Psicofisiologia

Psychophysiology.
Name: Cristian


Neuron articles.
Article N 1.
EFFETS OF ETHANOL AND DIAZEPAN ON AG-NOR NEURONAL ACTIVITY IN THE MEDIAL MAMMILLARY NUCLEUS |
 Luis M. GARCÍA-MORENO, Luis J.SANTIN, Sandra RUBIO, Héctor G.PARDO y Jorge L. ARIAS |
Laboratorio de Psicobiología, Facultad de Psicología. Universidad de Oviedo |

lt is intended here to study the disorders produced onmammillary bodies at both behavioural and morphological levels after diazepam and alcohol administration. For this purpose, 3 groups of rats were used, testing them in the water T-maze trial. One of the groups was treated with diazepam, another group alcoholized and the third was control group. The reaction time was recorded and also the errors commited in the last day. Histological analysis wasmade by evaluation of the number of Ag-NORS and the surface of these in each neuronal nucleus. The results show a statistically significant decrease in reaction time throughout the learning period, with almost no errors. There are not any differences in the estimated NOR surface of the experimental groups. However, differences were reported concerning the number of NOR quantified among the differenttreated groups in relation to control group.Key words: Alcohol; Diazepam; Ag-NOR; Mammillary Body; Rat.Efectos del etanol y el diazepan sobre la actividad Ag-NOR neuronal en el núcleo mamilar medial. Se pretende estudiar las alteraciones producidas en los mamilares tanto a nivel conductual como a nivel morfológico tras la administración de diazepam y alcohol. Para ello se emplearon 3 grupos deratas testadas en la prueba del laberinto en T de agua. Uno de los grupos tratado con diazepam, otro grupo alcoholizado y un tercer grupo control. Se registraron los tiempos de reacción y los errores cometidos el ultimo día. El estudio histológico consistió en la determinación del número de Ag-NORs y el área de los mismos en cada núcleo neuronal. Los resultados muestran una disminución en el tiempode reacción estadísticamente significativa a lo largo del aprendizaje, sin existir apenas errores. No aparecen diferencias en el área NORs estimada en los grupos experimentales. Sin embargo, se muestran diferencias en el número de NORs cuantificados entre los distintos grupos tratados en relación al grupo control.Palabras clave: Alcohol; Diazepam; Ag-NOR; Cuerpo Mamilar; Rata. |
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  | |Since the description by Cajal (1911) of the Mammillary Body (MB) (Hypothalamus) detailed morphological descriptions have been carried out accepting nowadays the division by Allen and Hopkins (1989) that establish the following nuclei: MedialMammillary(MM), Lateral Mammillary, Premammillary, Supramammillary and Tuberomammillary.Their connections with the frontal cortex have been described(Wouterlood, Steinbusch, Luiten and Bol, 1987), but also they show even more with the anterior thalamus (Seki and Zyo, 1984), mesencephalon (Shibata, 1987) and hippocampal formation (Guillery, 1956; Swanson and Cowan, 1977). These connections allow us to know about their important contribution in memory processes (Weiskrantz, 1978; O'Keefe and Nadel, 1978), the acquisition of spatial alternation (Irleand Markowitsh, 1982), reversal of the latter (Aggleton and Mishkin, 1985), defensive behaviour (Shibata and Furukawa, 1988), fluid and endocrine regulation (Morales and Puerto, 1988).Moreover, classical neuroanatomical studies (Kriekhaus, 1966) have shown the MB implication in pathologies such as Wernicke-Korsakoff syndrome, common in patients with a case history of chronical alcoholism (Aggletonand Mishkin, 1985; Lindboe, Erichsen and Strom, 1989) and Korsakoff's psychosis, the chronic phase of the Wernicke-Korsakoff syndrome, distinguished by several degrees of both retrograde and anterograde amnesia; confabulation frequently disappears in chronic stages of this disease.Ethanol is one of the most used neurotoxic drugs and it is also most commonly found in Korsakoff's patients. The...