RESUMO
The work aims were to describe the histological and histochemical structure of the gastroesophageal tube of Iguana iguana and verify the occurrence and distribution of immunoreactive serotonin (5-HT) and somatostatin (SS) cells. Fragments of the gastrointestinal tract (GIT) of five iguanas were which underwent standard histological and immunohistochemistry technique. Immunoreactive cells for 5-HT and SS were quantified using the STEPanizer. The oesophagus has ciliated columnar pseudostratified epithelium with staining Alcian blue (AB) + and goblet cells highly reactive to periodic acid Schiff (PAS). In the cervical oesophagus, the numerical density of 5-HT cells per unit area (QA [5-HT cells]/µm2) was 4.6x10-2 ± 2.0 and celomatic oesophagus presented QA = 4.0x10-2 ± 1.0. The epithelium of the stomach is simple columnar, PAS and AB +. The cranial and middle regions of the stomach presented (QA [5-HT cells]/µm2) = 6.18x10-2 ± 3.2 and the caudal region, QA = 0.6x10-2 ± 0.2. The SS cells were only observed in the caudal stomach, with numerical density (QA [SS cells]/µm2) = 1.4x10-2 ± 0.9 In I. iguana, variation was observed in terms of the distribution of mucus secretions and the pattern of occurrence of serotonin and somatostatin-secreting enteroendocrine cells in the TGI, which possibly will result in an interspecific adaptive response.
Os objetivos do trabalho foram descrever a estrutura histológica e histoquímica do tubo gastroesofágico da Iguana iguana e verificar a ocorrência e distribuição de células serotonina (5-HT) e somatostatina (SS) imunorreativas. Fragmentos do trato gastrointestinal (TGI) de cinco iguanas foram submetidos à técnica histológica e imunohistoquímica padrão. As células imunorreativas para 5-HT e SS foram quantificadas usando o STEPanizer. O esôfago apresenta epitélio pseudoestratificado colunar ciliado Alcian blue (AB) positivo, com células caliciformes altamente reativas ao ácido periódico de Schiff (PAS). No esôfago cervical, a densidade numérica de células 5-HT por unidade de área (QA [células 5-HT] / µm2) foi de 4.6x10-2 ± 2.0 e o esôfago celomático apresentou QA = 4.0x10-2 ± 1.0. O epitélio do estômago é colunar simples, PAS e AB positivo. As regiões cranial e média do estômago apresentaram (QA [células 5-HT] / µm2) = 6.18x10-2 ± 3.2 e a região caudal, QA = 0.6x10-2 ± 0.2. As células SS foram observadas apenas no estômago caudal, com densidade numérica (QA [células SS] / µm2) = 1.4x10-2 ± 0.9. Em I. iguana, foi observada variações em termos da distribuição das secreções de muco e padrão de ocorrência das células enteroendócrinas secretoras de serotonina e somatostatina no TGI, o que possivelmente reflete uma resposta adaptativa interespecifica.
Assuntos
Animais , Estômago , Esôfago , Iguanas/anatomia & histologia , Imuno-Histoquímica/veterinária , Serotonina/análise , Somatostatina/análise , Trato Gastrointestinal/anatomia & histologiaRESUMO
The work aims were to describe the histological and histochemical structure of the gastroesophageal tube of Iguana iguana and verify the occurrence and distribution of immunoreactive serotonin (5-HT) and somatostatin (SS) cells. Fragments of the gastrointestinal tract (GIT) of five iguanas were which underwent standard histological and immunohistochemistry technique. Immunoreactive cells for 5-HT and SS were quantified using the STEPanizer. The oesophagus has ciliated columnar pseudostratified epithelium with staining Alcian blue (AB) + and goblet cells highly reactive to periodic acid Schiff (PAS). In the cervical oesophagus, the numerical density of 5-HT cells per unit area (QA [5-HT cells]/µm2) was 4.6x10-2 ± 2.0 and celomatic oesophagus presented QA = 4.0x10-2 ± 1.0. The epithelium of the stomach is simple columnar, PAS and AB +. The cranial and middle regions of the stomach presented (QA [5-HT cells]/µm2) = 6.18x10-2 ± 3.2 and the caudal region, QA = 0.6x10-2 ± 0.2. The SS cells were only observed in the caudal stomach, with numerical density (QA [SS cells]/µm2) = 1.4x10-2 ± 0.9 In I. iguana, variation was observed in terms of the distribution of mucus secretions and the pattern of occurrence of serotonin and somatostatin-secreting enteroendocrine cells in the TGI, which possibly will result in an interspecific adaptive response.(AU)
Os objetivos do trabalho foram descrever a estrutura histológica e histoquímica do tubo gastroesofágico da Iguana iguana e verificar a ocorrência e distribuição de células serotonina (5-HT) e somatostatina (SS) imunorreativas. Fragmentos do trato gastrointestinal (TGI) de cinco iguanas foram submetidos à técnica histológica e imunohistoquímica padrão. As células imunorreativas para 5-HT e SS foram quantificadas usando o STEPanizer. O esôfago apresenta epitélio pseudoestratificado colunar ciliado Alcian blue (AB) positivo, com células caliciformes altamente reativas ao ácido periódico de Schiff (PAS). No esôfago cervical, a densidade numérica de células 5-HT por unidade de área (QA [células 5-HT] / µm2) foi de 4.6x10-2 ± 2.0 e o esôfago celomático apresentou QA = 4.0x10-2 ± 1.0. O epitélio do estômago é colunar simples, PAS e AB positivo. As regiões cranial e média do estômago apresentaram (QA [células 5-HT] / µm2) = 6.18x10-2 ± 3.2 e a região caudal, QA = 0.6x10-2 ± 0.2. As células SS foram observadas apenas no estômago caudal, com densidade numérica (QA [células SS] / µm2) = 1.4x10-2 ± 0.9. Em I. iguana, foi observada variações em termos da distribuição das secreções de muco e padrão de ocorrência das células enteroendócrinas secretoras de serotonina e somatostatina no TGI, o que possivelmente reflete uma resposta adaptativa interespecifica.(AU)
Assuntos
Animais , Iguanas/anatomia & histologia , Trato Gastrointestinal/anatomia & histologia , Estômago , Esôfago , Serotonina/análise , Somatostatina/análise , Imuno-Histoquímica/veterináriaRESUMO
Memory systems ought to store and discriminate representations of similar experiences in order to efficiently guide future decisions. This problem is solved by pattern separation, implemented in the dentate gyrus (DG) by granule cells to support episodic memory formation. Pattern separation is enabled by tonic inhibitory bombardment generated by multiple GABAergic cell populations that strictly maintain low activity levels in granule cells. Somatostatin-expressing cells are one of those interneuron populations, selectively targeting the distal dendrites of granule cells, where cortical multimodal information reaches the DG. Nonetheless, somatostatin cells have very low connection probability and synaptic efficacy with both granule cells and other interneuron types. Hence, the role of somatostatin cells in DG circuitry, particularly in the context of pattern separation, remains uncertain. Here, by using optogenetic stimulation and behavioral tasks in mice, we demonstrate that somatostatin cells are required for the acquisition of both contextual and spatial overlapping memories.
Assuntos
Giro Denteado/citologia , Giro Denteado/metabolismo , Aprendizagem por Discriminação/fisiologia , Memória Episódica , Células Secretoras de Somatostatina/metabolismo , Animais , Giro Denteado/química , Feminino , Ácido Glutâmico/análise , Ácido Glutâmico/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Optogenética/métodos , Somatostatina/análise , Somatostatina/metabolismo , Células Secretoras de Somatostatina/químicaRESUMO
The basal forebrain provides modulatory input to the cortex regulating brain states and cognitive processing. Somatostatin-expressing neurons constitute a heterogeneous GABAergic population known to functionally inhibit basal forebrain cortically projecting cells thus favoring sleep and cortical synchronization. However, it remains unclear if somatostatin cells can regulate population activity patterns in the basal forebrain and modulate cortical dynamics. Here, we demonstrate that somatostatin neurons regulate the corticopetal synaptic output of the basal forebrain impinging on cortical activity and behavior. Optogenetic inactivation of somatostatin neurons in vivo rapidly modified neural activity in the basal forebrain, with the consequent enhancement and desynchronization of activity in the prefrontal cortex, reflected in both neuronal spiking and network oscillations. Cortical activation was partially dependent on cholinergic transmission, suppressing slow waves and potentiating gamma oscillations. In addition, recruitment dynamics was cell type-specific, with interneurons showing similar temporal profiles, but stronger responses than pyramidal cells. Finally, optogenetic stimulation of quiescent animals during resting periods prompted locomotor activity, suggesting generalized cortical activation and increased arousal. Altogether, we provide physiological and behavioral evidence indicating that somatostatin neurons are pivotal in gating the synaptic output of the basal forebrain, thus indirectly controlling cortical operations via both cholinergic and non-cholinergic mechanisms.
Assuntos
Potenciais de Ação/fisiologia , Prosencéfalo Basal/fisiologia , Neurônios/fisiologia , Córtex Pré-Frontal/fisiologia , Somatostatina/fisiologia , Animais , Prosencéfalo Basal/química , Prosencéfalo Basal/citologia , Feminino , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/química , Optogenética/métodos , Técnicas de Cultura de Órgãos , Córtex Pré-Frontal/química , Córtex Pré-Frontal/citologia , Somatostatina/análiseRESUMO
Congenital hyperinsulinism (CHI) is a heterogenous disease caused by insulin secretion regulatory defects, being ABCC8/KCNJ11 the most commonly affected genes. Therapeutic options include diazoxide, somatostatin analogues and surgery, which is curative in focal CHI. We report the case of two siblings (born two years apart) that presented themselves with hypoketotic hyperinsulinemic persistent hypoglycemias during neonatal period. The diagnosis of diffuse CHI due to an ABCC8 compound mutation (c.3576delG and c.742C>T) was concluded. They did not benefit from diazoxide therapy (or pancreatectomy performed in patient number 1) yet responded to somatostatin analogues. Patient number 1 developed various neurological deficits (including epilepsy), however patient number 2 experienced an entirely normal neurodevelopment. We believe this case shows how previous knowledge of the firstborn sibling's disease contributed to a better and timelier medical care in patient number 2, which could potentially explain her better neurological outcome despite their same genotype.
Assuntos
Hiperinsulinismo Congênito/genética , Hiperinsulinismo Congênito/terapia , Mutação/genética , Irmãos , Receptores de Sulfonilureias/genética , Diazóxido/uso terapêutico , Feminino , Genótipo , Humanos , Recém-Nascido , Masculino , Pancreatectomia/métodos , Fenótipo , Somatostatina/análise , Resultado do TratamentoRESUMO
SUMMARY Congenital hyperinsulinism (CHI) is a heterogenous disease caused by insulin secretion regulatory defects, being ABCC8/KCNJ11 the most commonly affected genes. Therapeutic options include diazoxide, somatostatin analogues and surgery, which is curative in focal CHI. We report the case of two siblings (born two years apart) that presented themselves with hypoketotic hyperinsulinemic persistent hypoglycemias during neonatal period. The diagnosis of diffuse CHI due to an ABCC8 compound mutation (c.3576delG and c.742C>T) was concluded. They did not benefit from diazoxide therapy (or pancreatectomy performed in patient number 1) yet responded to somatostatin analogues. Patient number 1 developed various neurological deficits (including epilepsy), however patient number 2 experienced an entirely normal neurodevelopment. We believe this case shows how previous knowledge of the firstborn sibling's disease contributed to a better and timelier medical care in patient number 2, which could potentially explain her better neurological outcome despite their same genotype.
Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Irmãos , Hiperinsulinismo Congênito/genética , Hiperinsulinismo Congênito/terapia , Receptores de Sulfonilureias/genética , Mutação/genética , Pancreatectomia/métodos , Fenótipo , Somatostatina/análise , Resultado do Tratamento , Diazóxido/uso terapêutico , GenótipoRESUMO
OBJECTIVES: Severe congenital diarrhea occurs in approximately half of patients with Aristaless-Related Homeobox (ARX) null mutations. The cause of this diarrhea is unknown. In a mouse model of intestinal Arx deficiency, the prevalence of a subset of enteroendocrine cells is altered, leading to diarrhea. Because polyalanine expansions within the ARX protein are the most common mutations found in ARX-related disorders, we sought to characterize the enteroendocrine population in human tissue of an ARX mutation and in a mouse model of the corresponding polyalanine expansion (Arx). METHODS: Immunohistochemistry and quantitative real-time polymerase chain reaction were the primary modalities used to characterize the enteroendocrine populations. Daily weights were determined for the growth curves, and Oil-Red-O staining on stool and tissue identified neutral fats. RESULTS: An expansion of 7 alanines in the first polyalanine tract of both human ARX and mouse Arx altered enteroendocrine differentiation. In human tissue, cholecystokinin, glucagon-like peptide 1, and somatostatin populations were reduced, whereas the chromogranin A population was unchanged. In the mouse model, cholecystokinin and glucagon-like peptide 1 populations were also lost, although the somatostatin-expressing population was increased. The ARX protein was present in human tissue, whereas the Arx protein was degraded in the mouse intestine. CONCLUSIONS: ARX/Arx is required for the specification of a subset of enteroendocrine cells in both humans and mice. Owing to protein degradation, the Arx mouse recapitulates findings of the intestinal Arx null model, but is not able to further the study of the differential effects of the ARX protein on its transcriptional targets in the intestine.
Assuntos
Diarreia/genética , Duodenopatias/genética , Células Enteroendócrinas/fisiologia , Proteínas de Homeodomínio/genética , Pseudo-Obstrução Intestinal/genética , Peptídeos/metabolismo , Fatores de Transcrição/genética , Adolescente , Animais , Diferenciação Celular/genética , Colecistocinina/análise , Cromogranina A/análise , Diarreia/patologia , Modelos Animais de Doenças , Duodenopatias/patologia , Duodeno/patologia , Células Enteroendócrinas/química , Células Enteroendócrinas/patologia , Insuficiência de Crescimento/genética , Feminino , Peptídeo 1 Semelhante ao Glucagon/análise , Proteínas de Homeodomínio/análise , Humanos , Pseudo-Obstrução Intestinal/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mutagênese Insercional , Somatostatina/análise , Esteatorreia/genética , Fatores de Transcrição/análiseRESUMO
The main purpose of this study was to evaluate the regional distribution pattern and relative frequency of some endocrine cells in the three portions of the gastrointestinal tract (GIT)--the proventriculus, gizzard and duodenum- of the rufous-collared sparrow (Zonotrichia capensis subtorquata), by immunohistochemical methods using six types of polyclonal antisera, specific for serotonin (5-HT), somatostatin (D cells), glucagon, motilin, polypeptide YY (PYY) and insulin. In the proventriculus, endocrine cells immunoreactive for all of these markers were observed. The somatostatin-immunoreactive cells were found with greater frequency, with the presence of cytoplasmic processes. In the gizzard, endocrine cells secreting somatostatin, 5-HT and PYY were detected, while those secreting glucagon and insulin were not. In the final part of the gizzard, endocrine cells secreting 5-HT were more frequent, and cells secreting somatostatin and insulin were not detected. All of the cell types studied were observed in the duodenum in different frequencies, except for cells immunoreactive for glucagon and insulin. The somatostatin-positive (D cells) were the most numerous, being more prevalent in the intestinal glands. The other endocrine cells were identified in smaller numbers, some of them located in the intestinal villi and Lieberkuhn glands. The finding of these cell types in the duodenum confirms their preferential location in the final portions of the principal segments of the digestive system and suggests control by feedback of its functions. In conclusion, some interesting distributional patterns of gastrointestinal endocrine cells were found in this species of sparrow.
Assuntos
Duodeno/citologia , Células Endócrinas/citologia , Passeriformes , Estômago/citologia , Animais , Biomarcadores/análise , Duodeno/química , Células Endócrinas/química , Moela das Aves/química , Moela das Aves/citologia , Glucagon/análise , Imuno-Histoquímica , Insulina/análise , Motilina/análise , Peptídeo YY/análise , Serotonina/análise , Somatostatina/análise , Estômago/químicaRESUMO
The distribution of perikarya and fibers containing somatostatin was studied in the brain of the snake Bothrops jararaca by means of immunohistochemistry using an antiserum against synthetic somatostatin. Immunoreactive perikarya and fibers were localized in telencephalic, diencephalic and mesencephalic areas. In the telencephalon, numerous immunoreactive perikarya were found in the medial, dorsomedial, dorsal and lateral cortex, mainly in the deep plexiform layer, less so in the cellular layer, but not in the superficial plexiform layer. Immunoreactive perikarya were also observed in the dorsal ventricular ridge, the nucleus of the diagonal band of Broca, amygdaloid complex, septum and lamina terminalis. In the diencephalon, labelled cells were observed in the paraventricular, periventricular hypothalamic and in the recessus infundibular nuclei. In the mesencephalon, immunoreactive perikarya were seen in the mesencephalic reticular formation, reticular nucleus of the isthmus and torus semicircularis. Labelled fibers ran along the diencephalic floor and the inner zone of the median eminence, and ended in the neural lobe of the hypophysis. Other fibers were observed in the outer zone of the median eminence close to the portal vessels and in the septum, lamina terminalis, retrochiasmatic nucleus, deep layers of the tectum, periventricular gray and granular layer of the cerebellum. Our data suggest that somatostatin may function as a mediator of adenohypophysial secretion as well as neurotransmitter and/or neuromodulator which can regulate the neurohypophysial peptides in the snake B. jararaca.
Assuntos
Bothrops/metabolismo , Somatostatina/análise , Animais , Núcleo Arqueado do Hipotálamo/química , Química Encefálica , Córtex Cerebral/química , Diencéfalo/química , Epêndima/química , Epêndima/citologia , Feminino , Lobo Frontal/química , Imuno-Histoquímica , Masculino , Mesencéfalo/química , Núcleos da Linha Média do Tálamo/química , Fibras Nervosas/química , Núcleo Hipotalâmico Paraventricular/química , Telencéfalo/químicaRESUMO
In this paper, the distribution of NADH-positive and somatostatin (SOM) immunoreactive neurons in the myenteric plexus of the colon of mice infected with Trypanosoma cruzi was studied. Ten young, male, BALB/c mice were inoculated with the Y strain of T. cruzi, 60 days previously (chronic phase of the infection). Another 10 mice were uninfected controls. Distal and proximal colonic neurons from five chronically infected mice and their controls were stained using the NADH-diaphorase method. Quantitative results showed a significant decrease of 39% in the number of neurons in the proximal colon of infected mice and 58% in the distal colon (p<0.05). SOM was localized in five animals from each group by light microscopy, using an indirect immunofluorescence technique. It was observed that there were far fewer nerve cells and fibres and less intensely stained neuron bodies and varicose SOM-positive nerve fibres in both, control and chronic infected mice. These findings could be related to the disturbances in intestinal motility observed in patients in the chronic phase of Chagas' disease.