| Abstract [eng] |
Dementia is defined as cognitive impairment in more than one cognitive area characterized by loss of intellectual ability to interfere with usual social activities. One of the most common brain diseases that causes dementia is Alzheimer’s disease and the chance of getting dementia from Alzheimer’s disease increases with age. High research priority to develop animal model of dementia is due to disease prevalence and poor prognosis of the disease. Pharmacological scopolamine-induced amnesic model is frequently used to model cognitive dysfunctions and memory disturbances. The aim of the research was to implement a pharmacological model of memory impairment in Wistar rats. Goals of the thesis: to induce memory impairment in Wistar rats using scopolamine injections and to investigate the impact of memory impairment on animal behavior; to determine age-related memory impairment and behavioral changes in healthy Wistar rats and to compare to scopolamine induced memory impairment. Scopolamine-induced memory impairment in 3-month-old Wistar male rats was induced by administration of 1 mg/kg and 2 mg/kg intraperitoneal injections of scopolamine every day (1 time/day) for 3 weeks. Memory dysfunction was evaluated using an open field test and novel object recognition test. In order to determine whether scopolamine induced reversible memory impairment the same behavioral tests were repeated 1 week after discontinuation of scopolamine injections. Age-related memory impairment was analyzed in healthy female and male Wistar rats. Female Wistar rats were divided into three groups: young (3-5 months), middle-aged (9-12 months) and older (16-17 months) while male Wistar rats were divided into two groups: young (3 months) and middle-aged (8 months). Open field, novel object recognition and T-maze behavioral tests were performed for these groups. It was determined that administration of 1 mg/kg and 2 mg/kg scopolamine injections everyday reversibly impaired short-term memory and novel object recognition. Additionally, scopolamine injections increased locomotor activity. Short-term memory was not impaired in aged rats, however changes in working spatial memory were observed. Also, age-related decrease of locomotor activity was noticed. Pharmacological scopolamine model does not reflect age-related behavioral and memory changes. |
