1
|
Kong Q, Li T, Reddy S, Hodges S, Kong J. Brain stimulation targets for chronic pain: Insights from meta-analysis, functional connectivity and literature review. Neurotherapeutics 2024; 21:e00297. [PMID: 38237403 PMCID: PMC10903102 DOI: 10.1016/j.neurot.2023.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 10/11/2023] [Indexed: 02/16/2024] Open
Abstract
Noninvasive brain stimulation (NIBS) techniques have demonstrated their potential for chronic pain management, yet their efficacy exhibits variability across studies. Refining stimulation targets and exploring additional targets offer a possible solution to this challenge. This study aimed to identify potential brain surface targets for NIBS in treating chronic pain disorders by integrating literature review, neuroimaging meta-analysis, and functional connectivity analysis on 90 chronic low back pain patients. Our results showed that the primary motor cortex (M1) (C3/C4, 10-20 EEG system) and prefrontal cortex (F3/F4/Fz) were the most used brain stimulation targets for chronic pain treatment according to the literature review. The bilateral precentral gyrus (M1), supplementary motor area, Rolandic operculum, and temporoparietal junction, were all identified as common potential NIBS targets through both a meta-analysis sourced from Neurosynth and functional connectivity analysis. This study presents a comprehensive summary of the current literature and refines the existing NIBS targets through a combination of imaging meta-analysis and functional connectivity analysis for chronic pain conditions. The derived coordinates (with integration of the international electroencephalography (EEG) 10/20 electrode placement system) within the above brain regions may further facilitate the localization of these targets for NIBS application. Our findings may have the potential to expand NIBS target selection beyond current clinical trials and improve chronic pain treatment.
Collapse
Affiliation(s)
- Qiao Kong
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Tingting Li
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Sveta Reddy
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Sierra Hodges
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Jian Kong
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
| |
Collapse
|
2
|
Liu AR, Lin ZJ, Wei M, Tang Y, Zhang H, Peng XG, Li Y, Zheng YF, Tan Z, Zhou LJ, Feng X. The potent analgesia of intrathecal 2R, 6R-HNK via TRPA1 inhibition in LF-PENS-induced chronic primary pain model. J Headache Pain 2023; 24:141. [PMID: 37858040 PMCID: PMC10585932 DOI: 10.1186/s10194-023-01667-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 09/11/2023] [Indexed: 10/21/2023] Open
Abstract
BACKGROUND Chronic primary pain (CPP) is an intractable pain of unknown cause with significant emotional distress and/or dysfunction that is a leading factor of disability globally. The lack of a suitable animal model that mimic CPP in humans has frustrated efforts to curb disease progression. 2R, 6R-hydroxynorketamine (2R, 6R-HNK) is the major antidepressant metabolite of ketamine and also exerts antinociceptive action. However, the analgesic mechanism and whether it is effective for CPP are still unknown. METHODS Based on nociplastic pain is evoked by long-term potentiation (LTP)-inducible high- or low-frequency electrical stimulation (HFS/LFS), we wanted to develop a novel CPP mouse model with mood and cognitive comorbidities by noninvasive low-frequency percutaneous electrical nerve stimulation (LF-PENS). Single/repeated 2R, 6R-HNK or other drug was intraperitoneally (i.p.) or intrathecally (i.t.) injected into naïve or CPP mice to investigate their analgesic effect in CPP model. A variety of behavioral tests were used to detect the changes in pain, mood and memory. Immunofluorescent staining, western blot, reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) and calcium imaging of in cultured dorsal root ganglia (DRG) neurons by Fluo-8-AM were used to elucidate the role and mechanisms of 2R, 6R-HNK in vivo or in vitro. RESULTS Intrathecal 2R, 6R-HNK, rather than intraperitoneal 2R, 6R-HNK or intrathecal S-Ketamine, successfully mitigated HFS-induced pain. Importantly, intrathecal 2R, 6R-HNK displayed effective relief of bilateral pain hypersensitivity and depressive and cognitive comorbidities in a dose-dependent manner in LF-PENS-induced CPP model. Mechanically, 2R, 6R-HNK markedly attenuated neuronal hyperexcitability and the upregulation of calcitonin gene-related peptide (CGRP), transient receptor potential ankyrin 1 (TRPA1) or vanilloid-1 (TRPV1), and vesicular glutamate transporter-2 (VGLUT2) in peripheral nociceptive pathway. In addition, 2R, 6R-HNK suppressed calcium responses and CGRP overexpression in cultured DRG neurons elicited by the agonists of TRPA1 or/and TRPV1. Strikingly, the inhibitory effects of 2R, 6R-HNK on these pain-related molecules and mechanical allodynia were substantially occluded by TRPA1 antagonist menthol. CONCLUSIONS In the newly designed CPP model, our findings highlighted the potential utility of intrathecal 2R, 6R-HNK for preventing and therapeutic modality of CPP. TRPA1-mediated uprgulation of CGRP and neuronal hyperexcitability in nociceptive pathways may undertake both unique characteristics and solving process of CPP.
Collapse
Affiliation(s)
- An-Ran Liu
- Department of Anesthesiology and Pain Clinic, First Affiliated Hospital of Sun Yat-Sen University, No.58, 2Nd Zhongshan Road, Yuexiu District, Guangzhou, 510080, China
| | - Zhen-Jia Lin
- Department of Physiology and Pain Research Center, Zhongshan School of Medicine, Guangdong Province Key Laboratory of Brain Function and Disease, Sun Yat-Sen University, No.74, 2Nd Zhongshan Road, Yuexiu District, Guangzhou, 510080, China
| | - Ming Wei
- Department of Anesthesiology and Pain Clinic, First Affiliated Hospital of Sun Yat-Sen University, No.58, 2Nd Zhongshan Road, Yuexiu District, Guangzhou, 510080, China
| | - Yuan Tang
- Department of Physiology and Pain Research Center, Zhongshan School of Medicine, Guangdong Province Key Laboratory of Brain Function and Disease, Sun Yat-Sen University, No.74, 2Nd Zhongshan Road, Yuexiu District, Guangzhou, 510080, China
| | - Hui Zhang
- Department of Anesthesiology, Guangdong Second Provincial General Hospital, No.466, Mid Xingang Road, Haizhu District, Guangzhou, 510317, China
| | - Xiang-Ge Peng
- Department of Physiology and Pain Research Center, Zhongshan School of Medicine, Guangdong Province Key Laboratory of Brain Function and Disease, Sun Yat-Sen University, No.74, 2Nd Zhongshan Road, Yuexiu District, Guangzhou, 510080, China
| | - Ying Li
- Department of Physiology and Pain Research Center, Zhongshan School of Medicine, Guangdong Province Key Laboratory of Brain Function and Disease, Sun Yat-Sen University, No.74, 2Nd Zhongshan Road, Yuexiu District, Guangzhou, 510080, China
| | - Yu-Fan Zheng
- Department of Physiology and Pain Research Center, Zhongshan School of Medicine, Guangdong Province Key Laboratory of Brain Function and Disease, Sun Yat-Sen University, No.74, 2Nd Zhongshan Road, Yuexiu District, Guangzhou, 510080, China
| | - Zhi Tan
- Department of Physiology and Pain Research Center, Zhongshan School of Medicine, Guangdong Province Key Laboratory of Brain Function and Disease, Sun Yat-Sen University, No.74, 2Nd Zhongshan Road, Yuexiu District, Guangzhou, 510080, China.
| | - Li-Jun Zhou
- Department of Physiology and Pain Research Center, Zhongshan School of Medicine, Guangdong Province Key Laboratory of Brain Function and Disease, Sun Yat-Sen University, No.74, 2Nd Zhongshan Road, Yuexiu District, Guangzhou, 510080, China.
| | - Xia Feng
- Department of Anesthesiology and Pain Clinic, First Affiliated Hospital of Sun Yat-Sen University, No.58, 2Nd Zhongshan Road, Yuexiu District, Guangzhou, 510080, China.
| |
Collapse
|
3
|
Aucoin R, Lewthwaite H, Ekström M, von Leupoldt A, Jensen D. Impact of trigeminal nerve and/or olfactory nerve stimulation on activity of human brain regions involved in the perception of breathlessness. Respir Physiol Neurobiol 2023; 311:104036. [PMID: 36804472 DOI: 10.1016/j.resp.2023.104036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/07/2023] [Accepted: 02/12/2023] [Indexed: 02/17/2023]
Abstract
Breathlessness is a centrally processed symptom, as evidenced by activation of distinct brain regions such as the insular cortex and amygdala, during the anticipation and/or perception of breathlessness. Inhaled L-menthol or blowing cool air to the face/nose, both selective trigeminal nerve (TGN) stimulants, relieve breathlessness without concurrent improvements in physiological outcomes (e.g., breathing pattern), suggesting a possible but hitherto unexplored central mechanism of action. Four databases were searched to identify published reports supporting a link between TGN stimulation and activation of brain regions involved in the anticipation and/or perception of breathlessness. The collective results of the 29 studies demonstrated that TGN stimulation activated 12 brain regions widely implicated in the anticipation and/or perception of breathlessness, including the insular cortex and amygdala. Inhaled L-menthol or cool air to the face activated 75% and 33% of these 12 brain regions, respectively. Our findings support the hypothesis that TGN stimulation contributes to breathlessness relief by altering the activity of brain regions involved in its central neural processing.
Collapse
Affiliation(s)
- Rachelle Aucoin
- Clinical Exercise & Respiratory Physiology Laboratory, Department of Kinesiology and Physical Education, McGill University, 475 Pine Avenue West, Montréal, Quebec H2W 1S4, Canada.
| | - Hayley Lewthwaite
- College of Engineering, Science and Environment, School of Environment & Life Sciences, The University of Newcastle, 10 Chittaway Road, Ourimbah, NSW 2258, Australia
| | - Magnus Ekström
- Department of Respiratory Medicine, Allergology and Palliative Medicine, Institution for Clinical Sciences in Lund, Lund University, SE-221 00 Lund, Sweden
| | - Andreas von Leupoldt
- Health Psychology, University of Leuven, Tiensestraat 102 Box 3726, 3000 Leuven, Belgium
| | - Dennis Jensen
- Clinical Exercise & Respiratory Physiology Laboratory, Department of Kinesiology and Physical Education, McGill University, 475 Pine Avenue West, Montréal, Quebec H2W 1S4, Canada; Research Institute of the McGill University Health Centre, Translational Research in Respiratory Diseases Program and Respiratory Epidemiology and Clinical Research Unit, 2155 Guy Street Suite 500, Montréal, Quebec H3H 2R9, Canada
| |
Collapse
|
4
|
Zhang L, Yu W, Zhang Z, Xu M, Cui F, Song W, Cao Z. Altered brain activity and functional connectivity in migraine without aura during and outside attack. Neurol Res 2023; 45:603-609. [PMID: 36693797 DOI: 10.1080/01616412.2023.2170938] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND Migraine is commonly seen as a cyclic disorder with variable cortical excitability at different phases. Herein, we investigated the cortical excitability in migraine without aura patients during an attack (MWoA-DA) and interictal period (MWoA-DI) and further explored the functional connectivity (FC) in brain regions with cortical excitability abnormalities in patients. METHODS Seven MWoA-DA patients, twenty-seven MWoA-DI patients, and twenty-nine healthy controls (HC) underwent resting-state functional magnetic resonance imaging (rs-fMRI) scan. The amplitude of low-frequency fluctuations (ALFF) was assessed to identify spontaneous brain activity. Then, brain regions showing significant differences across groups were identified as regions of interest (ROI) in FC analysis. RESULTS Compared with MWoA-DI patients and HC, the ALFF in the trigeminocervical complex (TCC) was higher in the MWoA-DA patients. Decreased FC in MWoA-DA patients was found between TCC and left postcentral gyrus compared with MWoA-DI patients. Compared with HC, ALFF was lower in the right cuneus but higher in the right rolandic operculum of MWoA-DI patients. Additionally, the ALFF in the right cuneus was negatively correlated with the Migraine Disability Assessment Scale (MIDAS) in MWoA-DI patients. CONCLUSIONS The trigeminovascular system and impairments in descending pain modulatory pathways participate in the pathophysiology of migraine during the ictal period. The defense effect exists in the interictal phase, and the dysfunction in the cuneus may be related to the disease severity. This dynamic change in different brain regions could deepen our understanding of the physiopathology underlying migraine.
Collapse
Affiliation(s)
- Luping Zhang
- Department of Radiology, Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou, China
| | - Wenjing Yu
- The First Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhengxiang Zhang
- Department of Neurology, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Traditional Chinese Medicine), Hangzhou, China
| | - Maosheng Xu
- Department of Radiology, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Traditional Chinese Medicine), Hangzhou, China
| | - Feng Cui
- Department of Radiology, Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou, China
| | - Wenwen Song
- Department of Radiology, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Traditional Chinese Medicine), Hangzhou, China
| | - Zhijian Cao
- Department of Radiology, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Traditional Chinese Medicine), Hangzhou, China
| |
Collapse
|
5
|
Veldhuizen MG, Cecchetto C, Fjaeldstad AW, Farruggia MC, Hartig R, Nakamura Y, Pellegrino R, Yeung AWK, Fischmeister FPS. Future Directions for Chemosensory Connectomes: Best Practices and Specific Challenges. Front Syst Neurosci 2022; 16:885304. [PMID: 35707745 PMCID: PMC9190244 DOI: 10.3389/fnsys.2022.885304] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 04/13/2022] [Indexed: 01/14/2023] Open
Abstract
Ecological chemosensory stimuli almost always evoke responses in more than one sensory system. Moreover, any sensory processing takes place along a hierarchy of brain regions. So far, the field of chemosensory neuroimaging is dominated by studies that examine the role of brain regions in isolation. However, to completely understand neural processing of chemosensation, we must also examine interactions between regions. In general, the use of connectivity methods has increased in the neuroimaging field, providing important insights to physical sensory processing, such as vision, audition, and touch. A similar trend has been observed in chemosensory neuroimaging, however, these established techniques have largely not been rigorously applied to imaging studies on the chemical senses, leaving network insights overlooked. In this article, we first highlight some recent work in chemosensory connectomics and we summarize different connectomics techniques. Then, we outline specific challenges for chemosensory connectome neuroimaging studies. Finally, we review best practices from the general connectomics and neuroimaging fields. We recommend future studies to develop or use the following methods we perceive as key to improve chemosensory connectomics: (1) optimized study designs, (2) reporting guidelines, (3) consensus on brain parcellations, (4) consortium research, and (5) data sharing.
Collapse
Affiliation(s)
- Maria G. Veldhuizen
- Department of Anatomy, Faculty of Medicine, Mersin University, Mersin, Turkey
| | - Cinzia Cecchetto
- Department of General Psychology, University of Padova, Padua, Italy
| | - Alexander W. Fjaeldstad
- Flavour Clinic, Department of Otorhinolaryngology, Regional Hospital West Jutland, Holstebro, Denmark
| | - Michael C. Farruggia
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, United States
| | - Renée Hartig
- Department of Psychiatry and Psychotherapy, University Medical Center, Johannes Gutenberg University of Mainz, Mainz, Germany,Max Planck Institute for Biological Cybernetics, Tübingen, Germany,Functional and Comparative Neuroanatomy Laboratory, Werner Reichardt Centre for Integrative Neuroscience, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Yuko Nakamura
- The Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | | | - Andy W. K. Yeung
- Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Florian Ph. S. Fischmeister
- Institute of Psychology, University of Graz, Graz, Austria,Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria,BioTechMed-Graz, Graz, Austria,*Correspondence: Florian Ph. S. Fischmeister,
| |
Collapse
|
6
|
Caretta A, Mucignat-Caretta C. Are Multiple Chemosensory Systems Accountable for COVID-19 Outcome? J Clin Med 2021; 10:5601. [PMID: 34884303 PMCID: PMC8658083 DOI: 10.3390/jcm10235601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 11/26/2021] [Accepted: 11/27/2021] [Indexed: 01/03/2023] Open
Abstract
Chemosensory systems (olfaction, taste, trigeminus nerve, solitary chemoreceptor cells, neuroendocrine pulmonary cells, and carotid body, etc.) detect molecules outside or inside our body and may share common molecular markers. In addition to the impairment of taste and olfaction, the detection of the internal chemical environment may also be incapacitated by COVID-19. If this is the case, different consequences can be expected. (1) In some patients, hypoxia does not trigger distressing dyspnea ("silent" hypoxia): Long-term follow-up may determine whether silent hypoxia is related to malfunctioning of carotid body chemoreceptors. Moreover, taste/olfaction and oxygen chemoreceptors may be hit simultaneously: Testing olfaction, taste, and oxygen chemoreceptor functions in the early stages of COVID-19 allows one to unravel their connections and trace the recovery path. (2) Solitary chemosensory cells are also involved in the regulation of the innate mucosal immune response: If these cells are affected in some COVID-19 patients, the mucosal innate immune response would be dysregulated, opening one up to massive infection, thus explaining why COVID-19 has lethal consequences in some patients. Similar to taste and olfaction, oxygen chemosensory function can be easily tested with a non-invasive procedure in humans, while functional tests for solitary chemosensory or pulmonary neuroendocrine cells are not available, and autoptic investigation is required to ascertain their involvement.
Collapse
Affiliation(s)
- Antonio Caretta
- Department of Food and Drug Science, University of Parma, 43100 Parma, Italy;
- NIBB—National Institute for Biostructures and Biosystems, 00136 Rome, Italy
| | - Carla Mucignat-Caretta
- NIBB—National Institute for Biostructures and Biosystems, 00136 Rome, Italy
- Department of Molecular Medicine, University of Padova, 35131 Padova, Italy
| |
Collapse
|
7
|
Joshi A, Thaploo D, Yan X, Zang Y, Warr J, Hummel T. Habitual Exposure to Trigeminal Stimuli and Its Effects on the Processing of Chemosensory Stimuli. Neuroscience 2021; 470:70-77. [PMID: 34274425 DOI: 10.1016/j.neuroscience.2021.07.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 10/20/2022]
Abstract
Our objective was to compare brain responses to trigeminal and olfactory stimuli in frequent and non-frequent gum chewers in order to explore whether habitual exposure to trigeminal stimuli affects their central-nervous processing. In healthy subjects, fMRI brain scans were obtained for 20 frequent gum chewers (GC) and 20 non-frequent gum chewers (N'GC), in response to four odorous stimuli; 2 'trigeminal' (peppermint and spearmint) and 2 non-trigeminal or 'olfactory' (cherry and strawberry). During measurements, subjects reported intensity and pleasantness ratings for all stimuli. In addition, a test for general trigeminal sensitivity test (lateralization test) and an odor threshold test was performed. Brain activations in response to individual odors were investigated for the total study population followed by group wise (GC and N'GC) analysis separately for responses to trigeminal (peppermint + spearmint) and olfactory (cherry + strawberry) odors. (1) The GC group exhibited higher trigeminal sensitivity compared to the N'GC group. (2) Olfactory odors activated bilateral insular cortex and amygdala. Apart from olfactory areas (amygdala, insular cortex), trigeminal odors also produced activations in right thalamus and right substantia nigra. (3) In the GC group, olfactory odors produced higher bilateral insular cortex activation than in N'GC group, but no such differences were observed for trigeminal odors. GC subjects appeared to be more responsive to trigeminal chemosensory stimuli. However, this did not directly translate into differences in central-nervous activations to trigeminal stimuli; instead, the use of chewing gum was associated with stronger brain activation towards olfactory stimuli.
Collapse
Affiliation(s)
- A Joshi
- Department of Otorhinolaryngology, TU Dresden, Dresden, Germany.
| | - D Thaploo
- Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - X Yan
- Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - Y Zang
- Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - J Warr
- Department of Otorhinolaryngology, TU Dresden, Dresden, Germany; Takasago, Paris, France
| | - T Hummel
- Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| |
Collapse
|
8
|
Abo-Ahmed AI, Eshrah EA, Latifi F. Unique nasal septal island in dromedary camels may play a role in pain perception: microscopic studies. Saudi J Biol Sci 2021; 28:3806-3815. [PMID: 34220235 PMCID: PMC8241622 DOI: 10.1016/j.sjbs.2021.03.057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/20/2021] [Accepted: 03/22/2021] [Indexed: 12/13/2022] Open
Abstract
The septal island in dromedaries is a distinctive anatomical structure. It has a curiously rostral location and innervated by the trigeminal nerve. It has an unusual ultrastructure and may be specialized for nociception.
The septal organs are islands or patches of sensory epithelium, located in the ventral parts of the nasal septum and innervated by the olfactory nerve. The septal island in dromedaries (Camelus dromedarius) was unusually located in the rostro-dorsal part of the nasal septum, where the ethmoidal branch of the trigeminal nerve provides innervation to the island mucosa. Therefore, the objectives of this study were to reveal the microscopic and ultrastructure of this island and to explain the probable functions. Twelve septal islands from 12 healthy male camels were used. Unlike the olfactory epithelium, which has a pseudostratified structure, the island neuroepithelium had a true neural lamination. Furthermore, in electron micrographs, the receptor, bipolar, and basal cells were connected with an orderly, organized network of cell–cell communication, which had some spine synapses. This network substituted the absence of supporting cells, maintained the shape of the tissue, and held the cells together. Moreover, the receptor cells were not similar to any of the different types of olfactory sensory neurons. Instead, they possessed the apical domain that might be specialized for the detection of chemical stimuli. Interestingly, a resident population of immune cells, namely mast cells and macrophages, was observed. The probable functions were discussed based on the cellular context and architecture. The nasal septal island in dromedaries may have a role in pain perception. The receptor cells most probably work as nociceptive cells that interact with the resident immune cells to coordinate pain signaling with immune response.
Collapse
Affiliation(s)
- Ahmed I Abo-Ahmed
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Benha University, Toukh 13736, Egypt
| | - Eman A Eshrah
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Benha University, Toukh 13736, Egypt
| | - Fatgzim Latifi
- Department of Veterinary Medicine, Faculty of Agriculture and Veterinary, University of Prishtina "Hasan Prishtina", Prishtina, Kosovo
| |
Collapse
|
9
|
Sandri A, Cecchini MP, Riello M, Zanini A, Nocini R, Fiorio M, Tinazzi M. Pain, Smell, and Taste in Adults: A Narrative Review of Multisensory Perception and Interaction. Pain Ther 2021; 10:245-268. [PMID: 33635507 PMCID: PMC8119564 DOI: 10.1007/s40122-021-00247-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 02/13/2021] [Indexed: 12/31/2022] Open
Abstract
Every day our sensory systems perceive and integrate a variety of stimuli containing information vital for our survival. Pain acts as a protective warning system, eliciting a response to remove harmful stimuli; it may also be a symptom of an illness or present as a disease itself. There is a growing need for additional pain-relieving therapies involving the multisensory integration of smell and taste in pain modulation, an approach that may provide new strategies for the treatment and management of pain. While pain, smell, and taste share common features and are strongly linked to emotion and cognition, their interaction has been poorly explored. In this review, we provide an overview of the literature on pain modulation by olfactory and gustatory substances. It includes adult human studies investigating measures of pain threshold, tolerance, intensity, and/or unpleasantness. Due to the limited number of studies currently available, we have structured this review as a narrative in which we comment on experimentally induced and clinical pain separately on pain–smell and pain–taste interaction. Inconsistent study findings notwithstanding, pain, smell, and taste seem to interact at both the behavioral and the neural levels. Pain intensity and unpleasantness seem to be affected more by olfactory substances, whereas pain threshold and tolerance are influenced by gustatory substances. Few pilot studies to date have investigated these effects in clinical populations. While the current results are promising for the future, more evidence is needed to elucidate the link between the chemical senses and pain. Doing so has the potential to improve and develop novel options for pain treatment.
Collapse
Affiliation(s)
- Angela Sandri
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
| | - Maria Paola Cecchini
- Anatomy and Histology Section, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Marianna Riello
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Alice Zanini
- Anatomy and Histology Section, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Riccardo Nocini
- Otolaryngology Section, Department of Surgery, Dentistry, Paediatrics and Gynaecology , University of Verona, Verona, Italy
| | - Mirta Fiorio
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Michele Tinazzi
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
| |
Collapse
|
10
|
Lötsch J, Oertel BG, Felden L, Nöth U, Deichmann R, Hummel T, Walter C. Central encoding of the strength of intranasal chemosensory trigeminal stimuli in a human experimental pain setting. Hum Brain Mapp 2020; 41:5240-5254. [PMID: 32870583 PMCID: PMC7670645 DOI: 10.1002/hbm.25190] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 08/10/2020] [Accepted: 08/11/2020] [Indexed: 12/29/2022] Open
Abstract
An important measure in pain research is the intensity of nociceptive stimuli and their cortical representation. However, there is evidence of different cerebral representations of nociceptive stimuli, including the fact that cortical areas recruited during processing of intranasal nociceptive chemical stimuli included those outside the traditional trigeminal areas. Therefore, the aim of this study was to investigate the major cerebral representations of stimulus intensity associated with intranasal chemical trigeminal stimulation. Trigeminal stimulation was achieved with carbon dioxide presented to the nasal mucosa. Using a single-blinded, randomized crossover design, 24 subjects received nociceptive stimuli with two different stimulation paradigms, depending on the just noticeable differences in the stimulus strengths applied. Stimulus-related brain activations were recorded using functional magnetic resonance imaging with event-related design. Brain activations increased significantly with increasing stimulus intensity, with the largest cluster at the right Rolandic operculum and a global maximum in a smaller cluster at the left lower frontal orbital lobe. Region of interest analyses additionally supported an activation pattern correlated with the stimulus intensity at the piriform cortex as an area of special interest with the trigeminal input. The results support the piriform cortex, in addition to the secondary somatosensory cortex, as a major area of interest for stimulus strength-related brain activation in pain models using trigeminal stimuli. This makes both areas a primary objective to be observed in human experimental pain settings where trigeminal input is used to study effects of analgesics.
Collapse
Affiliation(s)
- Jörn Lötsch
- Institute of Clinical PharmacologyGoethe – UniversityFrankfurt am MainGermany
- Fraunhofer Institute for Molecular Biology and Applied Ecology IMEBranch for Translational Medicine and Pharmacology TMPFrankfurt am MainGermany
| | - Bruno G. Oertel
- Institute of Clinical PharmacologyGoethe – UniversityFrankfurt am MainGermany
| | - Lisa Felden
- Institute of Clinical PharmacologyGoethe – UniversityFrankfurt am MainGermany
| | - Ulrike Nöth
- Brain Imaging CenterGoethe – UniversityFrankfurt am MainGermany
| | - Ralf Deichmann
- Brain Imaging CenterGoethe – UniversityFrankfurt am MainGermany
| | - Thomas Hummel
- Smell & Taste Clinic, Department of OtorhinolaryngologyTU DresdenDresdenGermany
| | - Carmen Walter
- Institute of Clinical PharmacologyGoethe – UniversityFrankfurt am MainGermany
- Fraunhofer Institute for Molecular Biology and Applied Ecology IMEBranch for Translational Medicine and Pharmacology TMPFrankfurt am MainGermany
| |
Collapse
|