DEMENTIA: A COMPLETE LITERATURE REVIEW ON VARIOUS MECHANISMS INVOLVES IN PATHOGENESIS AND AN INTRACEREBROVENTRICULAR STREPTOZOTOCIN INDUCED ALZHEIMER’S DISEASE

Abstract

Dementia can be defined as loss of multiple components of intellectual function like memory and learning, attention, concentration, orientation, thinking, calculation, language, geographic orientation. Most common cause of dementia is Alzheimer’s disease (AD) which is a progressive, irreversible, age-related, neurological and psychiatric disorder characterized by a progressive decline in memory, cognitive performance and loss of acquired skills leading to apraxia, agnosia, anomia and aphasia. AD has been proposed to involve a number of linked pathophysiological mechanisms, such as amyloid β peptides (Aβ) toxicity, tau phosphorylation, neuroinflammation, excitotoxicity, oxidative stress and neurotransmitter abnormalities. Various experimental models of AD have been introduced today but not even single model has been found to be truly representative of the SAD. Therefore, considering the fact that AD has been recognized as an insulin resistant brain state, intracerebroventricular (ICV STZ) streptozotocin administered rat has become one of the proposed experimental models relevant to the sporadic type of AD. Intracerebroventricular administration of STZ results in IR desensitization and behavioral, biochemical, histological and neurochemical impairment along with progressive deterioration of cognitive function.