[Mentalization based treatment (MBT) for borderline personality disorder among a population of French-speaking patients]. / Implémentation francophone de la thérapie basée sur la mentalisation (TBM) pour le trouble de personnalité limite.

INTRODUCTION: Borderline Personality Disorder is a frequent disorder that is challenging for therapists to treat due to the prevalence of self-damaging and suicidal behaviours and interruptions of the therapeutic alliance, as well as a poor response to psychotropic treatments. In recent years, several empirically-validated psychotherapeutic treatments have been developed, including Mentalisation-Based Therapy, which is an integrative psychodynamic approach created in Britain. Although numerous studies have showed Mentalisation-Based Therapy to be an efficient treatment of Borderline Personality Disorder, its specific components have yet to be assessed. Furthermore, there have been no empirical studies conducted among groups of French-speaking patients. The purpose of this study is twofold: To provide an initial assessment of the efficacy of the mentalisation-based psycho-educational component, which is the first component of any mentalisation-based therapy, and to provide the first assessment of this approach among a population of French-speaking patients. METHOD: Over a three-month period, 14 Borderline Personality Disorder sufferers followed a psycho-educational Mentalisation-Based Therapy programme consisting of group sessions to introduce patients to mentalisation and weekly individual interviews. Patients filled in various question forms assessing, among others, the intensity of their depression, their degree of hopelessness, their emotional regulation strategies, and their reflective abilities. RESULTS: The psycho-educational component of Mentalisation-Based Therapy is significantly associated with improved cognitive emotional regulation, empathy and reflective abilities, and with a reduced sense of hopelessness. The programme retention rate was of 71.4%. CONCLUSION: Despite the small sample size and the short treatment period, these preliminary results demonstrate the efficiency of the psycho-educational phase of Mentalisation-Based Therapy, and in particular the positive effects of the treatment on depressive symptomatology and self-regulation processes among patients with a Borderline Personality Disorder diagnosis.

[Gastroesophageal cancer: an update on diagnosis and treatment]. / Cancer oesogastrique.

Esophago-gastric cancer remains a relatively rare pathology with, however, an ascending tendency in the recent years due to a variety of predisposing factors. An extensive preoperative workup and a thorough multidisciplinary discussion are the key elements to define treatment strategy. Surgery is the cornerstone of treatment for resectable tumors, even if it is associated with morbidity rates of 40-60% in medium and high-volume centers. Long-term consequences (e.g. malnutrition and late anastomotic stenosis) are present in a high proportion of patients and they raise the need for a close follow-up with the collaboration of the general practitioner, surgeon and oncologist. This multidisciplinary treatment and aftercare has the best chance to offer to the patient not only a longer overall survival, but a better quality of life as well.

New pool of cortical interneuron precursors in the early postnatal dorsal white matter.

The migration of cortical γ-aminobutyric acidergic interneurons has been extensively studied in rodent embryos, whereas few studies have documented their postnatal migration. Combining in vivo analysis together with time-lapse imaging on cortical slices, we explored the origin and migration of cortical interneurons during the first weeks of postnatal life. Strikingly, we observed that a large pool of GAD65-GFP-positive cells accumulate in the dorsal white matter region during the first postnatal week. Part of these cells divides and expresses the transcription factor paired box 6 indicating the presence of local transient amplifying precursors. The vast majority of these cells are immature interneurons expressing the neuronal marker doublecortin and partly the calcium-binding protein calretinin. Time-lapse imaging reveals that GAD65-GFP-positive neurons migrate from the white matter pool into the overlying anterior cingulate cortex (aCC). Some interneurons in the postnatal aCC express the same immature neuronal markers suggesting ongoing migration of calretinin-positive interneurons. Finally, bromodeoxyuridine incorporation experiments confirm that a small fraction of interneurons located in the aCC are generated during the early postnatal period. These results altogether reveal that at postnatal ages, the dorsal white matter contains a pool of interneuron precursors that divide and migrate into the aCC.

Inflammation, anxiety, and stress in bipolar disorder and borderline personality disorder: A narrative review.

Bipolar disorder (BD) and borderline personality disorder (BPD) are serious and prevalent psychiatric diseases that share common phenomenological characteristics: symptoms (such as anxiety, affective lability or emotion dysregulation), neuroimaging features, risk factors and comorbidities. While several studies have focused on the link between stress and peripheral inflammation in other affective disorders such as anxiety or depression, fewer have explored this relationship in BD and BPD. This review reports on evidence showing an interplay between immune dysregulation, anxiety and stress, and how an altered acute neuroendocrine stress response may exist in these disorders. Moreover, we highlight limitations and confounding factors of these existing studies and discuss multidirectional hypotheses that either suggest inflammation or stress and anxiety as the primum movens in BD and BPD pathophysiology, or inflammation as a consequence of the pathophysiology of these diseases. Untangling these associations and implementing a transdiagnostic approach will have diagnostic, therapeutic and prognostic implications for BD and BPD patients.

Excess of serotonin affects embryonic interneuron migration through activation of the serotonin receptor 6.

The discovery that a common polymorphism (5-HTTLPR, short variant) in the human serotonin transporter gene (SLC6A4) can influence personality traits and increase the risk for depression in adulthood has led to the hypothesis that a relative increase in the extracellular levels of serotonin (5-HT) during development could be critical for the establishment of brain circuits. Consistent with this idea, a large body of data demonstrate that 5-HT is a strong neurodevelopmental signal that can modulate a wide variety of cellular processes. In humans, serotonergic fibers appear in the developing cortex as early as the 10th gestational week, a period of intense neuronal migration. In this study we hypothesized that an excess of 5-HT could affect embryonic cortical interneuron migration. Using time-lapse videometry to monitor the migration of interneurons in embryonic mouse cortical slices, we discovered that the application of 5-HT decreased interneuron migration in a reversible and dose-dependent manner. We next found that 5-HT6 receptors were expressed in cortical interneurons and that 5-HT6 receptor activation decreased interneuron migration, whereas 5-HT6 receptor blockade prevented the migratory effects induced by 5-HT. Finally, we observed that interneurons were abnormally distributed in the cerebral cortex of serotonin transporter gene (Slc6a4) knockout mice that have high levels of extracellular 5-HT. These results shed new light on the neurodevelopmental alterations caused by an excess of 5-HT during the embryonic period and contribute to a better understanding of the cellular processes that could be modulated by genetically controlled differences in human 5-HT homeostasis.

Temporal patterning of apical progenitors and their daughter neurons in the developing neocortex.

During corticogenesis, distinct subtypes of neurons are sequentially born from ventricular zone progenitors. How these cells are molecularly temporally patterned is poorly understood. We used single-cell RNA sequencing at high temporal resolution to trace the lineage of the molecular identities of successive generations of apical progenitors (APs) and their daughter neurons in mouse embryos. We identified a core set of evolutionarily conserved, temporally patterned genes that drive APs from internally driven to more exteroceptive states. We found that the Polycomb repressor complex 2 (PRC2) epigenetically regulates AP temporal progression. Embryonic age-dependent AP molecular states are transmitted to their progeny as successive ground states, onto which essentially conserved early postmitotic differentiation programs are applied, and are complemented by later-occurring environment-dependent signals. Thus, epigenetically regulated temporal molecular birthmarks present in progenitors act in their postmitotic progeny to seed adult neuronal diversity.

Recruiting new neurons from the subventricular zone to the rat postnatal cortex: an organotypic slice culture model.

The neurogenic subventricular zone (SVZ) of the lateral ventricle is a potential source for neuronal replacement in the postnatal or adult neocortex after injury. Here we present a novel model system to directly explore the cellular mechanisms of this process. In order to visualize directed migration from the SVZ towards the cortex, we transplanted green fluorescent protein-labeled progenitor/stem cells into the SVZ of newborn rats. At 2 days after transplantation, we generated organotypic slice cultures and applied fluorescent time-lapse imaging to explore directly the migration and integration of donor cells into the host tissue for up to 2 weeks. Our studies revealed that subventricular grafts provide a significant number of immature neurons to neocortical regions. In the cortex, immature neurons first migrate radially towards the pial surface and then differentiate into GABAergic interneurons. We conclude that our model system presents a novel and effective experimental paradigm to evaluate the recruitment of SVZ-derived neurons into the postnatal cortex, a phenomenon that may represent a potential route for cortical repair.

Frequency of dysphoria and mixed states.

BACKGROUND: Mixed states are a complex entity in the field of mood disorders. Dysphoria has been advocated as an important clinical dimension of mixed states. The objective of this work is to study the frequency of dysphoria within a population of patients with DSM-IV major depressive and/or manic episodes and to determine if it may help establish diagnostic criteria for subthreshold cases of depressive or manic mixed states. SAMPLING AND METHODS: A total of 165 patients were assessed using the Mini International Neuropsychiatric Interview complemented by a section defining dysphoria as a constellation of 3 among 4 symptoms (inner tension, irritability, aggressive behavior and hostility). RESULTS: When classifying patients according to the number of symptoms of the opposite polarity, changes in the frequency of dysphoria revealed a clear contrast between the 2 opposite manic and depressive poles and the full mixed state (DSM-IV definition). The frequency of dysphoria was 17.5% in pure depression, 22.7% in pure mania and 73.3% in full mixed state. Two threshold effects were identified: (1) the frequency of dysphoria increased from 17.5 to 61.1% (p = 0.002) when the number of manic symptoms in DSM-IV depressed patients increased from 0 to 1, and (2) dysphoria increased from 14.3 to 69.2% (p = 0.057) when the number of depressive symptoms increased from 2 to 3 in DSM-IV manic patients. CONCLUSION: Dysphoria is strongly but not necessarily associated with mixed states. When used as a clinical marker for mixed states, dysphoria confirms the modern delimitations of sub-threshold mixed states by specifying the required number of symptoms of the opposite polarity (which could be lower for depressive mixed states than for manic mixed states). The study has limitations related to the inclusion of patients who are not drug-free, to the definition of dysphoria and to the sample size.

Early-life serotonin dysregulation affects the migration and positioning of cortical interneuron subtypes.

Early-life deficiency of the serotonin transporter (SERT) gives rise to a wide range of psychiatric-relevant phenotypes; however, the molecular and cellular targets of serotonin dyregulation during neural circuit formation remain to be identified. Interestingly, migrating cortical interneurons (INs) derived from the caudal ganglionic eminence (CGE) have been shown to be more responsive to serotonin-mediated signalling compared with INs derived from the medial ganglionic eminence (MGE). Here we investigated the impact of early-life SERT deficiency on the migration and positioning of CGE-derived cortical INs in SERT-ko mice and in mice exposed to the SERT inhibitor fluoxetine during the late embryonic period. Using confocal time-lapse imaging and microarray-based expression analysis we found that genetic and pharmacological SERT deficiency significantly increased the migratory speed of CGE-derived INs and affected transcriptional programmes regulating neuronal migration. Postnatal studies revealed that SERT deficiency altered the cortical laminar distribution of subtypes of CGE-derived INs but not MGE-derived INs. More specifically, we found that the distribution of vasointestinal peptide (VIP)-expressing INs in layer 2/3 was abnormal in both genetic and pharmacological SERT-deficiency models. Collectively, these data indicate that early-life SERT deficiency has an impact on the migration and molecular programmes of CGE-derived INs, thus leading to specific alterations in the positioning of VIP-expressing INs. These data add to the growing evidence that early-life serotonin dysregulation affects cortical microcircuit formation and contributes to the emergence of psychiatric-relevant phenotypes.

Borderline personality disorder and childhood maltreatment: a genome-wide methylation analysis.

Early life adversity plays a critical role in the emergence of borderline personality disorder (BPD) and this could occur through epigenetic programming. In this perspective, we aimed to determine whether childhood maltreatment could durably modify epigenetic processes by the means of a whole-genome methylation scan of BPD subjects. Using the Illumina Infinium® HumanMethylation450 BeadChip, global methylation status of DNA extracted from peripheral blood leucocytes was correlated to the severity of childhood maltreatment in 96 BPD subjects suffering from a high level of child adversity and 93 subjects suffering from major depressive disorder (MDD) and reporting a low rate of child maltreatment. Several CpGs within or near the following genes (IL17RA, miR124-3, KCNQ2, EFNB1, OCA2, MFAP2, RPH3AL, WDR60, CST9L, EP400, A2ML1, NT5DC2, FAM163A and SPSB2) were found to be differently methylated, either in BPD compared with MDD or in relation to the severity of childhood maltreatment. A highly relevant biological result was observed for cg04927004 close to miR124-3 that was significantly associated with BPD and severity of childhood maltreatment. miR124-3 codes for a microRNA (miRNA) targeting several genes previously found to be associated with BPD such as NR3C1. Our results highlight the potentially important role played by miRNAs in the etiology of neuropsychiatric disorders such as BPD and the usefulness of using methylome-wide association studies to uncover such candidate genes. Moreover, they offer new understanding of the impact of maltreatments on biological processes leading to diseases and may ultimately result in the identification of relevant biomarkers.

Polyoma virus infection after renal transplantation. Use of immunostaining as a guide to diagnosis.

BACKGROUND: Polyoma virus infection is characterized by lymphocytic interstitial infiltrate in the kidney, and it mimics acute rejection. The purpose of this study is to estimate renal allograft outcome with this infection and characterize the lymphocytic infiltrates in polyoma virus-infected renal allografts. METHODS: Patients who had polyoma virus inclusions in renal allograft biopsies were identified. Other viral inclusions were excluded by immunohistochemistry. The lymphocytic infiltrates of six cases of polyoma virus infection were compared with six cases of definite acute rejection by immunostaining for T and B cells. RESULTS: There were 10 cases of polyoma virus infections in renal transplant recipients. Immunosuppressants consisted of mycophenolate mofetil with tacrolimus in eight cases and mycophenolate mofetil with cyclosporine in two. The median time of diagnosis of polyoma virus infection after transplantation was 9.5 months, and the time to graft failure after the diagnosis was 4 months. Reduced allograft survival was seen in patients who had polyoma virus infection. Immunostaining for T and B cells revealed marked increase in the B cells (CD20) in renal allografts with polyoma virus infection of 21% (range, 5-40%) compared with 6% (range, 0-10%) in those with acute rejection (P=0.039). Reduced cytotoxic T cells (TIA-1: median, 7%; range, 2-15%) were seen in polyoma virus-infected allografts compared with 24% (range, 15-30%) in those patients who had acute rejection (P=0.0159). CONCLUSION: Irreversible graft failure is more prevalent with polyoma virus infection. Enhanced immunosuppressants with mycophenolate mofetil with tacrolimus may play a role in the development of this infection. An increase in CD20 and a decrease in cytotoxic T cells in allografts is characteristic of polyoma virus infection.

Levels of cytokine inhibitors: a possible marker of disease activity in childhood dermatomyositis and polymyositis.

The levels of cytokines and of their inhibitors were assessed by ELISA in serum samples from 3 children with dermatomyositis (DM) and polymyositis (PM) who were followed for several years. We observed normal levels of IL-6 and TNF alpha, but increased concentrations of IL-1Ra and TNF-sR75 at disease onset, which was followed by a decrease in the levels of IL-1Ra and TNF-sR75 in the patients with a favorable disease outcome. In contrast, in the one patient who relapsed no correlation with the levels of cytokines or of their inhibitors could be established. These results suggest that cytokine inhibitors such as IL-1Ra and TNF-sR may be useful additional parameters for monitoring the evolution of DM and PM.

Post-traumatic mutism in children: clinical characteristics, pattern of recovery and clinicopathological correlations.

Among the numerous clinical syndromes observed after severe traumatic head injury, post-traumatic mutism is a disorder rarely reported in adults and not studied in any detail in children. We report seven children between the ages of 3 1/2 and 14 years who sustained severe head injury and developed post-traumatic mutism. We aim to give a precise clinical characterization of this disorder, discuss differential diagnosis and correlations with brain imaging and suggest its probable neurological substrate. After a coma lasting from 5 to 25 days, the seven patients who suffered from post-traumatic mutism went through a period of total absence of verbal production lasting from 5 to 94 days, associated with the recovery of non-verbal communication skills and emotional vocalization. During the first days after the recovery of speech, all patients were able to produce correct small sentences with a hypophonic and monotonous voice, moderate dysarthria, word finding difficulties but no signs of aphasia, and preserved oral comprehension. The neurological signs in the acute phase (III nerve paresis in three of seven patients, signs of autonomic dysfunctions in five of seven patients), the results of the brain imaging and the experimental animal data all suggest the involvement of mesencephalic structures as playing a key role in the aetiology of post-traumatic mutism.

Axillary sentinel lymph node examination in breast carcinoma.

OBJECTIVE: To evaluate whether the type of pathologic examination of breast sentinel nodes (frozen section, step sections, and immunoperoxidase staining) results in different percentages of nodes positive for metastatic disease. DESIGN: Twenty-eight consecutive patients with breast sentinel node biopsies were evaluated by step-sectioning the sentinel node(s) along with performing immunoperoxidase stains for low-molecular-weight cytokeratin and epithelial membrane antigen. SETTING AND PARTICIPANTS: The patients were from a university hospital and large private hospital. MAIN OUTCOME MEASURES: The results of the step sections and immunoperoxidase stains were compared with routine examination, that is, intraoperative frozen section along with a single hematoxylin-eosin slide. RESULTS: Nine cases were positive by routine evaluation, 10 by step sections, and 11 by immunoperoxidase staining. CONCLUSIONS: The large, multi-institutional studies of sentinel node utility must take into account the surgical pathology methods used to evaluate these specimens so that uniform techniques, which reliably predict the status of the axillary nodes, can be instituted at all institutions that use this procedure.

Cervical cytology and immunohistochemical features in endometrial adenocarcinoma simulating microglandular hyperplasia. A case report.

BACKGROUND: The histology of a few cases of adenocarcinoma simulating cervical microglandular hyperplasia (MGH-AdCa) has been reported. However, the cytologic features of MGH-AdCa in cervical smears and the immunohistochemical profile have not been described. CASE: A 73-year-old female presented with vaginal bleeding. The cervical Pap smear was initially interpreted by the cytotechnologist as "reactive endocervical cells" and was referred for cytopathologist review. The final interpretation was atypical glandular cells of undetermined significance (AGUS), probably neoplastic. Endometrial biopsy and total abdominal hysterectomy with bilateral salpingo-oophorectomy showed International Federation of Gynecologists and Obstetricians grade 1 endometrial carcinoma. The superficial component of the tumor resembled cervical microglandular hyperplasia (MGH); the deeper component had an endometrioid pattern. The Pap smear predominantly showed a glandular component with features of MGH. However, the presence of scattered single cells with hyperchromatic nuclei, one to three nucleoli, easily detectable mitotic figures, randomly scattered apoptotic bodies and focal, watery diathesis suggested a neoplastic process. Immunohistochemistry was studied on paraffin sections. In addition to other markers, the tumor cells were immunoreactive for carcinoembryonic antigen (CEA). CONCLUSION: Although the cervical Pap smear in this case had an MGH-like pattern, some features were atypical enough to suggest a diagnosis of AGUS, probably neoplastic. CEA immunoreactivity of MGH-AdCa could also help to differentiate it from MGH.

Excess of serotonin affects neocortical pyramidal neuron migration.

The serotonin transporter (SERT) is a key molecule involved in the homeostasis of extracellular levels of serotonin and is regulated developmentally. Genetic deletion of SERT in rodents increases extracellular levels of serotonin and affects cellular processes involved in neocortical circuit assembly such as barrel cortex wiring and cortical interneuron migration. Importantly, pharmacological blockade of SERT during brain development leads to phenotypes relevant to psychiatry in rodents and to an increased risk for autism spectrum disorders in humans. Furthermore, developmental adversity interacts with genetically-driven variations of serotonin function in humans and nonhuman primates to increase the risk for a variety of stress-related phenotypes. In this study, we investigate whether an excess of serotonin affects the migration of neocortical pyramidal neurons during development. Using in utero electroporation combined with time-lapse imaging to specifically monitor pyramidal neurons during late mouse embryogenesis, we show that an excess of serotonin reversibly affects the radial migration of pyramidal neurons. We further identify that the serotonin receptor 5-HT(6) is expressed in pyramidal neuron progenitors and that 5-HT(6) receptor activation replicates the effects of serotonin stimulation. Finally, we show that the positioning of superficial layer pyramidal neurons is altered in vivo in SERT knockout mice. Taken together, these results indicate that a developmental excess of serotonin decreases the migration speed of cortical pyramidal neurons, affecting a fundamental step in the assembly of neural circuits. These findings support the hypothesis that developmental dysregulation of serotonin homeostasis has detrimental effects on neocortical circuit formation and contributes to increased vulnerability to psychiatric disorders.

Regulation of adult neurogenesis by stress, sleep disruption, exercise and inflammation: Implications for depression and antidepressant action.

Adult hippocampal neurogenesis, a once unorthodox concept, has changed into one of the most rapidly growing fields in neuroscience. The present report results from the ECNP targeted expert meeting in 2007 during which cellular plasticity changes were addressed in the adult brain, focusing on neurogenesis and apoptosis in hippocampus and frontal cortex. We discuss recent studies investigating factors that regulate neurogenesis with special emphasis on effects of stress, sleep disruption, exercise and inflammation, a group of seemingly unrelated factors that share at least two unifying properties, namely that they all regulate adult hippocampal neurogenesis and have all been implicated in the pathophysiology of mood disorders. We conclude that although neurogenesis has been implicated in cognitive function and is stimulated by antidepressant drugs, its functional impact and contribution to the etiology of depression remains unclear. A lasting reduction in neurogenesis following severe or chronic stress exposure, either in adult or early life, may represent impaired hippocampal plasticity and can contribute to the cognitive symptoms of depression, but is, by itself, unlikely to produce the full mood disorder. Normalization of reductions in neurogenesis appears at least partly, implicated in antidepressant action.

Phenomenology of mixed states: a principal component analysis study.

OBJECTIVES: To contribute to the definition of external and internal limits of mixed states and study the place of dysphoric symptoms in the psychopathology of mixed states. METHODS: One hundred and sixty-five inpatients with major mood episodes were diagnosed as presenting with either pure depression, mixed depression (depression plus at least three manic symptoms), full mixed state (full depression and full mania), mixed mania (mania plus at least three depressive symptoms) or pure mania, using an adapted version of the Mini International Neuropsychiatric Interview (DSM-IV version). They were evaluated using a 33-item inventory of depressive, manic and mixed affective signs and symptoms. RESULTS: Principal component analysis without rotation yielded three components that together explained 43.6% of the variance. The first component (24.3% of the variance) contrasted typical depressive symptoms with typical euphoric, manic symptoms. The second component, labeled 'dysphoria', (13.8%) had strong positive loadings for irritability, distressing sensitivity to light and noise, impulsivity and inner tension. The third component (5.5%) included symptoms of insomnia. Median scores for the first component significantly decreased from the pure depression group to the pure mania group. For the dysphoria component, scores were highest among patients with full mixed states and decreased towards both patients with pure depression and those with pure mania. CONCLUSIONS: Principal component analysis revealed that dysphoria represents an important dimension of mixed states.

Chronic recording from the His bundle of the awake dog.

The conventional catheter method for measuring specialized A-V nodal and His-ventricular conduction times in the intact dog heart precludes an unanesthetized control. This control is necessary for meaningful studies of the effect of drugs or drug-drug interactions on A-V conduction times. At right thoracotomy (halothane anesthesia), mongrel dogs had bipolar electrodes sutured to the epicardial surface of both atrial appendages, junctions of the sulcus terminalis with both vena cavae, and right ventricle. A unipolar needle electrode, referenced to a unipolar electrode on the ascending aorta, was inserted into the interatrial septum from the aortic root for recording the His bundle electrogram. After one to three weeks for stabilization, weekly measurements were made of A-V nodal conduction time (AVN) and His-ventricular conduction time (H-V) for up to 52 weeks (4 to 52 weeks). Mean values (13 dogs) for spontaneous cycle length, AVN and H-V conduction times were 477 +/- 25, 82 +/- 3, and 30 +/- 1 msec, respectively. Simultaneous recordings from catheter and implanted His bundle electrodes were made during changes in atrial paced rate (five dogs, pentobarbital anesthesia). Values for AVN and H-V conduction times from catheter or implanted electrodes were the same. AVN conduction time increased, H-V conduction time remained constant during increases in atrial rate. Atropine shortened and propranolol prolonged AVN conduction time in six unanesthetized, unsedated dogs; neither affected H-V conduction time. Histologic examination of electrode sites in two dogs at 43 and 52 weeks showed no evidence of damage to underlying myocardial recording sites. This preparation provides reproducible awake values for AVN and H-V conduction times, and hence a more meaningful control for pharmacologic investigations.

Localization of somatostatin-, bombesin-, and serotonin-like immunoreactivity in the lung of the fetal rhesus monkey.

Immunoreactivity of regulatory peptides has been demonstrated in the fetal lung of Macaca mulatta by the peroxidase anti-peroxidase method. Serotonin-immunoreactive neuroepithelial bodies are distributed in the airways from the bronchi to the alveolar ducts. Many neuroepithelial bodies also show bombesin-like immunoreactivity; a very few are immunoreactive to somatostatin antiserum. Four populations of neuroepithelial bodies were identified which contain immunoreactivity for 1) serotonin alone, 2) serotonin and bombesin, 3) serotonin and somatostatin, and 4) serotonin, bombesin, and somatostatin. Since bombesin and somatostatin have been demonstrated to have opposite effects on the release of other peptide hormones, it seems likely that the presence of these same peptides in neuroepithelial bodies may have a similar regulatory role in the lung.