RESUMO
Pathophysiological mechanisms involved in orofacial pain and their relationship with emotional disorders have emerged as an important research area for multidisciplinary studies. In particular, temporomandibular disorders (TMD) have been evaluated clinically from both physiological and psychological perspectives. We hypothesized that an altered neuronal activity occurs in the amygdala and the dorsal raphe nucleus (DR), encephalic regions involved in the modulation of painful and emotional information. Adult male Wistar rats were used in an experimental complete Freund's adjuvant (CFA)-induced temporomandibular joint (TMJ) inflammation model. CFA was applied for 1 or 10 days, and the animals were euthanized for brain samples dissection for FosB/ΔFosB and parvalbumin (PV) immunostaining. Our results were consistent in showing that the amygdala and DR were activated in the persistent inflammatory phase (10 days) and that the expression of PV+ interneurons in the amygdala was decreased. In contrast, in the DR, the expression of PV+ interneurons was increased in persistent states of CFA-induced TMJ inflammation. Moreover, at 10 days of inflammation, there was an increased co-localization of PV+ and FosB/ΔFosB+ neurons in the basolateral and central nucleus of the amygdala. Different nuclei of the amygdala, as well as portions of the DR, were activated in the persistent phase (10 days) of TMJ inflammation. In conclusion, altered activity of the amygdala and DR was detected during persistent inflammatory nociception in the temporomandibular joint. These regions may be essential for both sensory and affective dimensions of orofacial pain.
Assuntos
Tonsila do Cerebelo/metabolismo , Núcleo Dorsal da Rafe/metabolismo , Parvalbuminas/metabolismo , Articulação Temporomandibular/fisiologia , Animais , Inflamação , Masculino , Neurônios , Ratos , Ratos Sprague-Dawley , Ratos WistarRESUMO
Pathophysiological mechanisms involved in orofacial pain and their relationship with emotional disorders have emerged as an important research area for multidisciplinary studies. In particular, temporomandibular disorders (TMD) have been evaluated clinically from both physiological and psychological perspectives. We hypothesized that an altered neuronal activity occurs in the amygdala and the dorsal raphe nucleus (DR), encephalic regions involved in the modulation of painful and emotional information. Adult male Wistar rats were used in an experimental complete Freund's adjuvant (CFA)-induced temporomandibular joint (TMJ) inflammation model. CFA was applied for 1 or 10 days, and the animals were euthanized for brain samples dissection for FosB/ΔFosB and parvalbumin (PV) immunostaining. Our results were consistent in showing that the amygdala and DR were activated in the persistent inflammatory phase (10 days) and that the expression of PV+ interneurons in the amygdala was decreased. In contrast, in the DR, the expression of PV+ interneurons was increased in persistent states of CFA-induced TMJ inflammation. Moreover, at 10 days of inflammation, there was an increased co-localization of PV+ and FosB/ΔFosB+ neurons in the basolateral and central nucleus of the amygdala. Different nuclei of the amygdala, as well as portions of the DR, were activated in the persistent phase (10 days) of TMJ inflammation. In conclusion, altered activity of the amygdala and DR was detected during persistent inflammatory nociception in the temporomandibular joint. These regions may be essential for both sensory and affective dimensions of orofacial pain.
Assuntos
Animais , Masculino , Ratos , Parvalbuminas/metabolismo , Articulação Temporomandibular/fisiologia , Núcleo Dorsal da Rafe/metabolismo , Tonsila do Cerebelo/metabolismo , Ratos Wistar , Ratos Sprague-Dawley , Inflamação , NeurôniosRESUMO
The population genetic structure of the Cayapa cytospecies of Simulium exiguum, the vector of onchocerciasis, was analysed using allozyme frequency and chromosomal inversion polymorphism data from 6 and 15 populations respectively, collected in Ecuador. Eight allozyme loci were scored. No unique allozyme markers were found enabling us to identify biting adults of the vector from the non-vector Bucay cytotype. Mannose-phosphate isomerase (Mpi) contributed largely to the significant heterogeneity in gene frequency among populations of the Cayapa cytospecies and also to the overall population structuring (F(ST) = 0.015 +/- 0.014) which fitted the isolation by distance model. However, heterozygote deficits were recorded for Mpi in four of the six populations, which could indicate that selection is acting at this locus but this hypothesis will require further convincing evidence. Furthermore the significant population structuring of allozymes was not evident when Mpi was omitted from the analysis. All inversion polymorphisms (IIS-B, IIS-F, IIL-A and IIL-B) were in Hardy-Weinberg equilibrium, showed significant heterogeneity between populations and revealed the occurrence of an altitudinal cline in inversion IIS-B frequency. The inversion polymorphisms revealed a significant degree of population structuring (F(ST) = 0.083 +/- 0.027), which can be explained by the isolation by distance model. A UPGMA cluster analysis revealed the relatively remote, high altitude Rio Mira populations to be the most genetically distinct.
Assuntos
Inversão Cromossômica , Genética Populacional , Simuliidae/genética , Animais , Equador , Feminino , Insetos Vetores , Masculino , Oncocercose/transmissão , Polimorfismo GenéticoRESUMO
During studies of Simuliidae at a suspected new focus of human onchocerciasis in central Brazil a new species of Simulium was found. Full descriptions of the adults and pupae of this species, S. cuasiexiguum, are described here, its affinities to closely related species in the subgenus Notolepria are discussed and its distribution in Brazil recorded.
Assuntos
Insetos Vetores/classificação , Oncocercose/transmissão , Simuliidae/classificação , Animais , Brasil , Feminino , Insetos Vetores/anatomia & histologia , Masculino , Simuliidae/anatomia & histologiaRESUMO
During studies of Simuliidae at a suspected new focus of human onchocerciasis in central Brazil a new species of Simulium was found. Full descriptions of the adults and pupae of this species, S. cuasiexiguum, are described here, its affinities to closely related species in the subgenus Notolepria are discussed and its distribution in Brazil recorded
Assuntos
Animais , Masculino , Feminino , Insetos Vetores/classificação , Oncocercose/transmissão , Simuliidae/classificação , Insetos Vetores/anatomia & histologia , Simuliidae/anatomia & histologiaRESUMO
Monthly collections were made of man-biting female blackflies: Simulium auripellitum Enderlein, S. guianense Wise, S. minusculum Lutz and S. nigrimanum Macquart (Diptera: Simuliidae) from four catching stations in the newly discovered focus of human onchocerciasis at Minaçu (13 degrees 35 minutes S 48 degrees 18 minutes W), 300 km north of Brasília in Goiás State. These provided baseline data on biting habits, population density and seasonal prevalence during the year before completion of the Serra da Mesa hydroelectric dam on the Rio Tocantins near Minaçu, in a project investigating the effect of dam construction on onchocerciasis transmission in the area. All four simuliid species were most abundant during the dry season, and only bit in low numbers (S. auripellitum S. minusculum, S. nigrimanum) or were absent (S. guianense) in the wet season. Simulium minusculum was the predominant species at all catching stations, being particularly abundant by the large River Tocantins. The other three species were mainly associated with smaller rivers. In the dry season, biting rhythms of S. minusculum varied with catching site, while S. nigrimanum showed peaks of activity in early morning and during the afternoon. Experimental infection with Onchocerca volvulus (Leuckart) (Nematoda: Onchocercidae), from a human volunteer, showed that this parasite could develop fully in the four simuliid species, which are all considered to be potential vectors in the area.
Assuntos
Dípteros/parasitologia , Mordeduras e Picadas de Insetos , Insetos Vetores , Oncocercose/transmissão , Animais , Brasil/epidemiologia , Feminino , Humanos , Masculino , Oncocercose/epidemiologia , Dinâmica Populacional , Estações do AnoRESUMO
Four cytotypes of Simulium exiguum occur in Ecuador, where this morphospecies is the primary vector of onchocerciasis. In this paper, we give the first full description of the banding pattern of the larval polytene chromosomes of the Quevedo cytotypes differ from the chromosomal standard sequence (of the Cayapa cytotype) by the fixed inversions IIL-5 and IIL-6. The Quevedo cytotype additionally differs from the standard and Bucay cytotypes by processing a differentiated X chromosome, wich is indicated by the inversion IIS-A. As the degree of reproductive isolation between the Bucay and Quevedo cytotypes has not yet been estabilished, they must be regarded as intraspecific variants of the same species. In fact, isoenzyme characterizations showed that the Bucay and Quevedo cytotypes are differentiated only to the extent expected of incipient species or geographical populations. Moreover, the sibiling species status previously given to the Bucay cytotype needs be reassessed, there being inadequate analysis from areas in Ecuador where Bucay occurs in sympatry with the standard Cayapa cytotype. No isoenzyme electromorphs were discovered that identified all or mostadult females of any one (cytotype-pure) collection
Assuntos
Animais , Vetores de Doenças , Isoenzimas/análise , Simuliidae/análise , Equador , Oncocercose/transmissão , Simuliidae/parasitologiaRESUMO
Four cytotypes of Simulium exiguum occur in Ecuador, where this morphospecies is the primary vector of onchocerciasis. In this paper, we give the first full description of the banding pattern of the larval polytene chromosomes of the Quevedo cytotype and assess its degree of genetic separation from the Bucay cytotype. Both cytotypes differ from the chromosomal standard sequence (of the Cayapa cytotype) by the fixed inversions IIL-5 and IIL-6. The Quevedo cytotype additionally differs from the standard and Bucay cytotypes by possessing a differentiated X chromosome, which is indicated by the inversion IIS-A. As the degree of reproductive isolation between the Bucay and Quevedo cytotypes has not yet been established, they must be regarded as intraspecific variants of the same species. In fact, isoenzyme characterizations showed that the Bucay and Quevedo cytotypes are differentiated only to the extent expected of incipient species or geographical populations. Moreover, the sibling species status previously given to the Bucay cytotype needs be reassessed, there being inadequate analysis from areas in Ecuador where Bucay occurs in sympatry with the standard Cayapa cytotype. No isoenzyme electromorphs were discovered that identified all or most adult females of any one (cytotypepure) collection.