Kirill V. Nourski, Mitchell Steinschneider, Ariane E. Rhone, Rashmi N. Mueller, Matthew I. Banks
{"title":"Modulation of Auditory Novelty Processing by Dexmedetomidine and Natural Sleep: A Human Intracranial Electrophysiology Study","authors":"Kirill V. Nourski, Mitchell Steinschneider, Ariane E. Rhone, Rashmi N. Mueller, Matthew I. Banks","doi":"10.1111/ejn.70181","DOIUrl":"https://doi.org/10.1111/ejn.70181","url":null,"abstract":"<p>Identifying neural signatures of loss of consciousness is a major goal of neuroscience. The local/global auditory novelty paradigm has been useful in characterizing sensory processing across arousal states. Propofol suppresses responses to long-term novelty (global deviance, GD) at subhypnotic doses; suppression of responses to short-term novelty (local deviance, LD) outside auditory cortex may represent a biomarker of loss of consciousness. Dexmedetomidine is an alpha-2 adrenergic agonist that induces sleep-like sedation. This study examined whether the changes in auditory novelty processing observed with propofol, a GABA-ergic agent, also occur with dexmedetomidine and during sleep. Intracranial recordings were obtained in neurosurgical patients undergoing monitoring for refractory epilepsy. Stimuli were vowel sequences incorporating LD and GD. Neural activity was recorded during wakefulness, administration of dexmedetomidine, and sleep and was examined as the averaged evoked potential (AEP) and high gamma (70–150 Hz) power. AEP responses were more broadly distributed than high gamma activity. Results previously observed with propofol were replicated with dexmedetomidine. Subhypnotic doses led to decreased LD effects and a precipitous decline in GD effects. Loss of responsiveness was associated with loss of LD effects outside the auditory cortex. Likewise, daytime sleep was associated with cessation of GD effects and confinement of LD effects to the auditory cortex. Results support the generalizability of changes in auditory novelty processing to dexmedetomidine and sleep. Preservation of LD effects in the auditory cortex indicates that the auditory cortex continues to monitor the environment following loss of responsiveness.</p>","PeriodicalId":11993,"journal":{"name":"European Journal of Neuroscience","volume":"62 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ejn.70181","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144615349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Peyman Esmaili-Shahzade-Ali-Akbari, Arshia Bozorgnia, Mohammad Shaterian, Samiya Jandaghian, Samaneh Moghimi Shahri
{"title":"Oxytocin Neuropeptide in the Control of Drug Dependence: A Review of Past Studies and Future Challenges","authors":"Peyman Esmaili-Shahzade-Ali-Akbari, Arshia Bozorgnia, Mohammad Shaterian, Samiya Jandaghian, Samaneh Moghimi Shahri","doi":"10.1111/ejn.70197","DOIUrl":"https://doi.org/10.1111/ejn.70197","url":null,"abstract":"<div>\u0000 \u0000 <p>Oxytocin has been the focus of much research today. Although initially thought to be a simple peptide involved in uterine contractions, further research has shown that it is a neurotransmitter that influences human social behavior and also plays a role in anxiety and addiction. Interestingly, oxytocin receptors are present throughout the brain, and the oxytocin system interacts with the reward and glutamate systems at several sites. Therefore, many studies have investigated the effect of oxytocin administration on drug tolerance and dependence. Given the importance of the subject, the present literature specifically summarizes the results of studies (clinical and preclinical) conducted on the effect of oxytocin on drug dependence. We then review the possible cellular and molecular mechanisms involved in the anti-addictive effects of oxytocin, and finally address the challenges of clinical application of oxytocin. Despite some conflicting results, many findings have clearly demonstrated that oxytocin administration can reduce drug-induced dependence. The present review suggests further studies to address some of the challenges of the clinical application of oxytocin in addiction treatment, such as dose-dependent effects in different brain regions.</p>\u0000 </div>","PeriodicalId":11993,"journal":{"name":"European Journal of Neuroscience","volume":"62 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144598632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ingrid Buller-Peralta, Javier Diaz, Valeria Gonzalez, Alejandro Bassi, Adrian Ocampo-Garcés, José L. Valdés
{"title":"Disinhibition of the Ventral Tegmental Area After Trauma Restores REM Sleep Disturbances and Reduces Long-Term Behavioral Indices of Fear Memory","authors":"Ingrid Buller-Peralta, Javier Diaz, Valeria Gonzalez, Alejandro Bassi, Adrian Ocampo-Garcés, José L. Valdés","doi":"10.1111/ejn.70189","DOIUrl":"https://doi.org/10.1111/ejn.70189","url":null,"abstract":"<div>\u0000 \u0000 <p>Posttraumatic stress disorder (PTSD) is a pathological condition mainly characterized by the inability to extinct fear responses associated with a traumatic event and profound alteration in REM sleep. A decrease in the activity of dopaminergic neurons of the ventral tegmental area (VTA) after trauma has emerged as a potential neurophysiological substrate for PTSD development through reciprocal interactions between fear extinction and REM sleep. We disinhibited the neuronal activity of the VTA by blocking GABA transmission immediately after a foot shock trauma. Rats were treated during a six-hour sleep recording with bilateral microinjections of picrotoxin or vehicle. A group of picrotoxin and REM sleep deprivation was included to test the role of REM sleep. Conditioned fear was tested 24 h following a 5-day fear extinction protocol, after which extinction learning was evaluated before another 6 h of sleep recording. Animals treated with picrotoxin could extinguish fear and did not show REM sleep disturbances compared to vehicle-treated animals. This improvement was REM sleep–dependent, as deprived rats evidenced similar REM sleep decrease and memory fear extinction impairments compared to the vehicle group. The effect on REM sleep was achieved by preserving the number of bouts but not increasing their duration, suggesting a protective effect over the ability to transition towards REM. Our results suggest that the disinhibition of dopaminergic neurons during a critical window after trauma could reduce the REM sleep and memory fear extinction disturbances induced by trauma, opening new avenues for therapeutic interventions.</p>\u0000 </div>","PeriodicalId":11993,"journal":{"name":"European Journal of Neuroscience","volume":"62 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144598633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sarah Beggiato, P. Leon Brown, Snezana Milosavljevic, Marian A. R. Thomas, Maria V. Piroli, Korrapati V. Sathyasaikumar, Francesca M. Notarangelo, Robert Schwarcz, Ana Pocivavsek
{"title":"Functional Impairments in Learning and Signal Propagation Following Prenatal Kynurenine Treatment in Mice","authors":"Sarah Beggiato, P. Leon Brown, Snezana Milosavljevic, Marian A. R. Thomas, Maria V. Piroli, Korrapati V. Sathyasaikumar, Francesca M. Notarangelo, Robert Schwarcz, Ana Pocivavsek","doi":"10.1111/ejn.70185","DOIUrl":"https://doi.org/10.1111/ejn.70185","url":null,"abstract":"<p>The levels of kynurenic acid (KYNA), a metabolite of the kynurenine pathway (KP) of tryptophan degradation, are elevated in the brain of persons with schizophrenia (SZ) and may be linked to cognitive dysfunctions in the disease. Studies in rats indicate that abnormally high fetal brain KYNA may play a pathophysiologically significant role in this context (“EKyn model”). Here, we fed pregnant C57Bl/6J mice with the immediate KYNA precursor kynurenine (10 mg or 30 mg/day; EKyn) or with control chow (ECon) from embryonic day (ED) 11 to ED 18 and assessed offspring postnatally both functionally and biochemically. In adulthood, male, but not female, EKyn mice showed significant impairments in spatial and reversal learning. Moreover, ex vivo recording of evoked local field potentials in coronal brain slices revealed a longer contralateral response latency in EKyn than in ECon animals, suggesting impaired white matter function. However, plasma and brain levels of KYNA and of another KP metabolite, 3-hydroxykynurenine, did not differ between groups on postnatal day (PD) 21, on PD 35 (adolescence), or in adulthood (PD 56–75). Separate mice were fed prenatally with 4-chloro-kynurenine (20 mg/day), which is converted to the selective NMDA receptor antagonist 7-chloro-KYNA in vivo. Offspring did not show electrophysiological impairments in adulthood, indicating that NMDA receptors in the fetal brain were not the sole cause of functional deficits of EKyn mice later in life. The implications of these experiments for the study of psychiatric symptoms, as well as the unexpected differences between rats and mice, are discussed.</p>","PeriodicalId":11993,"journal":{"name":"European Journal of Neuroscience","volume":"62 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ejn.70185","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144598551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fábio Leite do Amaral Júnior, Thalyta Alves Rodrigues, Nonata Lúcia Trévia da Silva, Izabela Negrão Almeida Diniz, Luciana Negrão Almeida de Morais, Daniel Guerreiro Diniz, Dora Brites, Daniel Clive Anthony, Cristovam Wanderley Picanço Diniz
{"title":"Comparative Neuroplasticity in Frontal- and Lateral-Eyed Mammals With Induced-Binocular Vision Dysfunction: Insights From Monocular Deprivation Models","authors":"Fábio Leite do Amaral Júnior, Thalyta Alves Rodrigues, Nonata Lúcia Trévia da Silva, Izabela Negrão Almeida Diniz, Luciana Negrão Almeida de Morais, Daniel Guerreiro Diniz, Dora Brites, Daniel Clive Anthony, Cristovam Wanderley Picanço Diniz","doi":"10.1111/ejn.70179","DOIUrl":"https://doi.org/10.1111/ejn.70179","url":null,"abstract":"<p>Visual cortical plasticity during early postnatal life is profoundly shaped by species-specific ocular anatomy and ecological demands. This review synthesizes comparative evidence on how monocular deprivation (MD)—a classical model of amblyopia—affects visual system development in frontal- versus lateral-eyed mammals. Frontal-eyed species, including cats and primates, exhibit extensive binocular field overlaps and columnar architecture in the primary visual cortex (V1), making them highly susceptible to MD-induced shifts in ocular dominance and synaptic remodeling. In contrast, lateral-eyed species such as rodents and ungulates possess limited binocular overlaps and lack well-defined ocular dominance columns yet still demonstrate significant MD-induced plasticity involving callosal reorganization, glial activation, and extracellular matrix remodeling. We examine shared and divergent cellular mechanisms underpinning these responses, including the role of parvalbumin-expressing interneurons, perineuronal nets, and neuromodulators like BDNF and NRG1. Rodent models support the notion that even in the absence of classical columnar organization, lateral-eyed species can undergo region-specific structural remodeling in V1 following MD. These distinctions underscore how binocular integration circuits are fine-tuned through extended critical periods in frontal-eyed species, whereas plasticity in lateral-eyed species is more diffusely distributed. The integration of cross-species data revealed conserved principles of visual cortical plasticity and identified mechanisms potentially targetable for amblyopia therapy. Understanding the ecological and anatomical context of plasticity allows for a more accurate interpretation of animal models and supports the development of precision strategies for visual rehabilitation. This comparative framework expands the scope of amblyopia research and offers new avenues for translational interventions.</p>","PeriodicalId":11993,"journal":{"name":"European Journal of Neuroscience","volume":"62 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ejn.70179","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144589645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Li-Ann Leow, Welber Marinovic, Scott Albert, Timothy J. Carroll
{"title":"Time Alters Distinct Memories Driven by Sensory Prediction Errors and Task Errors in Sensorimotor Adaptation","authors":"Li-Ann Leow, Welber Marinovic, Scott Albert, Timothy J. Carroll","doi":"10.1111/ejn.70196","DOIUrl":"https://doi.org/10.1111/ejn.70196","url":null,"abstract":"<p>Prior learning can impair future learning when the requirements of the two memories conflict, a phenomenon termed anterograde interference. In sensorimotor adaptation, the passage of time between initial and future learning can reduce such interference effects, leading to the interpretation that time consolidates motor memories, protecting motor memories from interference. However, we still do not fully understand how time affects learning, as some studies found no effects of time on interference. One possible explanation for such inconclusive findings is that time has distinct effects on the multiple processes underpinning sensorimotor adaptation, and these processes may compensate for each other's effects on behaviour. Here, we used task manipulations that (1) dissociate adaptation processes driven by task errors from adaptation processes driven by sensory prediction errors and (2) separate the task-error driven adaptation processes into a flexible component that could not be acquired under time–pressure from a less flexible component that could be acquired under time–pressure. Consistent with interpretations from early reports, we found that the passage of time reduced anterograde interference effects in the adaptation component driven by sensory prediction errors. The passage of time between initial and subsequent learning also enhanced components of adaptation driven by task error: enhancing both the flexible, time-consuming component and the inflexible, time-efficient component driven by task errors. Thus, we provide evidence that multiple components of sensorimotor adaptation are sensitive to the passage of time.</p>","PeriodicalId":11993,"journal":{"name":"European Journal of Neuroscience","volume":"62 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ejn.70196","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144589599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhen Tan, Weilong Li, Weijing Wang, Dongfeng Zhang, Qihua Tan
{"title":"Differential Epigenetic Regulation of Glutamatergic Synapse Pathway in Adults With Prenatal Exposure to Famine","authors":"Zhen Tan, Weilong Li, Weijing Wang, Dongfeng Zhang, Qihua Tan","doi":"10.1111/ejn.70195","DOIUrl":"https://doi.org/10.1111/ejn.70195","url":null,"abstract":"<p>It has been hypothesized that poor nutrition during prenatal growth may alter the development of vital organs like the brain, thus “program” predisposition to certain diseases later in life, including mental disorders. Although with support from studies using animal models and epidemiologic observations, the biological aspect of the hypothesis has been rarely studied in humans. Using famine as a natural experiment, we explored the altered DNA methylation patterns in genes of the glutamate synapse pathway in whole blood of adults born during the Chinese famine of 1959–1961. We detected significant patterns of hypomethylation for the whole pathway (<i>p</i> = 0.025), for the <i>GRIA1</i> gene in the AMPA subunit (<i>p</i> = 0.004), for <i>GRM2</i> (<i>p</i> = 0.023) and <i>GRM3</i> (<i>p</i> = 0.019) genes in the metabotropic receptor subunit. Our sex-stratified analysis identified significant enrichment of hypomethylation for the overall pathway (<i>p</i> = 0.031), for <i>GRIA1</i> genes (<i>p</i> = 0.009), <i>GRIA4</i> gene (<i>p</i> = 0.014), and <i>GRM3</i> gene (<i>p</i> = 0.031) in females but no significantly enriched pattern in males. Further analysis by location in gene locus found significant enrichment of hypomethylation of the pathway genes in the gene body in sex-combined (<i>p</i> = 0.020) and in female (<i>p</i> = 0.026) samples. In conclusion, our epigenetic association analysis found significantly enriched hypomethylation patterns for the glutamate synapse pathway and for genes in subunits of the pathway, which are more pronounced in female than in male samples prenatally exposed to famine.</p>","PeriodicalId":11993,"journal":{"name":"European Journal of Neuroscience","volume":"62 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ejn.70195","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144589644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Brain–Computer Interfaces in Spinal Cord Injury: A Promising Therapeutic Strategy","authors":"Shizhe Li, Shutao Gao, Yukun Hu, Jianlin Xu, Weibin Sheng","doi":"10.1111/ejn.70183","DOIUrl":"https://doi.org/10.1111/ejn.70183","url":null,"abstract":"<div>\u0000 \u0000 <p>The current treatment regimen for spinal cord injury (SCI), a neurological disorder with a high incidence of disability, is based on early surgical decompression and administration of pharmacological agents. However, the efficacy of such an approach remains limited, and most patients have sensory and functional deficits below the level of injury, which seriously affects their quality of life. This necessitates further exploration into effective treatment modalities. In recent years, considerable advancements have been made in developing and utilizing brain–computer interfaces (BCI), which facilitate neurorehabilitation and enhance motor function by transforming brain signals into diverse forms of output commands. BCI-assisted systems provide alternative means of rehabilitative exercise or limb movement in patients with SCI, including electrical stimulation and exoskeleton robots. BCI shows great potential in the rehabilitation of patients with SCI. This review summarizes the current research status and limitations of BCI for SCI to provide novel insights into the concept of multimodal rehabilitation and treatment of SCI and facilitate BCI's future development.</p>\u0000 </div>","PeriodicalId":11993,"journal":{"name":"European Journal of Neuroscience","volume":"62 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144573703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sex Differences in Motor Unit Behavior in Patients With Parkinson's Disease","authors":"Yuichi Nishikawa, Kohei Watanabe, Aleš Holobar, Tetsuya Takahashi, Noriaki Maeda, Hirofumi Maruyama, Allison Hyngstrom","doi":"10.1111/ejn.70191","DOIUrl":"https://doi.org/10.1111/ejn.70191","url":null,"abstract":"<p>The aim of this study was to determine whether there are sex differences in motor unit firing behavior in patients with Parkinson's disease. Twenty-seven patients with Parkinson's disease (females = 14 [age = 71.1 ± 6.8], males = 13 [age = 69.2 ± 10.3], Unified Parkinson's Disease Rating Scale Part III score; females = 10.8 ± 4.8, males = 11.4 ± 1.4) performed a contraction at 30% of the maximal voluntary contraction. For each participant, motor unit spike trains were decomposed from high-density surface electromyography data recorded from bilateral vastus lateralis muscles via blind source separation algorithms. In addition to the mean discharge rates, persistent inward currents were estimated via a paired motor unit analysis. Females presented significantly greater laterality of discharge rate (<i>p</i> = 0.001) and persistent inward currents (<i>p</i> = 0.0121) than males. A significant correlation was observed between the discharge rate and the recruitment threshold on the bilateral side of males and the less-affected side of females but not on the more-affected side of females. These findings indicate that sex differences in motor unit behavior exist in Parkinson's disease patients. Motor unit behavior may be a sensitive and quantitative evaluation tool to highlight differences in disease presentation between males and females.</p>","PeriodicalId":11993,"journal":{"name":"European Journal of Neuroscience","volume":"62 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ejn.70191","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144573688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Julian Colard, Julien Duclay, Yohan Betus, Thomas Cattagni, Marc Jubeau
{"title":"Muscle Length Modulates Recurrent Inhibition and Presynaptic Inhibition of Ia Afferents Differently Depending on Type of Contraction","authors":"Julian Colard, Julien Duclay, Yohan Betus, Thomas Cattagni, Marc Jubeau","doi":"10.1111/ejn.70172","DOIUrl":"https://doi.org/10.1111/ejn.70172","url":null,"abstract":"<div>\u0000 \u0000 <p>It is well documented that, in soleus, motoneuron output and the effectiveness of activated Ia afferents to discharge α-motoneurons both decrease during eccentric contractions. Evidence suggests that these regulations can be explained by recurrent inhibition and greater presynaptic inhibition of Ia afferents. However, the influence of muscle length on the regulation of the effectiveness of activated Ia afferents to discharge α-motoneurons observed during eccentric contractions remains unclear. We conducted a study on 16 healthy young individuals. We used simple and conditioned Hoffmann reflex with different conditioning techniques such as H′ method, D1 method and heteronymous Ia facilitation coupled with electromyography during eccentric, isometric and concentric contractions at long, intermediate and short soleus muscle lengths. Our results confirm that during eccentric contraction effectiveness of activated Ia afferents to discharge α-motoneurons decreases only at intermediate and short muscle lengths but is similar between all contraction types at long muscle length. Findings are similar for recurrent inhibition. Presynaptic inhibition of Ia afferents is significantly more pronounced during eccentric contractions compared with isometric and concentric contractions at long muscle length. These findings highlight the significant impact of joint position on spinal regulatory mechanisms, particularly during eccentric contractions. Our analysis also reveals that recurrent inhibition and presynaptic inhibition of Ia afferents are more pronounced at long muscle lengths compared to short muscle lengths, regardless of the contraction type. This result has uncovered a previously unknown function of recurrent inhibition, potentially modulating motoneuron frequency discharge in response to changes in muscle length.</p>\u0000 </div>","PeriodicalId":11993,"journal":{"name":"European Journal of Neuroscience","volume":"62 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144550990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}