Biology subjects

Lojkiewiez, M.

Publications and source records attributed to Lojkiewiez, M..

3 recordsLinked to original sources

bioRxiv2025

Multi-focal ultrasound neuromodulation to the dorsal anterior cingulate cortex disrupts behavioural and neural pain processing

Transcranial ultrasound stimulation (TUS) is a promising non-invasive technique for modulating deep brain regions involved in pain. TUS applied to the dorsal anterior cingulate cortex (dACC), a region implicated in chronic pain and established target for deep brain stimulation, has shown potential for reducing pain. This study aimed to investigate the neural mechanisms underlying TUS effects on pain in healthy participants using neuroimaging. Thirty-two participants underwent two double-blind, randomised TUS-fMRI sessions (active or sham). A tonic cold stimulus was applied during multifocal dACC-TUS and during fMRI and magnetic resonance spectroscopy (MRS) blocks. While no significant main effect of TUS on pain intensity was observed, active TUS showed a significantly greater reduction in pain ratings between 28- and 55-minutes post-stimulation, suggesting a delayed analgesic effect. Active TUS also disrupted the typical relationship between stimulus temperature and reported pain intensity, indicating altered sensory encoding. There was increased functional connectivity between the dACC and the supplementary motor area, pre-motor cortex, mid-ACC and the supramarginal gyrus, along with decreased coupling with the periaqueductal grey (PAG), and altered salience network connectivity. Overall, these findings suggest TUS to the dACC has multidimensional effects across behavioural and neural aspects of pain processing, supporting its potential therapeutic value.

neuroscience↗

bioRxiv2024

Non-invasive Ultrasound Deep Neuromodulation of the Human Nucleus Accumbens Increases Win-Stay Behaviour

Precisely neuromodulating deep brain regions could bring transformative advancements in both neuroscience and treatment. We demonstrate that non-invasive transcranial ultrasound stimulation (TUS) can selectively modulate deep brain activity and affect learning and decision making, comparable to deep brain stimulation (DBS). We tested whether TUS could causally influence neural and behavioural responses by targeting the nucleus accumbens (NAcc) using a reinforcement learning task. Twenty-six healthy adults completed a within-subject TUS-fMRI experiment with three conditions: TUS to the NAcc, dorsal anterior cingulate cortex (dACC), or Sham. After TUS, participants performed a probabilistic learning task during fMRI. TUS-NAcc altered BOLD responses to reward signals in the NAcc and surrounding areas. It also affected reward-related features, including win-stay strategy use, learning rate following rewards and learning curves. DBS-NAcc perturbed the same features, confirming target engagement. These findings establish TUS as a viable approach for non-invasive deep-brain neuromodulation.

neuroscience↗

bioRxiv2021

Social prediction modulates activity of macaque superior temporal cortex

The ability to attribute thoughts to others, also called theory of mind (TOM), has been extensively studied. Computationally, the basis of TOM in humans has been interpreted within the predictive coding framework and associated with activity in the temporo-parietal junction (TPJ). However, the evolutionary origins of these human mindreading abilities have been challenged since the concept was coined. Here we identify a brain region in the Rhesus macaque that shares computational properties with the human TPJ. We revealed, using a non-linguistic task and functional magnetic resonance imaging, that activity in a region of the macaque middle superior temporal cortex was specifically modulated by the predictability of social interactions. As in human TPJ, this region could be distinguished from other temporal regions involved in face processing. Our result suggests the existence of a precursor for the theory of mind ability in the last common ancestor of human and old-world monkeys.

neuroscience↗