Frontiers in Integrative Neuroscience

The nucleus tractus solitarii across vertebrates: developmental origins, comparative organization, and supranuclear modulation in humans

2026-03-17

Yong-Shin Hong, Young-seok Park

The nucleus tractus solitarii (NTS) is a highly conserved brainstem structure that has served as a principal hub for visceral sensory integration across vertebrate evolution. While the NTS has long been described as a relay for cardiovascular and respiratory reflexes, recent work increasingly frames it as an integrative node that transforms diverse afferent signals into adaptive, context-sensitive responses. In this review, we synthesize evidence on the developmental origins of the NTS (including contributions from the dorsal alar plate and epibranchial placodes) and its comparative organization across vertebrate taxa. We argue that many interspecies differences are more plausibly interpreted as functional reweighting within a conserved circuit framework—shaped by species-specific respiratory–feeding strategies and ecological demands—rather than as wholesale rewiring of the core network. Within this comparative context, the extensive supranuclear modulation observed in humans is discussed not as biological “superiority,” but as layered control that has become particularly prominent in response to human-specific anatomical constraints and behavioral demands, including those associated with speech and complex social interaction. Clinically, we revisit dysphagia, cough hypersensitivity, and nausea/vomiting as manifestations of network-level dysregulation and gating failure rather than isolated breakdowns of single reflex arcs. Finally, we suggest that neuromodulation strategies, including vagus nerve stimulation, may be best conceptualized as delivering patterned afferent input capable of shaping NTS network plasticity, rather than as non-specific electrical activation.

Conceptualizing the studies of time perception in spinal cord injury

2026-02-13

Ekaterina D. Slovenko, Pavel E. Musienko, Olga V. Sysoeva

Kiperin Mind Focus supplement mitigates chronic stress–induced neuroinflammation and molecular dysregulation and improves stress-related affective and exploratory behaviors in rats

2026-01-29

Lutfiye Karcioglu Batur, Cuneyd Yavas, Aysu Kilic, Tunay Dogan, Mert Yilmaz, Ahsen Pektas, Huri Demirci, Savas Ustunova

BackgroundChronic stress is known to impair emotional regulation and adaptive behavioral responses through neuroinflammatory activation, oxidative imbalance, and dysregulation of neuroplasticity-related genes. Kiperin Mind Focus, a nootropic nutraceutical containing L-theanine, citicoline, phosphatidylserine, Rhodiola rosea, Ginkgo biloba, caffeine, and Lion’s Mane mushroom extract has been formulated to support stress resilience, mood regulation and neural health. This study aimed to investigate the neuroprotective and neuroregulatory effects of the combined formulation on behavioral, biochemical, histopathological, and molecular parameters in rats exposed to chronic unpredictable mild stress (CUMS).MethodsThirty-two adult male Wistar rats were randomized into four groups (n = 8): Control, Stress, Kiperin Mind Focus (MF), and Stress + Mind Focus (SMF). CUMS was applied for 45 days, and the combined formulation was administered by oral gavage (130 mg/kg/day). Behavioral outcomes were evaluated using the sucrose preference (SPT), open field (OFT), elevated plus maze (EPM), and forced swim (FST) tests. Serum and tissue cytokine levels (IL-1β, IL-6, IL-10, TNF-α) and oxidative stress index (TOS/TAS ratio) were measured. Hippocampal and prefrontal gene expression of FOS, DBH, NMB, BDNF, CREB1, GRIN2A, and GABRB1 was assessed via qPCR, and histopathological changes were semi-quantitatively scored.ResultsChronic stress induced anhedonia, anxiety-like behavior, and behavioral despair, accompanied by elevated proinflammatory cytokines, oxidative imbalance, and neuronal degeneration in the hippocampus and prefrontal cortex. The supplementation significantly improved SPT, OFT, EPM, and FST performance, normalized cytokine and oxidative parameters, and reduced neuronal injury scores. At the molecular level, supplementation attenuated stress-induced upregulation of FOS, DBH, and NMB while maintaining neurotrophic (BDNF, CREB1) and GABAergic (GABRB1) expression near control levels.ConclusionKiperin Mind Focus exerted robust neuroprotective, anti-inflammatory, and antioxidant effects under chronic stress, restoring molecular homeostasis and stabilizing stress-related behavioral outcomes. These findings support its role as a stress-buffering and mood-stabilizing supplement, that promotes emotional regulation and adaptive exploratory behavior under prolonged stress conditions.

Noise-induced vestibular dysfunction in rats: longitudinal assessment using cVEMP and behavioral testing after low-frequency acoustic trauma

2026-01-05

Fatma Nur Komur, Bugra Genc, Luis Roberto Cassinotti, Gabriel Corfas, Ayca Ciprut, Ali Cemal Yumusakhuylu

Background and objectiveHigh-intensity noise exposure is a well-established risk factor for auditory dysfunction; however, its effects on the vestibular system remain poorly understood. This is an important question due to the anatomical proximity and shared vulnerability of cochlear and vestibular structures. This study aims to determine the longitudinal effects of prolonged low-frequency noise (LFN) exposure at two different sound intensities (110- and 120-dB SPL) on vestibular function in Sprague-Dawley rats using behavioral and electrophysiological assessments.Materials and methodsAdult male Sprague-Dawley rats (3-months-old) were exposed to LFN (0.5–4.0 kHz) at either 110- or 120-dB SPL for 6 h and monitored over 21 days. Cervical vestibular-evoked myogenic potentials (cVEMPs), auditory brainstem responses (ABRs), and balance-related behaviors were evaluated at baseline and different times after exposure.ResultsExposure to 120 dB SPL resulted in significant and permanent vestibular dysfunction, evidenced by elevated cVEMP thresholds and reduced cVEMP P1-N1 suprathreshold amplitudes. These parameters partially recovered over 21 days but did not return to baseline levels. As expected for this noise exposure, large ABR thresholds increases and peak I amplitudes reductions were observed. In addition, behavioral tests showed impaired motor coordination over 21 days. In contrast, 110 dB SPL exposure only caused temporary cVEMP P1-N1 amplitude decreases and much smaller ABR threshold increases.ConclusionThese results show that, similar to the auditory system, LFN exposure has an intensity-dependent effect on vestibular function and highlight the importance of including vestibular evaluations for a comprehensive assessment of noise-induced health conditions.

Examining the role of early bilingualism on interference suppression and prefrontal connectivity

2025-12-17

Matthew L. Cook, Lisa K. Boyce, Allison S. Hancock, Makenzy S. Turner, Spencer D. Bradshaw

Inhibitory control is a core cognitive function that is primarily associated with activation in the prefrontal cortex (PFC) and is the cognitive function that inhibits impulses, thoughts, and suppresses irrelevant information to an identified goal or task. Prior research suggests that bilingualism may affect brain activity related to inhibitory control, yet few studies have compared functional activity between monolingual and bilingual children. The current study used functional near-infrared spectroscopy (fNIRS) to examine region of interest comparisons and task-state functional connectivity across the PFC during an interference suppression Simon task with 13 bilingual (East Asian or Ibero-romance paired with English) and 13 age-matched English monolingual preschoolers. Results showed no significant differences in behavioral measures of interference suppression. However, bilingual preschoolers showed lower oxygenated hemoglobin activation and more localized patterns of connectivity within the PFC, suggesting more efficient processing during suppression compared to their monolingual peers. This may reflect the bilingual experience of regularly suppressing their second language when not in use, thus facilitating neural efficiency. These findings contribute to the growing body of literature on bilingual cognitive development suggesting that functional connectivity during executive function may differ in bilingual children, even at a young age, despite no observable behavioral differences. This highlights the importance of integrating neuroimaging with behavioral data to gain a more comprehensive understanding of bilingual cognitive development.