Learning and memory promoting effects of crude garlic extract.

Chronic administration of aged garlic extract has been shown to prevent memory impairment in mice. Acute and chronic (21 days) effects of marketed formulation of crude garlic extract (Lasuna) were evaluated on learning and memory in mice using step down latency (SDL) by passive avoidance response and transfer latency (TL) using elevated plus maze. Scopolamine (0.4 mg/kg, ip) was used to induce amnesia in mice and piracetam (200 mg/kg, ip) served as positive control. In the acute study, Lasuna (65 mg/kg, po) partially reversed the scopolamine-induced amnesia but failed to improve learning and memory in untreated animals. Chronic administration of Lasuna (40 mg/kg/day for 21 days) significantly improved learning both in control and scopolamine induced amnesic animals. Influence of Lasuna on central cholinergic activity and its antioxidant properties were also studied by estimating the cortical acetylcholinesterase (AchE) activity and reduced glutathione (GSH) levels respectively. Chronic administration of Lasuna inhibited AchE, while increasing GSH levels. Thus the results indicate that long-term administration of crude garlic extract may improve learning and memory in mice while the underlying mechanism of action may be attributed to the anti-AchE activity and anti-oxidant property of garlic.

Effect of scopolamine-based amnesia on the number of astrocytes in the rat's hippocampus / Efecto de la amnesia inducida por escopolamina sobre el número de astrocitos en el hipocampo de ratas

As neuron­astrocyte interactions play a crucial role in the adult brain, it is thought that astrocytes support learning and memory through specific mechanisms. In this study, the effect of scopolamine based amnesia on the number of astrocytes in rats' hippocampus was studied. Adult male albino Wistar rats were bilaterally cannulated into the CA1 region and animals received saline or different doses of scopolamine (0.5, 1 and 2 mg/ rat, intra - CA1), immediately after training. Then all the rats were sacrificed and coronal sections were taken from the dorsal hippocampal formation of the right cerebral hemispheres and stained with PTAH. The area densities of the astrocytes in dentate gyrus were measured and compared in the all groups (p < 0.05). Data showed that post-training scopolamine (0.5, 1 and 2 ug/rat, intra-CA1) dose-dependently reduced the step-through latency in the inhibitory avoidance task, showing scopolamine-induced amnesia. Also we found different response of astrocytes in different subfields of hippocampal formation. In dentate gyrus the number of astrocytes was increased, but in other areas scopolamine can decreased the density of astrocytes. We concluded that scopolamine can cause amnesia and this phenomenon can have an effect on astrocyte numbers in the rats hippocampal formation.

Las interacciones neuronas-astrocitos desempeñan un papel crucial en el cerebro adulto, y se cree que los astrocitos apoyan el aprendizaje y la memoria a través de mecanismos específicos. Fue estudiado el efecto de amnesia inducida por escopolamina en el número de astrocitos del hipocampo de ratas. Ratas Wistar albinas macho adultas fueron canuladas bilateralmente en la región CA1 recibiendo solución salina o diferentes dosis de escopolamina (0,5, 1 y 2mg/rata, intra - CA1), inmediatamente después del entrenamiento. Luego, todas las ratas se sacrificaron y se tomaron secciones coronales de la formación del hipocampo dorsal del hemisferio cerebral derecho y se tiñeron con PTAH. Las densidades de área de los astrocitos en el giro dentado fueron medidas y comparadas en todos los grupos (p <0,05). Los datos mostraron que la escopolamina (0,5, 1 y 2 mg / rata, intra-CA1) dosis-dependiente post-entrenamiento redujo el paso de latencia de la tarea de evitación inhibitoria, mostrando amnesia inducida por escopolamina. También encontramos diferentes respuestas de los astrocitos en los distintos subcampos de la formación hipocampal. En el giro dentado, el número de astrocitos se incrementó, pero en otras áreas la escopolamina pudo disminuir la densidad de los astrocitos. Se concluye que la escopolamina puede causar amnesia y este fenómeno puede afectar el número astrocitos en la formación hipocampal de ratas.

Neuroprotective potential of ethanolic extract of Pseudarthria viscida (L) Wight and Arn against -amyloid(25-35)-induced amnesia in mice.

The neuroprotective potential of ethanolic extract of roots of Pseudarthria viscida (L) Wight and Arn (EEPV) was investigated against -amyloid(25-35)-induced amnesia in mice which is a suitable animal model for Alzheimer’s disease (AD). The senile plaques of -amyloid (A) are major constituents accumulated during the progression of AD as a potent neurotoxicant. In our investigation, intracerebroventricular injection of A(25-35) in mice induced the neurodegeneration, exhibited the increased time of escape latency in behavioral pattern using water maze and decreased the levels of antioxidants namley superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and vitamin C with elevated level of acetylcholinesterase enzyme (AChE). The neuroprotective potential of EEPV was determined by behavioral pattern using water maze and biochemical parameters such as SOD, CAT and GPx and vitamin C content as well as AChE. Mice were treated with EEPV at 200 and 400 mg/kg doses for 21 days. Except control, all animals received a single injection of neurotoxicant A(25-35) on 14th day. In behavioural assessment, treatment with ethanolic extract improved the cognitive function in the water maze and attenuated the elevated levels of AChE with increase in antioxidant enzymes, indicating the neuroprotection with increased levels of vitamin C. These findings suggest that ethanolic extract of P. viscida exerts anti-amnesiac effects and enhances cognitive function.

Caracterización de síntomas neuropsiquiátricos en pacientes con DCL de tipo amnésico en una población colombiana / Characterization of neuropsychiatric symptoms in patients with amnestic-type MCI in a Colombian population

Introducción: el deterioro cognitivo leve (DCL) se caracteriza por la alteración de uno o varios procesos cognitivos sin afectación significativa en las actividades de la vida diaria del paciente y que puede presentarse acompañado de síntomas neuropsiquiátricos, lo que incrementa el riesgo a evolucionar a demencia. Objetivo: identificar la frecuencia y severidad de las alteraciones comportamentales en una población con deterioro cognitivo leve de tipo amnésico. (DCL-A)Procedimiento: estudio no experimental, transversal de alcance descriptivo, que contó con 70 personas, con diagnostico de DCL-A. Seleccionada la muestra los cuidadores respondieron el inventario neuropsiquiátrico. Resultados: el 65.7 por ciento de los participantes presentaron síntomas comportamentales, donde la irritabilidad fue la mas frecuente (32.9 por ciento), seguido por depresión (30 por ciento) y agitación (25.7 por ciento). La apatía fue el síntoma que se presenta con mayor severidad sin ser el más frecuente. Discusión: dentro del cuadro clínico propio del DCL-A se reportan síntomas neuropsiquiátricos que acompañan el déficit cognitivo. En la población estudiada el 65.7 por ciento presentaba dichos síntomas, dato que se aproxima a lo encontrado en la literatura; sin embargo el síntoma más frecuente fue la irritabilidad, no la depresión como se ha reportado en otros estudios; los síntomas menos frecuentes fueron conductas eufóricas y conductas motoras aberrantes.

Introduction: Mild Cognitive Impairment (MCI) is characterized by the alteration of one or more cognitive processes without significant impairment in the activities of patient’s daily life and may be accompanied by neuropsychiatric symptoms, which increase the risk to develop dementia. Objective: To identify the frequency and severity of behavioral alterations in a population with mild cognitive impairment amnesiac type (MCI-A) Procedure: non experimental study, with a cross-sectional descriptive scope, attended by 70 people with diagnosis of MCI-A.Selected sample of caregivers responded neuropsychiatric inventory. Results: 65.7 percent of participants had behavioral symptoms, where irritability was the most frequent (32.9 percent), followed by depression (30 percent) and agitation (25.7 percent). Apathy was the symptom presented with most severity but not the most frequent. Discussion: Neuropsychiatric symptoms that accompany cognitive deficits are reported in clinical features of MCI-A. In the population studied, 65.7 percent had such symptoms, data that approximates those found in literature. Nonetheless, the most common symptom was irritability and not depression, as has been reported in other studies; euphoric and aberrant motor behaviors were theless frequent symptoms.