Search bioRxiv⌕ Search

bioRxiv · 10.1101/2025.10.26.684693

Frequency-Dependent Modulation of the Prefrontal Cortex by Low-Intensity Focused Ultrasound: Impact on Mesolimbic Dopamine Signaling

Abstract

Synchronized neural oscillations are fundamental for cognitive function and orchestrate inhibitory and excitatory neurotransmission and downstream signaling. We hypothesized that low-intensity focused ultrasound (LIFU) with frequency parameters mimicking oscillatory patterns would enable targeted neuromodulation. Building on prior findings of the ability of LIFU to modulate neurotransmission, we investigated the effects of frequency-modulated LIFU applied to the prelimbic cortex (PLC) on dopamine release in the nucleus accumbens (NAcc) core as well as neuronal and astrocytic activity. After three 80-second LIFU stimulations spaced 30 minutes apart, we found that LIFU excited or inhibited NAcc dopamine release for up to 90 minutes, and these effects were dependent on oscillation frequency and sex. In male rats, theta (8 Hz)-coupled beta (16 Hz) LIFU reduced both dopamine release by 58% and the level of the astrocytic marker GFAP by 50%. Similar decreases in dopamine density were observed in females. Delta (2 Hz)-coupled beta (16 Hz) stimulation produced similar inhibitory effects. Conversely, theta (5 Hz)-coupled gamma (50 Hz) LIFU increased dopamine release by 28% in males. However, similar excitation levels were observed only in females with an increased gamma frequency of 70 Hz (coupled with a theta frequency of 7 Hz). Histological analysis revealed no cell death, but both 8:16 Hz and 5:50 Hz LIFU elevated neuronal activation (cFOS) in the PLC in males, while 5:50 Hz also upregulated GFAP by 30%, suggesting astrocytic involvement. Thus, LIFU stimulation of the PLC can be frequency-tuned to selectively excite or inhibit dopaminergic signaling in the NAcc, suggesting a novel approach for manipulating neurotransmission.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Olaitan, G. O., Okojie, A. K., Lynch, W. J., Venton, B. J.. 2025-10-27. Frequency-Dependent Modulation of the Prefrontal Cortex by Low-Intensity Focused Ultrasound: Impact on Mesolimbic Dopamine Signaling. https://doi.org/10.1101/2025.10.26.684693

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

A Mechanistic Account of Dedifferentiation in the Aging Visual System

To uncover the mechanisms of age-related dedifferentiation, we simulated neural degradation in a computational model of the ventral visual stream. Severing connections or adding noise, whether in inferotemporal cortex (IT) or upstream, reduced IT differentiation, indicating that dedifferentiation need not originate locally. Degrading peripheral V1, which preferentially drove place-selective IT neurons, selectively reduced place differentiation, a candidate mechanism for the stronger place dedifferentiation reported in aging.

neuroscience↗

Reusing pipettes in Patch-seq: a foundation for automated multimodal profiling

Patch-seq is a technique for single-cell multimodal characterization. It combines whole-cell electrophysiology, single-cell transcriptomics, and morphological reconstruction in single neurons. Patch-seq morphologies are a critical bridge among cell types, genes, physiology, and large-scale connectivity platforms such as EM connectomes and single-cell-resolution projectomes. However, patch-seq experimental complexity and operator dependence limit throughput. Automation could enable scalable Patch-seq but requires procedural adaptations, including detergent-based pipette cleaning, robotic nucleus extraction and collection. The impact of these automations on Patch-seq quality has not been systematically evaluated. Here, we show that each of these modifications preserves or improves key Patch-seq outcomes. Automated nucleus extraction performs comparably to, or better than, expert manual operation, preserving key RNA and morphological metrics. Detergent-cleaned, reused pipettes supported a viable sealing success rate across multiple cleaning cycles and preserved electrophysiological quality and transcriptomic yield without introducing excess contamination. Sonication effectively allows collection of nuclear material without damaging RNA and supports subsequent pipette cleaning and reuse. Enhanced automated sealing and break-in procedures increased throughput regardless of brain region, cell type or species. Together, these results validate the core procedural adaptations required for automated Patch-seq and establish a foundation for high-throughput, standardized multimodal single-cell characterization.

neuroscience↗

Development of direction selectivity in the Xenopus tadpole optic tectum and midbrain tegmentum

Detecting motion direction is a fundamental function performed by direction selective (DS) neurons. DS neurons in the optic tectum (superior colliculus in mammals) enable the tracking of moving objects. DS neurons of the accessory optic system support reflexive eye / head movements that stabilize gaze during self-motion. By developmental stage 48 (10 days postfertilization), Xenopus tadpoles display visually guided behaviors that require both types of DS neurons. Our previous work has shown that these two regions are not only functionally distinct but also follow different developmental programs. Here we characterized and compared how direction selectivity develops in both visual processing centers. Using in vivo electrophysiological recordings during moving bar visual stimulation, we measured DS synaptic inputs and spiking outputs in both regions across three key developmental stages of the retinotectal projection. Tegmental neurons were direction selective ab initio, and both input and output tuning remained stable across development. Tectal neurons were observed to receive DS inputs early, and their input selectivity also remained stable across development. However, their spiking output grew substantially more DS at the later developmental stage. This was due at least in part to a naturally occurring decrease in intrinsic excitability which preferentially dampened overall spike rates, but especially in response to the non-preferred direction of motion, thereby increasing direction selectivity. These results reveal distinct developmental trajectories in parallel visual pathways. Tegmental direction selectivity is established early and stays stable, whereas tectal output tuning sharpens during development through a decrease in intrinsic excitability.

neuroscience↗