NEUROSCIENCES

Author: ÑECO ALADID PATRICIA.
Year: 2003.
University: MIGUEL HERNÁNDEZ DE ELCHE [More theses of this university] [www.umh.es].
Place of defense: MEDICINA.
Place of preparation: INSTITUTO DE NEUROCIENCIAS, FAC. DE MEDICINA.

Summary: The cell cromafín has proved to be a very useful system for studying the cellular and molecular mechanisms of neurotransmitter release. The regulated secretion is triggered by an increase of Ca2 + intracellular (Douglas et al., 1961). Although the role of Ca2 + in the neurosecreción has been studied for many years, the mechanisms by which the Ca2 + is involved in this process have not been clarified yet. One attractive hypothesis is that one of the sites of action of Ca2 + secretion is controlling citosqueleto. The citosqueleto interacts with subcellular organelle, inlcuildas the vesículas secretory and because its location is peripheral and most vesicles are excluded from active areas of exocytosis, has been linked its participation in the secretion as a barrier preventing access ue seen sículas secretory to the sites of exocytosis of the plasma membrane (Vitale et al., 1991). But there is evidence supporting the existence of an active vesicular transport of translocation of vesículas toward the active sites of exocytosis, where they are involved as the motor protein myosin (Nakanishi and cabbage, m 1989; Kumakura et al., 1994) and system microtubules (Thuret. Carnahan et al., 1985; Neco et al., 2003). And more recent work of direct visualization of vesicles corticale spor wave evanescent (Lang et al., 2000) and confocal microscopy dynamics (Ñeco et al., 2002)

Author: BONILLA JIMENEZ SONIA.
Year: 2003.
University: MIGUEL HERNÁNDEZ DE ELCHE [More theses of this university] [www.umh.es].
Place of defense: MEDICINA.
Place of preparation: INSTITUTO DE NEUROCIENCIAS.

Summary: In this thesis we have shown as progenitor cells in the bone marrow of adult mice show its potential in differentiating neural cells of the main types of neural SNC (neurons, oligodendrocytes astrositos and neural stem cells (CMN)) thus opening up new prospects for possible strategies Therapeutic in the treatment of neurodegenerative diseases. This has been characterized by the use of specific markers of hematopoietic stem cells (HCM), CD117 and Sca-1, in combination with the characteristics of size and complexity, a subpopulation of bone marrow enriched in HCM (CD117 + and Sca- 1 +) through cell sorter. This subpopulation to be transplanted intracerebralmente in neonatal mice show a neural plasticity rise after 4-6 days post transplant neurons, oligodendrocytes, astrositos and microglía, as well as neural stem cells capable of integrating active in the ventricular zone and subventricular the lateral ventricle . In post longer periods, 15 days, 1 and 2 months, generating cells from neural progenitor cells in the bone marrow appears to be restricted to the formation of neural cells that would be housed in the host brain. These CMN derived from the donor neural showed their ability to form neuroesteras, characteristics of this cell type, and differentiate the different neural growing. Similarly these CMN arising from the parents of the bone marrow 1 month after the transplant, were able to proliferate when stimulated as a result of targeted demyelinating lesions, and differentiated into oligodendrocytes functional actively contributed to the regeneration of the area injured from 7 days and until 1 month after the injury.

Author: JIMÉNEZ DÍAZ LYDIA.
Year: 2003.
University: PABLO DE OLAVIDE [More theses of this university] [www.upo.es].
Place of defense: CIENCIAS EXPERIMENTALES.
Place of preparation: UNIVERSIDADES PABLO DE OLAVIDE DE SEVILLA.

Summary: The neural mechanisms that underlie the processes of learning and memory are the subject of intense study at present. Its relevance in the development of the normal life of animals, including humans, as well as the dramatic increase in recent years of diseases associated with these processes, for example, Alzheimer's disease, have led to the achievement of important scientific advances in this field. The data collected at the bottom of this Doctoral Thesis indicate that the motor system lid is an excellent model for the study of motor reflex responses and aprendidas.Por Furthermore, the classical conditioning of palpebral reflex is a simple model of partnership between learning two stimuli and has been used for years as an experimental model very adecuadopara study of the neural mechanisms involved in the acquisition of new skills motora.Se have proposed distintasestructuras brain like / site / s where the answers palpabrales conditioned are generated, controlled and / or stored. The cerebral cortex and cerebellum are some of the most relevantes.En any case, the importance ralativa and the specific role of these regions in the adquesición of RCs Blink are issues that remain unresolved in its totalidad.Además, using approximations pharmacological, genetic, or injury, helped the study of molecular and cellular processes that are the cause or result of motor learning. However, many of these processes have not been identified yet or have not been fully clarified yet. Therefore, the main objective of this thesis has been to describe the participation of three structures brain (cerebellum, hippocampus and other regions of the cerebral cortex) in the condition of flickering in mammals, as well as identify and describe in these regions cerbrales, some of the cellular processes specifically related associative learning.

Author: ALONSO NANCLARES LIDIA.
Year: 2004.
University: COMPLUTENSE DE MADRID [More theses of this university] [www.ucm.es].
Place of defense: FACULTAD DE BIOLOGÍA.
Place of preparation: FACULTAD BIOLOGÍA.

Summary: In this Doctoral Thesis have studied the organization of cortical abnormalities associated with epilepsy. It analyzed the inmunorreactividad vesicular transporter of glumato 1 (VGLUT1-ir) neocorteza both in the rat and in the human. In both species, inmunorreactividad of VGLIT1 is located in structures puntiformes distributed by the neuropilo in all cortical layers. Through methods correlacón of optical and electronic microscopy, we found that VGLUT1 expressed in terminals axónicos which provide only asymmetrical synapses (excitadoras) with stems and dendritic spines. Therefore, the distribution of marking immunocytochemical for VGLUT1 and ultrastructural localization is the same in both species, which makes it a useful tool in the stadium of systems glutamatéricos. The study of inmunorreactividad of VGLUT1 in the bark of peritumoral epileptic patients with cortical tumors revealed alterations in its marking pattern, which coincide with the loss of terminals axónicos VGLUT1-positivos and with a reduction in the number of synapses asymmetrical. Therefore, marking with VGLUT1 is a good method for the study of the system glutamatérgico in neocorteza human altered. Moreover, we studied cortical tissue from epileptic patients with focal cortical dysplasia to identify potential disruptions of sinápticos circuits. In the white matter of this tissue formations appear in hypertrophic basket marked parvolabúmina, are located around giant ectopic neurons forming synapses with symmetrical (inhibitors). Changes in sinápticos circuits in the crust displastic include a variety of changes in the density of synapses excitadoras and inhibitory per neuron, as well as changes in the proportion of synapses excitadoras and inhibitory. These alterations are very heterogeneous, both within the same patient and between patients, suggesting that cortical dysplasia leads to a multitude of changes in the circuits sinápticos.

Author: ETXEBARRIA GALNARES ESTIBALIZ.
Year: 2005.
University: PAÍS VASCO [More theses of this university] [www.ehu.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: UNVIERSIDAD DE PABLO DE OLAVIDE.

Summary: The objective of this study is to characterize Doctoral Thesis effect dela inhibition of glutamate transporters on cultured oligodendrocytes, isolated rat optic nerve and optic nerve in vivo rabbit, and find out their involvement in the death excitotóxica oligodendroglial and axonal damage. We also plan to characterize the effect dela activaición of recipients purinérgicos in particular P27X in the optic nerve of rabbits in vivo, and to determine the relevance of these receptors in the injury in acute ischemic processes in white matter, using as a model the optic nerve isolated subjected to conditions anóxicas and deprivation of oxygen and glucose. Our results indicate that glutamate uptake by the transporter GLT-1 (EAAT2), is key to the maintenance of homeostasis of this neurotransmitter in tractors axonales. Similarly, the data show that oligodendrocytes are very vulnerable to sobreactivación-receptor P2X7. These facts suggest that the disruption of transport as sobreactivación of glutamate receptor P2X7 can be triggers death oligodendroglial exitotóxica and axonal injury in white substances observed in chronic diseases such as multiple sclerosis and cerebral ischemia as a result of accidents cerebrobasculares. Also, recipients purinérgicos P2X7 are an important part of the cell machinery responsible for the death oligodendroglial excitotóxica ischemic at early stage. There is a time sequence of arrival on the scene of the various components that comprise events exitotóxicos in ischemia. Therefore, the glial glutamate transporters and receptor P2X7 pose interesting therapeutic targets for the treatment of neurological diseases where exitotoxicidad play a major role.

Author: PUENTE BUSTINZA NAGORE.
Year: 2005.
University: PAÍS VASCO [More theses of this university] [www.ehu.es].
Place of defense: FACULTAD DE MEDICINA Y ODONTOLOGÍA.
Place of preparation: FACULTAD DE MEDICINA Y ODONTOLOGÍA.

Summary: The metabotropic glutamate receptors are expressed widely in the central nervous system regulating nerve transmission. There are both anatomical and electrophysiological evidence of the expression presináptica of mGluRs group II and III and a location preferably postsynaptic of mGluRs Group I. However, many physiological and neurochemical studies suggest that group I metabotropic receptors exert a modulation of neurotransmission at presináptico. This apparent contradiction could be explained by the existence of an interaction of group I mGluRs of I and the receiver CB1, which is the largest recipient of cannabionoides in the central nervous system. In this dissertation we intended to provide information on the subcellular localization of the receptor metabotrópico of glutamanto mGluiR1 to group I receptor cannabionoides CB1 in the scheme of Goblet of Held-neurona main level medial nucleus of the trapezoid body of the auditory pathway. In this study, we employ techniques inmunocitoquímicas high resolution electron microscopy. The results showed that the receiver mGluR1a is postsináptico in 90% of primary neurons, while the receiver CB1 is presináptico in half the chalices of Held making synapses on the cell bodies of neurons major. These observations support the electrophysiological and pharmacological evidence on the modulatory effect exerted by the recipient postsináptico mGluR1a about transmission in the nervous system Goblet of Held-neurona main through the activation of receptor CB1 presináptico. Moreover, we also propose to study the subcellular localization of different glutamate transporters during the postnatal development of the system of Goblet of Held-neurona chief. The chalices Held consist of multiple fingering thick embrace a single neuron chief. The terminal caliciforme contains numerous areas of active synaptic vesicle fusion of Synaptic Transmission allowing for a quick and reliable, so that an action potential triggers presináptico evoked potential action, even when the signals are transmitted HF. The mechanisms therefore exist to end the extracellular glutamate presináptica after their release must be perfectly adjusted. In immature animals, cáliza of Held involves approximately 40-50% of soma postsináptico. However, the terminal becomes very fenestrado toward the day 14 postnatal so many seem spaces for which facilitates the dissemination of glutamate. Despite the wide investigaicón done in the recent past, the functional significance of these morphological changes such important remains disputed, as well as changes in the diffusion kinetics of glutamate from the synaptic cleft him during development, which leads to varying degrees of AMPA-receptor desensitization. We believe that glutamate transporters have to be involved in these morphological and physiological changes that occur during postnatal development. In this part of the work demonstrated the technique with immunocytochemistry of inmuno-oro postinclusión that glutamate transporters and GLAST GLT have a location in glial processes astrocíticos surrounding the synapses of the chalices of Held neurons leading to the ages of Q9 to adult. In addition, there is a change in the expression of both carriers during postnatal development, reaching the highest levels in glía medial nucleus of the body trapezoid adult.