Study of the effects of sleep deprivation by gentle handling method on the performance on object recognition and habituation tasks.

• Grant number: 11/16892-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2011
• End date: October 31, 2012
• Field of knowledge: Biological Sciences - Physiology
• Principal Investigator: Débora Cristina Hipólide
• Grantee: Larissa Beatriz Torres Ferreira
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Sleep is the current focus of many researches due to its great importance for maintaining the proper activities of the organism and the fact that its function has not yet been fully described. Studies show that sleep deprivation (SD) impair memory and learning, an effect that has been evidenced through the use of various memory tasks. Many of these tasks employ aversive stimuli or require intense physical activity of the animal to perform, factors that may interfere in the analysis of the SD effects. Another important factor is the duration of SD. Studies of our laboratory show that SD prejudice memory when employed for long periods of SD, a condition that produces changes in several physiological systems, and consequently interferes with specific effects of SD on memory. Therefore, the study and development of alternative models for the assessment of memory of sleep deprived animals is of great importance to the area. Thus, this study aims to evaluate the performance of sleep-deprived mice in the novel object recognition (NOR) and habituation (HA) tasks. The NOR task is divided in two sessions: acquisition and test. At acquisition, animals will be presented to three different objects in a 5 minutes interval, and then they return to their homecages. This procedure will be repeated for 5 times with 15 minutes intervals. Between acquisition and test will be an interval of 24 hours. After this interval the test will be achieved, and the animals will be exposed to three new objects (two identical and one new) during 5 minutes. The HA task is also divided in two sessions. In the first session (exposition) the animals will be exposed to an open field arena during 10 minutes. After a 24 hours interval, the animal will be re-exposed to the same environment. In both sessions rearing and locomotion will be observed and registered. The SD method by gentle handling will be held immediately after the acquisition phase of each memory task, and will last for 6 hours.