RESUMO
BACKGROUND AND AIM: Appropriate end of life (EOL) management in Internal Medicine wards is challanging. The aim of this study was to analyze the burden of an educational program on EOL management in a Internal Medicine ward. Materials and methods: We retrospectively analysed characteristics and management of patients consecutively died in an italian Internal Medicine ward along one year. We compared demographic, co-morbidity, pharmacological treatment in the last 48-hours of life and procedures during hospital stay in patients died six months before and after an educational program on palliative cares and EOL management addressed to a team of physicians and nurses. RESULTS: Study population was composed by 354 patients (190 females), with mean age ± DS 83.5 ± 10.6 years, one half admitted after the educational program. Eighty-four percent of deaths was exepected in the last 48 hours before exitus. Demographic characteristics and causes of hospitalization were not different before and after educational program. After the educational program the sharing of palliative care program with patient, relatives and/or caregivers (97.7% vs 85.8%, p=0.0001) and written order to withdrawal vital parameters relevation (39.5% vs 22%, p=0.0005) significantly increased, while difference in pharmacological classes prescribed in the last 48 hours of life was not find. Blood (54.8% vs 67.2%, p=0.0219) and arterial gas analysis (28.8% vs 39.5%, p=0.0435) samples in the last 48 hours of life were significantly reduced. Radiological and/or endoscopic examinations, red cells or platelets transfusion were reduced and palliative therapy was increased, despite difference between the two periods was not statistically significant. CONCLUSION: Educational program in Internal Medicine wards aimed to improve skills could contribute to make EOL management more appropriate and patient-oriented and it should be strongly encour-aged.
Assuntos
Educação Médica Continuada/organização & administração , Educação Continuada em Enfermagem/organização & administração , Hospitais , Medicina Interna/educação , Assistência Terminal/organização & administração , Idoso , Idoso de 80 Anos ou mais , Cuidadores , Comorbidade , Morte , Feminino , Humanos , Itália , Tempo de Internação , Masculino , Cuidados Paliativos/organização & administração , Estudos Retrospectivos , Fatores SocioeconômicosRESUMO
The present study describes in primates the effects of a spinal cord injury on the number and size of the neurons in the magnocellular part of the red nucleus (RNm), the origin of the rubrospinal tract, and evaluates whether a neutralization of Nogo-A reduces the lesioned-induced degenerative processes observed in RNm. Two groups of monkeys were subjected to unilateral section of the spinal cord affecting the rubrospinal tract; one group was subsequently treated with an antibody neutralizing Nogo-A; the second group received a control antibody. Intact animals were also included in the study. Counting neurons stained with a monoclonal antibody recognizing non-phosphorylated epitopes on neurofilaments (SMI-32) indicated that their number in the contralesional RNm was consistently inferior to that in the ipsilesional RNm, in a proportion amounting up to 35%. The lesion also induced shrinkage of the soma of the neurons detected in the contralesional RNm. Infusing an anti-Nogo-A antibody at the site of the lesion did not increase the proportion of SMI-32 positive rubrospinal neurons in the contralesional RNm nor prevent shrinkage.
Assuntos
Anticorpos Monoclonais/farmacologia , Proteínas da Mielina/antagonistas & inibidores , Neurônios/patologia , Tratos Piramidais/patologia , Núcleo Rubro/patologia , Traumatismos da Medula Espinal/patologia , Animais , Axotomia , Vértebras Cervicais , Lateralidade Funcional/fisiologia , Humanos , Macaca , Proteínas de Neurofilamentos/efeitos dos fármacos , Proteínas NogoRESUMO
This study focused on the temporal and spatial pattern of expression of the cell adhesion molecule axonin-1 in amacrine cells and the identification of these cells in the developing chick retina. We analyzed 5-20-day-old chick embryos. The antigen was localized and visualized by the indirect immunogold and the immunofluorescence technique. Colocalization studies with antibodies against tyrosine hydroxylase, acetylcholinesterase, choline acetyltransferase, parvalbumin, calbindin, and calretinin served to characterize these cells further and to explore whether they have other properties in common. Axonin-1 was expressed in amacrine cells from E8 onward in the inner nuclear, in the inner plexiform, and in the ganglion cell layer. Their maturation showed a gradient similar to that found for amacrinogenesis. Expression was closely correlated with the period when the cells develop and shape their processes. The interneurons were classified with reference to Cajal, and most of the morphological types described by him were found. In addition, some cells were considered as axon-bearing amacrine cells. However, the total number of labeled cells was rather small. At least two morphologically different types terminated in each of the inner plexiform sublayers. Narrow- and wide-field arbors indicated the existence of a diversified network. The colocalization studies revealed that the neurotransmitters and neuropeptides overlapped partially with axonin-1 expression. This indicated that axonin-1-immunoreactive amacrine cells were also functionally diverse.
Assuntos
Células Amácrinas/metabolismo , Moléculas de Adesão Celular Neuronais/metabolismo , Diferenciação Celular/fisiologia , Retina/embriologia , Retina/metabolismo , Acetilcolinesterase/metabolismo , Células Amácrinas/citologia , Animais , Axônios/metabolismo , Axônios/ultraestrutura , Biomarcadores , Proteínas de Ligação ao Cálcio/metabolismo , Embrião de Galinha , Colina O-Acetiltransferase/metabolismo , Contactina 2 , Dendritos/metabolismo , Dendritos/ultraestrutura , Imuno-Histoquímica , Retina/citologia , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Cell surface glycoproteins expressed on growth cones and axons during brain development have been postulated to be involved in the cell-cell interactions that guide axons into their target area. Nevertheless, an unequivocal description of the mechanism by which such molecules exert control over the pathway of a growing axon has not been done. As a crucial requirement in support of a relevant involvement of an axonal surface molecule in growth cone guidance, this molecule should be expressed in the growth cone. The developing retinotectal system provides an excellent opportunity to test whether a particular neuronal surface molecule fulfills the requirement of the spatiotemporal coincidence between its appearance and the emergence of growth cones because its setup follows the rule of chronotopy, i.e., the position of axons in a certain site is determined by the time of their arrival. We have analyzed axonin-1 and the neuron-glia cell adhesion molecule (Ng-CAM), two axonal surface molecules that promote neurite growth in vitro, for their expression in the retina and in the retinotectal system of the chick throughout its development. At stage 18, both axonin-like (A-LI) and Ng-CAM-like immunoreactivity (Ng-CAM-LI) are clearly present in the area where first retinal ganglion cells (RGCs) are generated. The immunoreactivity spreads synchronously with the formation of RGCs over the developing retina. From stage 32 on, the inner plexiform layer is also stained according to its temporospatial gradient of maturation. In later stages, the outer plexiform layer and the inner segments of photoreceptors also show immunoreactivity. The development of A-LI and Ng-CAM-LI along the optic nerve, chiasm, optic tract, and in the superficial layers of the optic tectum follows the chronotopic pattern of axons, as was found by earlier morphological investigations. Older axons loose their A-LI. This allows to localize the position of newly formed axons. The fact that A-LI and Ng-CAM-LI parallel the formation and maturation of axons suggests that axonin-1 and Ng-CAM may play an important role in the organization of the retinotectal system.
Assuntos
Envelhecimento/fisiologia , Moléculas de Adesão Celular Neurônio-Glia/biossíntese , Moléculas de Adesão Celular Neuronais/biossíntese , Galinhas/crescimento & desenvolvimento , Quiasma Óptico/metabolismo , Nervo Óptico/metabolismo , Retina/metabolismo , Colículos Superiores/metabolismo , Animais , Axônios/fisiologia , Moléculas de Adesão Celular Neurônio-Glia/análise , Moléculas de Adesão Celular Neuronais/análise , Embrião de Galinha , Contactina 2 , Regulação da Expressão Gênica no Desenvolvimento , Imuno-Histoquímica , Quiasma Óptico/embriologia , Quiasma Óptico/crescimento & desenvolvimento , Nervo Óptico/embriologia , Nervo Óptico/crescimento & desenvolvimento , Retina/embriologia , Retina/crescimento & desenvolvimento , Células Ganglionares da Retina/citologia , Células Ganglionares da Retina/fisiologia , Colículos Superiores/embriologia , Colículos Superiores/crescimento & desenvolvimento , Vias Visuais/embriologia , Vias Visuais/crescimento & desenvolvimento , Vias Visuais/metabolismoRESUMO
The anterograde tracer Phaseolus vulgaris-leucoagglutinin was used to examine the organization of the projections to the striatum from medial prefrontal and frontal cortical areas in the rat with reference to their relation to cholecystokinin-like immunoreactivity in the striatum. Medial prefrontal cortical areas projected bilaterally, with an ipsilateral predominance, to the striatum. Most of the positive fibres were found in medial and ventral areas of the caudate-putamen and in the nucleus accumbens. Labelled fibres formed distinct patch-like arrangements throughout the dorsomedial striatum, whereas more ventrally the fibres were densely packed and spread to lateral areas. Almost no fibres were found in the dorsolateral aspects of the caudate-putamen. Cholecystokinin-like immunoreactivity in the striatum was diffusely distributed in the medial aspects, in fine punctate elements as well as in patches of fibres. Overlapping of corticostriatal clusters of fibres, from medial prefrontal cortex, with cholecystokinin-immunoreactive patches was found at all rostrocaudal levels studied, but predominantly in rostral areas. The overlap was present both in the ipsilateral and the contralateral side. Often the cluster of corticostriatal fibres was completely and precisely overlaid by a cholecystokinin-immunoreactive patch. At more caudal planes the overlap was only partial and in some instances cholecystokinin-positive patches "avoided" zones of dense corticostriatal fibre terminations. Frontal cortex injections of tracer gave rise to a network of fibres in the lateral aspects of the striatum, sparing the medial areas. No overlap with cholecystokinin-immunoreactive patches was found in these cases. These results suggest that a large number of cholecystokinin-containing striatal fibres originate in medial prefrontal cortical areas.
Assuntos
Colecistocinina/fisiologia , Corpo Estriado/anatomia & histologia , Lobo Frontal/anatomia & histologia , Fito-Hemaglutininas , Animais , Transporte Axonal , Mapeamento Encefálico , Corpo Estriado/fisiologia , Giro do Cíngulo/anatomia & histologia , Sistema Límbico/anatomia & histologia , Sistema Límbico/fisiologia , Masculino , Fibras Nervosas/ultraestrutura , Vias Neurais/anatomia & histologia , Ratos , Ratos Sprague-DawleyRESUMO
The distribution and origin of neurotensin-like immunoreactivity in the substantia nigra pars reticulata of the rat have been analysed using immunohistochemistry combined with different drug treatments and lesioning techniques. In normal rats, a distinct but weakly fluorescent network of neurotensin-immunoreactive fibers was found in the central part of the substantia nigra pars reticulata. When the animals were treated with reserpine, which suppresses dopamine transmission, a similar pattern of immunoreactivity was found, though the intensity of staining was slightly enhanced. However, when rats were treated with methamphetamine, a potent dopamine releaser, the intensity of immunoreactivity was dramatically increased. In particular, densely packed neurotensin-immunoreactive fibers were found at the dorsal border and at the ventral periphery of the substantia nigra pars reticulata. This pattern of immunoreactivity was found to be similar to that displayed by dynorphin. In the nucleus caudatus, several neurotensin-immunoreactive cell bodies were seen after reserpine treatment. Morphologically similar perikarya were observed in methamphetamine-treated rats, but they were less numerous, whereas no cell bodies were detectable in untreated animals. When a unilateral mechanical transection or an ibotenic acid injection was performed in the striatum, the patterns of neurotensin as well as dynorphin and substance P immunoreactivities in the substantia nigra pars reticulata were strongly affected. Both types of lesion caused a marked, parallel depletion of all three immunoreactive substances on the side ipsilateral to the lesion, where a restricted area was virtually devoid of immunoreactive elements. Thus the present study provides evidence for the existence of a unilateral neurotensin striatonigral pathway, terminating in the pars reticulata. The origin of the neurotensin fibers in the pars compacta has not been established but does not appear to be the caudate nucleus. These results together with evidence from the literature suggest that methamphetamine induced a massive release of dopamine from nigral dendrites acting on presynaptic D1 dopamine receptors located on neurotensinergic terminals leading to a marked increase in neurotensin-like immunoreactivity in the pars reticulata.
Assuntos
Corpo Estriado/química , Neurotensina/fisiologia , Ratos/anatomia & histologia , Substância Negra/química , Animais , Corpo Estriado/anatomia & histologia , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/lesões , Dopamina/metabolismo , Imunofluorescência , Ácido Ibotênico/toxicidade , Masculino , Metanfetamina/farmacologia , Fibras Nervosas/química , Fibras Nervosas/ultraestrutura , Proteínas do Tecido Nervoso/análise , Vias Neurais/anatomia & histologia , Vias Neurais/química , Neurotensina/análise , Ratos/fisiologia , Ratos Sprague-Dawley , Reserpina/farmacologia , Substância Negra/anatomia & histologia , Substância Negra/efeitos dos fármacos , Tirosina 3-Mono-Oxigenase/análiseRESUMO
In addition to the excitatory role played by the amino acid transmitters glutamate and aspartate in the central nervous system, their sulfur-containing analogues homocysteic acid (HCA) and cysteine sulfinic acid (CSA) may also play a similar role. HCA is released and taken up by rat CNS tissue; it excites neurons predominantly via NMDA receptors whenever present, and is neurotoxic. The pattern of HCA-like immunoreactivity in the rat indicates a localization of HCA mostly in glial elements, although its presence in nerve terminals and neuronal perikarya cannot be excluded. In the cerebellum of newborn and adult animals, the Bergmann glial cells and the astrocyte endfeet are immunoreactive, either in the presence or in the absence of climbing fibers. In the cortex, hippocampus, and retina, labeling is seen in both glial and neuronal elements. Excitatory signaling involving glial elements is discussed.
Assuntos
Homocisteína/análogos & derivados , Animais , Encéfalo/metabolismo , Química Encefálica , Homocisteína/análise , Homocisteína/metabolismo , Homocisteína/toxicidade , Imuno-Histoquímica , Distribuição TecidualRESUMO
It has been reported that methamphetamine (METH) upregulates striatal neurotensin (NT) mRNA levels. The present in situ hybridization study demonstrates, using the dopamine D1 antagonist SCH23390 that this effect is mediated through D1 receptors. Sulpiride, a selective D2 antagonist, induces an upregulation of NT expression, which in some striatal areas is additive to the METH effect. This suggests the existence of at least two NT striatal neuronal populations. One, sensitive to D1 receptors, corresponds to the recently described striatonigral NT pathway. The second one, modulated by D2 receptors, may project to the globus pallidus and/or represent interneurones.
Assuntos
Neostriado/metabolismo , Neurotensina/biossíntese , Receptores de Dopamina D1/efeitos dos fármacos , Substância Negra/metabolismo , Animais , Autorradiografia , Benzazepinas/farmacologia , Hibridização In Situ , Masculino , Neostriado/efeitos dos fármacos , Sondas de Oligonucleotídeos , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Substância P/farmacologia , Substância Negra/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacosRESUMO
The release of striatal cholecystokinin, glutamate, aspartate and dopamine was studied in vivo with microdialysis in decorticated rats, with or without callosotomy. Unlesioned rats were also analysed. Unilateral decortication produced a unilateral decrease in K(+)-stimulated extracellular striatal glutamate and aspartate levels, without decreasing cholecystokinin or dopamine levels. However, following decortication plus callosotomy, basal and K(+)-stimulated extracellular cholecystokinin and glutamate levels were significantly decreased in the striatum ipsilateral to side of decortication. Aspartate levels were bilaterally decreased. These results give evidence for the existence of crossed corticostriatal projections containing releasable cholecystokinin and glutamate.
Assuntos
Córtex Cerebral/metabolismo , Colecistocinina/metabolismo , Corpo Estriado/metabolismo , Animais , Ácido Aspártico/metabolismo , Estado de Descerebração/metabolismo , Diálise , Dopamina/metabolismo , Espaço Extracelular/metabolismo , Glutamatos/metabolismo , Ácido Glutâmico , Masculino , Vias Neurais/metabolismo , Potássio/farmacologia , Radioimunoensaio , Ratos , Ratos Sprague-Dawley , Técnicas EstereotáxicasRESUMO
Recently the existence of a neurotensin striatonigral pathway strongly up-regulated by methamphetamine has been demonstrated. The aim of the present study was to investigate, using immunohistochemistry and radioimmunoassay, the modulation of this pathway by dopamine antagonists. Rats were injected either with methamphetamine alone or together with the dopamine D1 receptor antagonist, SCH 23390 (R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-be nzapine hydrochloride), or with the dopamine D2 receptor antagonist, sulpiride. Both techniques showed that this neurotensin striatonigral pathway is regulated by dopamine D1 receptors, since SCH 23390 totally prevented the methamphetamine-induced increase in neurotensin-like immunoreactivity, both in the striatum and in the substantia nigra pars reticulata. Conversely, sulpiride was unable to counteract the effect of methamphetamine in these two areas, suggesting that dopamine D2 receptors are not involved in the regulation of this neurotensin pathway. On the other hand, neurotensin-like immunoreactivity was markedly increased in striatal cell bodies and in the globus pallidus after treatment with sulpiride, indicating that this pathway is mainly regulated by dopamine D2 receptors.
Assuntos
Corpo Estriado/efeitos dos fármacos , Antagonistas de Dopamina/farmacologia , Globo Pálido/efeitos dos fármacos , Neurotensina/metabolismo , Substância Negra/efeitos dos fármacos , Animais , Benzazepinas/administração & dosagem , Benzazepinas/farmacologia , Corpo Estriado/citologia , Corpo Estriado/metabolismo , Sinergismo Farmacológico , Fluoresceína-5-Isotiocianato/química , Globo Pálido/citologia , Globo Pálido/metabolismo , Imuno-Histoquímica , Injeções Intraperitoneais , Masculino , Metanfetamina/administração & dosagem , Metanfetamina/farmacologia , Microscopia de Fluorescência , Radioimunoensaio , Ratos , Ratos Sprague-Dawley , Substância Negra/citologia , Substância Negra/metabolismo , Sulpirida/administração & dosagem , Sulpirida/farmacologia , Regulação para CimaRESUMO
Cell adhesion molecules expressed on the axonal membrane have been thought to be involved in the guidance of axons to their target area. In the chick, axonin-1 and NgCAM have been shown to promote, through reciprocal interactions, neurite outgrowth in vitro. We have recently shown that chick retinal ganglion cells (RGC) express both proteins as early as the axonal elongation begins. Their expression continues throughout the development of the retinotectal system synchronously with the chronotopic spread of axons. To further investigate the spatiotemporal distribution of axonin-1 and NgCAM in the retina, we have analysed the expression of their mRNAs in the present study. From stage 36 (E10) until hatching photoreceptors express axonin-1 but not NgCAM. In the inner nuclear layer groups of amacrine cells were strongly labelled with both probes but they seemed to belong to different subgroups. These patterns of expression might indicate a differential influence of the two proteins on the development of the local neural circuits of the retina.
Assuntos
Axônios/fisiologia , Moléculas de Adesão Celular Neuronais/genética , Moléculas de Adesão Celular , Retina/fisiologia , Animais , Embrião de Galinha , Contactina 2 , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Hibridização In Situ , Interneurônios/fisiologia , Células Fotorreceptoras/fisiologia , RNA Mensageiro/metabolismo , Retina/citologia , Retina/embriologiaRESUMO
The localization of galanin (GAL) and GAL mRNA was studied in rat brain after colchicine or vinblastine treatment using in situ hybridization and immunohistochemistry. GAL-like immunoreactivity was found in glial cells, presumably activated microglia, in the cortex, caudate nucleus and septum, mainly on the injection side. GAL mRNA expression was found in small cells in the same areas with an overlapping distribution, including the adjacent white matter. The results suggest that the glial cells initiate synthesis of the peptide GAL in response to intraventricular injection of high doses of the 2 mitosis inhibitors.
Assuntos
Colchicina/farmacologia , Neuroglia/metabolismo , Biossíntese Peptídica , Regulação para Cima/efeitos dos fármacos , Animais , Imunofluorescência , Galanina , Hibridização In Situ , Masculino , Microscopia Eletrônica , Neuroglia/efeitos dos fármacos , Plasticidade Neuronal/efeitos dos fármacos , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Vimblastina/farmacologiaRESUMO
Using the indirect immunofluorescence technique, the effects of decortication and callosotomy on the pattern of cholecystokinin (CCK)-like immunoreactivity were studied in the striatum of the rat. Decortication plus callosotomy, but not decortication alone, caused a strong decrease in the immunoreactivity on the side ipsilateral to the lesion. An almost complete disappearance of CCK immunoreactive patches in the medial-dorsal aspects of the striatum was observed. These results indicate that part of the striatal CCK immunoreactive fibres are of cortical origin, to a considerable extent from the contralateral side.
Assuntos
Núcleo Caudado/fisiologia , Córtex Cerebral/fisiologia , Colecistocinina/análise , Corpo Caloso/fisiologia , Animais , Núcleo Caudado/citologia , Córtex Cerebral/citologia , Corpo Caloso/citologia , Imunofluorescência , Imuno-Histoquímica , Ácido Caínico/administração & dosagem , Masculino , Fibras Nervosas/ultraestrutura , Ratos , Ratos Sprague-Dawley , Técnicas EstereotáxicasRESUMO
A multicenter study involving six palliative care units in Italy was carried out on 159 terminal cancer patients seen at home or in hospital. The physician or the nurse completed independently from the patient the Therapy Impact Questionnaire (TIQ), a questionnaire devised for quality-of-life evaluation in terminal cancer patients. The patient's assessment was used as the valid reference measurement to compare with the health-care workers' evaluation to assess the validity of the latter. The results showed that percentages of agreement were higher for physical than for psychological and cognitive symptoms, and that there was a greater agreement on the absence rather than on the presence of a problem. None of the characteristics of the patient nor of the proxy showed any statistically significant relationship with the two disagreement indexes. The results suggest that caution is needed in the use of health-care workers as alternative sources of information regarding patients' quality of life.
Assuntos
Pessoal de Saúde , Neoplasias/terapia , Qualidade de Vida , Assistência Terminal , Estudos de Avaliação como Assunto , Humanos , Reprodutibilidade dos Testes , Inquéritos e QuestionáriosAssuntos
Córtex Cerebral/química , Colecistocinina/análise , Medula Espinal/química , Animais , Córtex Cerebral/citologia , Corpo Estriado/química , Corpo Estriado/citologia , Neurônios/química , Neurônios/citologia , Neurônios Aferentes/química , Neurônios Aferentes/citologia , Medula Espinal/citologiaRESUMO
AIM: The aim of this paper was to describe the frequency and the characteristics of continuous deep sedation in terminally ill patients. METHODS: All patients who died in home palliative care units in the Florence area between March 1-December 31, 2000 and July 1, 2003-June 30, 2004 were prospectively analysed with regard to social, demographic, and clinical characteristics. RESULTS: The data presented refer to 1075 patients (331 in 2000 and 744 in 2003-2004). Continuous deep sedation was applied in 14.2% and in 12% of patients, respectively. At baseline, patients who were sedated during the final stages of their life were more likely to be younger in age, to have poorer quality of life and better performance status. Such characteristics did not differ between the two periods. Hydration was not performed in 65% of all patients who finally received sedation in the period 2003-2004 versus 33% in those who did in 2000. In 2003-2004, the decision to use sedation was discussed with patients in 39% of those who were sedated. In 2003-2004, we noticed an increase in the use of benzodiazepines for continuous deep sedation from 43% to 87%. The increase in opioid average dosage from the onset of sedation until the last 24 h of their life was about seven-fold in 2000 and almost twice that amount in 2003-2004 in those patients who were not undergoing treatment with opioids when sedation started. CONCLUSION: The monitoring of end-of-life decision making and of medical practices involved in continuous deep sedation contributes to an enhancement in the quality of caring for terminally ill patients.
Assuntos
Sedação Consciente , Cuidados Paliativos , Idoso , Analgésicos Opioides/uso terapêutico , Benzodiazepinas , Feminino , Humanos , Hipnóticos e Sedativos , Itália , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida , Fatores SocioeconômicosRESUMO
The distribution of gamma-aminobutyric acid (GABA) immunoreactivity was studied in the brain of two amphibian species (Triturus cristatus carnifex, Urodela; Rana esculenta, Anura) by employing a specific GABA antiserum. A noteworthy immunoreactive neuronal system was found in the telencephalic dorsal and medial pallium (primordium pallii dorsalis and primordium hippocampi) and in the olfactory bulbs. In the diencephalic habenular nuclei there was a rich GABAergic innervation, and immunoreactive neurons were observed in the dorsal thalamus. In the hypothalamus the GABA immunoreactivity was found in the preoptic area, the paraventricular organ and in the hypothalamo-hypophysial complex. In the preoptic area of the frog some GABA-immunoreactive CSF-contacting cells were shown. In the optic tectum immunolabeled neurons were present in all the cellular layers. A rich GABAergic innervation characterized both the fibrous layers of the tectum and the neuropil of the tegmentum and interpeduncular nucleus. In the cerebellum, in addition to the Purkinje cells showing a variable immunopositivity, some immunoreactive cells bodies appeared in the central grey. Abundant immunolabeled nerve fibers in the acoustico-lateral area and some immunopositive neurons in the region of the raphe nucleus were observed. In conclusion, the GABAergic central systems, well-developed in the amphibian species studied, were generally characterized by close similarities to the pattern described in mammals.
Assuntos
Encéfalo/imunologia , Neurônios/imunologia , Rana esculenta/imunologia , Triturus/imunologia , Ácido gama-Aminobutírico/imunologia , Animais , Encéfalo/metabolismo , Cerebelo/imunologia , Cerebelo/metabolismo , Diencéfalo/imunologia , Diencéfalo/metabolismo , Feminino , Imuno-Histoquímica , Masculino , Bulbo/imunologia , Bulbo/metabolismo , Mesencéfalo/imunologia , Mesencéfalo/metabolismo , Neurônios/metabolismo , Telencéfalo/imunologia , Telencéfalo/metabolismo , Ácido gama-Aminobutírico/metabolismoRESUMO
The effect of acute subcutaneous administration of methamphetamine on the expression of neurotensin mRNA was investigated in the adult rat striatum. At different time points (2, 6 and 24 h) following drug administration rats were killed, and mRNA levels were quantified both on films and emulsion-dipped tissue sections from two striatal levels. Two hours after methamphetamine injection, a dramatic increase in neurotensin mRNA levels was detected in different areas of the striatum at both rostral and caudal levels. Numerous positive cells were observed in the dorsomedial, dorsolateral and ventrolateral parts of the striatum. This up-regulation reflected an increase both in the number of cells expressing neurotensin mRNA and in the mean mRNA levels. This increase was still present after 6 h and was similar to the 2 h treated group at the rostral level of the striatum, but lower at the caudal one. Twenty-four hours after methamphetamine injection, neurotensin mRNA levels were back to control values, or in some areas even below. A strong increase in neurotensin mRNA-expressing cells was also seen in the olfactory tubercle, and the time-course was similar to the one observed in the striatum. In a second set of experiments, the effect of methamphetamine was evaluated on adjacent striatal sections hybridized with probes directed against neurotensin and substance P mRNAs, respectively. Two hours after drug administration, a significant increase in the levels of both peptide mRNAs was observed (+190% for neurotensin, +80% for substance P). These results demonstrate that methamphetamine is able to induce a dramatic, rapid and transient increase in striatal neurotensin mRNA levels, which may partly account for the elevation in neurotensin peptide levels observed in the striatonigral pathway after methamphetamine. The different anatomical localization of neurotensin mRNA-expressing cells observed after haloperidol and methamphetamine treatments, as well as the fact that the D1 receptor antagonist SCH-23390 is able to counteract the effect of methamphetamine but not that of haloperidol on neurotensin mRNA expression, suggests that there are at least two different subpopulations of neurotensin cells in the striatum. One population is regulated via D1 receptors and projects to the substantia nigra pars reticulata. The second is sensitive to D2 receptor stimulation and may project to the globus pallidus and/or may represent interneurons.