Frontiers in Neural Circuits最新文献

{"title":"Representations of facial features and surface quality in monkey area TE compared to neural network models.","authors":"Keisuke Shioya, Kazuko Hayashi, Bing Li, Narihisa Matsumoto, Keiji Matsuda, Kenichiro Miura, Mark A G Eldridge, Richard C Saunders, Barry J Richmond, Yuji Nagai, Naohisa Miyakawa, Takafumi Minamimoto, Shun Katakami, Masato Okada, Kenji Kawano, Yasuko Sugase-Miyamoto","doi":"10.3389/fncir.2026.1783892","DOIUrl":"10.3389/fncir.2026.1783892","url":null,"abstract":"<p><p>The shape and spacing of facial features are essential for the perception of emotional expressions and the identification of individuals. The surface quality of faces, such as skin texture, eye twinkle, and hair gloss, is valuable for estimating health status. A previous fMRI study in monkeys revealed that regions selective for faces overlapped regions selective for object gloss in the central inferior temporal (IT) cortex, suggesting that the surface quality of faces is processed in area TE. However, the representation of facial surface quality has not been directly examined in this area. To understand neural processing of surface quality in face images, neuronal activity was recorded in area TE of three monkeys while face images with different expressions, identities, and surface qualities were presented. The surface qualities included gloss modulations - high-gloss and low-gloss, and \"style-transfer\" where facial texture was replaced with fabric. These representations were compared to those in several models, including Convolutional Neural Networks and Vision Transformer. Our results revealed that the style-transferred face images strongly modulated activity in TE neurons and that some neurons were tuned to monkey facial expressions, whereas others were more influenced by surface quality. In contrast, the models showed relatively large contributions of surface-quality representation, particularly to the separation between the original and style-transferred faces, compared with those of facial expression and identity. This trend was observed even in models trained on the stylized ImageNet dataset, which was designed to reduce reliance on texture-based classification. These results suggest a strong influence of image style transfer on both TE neurons and models, the diversity of the facial representations by TE neurons, and the tendency of models to emphasize the style-transferred images regardless of training. These findings highlight a potential limitation in current artificial vision models and underscore the value of examining biological representations to inspire more robust and adaptable visual recognition in future model designs.</p>","PeriodicalId":12498,"journal":{"name":"Frontiers in Neural Circuits","volume":"20 ","pages":"1783892"},"PeriodicalIF":2.9,"publicationDate":"2026-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13478094/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148791174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Whole-brain input organization of <i>Kremen1</i>-positive striatal spiny projection neurons revealed by monosynaptic rabies tracing.","authors":"Victor M Martinez Smith, Jie Dong, Ronald F Paletzki, Lisa Chang, Lupeng Wang, Charles R Gerfen, Huaibin Cai","doi":"10.3389/fncir.2026.1895042","DOIUrl":"10.3389/fncir.2026.1895042","url":null,"abstract":"<p><p>Determining the organization of inputs to subtypes of striatal spiny projection neurons (SPNs) is essential to understand how the striatum integrates information to regulate motor control and decision making. Here, we employed monosynaptic rabies tracing in <i>Kremen1</i> ^2A-Cre knock-in mice to map inputs to <i>Kremen1</i>-positive (<i>Kremen1</i> ⁺) SPNs, a subtype enriched in patch (striosome) compartments of the dorsal striatum. Starter cells were broadly distributed along the rostrocaudal axis of the dorsal striatum. Whole-brain analysis revealed that <i>Kremen1</i> ⁺ SPNs receive prominent inputs from motor, somatosensory, and prefrontal cortices, as well as from multiple thalamic nuclei. Additional inputs originated from the amygdala, basal ganglia, and midbrain regions, including dopaminergic populations. Quantitative analysis indicated a strong bias toward sensorimotor-related circuits. Together, these results provide a comprehensive whole-brain input map of <i>Kremen1</i> ⁺ SPNs and suggest that these neurons are positioned to integrate cortical, thalamic, and neuromodulatory signals within basal ganglia networks to regulate motor function.</p>","PeriodicalId":12498,"journal":{"name":"Frontiers in Neural Circuits","volume":"20 ","pages":"1895042"},"PeriodicalIF":2.9,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13462475/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148721974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transsynaptic viral tools in neural circuit analysis: from anatomical mapping to functional interrogation.","authors":"Zsolt Boldogkői, Gábor Torma, Zsolt Csabai, Zoltán Máté, Rebeka Fekete, Máté Mizik, Ferenc Erdélyi, Dóra Tombácz, Ádám Dénes","doi":"10.3389/fncir.2026.1893057","DOIUrl":"10.3389/fncir.2026.1893057","url":null,"abstract":"<p><p>The application of transsynaptic viruses has transformed neural circuit analysis, enabling increasingly precise mapping of neuronal connectivity. These approaches can be broadly divided into polysynaptic and monosynaptic strategies. Polysynaptic retrograde tracers based on pseudorabies virus, including the classically selected Bartha strain and genetically engineered retrograde variants have provided important insights into multisynaptic circuit organization in rodents. For polysynaptic anterograde tracing, herpes simplex virus strain H129 and its derivatives have been used to map output pathways, with later genetic modifications improving detectability and experimental control. Over the past few years, growing attention has shifted toward monosynaptic tracing based on engineered rabies virus platforms used in combination with adeno-associated virus helper systems, which enable genetically restricted spread to direct presynaptic partners. Viral tracing is increasingly integrated with functional approaches, including calcium and voltage imaging, optogenetics, chemogenetics, and recombinase-based genetic strategies, thereby extending circuit analysis from anatomical mapping to causal interrogation of the function of defined neuronal populations. Looking forward, improved control of polysynaptic spread, together with large transgene capacity, suitability for tracing hierarchical circuit architecture, and the ability to incorporate functional readouts, is expected to revive interest in multisynaptic tracing.</p>","PeriodicalId":12498,"journal":{"name":"Frontiers in Neural Circuits","volume":"20 ","pages":"1893057"},"PeriodicalIF":2.9,"publicationDate":"2026-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13438269/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148677878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transspinal stimulation preceding step training reorganizes spinal locomotor circuits in human spinal cord injury: a randomized sham-controlled clinical trial.","authors":"Timothy S Pulverenti, Abdullah M Sayed Ahmad, Noam Y Harel, Maria Knikou","doi":"10.3389/fncir.2026.1876368","DOIUrl":"10.3389/fncir.2026.1876368","url":null,"abstract":"<p><strong>Introduction: </strong>Activity-based rehabilitation, such as locomotor training, is commonly used to induce positive systemic physiological adaptations and restore locomotion in individuals with chronic spinal cord injury (SCI). Restoration of locomotion with activity-based rehabilitation alone is not optimal and may require augmentation with neuromodulation strategies.</p><p><strong>Materials and methods: </strong>We characterized the excitability of spinal locomotor circuits during stepping in humans with SCI who underwent transspinal stimulation before locomotor training, within the same session. A total of 14 participants with chronic SCI received an average of 40 sessions of 30 Hz transspinal stimulation delivered for 30 min during standing (active or sham) or in the supine (active) position, followed by 30 min of robotic-assisted step training. Before and after the completion of all training sessions, we assessed the soleus H-reflex phase-dependent amplitude modulation and reciprocal Ia and presynaptic inhibition in response to a conditioning stimulus delivered to the common peroneal nerve.</p><p><strong>Results: </strong>Transspinal stimulation administered before locomotor training promoted soleus H-reflex depression during the swing phase in the active standing group (<i>n</i> = 5; <i>F</i> _{1, 309} = 4.52, <i>p</i> = 0.034), stabilized soleus H-reflex excitability during the stance phase in the active supine group (<i>n</i> = 5; <i>F</i> _{1, 327} = 18.44, <i>p</i> < 0.001), and promoted reduced ankle co-contraction during assisted stepping in all groups. Reciprocal inhibition between ankle flexors and extensors after treatment was reduced at mid-stance and during the swing-to-stance transition phase in the active standing group (<i>n</i> = 4; <i>F</i> _{1, 81} = 7.4, <i>p</i> = 0.008), while it was markedly potentiated through the swing phase in the sham standing group (<i>n</i> = 3; <i>F</i> _{1, 108} = 22.46, <i>p</i> < 0.001). Finally, generalized soleus H-reflex depression after the intervention in the active (<i>n</i> = 4; <i>F</i> _{1, 150} = 42.32, <i>p</i> < 0.001) and sham (<i>n</i> = 3; <i>F</i> _{1, 64} = 13.19, <i>p</i> < 0.001) standing groups supported potentiation for presynaptic inhibition.</p><p><strong>Conclusion: </strong>This study demonstrated that transspinal stimulation preceding locomotor training was associated with modulation of the spinal reflex pathways. These neurophysiological adaptations suggest increased responsiveness of spinal circuits, although further studies are needed to determine whether these changes translate into functional improvements in people with chronic SCI.</p>","PeriodicalId":12498,"journal":{"name":"Frontiers in Neural Circuits","volume":"20 ","pages":"1876368"},"PeriodicalIF":2.9,"publicationDate":"2026-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13422473/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148630042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predictive interception across speed profiles.","authors":"Inmaculada Márquez, Mario Treviño","doi":"10.3389/fncir.2026.1848603","DOIUrl":"10.3389/fncir.2026.1848603","url":null,"abstract":"<p><p>Visuomotor interception requires predicting a moving target's future state to compensate for sensorimotor delays. Predictive control has been studied mainly under constant-speed motion. How observers adapt when the temporal structure of target speed (<i>v</i> _<i>T</i> ) varies remains unclear. We examined interception across <i>v</i> _<i>T</i> profiles within the same individuals: constant, linear-ramp, and nonlinear (sinusoidal and semicircular). Participants intercepted a moving target while eye and hand movements were recorded; on a subset of trials, visual feedback was removed after an observation period to force reliance on internal estimates. Behavior stayed strongly dependent on <i>v</i> _<i>T</i> even under transient visual loss, but this dependence was constrained by how <i>v</i> _<i>T</i> evolved over time. Removing feedback increased spatial error and gaze-target distance, with modest effects at constant and linear <i>v</i> _<i>T</i> and larger errors at nonlinear <i>v</i> _<i>T</i> . Speed matching stayed stable, indicating that local velocity estimates are preserved but insufficient to prevent cumulative spatial error under more complex dynamics. Oculomotor measures were more sensitive than manual control, suggesting partially dissociable effectors. A within-cycle matched-velocity test on the linear-ramp data revealed acceleration-deceleration differences at every velocity bin and metric; the representation is velocity-dominated but not velocity-only, and it exploits higher-order kinematic information at least partially. Exploratory pupillometry showed stable pupil size during full visibility and a reduction late in masked trials, with outcome-dependent modulation independent of gaze position at target disappearance. Predictive interception thus relies on velocity-dominated representations that preserve sensitivity to higher-order kinematic information, enabling robust performance across simple motion profiles but imposing limits when target dynamics become nonlinear.</p>","PeriodicalId":12498,"journal":{"name":"Frontiers in Neural Circuits","volume":"20 ","pages":"1848603"},"PeriodicalIF":2.9,"publicationDate":"2026-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13402429/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148601600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cortical vestibular-visual interactions and cross-modal plasticity-adaptive neural processes for stable perception.","authors":"Huizhe Sun, Ziyi Tan, Fu Zeng, Aihua Chen","doi":"10.3389/fncir.2026.1876597","DOIUrl":"10.3389/fncir.2026.1876597","url":null,"abstract":"<p><p>The integration of vestibular and visual signals is essential for spatial orientation, self-motion perception, and postural stability. However, sensory conflicts and environmental changes demand adaptive neural mechanisms to maintain perceptual reliability. Cross-modal plasticity provides a key mechanism for this adaptation by dynamically recalibrating sensory representations in response to discordant or altered inputs. In this review, we summarize the cortical pathways underlying vestibular and visual processing, discuss how multisensory integration and segregation are implemented through distinct neuronal populations and computational principles. We further emphasize recalibration as a core adaptive mechanism that operates across multiple timescales-from gradual adjustments to persistent cue discrepancies to rapid updates shaped by recent sensory history and prior decisions. By synthesizing behavioral and neural evidence, we reveal differential adaptive responses across multisensory cortical areas and propose visual-vestibular recalibration as a fundamental principle of multisensory plasticity, with broad implications for understanding brain function and developing translation approaches for sensory and balance disorders.</p>","PeriodicalId":12498,"journal":{"name":"Frontiers in Neural Circuits","volume":"20 ","pages":"1876597"},"PeriodicalIF":2.9,"publicationDate":"2026-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13376239/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148577843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Volume electron microscopy in axon regeneration research: insights into mitochondria, endoplasmic reticulum, and membrane contacts.","authors":"Hiromi Tamada","doi":"10.3389/fncir.2026.1870424","DOIUrl":"10.3389/fncir.2026.1870424","url":null,"abstract":"<p><p>Analysing organelle structures in tissue samples that preserve the <i>in vivo</i> environment, rather than in isolated cells, can provide valuable information on the mechanisms underlying nerve recovery and repair. However, determining organelle ultrastructure within tissue samples remains challenging with conventional microscopic techniques. To address this limitation, volume electron microscopy, particularly focused ion beam/scanning electron microscopy (FIB/SEM), has provided novel insights into organelle morphology, distribution, and membrane contacts, in three-dimensions and even within intact tissues. This review highlights the application of FIB/SEM for exploring the three-dimensional organization of mitochondria in motor neuron cell bodies and along the axon initial segments (AIS), where simultaneous investigation of intracellular and extracellular environments is difficult using other approaches. These analyses have revealed novel findings regarding mitochondrial distribution under healthy conditions and its dramatic alteration following injury, as well as microglial attachment around the AIS. Furthermore, FIB/SEM has enabled detailed characterization of the complex endoplasmic reticulum (ER) architecture within motor neuron cell bodies. Three-dimensional reconstructions have demonstrated a distinct uneven distribution of the ER in healthy neurons and revealed disruption of this organization following injury. In addition, ER-plasma membrane (ER-PM) contacts have been characterized as sheet-like structures, and quantitative analyses have shown significant increases in ER-PM contacts after injury. The novel findings obtained through FIB/SEM provide new perspectives on the cellular mechanisms underlying neuroregeneration and highlight the value of volume electron microscopy in advancing our understanding of nerve repair processes.</p>","PeriodicalId":12498,"journal":{"name":"Frontiers in Neural Circuits","volume":"20 ","pages":"1870424"},"PeriodicalIF":2.9,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13368917/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148455095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in cortical plasticity induced by paired associative stimulation in people with mild cognitive impairment and Alzheimer's disease: a systematic review and meta-analysis.","authors":"Xiaying Fu, Xiaomin Niu, Xiaoying Lin, Wenqi He, Chunyang Liao, Tiantian Xin, Shuqin Li, Sharie Xiao Wang, Jae Q J Liu, Bin Li, Jianghua Cheng","doi":"10.3389/fncir.2026.1853684","DOIUrl":"10.3389/fncir.2026.1853684","url":null,"abstract":"<p><strong>Background: </strong>Paired associative stimulation (PAS) is a non-invasive neuromodulation paradigm capable of inducing long-term potentiation (LTP)- or long-term depression (LTD)-like plasticity. It has been used to probe neuroplasticity and corticospinal excitability alterations in Alzheimer's disease (AD) and mild cognitive impairment (MCI). However, existing studies report inconsistent directions and magnitudes of PAS-induced plasticity changes across the AD continuum.</p><p><strong>Methods: </strong>We searched PubMed, Web of Science, Embase, and the Cochrane Library from database inception to December 2025. Eligible studies were case-control studies and randomized controlled trials (RCTs) that assessed PAS-induced cortical plasticity in individuals with AD or MCI, with healthy older adults as controls. Study quality was evaluated using the Newcastle-Ottawa Scale (NOS) for non-randomized studies and the Cochrane Risk of Bias tool (RoB 2) for RCTs. This review was registered in PROSPERO (CRD420251178441).</p><p><strong>Results: </strong>Five studies met the inclusion criteria. Four studies quantified motor cortical plasticity using changes in motor-evoked potential (MEP) amplitude (total <i>N</i> = 135; 64 MCI/AD and 71 controls). The pooled analysis showed no significant difference in PAS-induced MEP changes between participants with MCI/AD and healthy controls [mean difference (MD) = 0.06, 95% CI (-0.05, 0.17), <i>p</i> = 0.32]. This pooled estimate was restricted to MEP-based outcomes and should be interpreted as an exploratory synthesis of motor-system readouts rather than definitive evidence of preserved cortical plasticity in MCI or AD. The remaining RCT, which assessed dorsolateral prefrontal cortex (DLPFC) plasticity using a repetitive PAS (rPAS) intervention without MEP outcomes, also found no significant improvement in prefrontal plasticity relative to control stimulation.</p><p><strong>Conclusion: </strong>Based on the currently available MEP-based evidence, PAS-induced motor-system plasticity findings in individuals with MCI or AD remain inconclusive. Given the limited number of studies and heterogeneity in experimental designs, the pooled negative results should not be interpreted as evidence that cortical plasticity is preserved. Corticospinal hyperexcitability and network-level PAS findings should be regarded as preliminary, hypothesis-generating observations requiring validation in larger, longitudinal, and biomarker-characterized cohorts.</p>","PeriodicalId":12498,"journal":{"name":"Frontiers in Neural Circuits","volume":"20 ","pages":"1853684"},"PeriodicalIF":2.9,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13357726/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148436235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Altered structural connectivity in white matter lesion-induced mild cognitive impairment: a probabilistic fiber tracking and graph theory analysis.","authors":"An-Ming Hu, Yan-Ling Ma, Yue-Xiu Li, Qing-Li Shi, Yu-Mei Zhang","doi":"10.3389/fncir.2026.1852574","DOIUrl":"10.3389/fncir.2026.1852574","url":null,"abstract":"<p><p>White matter lesions (WMLs) are a common cause of vascular cognitive impairment, yet the nature of whole-brain structural connectivity alterations in WML-related mild cognitive impairment (MCI) remains incompletely understood. In this study, an integrated approach combining whole-brain probabilistic fiber tracking with graph theory analysis was employed to investigate structural network changes in 33 patients with WML-related MCI and 37 healthy controls. The results revealed that, at the MCI stage, the brain's structural network exhibited not only reduced connectivity in specific neural circuits-primarily fronto-basal ganglia pathways-but also widespread increased connectivity, particularly between the frontal lobe and other cortical regions. Group comparisons identified 50 significantly altered connections (42 increased, 8 decreased), predominantly involving cortico-cortical, cortico-deep gray matter, and deep gray matter-deep gray matter pathways. Despite these connection-level abnormalities, no significant differences were observed in global or nodal graph-theoretical metrics. Notably, eight of the altered connections showed significant correlations with Montreal Cognitive Assessment (MoCA) scores. These structural alterations were closely associated with cognitive and behavioral deficits, indicating that they might serve as exploratory imaging indicators for WML-induced cognitive impairment.</p>","PeriodicalId":12498,"journal":{"name":"Frontiers in Neural Circuits","volume":"20 ","pages":"1852574"},"PeriodicalIF":2.9,"publicationDate":"2026-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13328367/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148390547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Respiration-coordinated attentional switch from feedforward to top-down informational flow directed by the basal forebrain: layer-specific blanket inhibition of pyramidal cells by neurogliaform cells in the piriform cortex.","authors":"Kensaku Mori, Hitoshi Sakano","doi":"10.3389/fncir.2026.1859031","DOIUrl":"10.3389/fncir.2026.1859031","url":null,"abstract":"<p><p>When we are awake, we pay attention to a specific object in the surrounding world. Feedforward transmission of sensory information is enhanced in the cortico-cortical networks during the inhalation phase of the respiratory cycle for identification and evaluation of sensory information. Memory engrams of the associated scene are recalled by the sensory signal as a search tag. In the mammalian olfactory system, a topographic pattern of activated glomeruli in the olfactory bulb is transferred to the piriform cortex via the anterior olfactory nucleus, and then to higher cognitive areas. The odor map is utilized as a QR code (two-dimensional bar code) for recollection of the associative memory scene. Higher cognitive areas generate imagery of the multisensory cognitive scene, determine the valence of input information, and make behavioral decisions during the exhalation phase of respiration. The cognitive scene information for valence decision is transmitted back to the olfactory cortical areas in the top-down direction through the same set of pyramidal cells as used for the feedforward transmission of sensory information. The top-down information not only directs the output behaviors and generates emotional states but also rewrites the existing memory engrams. Then, How is this attentional switch from the surrounding outer world to the cognitive inner world regulated in a respiration-phase correlated manner? We propose that the basal forebrain inputs to neurogliaform cells in the piriform cortex may play a key role in switching attention by layer-specific blanket inhibition of pyramidal cells.</p>","PeriodicalId":12498,"journal":{"name":"Frontiers in Neural Circuits","volume":"20 ","pages":"1859031"},"PeriodicalIF":2.9,"publicationDate":"2026-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13328436/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148390591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}