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A 6-year-old male child was admitted to the hospital because of abdominal trauma and acute stomach pain. Computed tomography scan revealed a jejunal mesenteric hematoma and an enhanced intestinal wall compressed by the hematoma. The patient presented with vomiting 10 days after the injury. He underwent upper endoscopy under tracheal intubation and general anesthesia 12 days after the injury. A double elementary diet tube was inserted endoscopically with the tip placed in the jejunum beyond the stenosis and the decompressed portion of the stomach. Stenosis was improving, and the patient was discharged on the 27th day after the injury. In conclusion, a double elementary diet tube can be effective for treating posttraumatic duodenal stenosis in pediatric patients.
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BACKGROUND: Anastomotic recurrence of colorectal cancer is rare, but reoperation improves prognosis. However, there is no clear evidence regarding the extent of dissection, and there are few reports on the details of surgery. We used intraoperative lymphatic flow imaging with indocyanine green (ICG) fluorescence as a reference to determine the range of additional resection. CASE PRESENTATION: The patient was a 75-year-old man who underwent laparoscopic right hemicolectomy and extracorporeal functional terminal anastomosis for ascending colon cancer 4 years ago. Histopathological examination revealed a well-differentiated tubular adenocarcinoma, T4aN0M0, pathological stageIIB. During follow-up, anemia was observed, and colonoscopy indicated anastomotic recurrence, so additional laparoscopic resection was performed. Intraoperatively, ICG was injected into the anastomotic site, and the operation proceeded under near-infrared light observation. Lymphatic vessels along the middle colonic artery were visualized down to the root of the vessel. Using this as an indicator, the vessel was ligated from the root. Using the fact that the lymphatic vessels were also depicted in the small intestinal mesentery on the oral side of the anastomosis as an indicator, the small intestine and mesentery were resected about 7 cm from the anastomosis. CONCLUSIONS: The optimal surgical approach for anastomotic recurrence of colorectal cancer has not been defined. Intraoperative ICG fluorescence imaging can provide images of lymphatic flow from the site of recurrence and may be an indicator of lymph node dissection in the case of anastomotic recurrence.
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BACKGROUND: In previously reported cases of lesser omental hernia, a rare clinical presentation, the herniated intestinal tract was passing through both peritoneal layers of the lesser omentum to herniate into the peritoneal cavity or bursa omentalis. Here we present a very rare case of lesser omentum hernia, where the transverse colon entered through only the posterior layer of the lesser omentum to form a hernia between the anterior and posterior layers. CASE PRESENTATION: A 43-year-old man was admitted to the emergency department with acute abdominal pain. Plain abdominal computed tomography (CT) revealed a change in the caliber of the transverse colon between the stomach and pancreas, forming a closed loop on the cephaloventral side of the stomach. On contrast-enhanced CT images, vessels were observed in the contrast-enhanced lesser omentum surrounding the herniated intestine. The patient was diagnosed with a lesser omental hernia and underwent laparoscopic surgery. Intraoperatively, the transverse colon was covered by the anterior layer of the lesser omentum, and a defect was found in the posterior layer of the lesser omentum on the dorsal side of the stomach. A 2-cm incision was made in the posterior layer of the lesser omentum to widen the small defect. The herniated intestinal section was removed from the hernia sac, and the transverse colon was retained unresected. The postoperative course was uneventful. CONCLUSIONS: As illustrated in this first case of a lesser omental hernia forming between the anterior and posterior layers, characteristic CT findings may play an active role in the diagnosis of this rare presentation.
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This study aims to compare the effectiveness of Hybrid and Pure problem-based learning (PBL) in teaching clinical reasoning skills to medical students. The study sample consisted of 99 medical students participating in a clerkship rotation at the Department of General Medicine, Chiba University Hospital. They were randomly assigned to Hybrid PBL (intervention group, n = 52) or Pure PBL group (control group, n = 47). The quantitative outcomes were measured with the students' perceived competence in PBL, satisfaction with sessions, and self-evaluation of competency in clinical reasoning. The qualitative component consisted of a content analysis on the benefits of learning clinical reasoning using Hybrid PBL. There was no significant difference between intervention and control groups in the five students' perceived competence and satisfaction with sessions. In two-way repeated measure analysis of variance, self-evaluation of competency in clinical reasoning was significantly improved in the intervention group in "recalling appropriate differential diagnosis from patient's chief complaint" (F(1,97) = 5.295, p = 0.024) and "practicing the appropriate clinical reasoning process" (F(1,97) = 4.016, p = 0.038). According to multiple comparisons, the scores of "recalling appropriate history, physical examination, and tests on clinical hypothesis generation" (F(1,97) = 6.796, p = 0.011), "verbalizing and reflecting appropriately on own mistakes," (F(1,97) = 4.352, p = 0.040) "selecting keywords from the whole aspect of the patient," (F(1,97) = 5.607, p = 0.020) and "examining the patient while visualizing his/her daily life" (F(1,97) = 7.120, p = 0.009) were significantly higher in the control group. In the content analysis, 13 advantage categories of Hybrid PBL were extracted. In the subcategories, "acquisition of knowledge" was the most frequent subcategory, followed by "leading the discussion," "smooth discussion," "getting feedback," "timely feedback," and "supporting the clinical reasoning process." Hybrid PBL can help acquire practical knowledge and deepen understanding of clinical reasoning, whereas Pure PBL can improve several important skills such as verbalizing and reflecting on one's own errors and selecting appropriate keywords from the whole aspect of the patient.
Subject(s)
General Practice , Students, Medical , Humans , Female , Male , Problem-Based Learning/methods , Problem Solving , LearningABSTRACT
BACKGROUND: Physicians frequently experience patients as difficult. Our study explores whether more empathetic physicians experience fewer patient encounters as difficult. OBJECTIVE: To investigate the association between physician empathy and difficult patient encounters (DPEs). DESIGN: Cross-sectional study. PARTICIPANTS: Participants were 18 generalist physicians with 3-8 years of experience. The investigation was conducted from August-September 2018 and April-May 2019 at six healthcare facilities. MAIN MEASURES: Based on the Jefferson Scale of Empathy (JSE) scores, we classified physicians into low and high empathy groups. The physicians completed the Difficult Doctor-Patient Relationship Questionnaire-10 (DDPRQ-10) after each patient visit. Scores ≥ 31 on the DDPRQ-10 indicated DPEs. We implemented multilevel mixed-effects logistic regression models to examine the association between physicians' empathy and DPE, adjusting for patient-level covariates (age, sex, history of mental disorders) and with physician-level clustering. KEY RESULTS: The median JSE score was 114 (range: 96-126), and physicians with JSE scores 96-113 and 114-126 were assigned to low and high empathy groups, respectively (n = 8 and 10 each); 240 and 344 patients were examined by physicians in the low and high empathy groups, respectively. Among low empathy physicians, 23% of encounters were considered difficulty, compared to 11% among high empathy groups (OR: 0.37; 95% CI = 0.19-0.72, p = 0.004). JSE scores and DDPRQ-10 scores were negatively correlated (r = -0.22, p < 0.01). CONCLUSION: Empathetic physicians were less likely to experience encounters as difficult. Empathy appears to be an important component of physician perception of encounter difficulty.
Subject(s)
Physician-Patient Relations , Physicians , Humans , Cross-Sectional Studies , Empathy , Surveys and QuestionnairesABSTRACT
Deep tendon reflexes (DTR) are a prerequisite skill in clinical clerkships. However, many medical students are not confident in their technique and need to be effectively trained. We evaluated the effectiveness of a flipped classroom for teaching DTR skills. We recruited 83 fifth-year medical students who participated in a clinical clerkship at the Department of General Medicine, Chiba University Hospital, from November 2018 to July 2019. They were allocated to the flipped classroom technique (intervention group, n = 39) or the traditional technique instruction group (control group, n = 44). Before procedural teaching, while the intervention group learned about DTR by e-learning, the control group did so face-to-face. A 5-point Likert scale was used to evaluate self-confidence in DTR examination before and after the procedural teaching (1 = no confidence, 5 = confidence). We evaluated the mastery of techniques after procedural teaching using the Direct Observation of Procedural Skills (DOPS). Unpaired t-test was used to analyze the difference between the two groups on the 5-point Likert scale and DOPS. We assessed self-confidence in DTR examination before and after procedural teaching using a free description questionnaire in the two groups. Additionally, in the intervention group, focus group interviews (FGI) (7 groups, n = 39) were conducted to assess the effectiveness of the flipped classroom after procedural teaching. Pre-test self-confidence in the DTR examination was significantly higher in the intervention group than in the control group (2.8 vs. 2.3, P = 0.005). Post-test self-confidence in the DTR examination was not significantly different between the two groups (3.9 vs. 4.1, P = 0.31), and so was mastery (4.3 vs. 4.1, P = 0.68). The questionnaires before the procedural teaching revealed themes common to the two groups, including "lack of knowledge" and "lack of self-confidence." Themes about prior learning, including "acquisition of knowledge" and "promoting understanding," were specific in the intervention group. The FGI revealed themes including "application of knowledge," "improvement in DTR technique," and "increased self-confidence." Based on these results, teaching DTR skills to medical students in flipped classrooms improves readiness for learning and increases self-confidence in performing the procedure at a point before procedural teaching.
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Clinical Clerkship , Students, Medical , Clinical Competence , Curriculum , Educational Measurement , Humans , Problem-Based Learning/methods , Reflex, StretchABSTRACT
OBJECTIVE: To clarify the factors associated with prolonged hospital stays, focusing on the COMplexity PRediction Instrument (COMPRI) score's accuracy in predicting the length of stay of newly hospitalised patients in general internal medicine wards. DESIGN: A case-control study. SETTING: Three general internal medicine wards in Chiba Prefecture, Japan. PARTICIPANTS: Thirty-four newly hospitalised patients were recruited between November 2017 and December 2019, with a final analytic sample of 33 patients. We included hospitals in different cities with general medicine outpatient and ward facilities, who agreed to participate. We excluded any patients who were re-hospitalised within 2 weeks of a prior discharge. PRIMARY AND SECONDARY OUTCOME MEASURES: Patients' COMPRI scores and their consequent lengths of hospital stay. RESULTS: The 17 patients (52%) allocated to the long-term hospitalisation group (those hospitalised ≥14 days) had a significantly higher average age, COMPRI score and percentage of participants with comorbid chronic illnesses than the short-term hospitalisation group (<14 days). A logistic regression model (model A, comprising only the COMPRI score as the explanatory variable) and a multiple logistic regression model (model B, comprising variables other than the COMPRI score as explanatory variables) were created as prediction models for the long-term hospitalisation group. When age ≥75 years, a COMPRI score ≥6 and a physician with 10 years' experience were set as explanatory variables, model A showed better predictive accuracy compared with model B (fivefold cross-validation, area under curve of 0.87 vs 0.78). The OR of a patient with a COMPRI score of ≥6 joining the long-term hospitalisation group was 4.25 (95% CI=1.43 to 12.63). CONCLUSIONS: Clinicians can use the COMPRI score when screening for complexity assessment to identify hospitalised patients at high risk of prolonged hospitalisation. Providing such patients with multifaceted and intensive care may shorten hospital stays.
Subject(s)
Hospitalization , Patient Discharge , Aged , Case-Control Studies , Humans , Japan , Length of StayABSTRACT
During clinical reasoning case conferences, a learner-centered approach using teleconferencing can create a psychologically safe environment and help learners speak up. This study aims to measure the psychological safety of students who are supposed to self-explain their clinical reasoning to conference participants. This crossover study compared the effects of two clinical reasoning case conference methods on medical students' psychological safety. The study population comprised 4th-5th year medical students participating in a two-week general medicine clinical clerkship rotation, from September 2019 to February 2020. They participated in both a learner-centered approach teleconference and a traditional, live-style conference. Teleconferences were conducted in a separate room, with only a group of students and one facilitator. Participants in group 1 received a learner-centered teleconference in the first week and a traditional, live-style conference in the second week. Participants assigned to group 2 received a traditional, live-style conference in the first week and a learner-centered approach teleconference in the second week. After each conference, Edmondson's Psychological Safety Scale was used to assess the students' psychological safety. We also counted the number of students who self-explained their clinical reasoning processes during each conference. Of the 38 students, 34 completed the study. Six out of the seven psychological safety items were significantly higher in the learner-centered approach teleconferences (p<0.01). Twenty-nine (85.3%) students performed self-explanation in the teleconference compared to ten (29.4%) in the live conference (p<0.01). A learner-centered approach teleconference could improve psychological safety in novice learners and increase the frequency of their self-explanation, helping educators better assess their understanding. Based on these results, a learner-centered teleconference approach has the potential to be a method for teaching clinical reasoning to medical students.
Subject(s)
Clinical Reasoning , Education, Medical, Undergraduate/methods , Stress, Psychological/prevention & control , Students, Medical/psychology , Telecommunications , Adult , Clinical Clerkship/methods , Clinical Clerkship/statistics & numerical data , Clinical Competence/statistics & numerical data , Cross-Over Studies , Education, Medical, Undergraduate/statistics & numerical data , Female , Humans , Japan , Male , Problem-Based Learning/methods , Problem-Based Learning/statistics & numerical data , Stress, Psychological/etiology , Students, Medical/statistics & numerical data , Young AdultABSTRACT
Objective This case series aimed to investigate the clinical and pathological characteristics of persistent postural perceptual dizziness (PPPD). Methods We retrospectively examined the medical records of patients with chronic dizziness in our department, and tracked the percentage of PPPD, the age and sex, disorder duration, exacerbating factors for dizziness, and duration of momentary worsening dizziness. We also examined the duration of momentary worsening dizziness in cases of depression, anxiety disorder, and somatic symptom disorder. Results Among 229 patients with chronic dizziness, 14.4% (33/229) met the diagnostic criteria for PPPD. PPPD was the second most common disorder of patients with chronic dizziness after depression. The median age of patients with PPPD was 75 (75.8% female) and the median duration of the disorder was 60 months (range: 3-360 months). The exacerbating factors were motion without regard to direction or position (90.9%), upright posture (66.7%), and exposure to moving visual stimuli or complex visual patterns (30.3%). While the duration of momentary worsening dizziness was less than 10 minutes in 93.9% of patients with PPPD, the duration in patients with depression, anxiety disorder, and somatic symptom disorder were 3.6 % (2/55), 16.1% (5/31), and 0% (0/11), respectively. When the duration was less than 10 minutes, the odds ratios of PPPD for depression and anxiety disorder were 46.5 (95% CI: 6.1-362.0) and 40.3 (95% CI: 7.4-219.3), respectively. Conclusion Short episodes of momentary worsening dizziness constitute a distinctive feature of PPPD that may be useful for differentiating PPPD from other types of psychogenic dizziness.
Subject(s)
Dizziness , Medicine , Female , Humans , Male , Dizziness/diagnosis , Dizziness/epidemiology , Outpatients , Retrospective Studies , VertigoABSTRACT
BACKGROUND: Frequent and repeated visits from patients with mental illness or free medical care recipients may elicit physicians' negative emotions and influence their clinical decision making. This study investigated the impact of the psychiatric or social background of such patients on physicians' decision making about whether to offer recommendations for further examinations and whether they expressed an appropriate disposition toward the patient. METHODS: A randomized, controlled multi-centre study of residents in transitional, internal medicine, or emergency medicine was conducted in five hospitals. Upon randomization, participants were stratified by gender and postgraduate year, and they were allocated to scenario set 1 or 2. They answered questions pertaining to decision-making based on eight clinical vignettes. Half of the eight vignettes presented to scenario set 1 included additional patient information, such as that the patient had a past medical history of schizophrenia or that the patient was a recipient of free care who made frequent visits to the doctor (biased vignettes). The other half included no additional information (neutral vignettes). For scenario set 2, the four biased vignettes presented to scenario set 1 were neutralized, and the four neutral vignettes were rendered biased by providing additional information. After reading, participants answered decision-making questions regarding diagnostic examination, interventions, or patient disposition. The primary analysis was a repeated-measures ANOVA on the mean management accuracy score, with patient background information as a within-subject factor (no bias, free care recipients, or history of schizophrenia). RESULTS: A total of 207 questionnaires were collected. Repeated-measures ANOVA showed that additional background information had influence on mean accuracy score (F(7, 206) = 13.84, p < 0.001 partial η2 = 0.063). Post hoc pairwise multiple comparison test, Sidak test, showed a significant difference between schizophrenia and no bias condition (p < 0.05). The ratings for patient likability were lower in the biased vignettes compared to the neutral vignettes, which was associated with the lower utilization of medical resources by the physicians. CONCLUSIONS: Additional background information on past medical history of schizophrenia increased physicians' mistakes in decision making. Patients' psychiatric backgrounds should not bias physicians' decision-making. Based on these findings, physicians are recommended to avoid being influenced by medically unrelated information.
Subject(s)
Attitude of Health Personnel , Clinical Decision-Making , Physicians/psychology , Adult , Female , Humans , Male , Mentally Ill Persons , Physician-Patient Relations , Surveys and QuestionnairesABSTRACT
We experienced a case of a subtype of spontaneous hemopneumothorax caused by external forces associated with a seat-belt injury. A female aged 39 years sustained a minor collision with an oncoming car while she was driving. Although pneumothorax was not detected, hemothorax and bleeding from the area surrounding the subclavian artery were observed on contrast-enhanced chest computed tomography (CT). After confirming continuous bleeding into the thoracic cavity after superselective arterial embolization, we performed emergency open surgery. We found a bulla in the apex of the lung, and the thoracic stump of the bulla was considered the source of bleeding. In this case, the direct cause of hemothorax was considered to be the external force associated with the seat-belt injury. When a bulla in the apex of the lung and continuous bleeding are both observed on CT, spontaneous hemopneumothorax should be suspected, necessitating open chest surgery in cases where pneumothorax is not observed.
Subject(s)
Hemopneumothorax/etiology , Hemothorax/etiology , Lung Injury/etiology , Seat Belts/adverse effects , Wounds, Nonpenetrating/etiology , Accidents, Traffic , Adult , Blister/etiology , Contrast Media , Emergencies , Emergency Treatment/methods , Female , Hemopneumothorax/diagnostic imaging , Hemothorax/diagnostic imaging , Humans , Lung Injury/diagnostic imaging , Subclavian Artery/diagnostic imaging , Subclavian Artery/injuries , Tomography, X-Ray Computed , Wounds, Nonpenetrating/diagnostic imagingABSTRACT
Human macrophage dectin-1, a type II transmembrane ß-glucan receptor, was expressed as a fusion protein with an N-terminal hexahistidine tag in a baculovirus-silkworm expression system and assayed for binding activity. Recombinant dectin-1 specifically bound to some ß-glucans, and the neck domain and N-linked oligosaccharide chains of human dectin-1 did not affect the ligand binding activity and specificity of the receptor.
Subject(s)
Baculoviridae/genetics , Bombyx/genetics , Genetic Engineering/methods , Lectins, C-Type/genetics , Lectins, C-Type/metabolism , Macrophages/metabolism , beta-Glucans/metabolism , Animals , Cell Line , Gene Expression , Humans , Protein Binding , Protein Isoforms/genetics , Protein Isoforms/metabolism , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolismABSTRACT
Planarians are useful animals for regenerative and neuroscience research at the molecular level. Previously, we have reported the distribution and function of neurotransmitter-synthesizing neurons in the planarian central nervous system. In order to understand the neural projections and connections, it is important to understand the distribution of neurotransmitter receptors. In this study, we isolated a serotonin receptor gene and named it DjSER-7 (Dugesia japonica serotonin receptor type 7). DjSER-7-expressing cells were distributed in the planarian brain. According to electrophysiological analysis using Xenopus oocytes, current response was detected upon exposure to serotonin, but not other neurotransmitters in oocytes that were co-injected with mRNAs of both DjSER-7 and Galpha chimera B-2, which can interact with either Gq-, Gs- or Gi-coupled receptor. In contrast, current response was not detected after exposure to neurotransmitters in oocytes injected with only DjSER-7 mRNA. Our results indicated that DjSER-7 responds to serotonin, as indicated by electrophysiological analysis using Xenopus oocytes.
Subject(s)
Central Nervous System/metabolism , Genes, Helminth , Planarians/genetics , Receptors, G-Protein-Coupled/genetics , Receptors, Serotonin/metabolism , Serotonin/metabolism , Xenopus laevis/metabolism , Amino Acid Sequence , Animals , Central Nervous System/cytology , DNA, Complementary , In Situ Hybridization , Molecular Sequence Data , Oocytes/metabolism , Planarians/metabolism , RNA, Messenger/metabolism , Receptors, G-Protein-Coupled/metabolism , Receptors, Serotonin/genetics , Xenopus laevis/geneticsABSTRACT
3,4-Methylenedioxymethamphetamine (MDMA) selectively releases serotonin (5-HT) from neurons after uptake by the serotonin transporter (SERT) and causes psychostimulant effects accompanied by hyperthermia. Since rapid increases in CNS lactate levels are suggested in response to MDMA, we investigated the effects of the physiologically-relevant increase in H(+) concentration on the two conducting states of SERT expressed in Xenopus oocytes. Perfusion with SERT substrates at pH 7.4 dose-dependently evoked a transport-associated inward current response with the following rank order of potency: 5-HT>MDMA>dopamine>>norepinephrine. In the absence of transport substrates, a step hyperpolarization pulse activated a transient Na(+) leak current, which was inhibited by SERT substrates with the same rank, as well as by a SERT inhibitor, citalopram. At pH 6.4, the K(m) values of 5-HT and dopamine for the transport-associated current were not altered, while that of MDMA was three-fold lower. In contrast, the K(i) values of all these substrates for transient leak current were unchanged at pH 6.4, suggesting that the affinities to SERT binding sites are not influenced. These results suggest that the effect of MDMA on SERT is enhanced by acidic conditions.
Subject(s)
N-Methyl-3,4-methylenedioxyamphetamine/pharmacology , Serotonin Agents/pharmacology , Serotonin Plasma Membrane Transport Proteins/drug effects , Serotonin Plasma Membrane Transport Proteins/metabolism , Serotonin/metabolism , Animals , Binding Sites/drug effects , Binding Sites/physiology , Binding, Competitive/drug effects , Binding, Competitive/physiology , Biological Transport, Active/drug effects , Biological Transport, Active/physiology , Brain/drug effects , Brain/metabolism , Brain/physiopathology , Dopamine/metabolism , Dopamine/pharmacology , Dose-Response Relationship, Drug , Female , Hydrogen-Ion Concentration , Lactic Acid/metabolism , Membrane Potentials/drug effects , Membrane Potentials/physiology , Neurons/drug effects , Neurons/metabolism , Norepinephrine/metabolism , Norepinephrine/pharmacology , Oocytes , Protons , Rats , Serotonin/pharmacology , Serotonin Antagonists/pharmacology , Serotonin Plasma Membrane Transport Proteins/genetics , Sodium Channels/drug effects , Sodium Channels/metabolism , Xenopus laevisABSTRACT
Pain is a multidimensional conscious experience including sensory and negative affective components. The neural systems of the sensory component of pain have been extensively studied, while those of the negative affective component are less clear. The amygdala is a forebrain structure composed of several distinct nuclei including the basolateral (BLA) and central (CeA) nuclei, and is thought to be a key neural substrate underlying emotional responses. Recently, we reported that intraplantar (i.pl.) injection of formalin as a chemical somatic noxious stimulus increased c-fos mRNA expression in the BLA, but not CeA, while intraperitoneal (i.p.) injection of acetic acid as a chemical visceral noxious stimulus induced it highly in the CeA, and hardly in BLA [Nakagawa et al. (2003) Neurosci. Lett., 344, 197-200]. In this study, we examined the effects of discrete bilateral excitotoxic lesions of the BLA or CeA on the sensory and negative affective components of the two types of pain in Sprague-Dawley rats. In the place-conditioning paradigm, both i.pl. formalin and i.p. acetic acid produced conditioned place aversion. The i.pl. formalin-induced conditioned place aversion was abolished by the lesion of the BLA or CeA, while the i.p. acetic acid-induced conditioned place aversion was abolished by the CeA-, but not BLA-lesion. On the other hand, the BLA- or CeA-lesion failed to reduce the i.pl. formalin- and i.p. acetic acid-produced nociceptive behaviours. Taken together, these results suggest that activation of distinct amygdaloid nuclei could differentially contribute to chemical somatic and visceral noxious stimuli-induced negative affective, but not sensory components of pains.
Subject(s)
Affect/drug effects , Amygdala/pathology , Pain/physiopathology , Acetic Acid , Amygdala/injuries , Animals , Avoidance Learning , Behavior, Animal , Conditioning, Psychological , Escape Reaction , Excitatory Amino Acid Agonists , Formaldehyde , Ibotenic Acid , Male , Pain/chemically induced , Pain Measurement/methods , Rats , Rats, Sprague-Dawley , Staining and LabelingABSTRACT
Pain includes a negative affective component, although the neural system is unclear. The amygdala including the lateral (La), basolateral (BL) and central (Ce) nuclei is thought to play a key role in emotional responses. In this study, we analyzed the c-fos mRNA expression, as a marker of neuronal activity, induced by two types of pain, chemical somatic and visceral noxious stimuli, in each amygdaloid nucleus in unanesthetized rats. We found that intraplantar injection of formalin as a chemical somatic noxious stimulus increased c-fos mRNA expression in the La and BL, but not Ce. On the other hand, intraperitoneal injection of acetic acid as a chemical visceral noxious stimulus induced it highly in the Ce, moderately in La and hardly in BL. These results suggest that distinct amygdaloid nuclei are activated by chemical somatic and visceral noxious stimuli, which might differentially contribute to emotional responses by them.