ABSTRACT
Although normal aging has been related to several cognitive difficulties, other processes have been studied less, such as spatial memory. Our aim was to compare egocentric and allocentric memory in an elderly population using ecological tasks. Twenty-eight cognitively unimpaired participants performed Egocentric and Allocentric Spatial Memory Tasks, as well as Spatial Span from CANTAB, Benton's Judge of Line Orientation test (JoLO), and Montreal Cognitive Assessment test (MoCA). The results revealed that younger participants showed better performance than older participants on both the Egocentric and Allocentric Spatial Memory Tasks, although only the Egocentric test was able to discriminate between younger, middle, and older elderly participants. Learning effect was found in Allocentric Spatial Memory Task in younger and older groups, but not in the middle group. Allocentric and egocentric performance was not related to other visuospatial neuropsychological scores and gender did not influence performance in any task. Egocentric and Allocentric Spatial Memory Tasks may be useful tools in early screening for cognitive decline, as they are able to detect age differences in the cognitive unimpaired elderly population.
Subject(s)
Humans , Male , Female , Middle Aged , Aged , Aged, 80 and over , Space Perception/physiology , Task Performance and Analysis , Spatial Memory/physiology , Healthy Aging/physiology , Healthy Aging/psychology , Aging/physiology , Aging/psychology , Sex Factors , Analysis of Variance , Cognitive Dysfunction/physiopathology , Cognitive Dysfunction/psychology , Spatial Navigation/physiology , Neuropsychological TestsABSTRACT
The serious neuropsychological repercussions of hepatic encephalopathy have led to the creation of several experimental models in order to better understand the pathogenesis of the disease. In the present investigation, two possible causes of hepatic encephalopathy, cholestasis and portal hypertension, were chosen to study the behavioral impairments caused by the disease using an object recognition task. This working memory test is based on a paradigm of spontaneous delayed non-matching to sample and was performed 60 days after surgery. Male Wistar rats (225-250 g) were divided into three groups: two experimental groups, microsurgical cholestasis (N = 20) and extrahepatic portal hypertension (N = 20), and a control group (N = 20). A mild alteration of the recognition memory occurred in rats with cholestasis compared to control rats and portal hypertensive rats. The latter group showed the poorest performance on the basis of the behavioral indexes tested. In particular, only the control group spent significantly more time exploring novel objects compared to familiar ones (P < 0.001). In addition, the portal hypertension group spent the shortest time exploring both the novel and familiar objects (P < 0.001). These results suggest that the existence of portosystemic collateral circulation per se may be responsible for subclinical encephalopathy.
Subject(s)
Animals , Male , Rats , Cholestasis/complications , Disease Models, Animal , Hepatic Encephalopathy/etiology , Hypertension, Portal/complications , Memory/physiology , Pattern Recognition, Visual/physiology , Recognition, Psychology/physiology , Exploratory Behavior/physiology , Hepatic Encephalopathy/physiopathology , Hepatic Encephalopathy/psychology , Rats, Wistar , Task Performance and Analysis , Time FactorsABSTRACT
La inyección de agentes neurolíticos es un tratamiento sintomático indicado principalmente en dolores de origen neoplásico en fase avanzada de la enfermedad y cuya eficacia es casi siempre temporal. El neurolítico ideal, capaz de producir un bloqueo permanente y prolongado sin destrucción de fibras nerviosas, no existe y todos los neurolíticos actualmente en uso presentan características individuales que limitan su empleo clínico. El alcohol, a pesar de sus inconvenientes, es el agente más eficaz para conseguir un bloqueo sensorial prolongado. Su utilización más frecuente es en la neuralgia del trigémino y por vía intradural en dolores neoplásicos. Para minimizar sus complicaciones no debe inyectarse más de 1 ml, muy lentamente, observando estrictamente los requisitos posturales durante la inyección y la primera hora después. El fenol se utiliza en solución acuosa pero sobre todo se utiliza como vehículo la glicerina a concentraciones del 5 al 10%. A diferencia del alcohol el bloqueo que produce es más selectivo y su densidad es superior a la del líquido cefalorraquídeo. Su eficacia máxima se observa en dolores neoplásicos de abdomen bajo y pelvis. Las sales de amonio son eficaces a concentraciones superiores al 6%. El nitrato de plata provoca una intensa reacción meníngea que limita su uso al fracaso del fenol. El clorocresol es más eficaz que el fenol, pero sus efectos son más tardíos. El éter intradural es efectivo, pero su hipobaricidad lo hace difícil de manejar. Las soluciones salinas hiperosmolares, o a bajas temperaturas, y el agua destilada también a bajas temperaturas han demostrado su utilidad. El último neurolítico, el glicerol, ha dado muy buenos resultados en la neuralgia del trigémino. El riesgo de producir lesiones neurológicas permanentes no justifica la utilización de neurolíticos en dolores no neoplásicos ni por personal no especializado