and rodent electroencephalogram (EEG) recordings. Discrete epochs of beta (or Beta2) oscillations are prevalent in the hippocampus and other brain areas during exploration of novel environments. However, little is known about the spatial distribution and temporal relationships of beta oscillations across the cortex in response to novelty. To investigate this, mice fitted with 30-channel EEG-style multi-electrode arrays underwent a single recording session in a novel environment. While changes to spectral properties of cortical oscillations were minimal, there was a profound increase in the rate of beta bursts during the initial part of the recording session, when the environment was most novel. This was true across the cortex but most notable in recording channels situated above the retrosplenial cortex. Additionally, novelty was associated with greater connectivity between retrosplenial areas and the rest of the cortex, specifically in the beta frequency range. However, it was also found that the cortex in general, is highly modulated by environmental novelty. This data further suggests the retrosplenial cortex is an important hub for distinguishing environmental context and highlights the diversity of functions for beta oscillations across the brain, which can be observed using high-density EEG.

neuroscience↗

bioRxiv2020

Voltage-gated calcium channel subunit α2δ-3 shapes light responses of mouse retinal ganglion cells mainly in low and moderate light levels

Little is known about the function of the auxiliary 2{delta} subunits of voltage-gated calcium channels in the retina. We investigated the role of 2{delta}-3 (Cacna2d3) using a mouse in which 2{delta}-3 was knocked out by LacZ insertion. Behavior experiments indicated a normal optokinetic reflex in 2{delta}-3 knockout animals. Strong expression of 2{delta}-3 could be localized to horizontal cells using the LacZ-reporter, but horizontal cell mosaic and currents carried by horizontal cell voltage-gated calcium channels were unchanged by the 2{delta}-3 knockout. In vivo electroretinography revealed unaffected photoreceptor activity and signal transmission to depolarizing bipolar cells. We recorded visual responses of retinal ganglion cells with multi-electrode arrays in scotopic to photopic luminance levels and found subtle changes in 2{delta}-3 knockout retinas. Spontaneous activity in OFF ganglion cells was elevated in all luminance levels. Differential response strength to high- and low-contrast Gaussian white noise was compressed in ON ganglion cells during mesopic ambient luminance and in OFF ganglion cells during scotopic and mesopic ambient luminances. In a subset of ON ganglion cells, we found a sharp increase in baseline spiking after the presentation of drifting gratings in scotopic luminance. This increase happened after gratings of different spatial properties in knockout compared to wild type retinas. In a subset of ON ganglion cells of the 2{delta}-3 knockout, we found altered delays in rebound-like spiking to full-field contrast steps in scotopic luminance. In conclusion, 2{delta}-3 seems to participate in shaping visual responses mostly within brightness regimes when rods or both rods and cones are active.

neuroscience↗