26th IBRO/AFRICA school on Advanced Behavioral Neuroscience, ICIPE, Nairobi Kenya 17 th December 2010

Transcription

1 26th IBRO/AFRICA school on Advanced Behavioral Neuroscience, ICIPE, Nairobi Kenya 17 th December 2010

2 Dominic Ochwang'i (Kenya), Moto Fleur (Cameroon), Duncan Matheka (Kenya), Denver Ncube (Zimbabwe), Tadesse Seda (Ethiopia),Alinia Codita(Romenia).

3 STRAIN DIFFERENCES BETWEEN BALB/c AND C57BL/6 MICE IN A BATTERY OF BEHAVIOURAL TESTS

4 Introduction Objective Methodology Results Discussion STUDY OUTLINE

5 INTRODUCTION Genetically modified mice have become the most commonly used subjects in the study of the molecular and cellular mechanisms underlying learning and memory processes. Wolfer et al. 1998; Nguyen and Gerlai 2002; Tonegawa et al. 2003; Mineur etal. 2004; Josselyn 2005

6 INTRODUCTION This study focused on the behavioral differences between BALB/c and C57 strains of mice using different experiments: Open field Elevated plus maze Hole board T maze Puzzle box

7 INTRODUCTION C57 mice is an inbred strain of lab mice Most widely due to the availability of congenic strains easy breeding, robustness. Easily irritable temperament C57BL/6 MICE Sarna JR, Dyck RH, Whishaw IQ. 2000

8 BALB C MICE Jackson Laboratory. Retrieved Balb C is an albino, laboratory-bred strain of the House Mouse Most widely used strain in animal experimentation Male BALB/c mice are aggressive and will fight other males if housed together Most substrains have a "long reproductive life-span" are noted for displaying high levels of anxiety; used in cardiovascular research Studies describe them as poor learners,this may affect learning and memory

9 OBJECTIVE The main objective of the present study is to compare the behavioral differences between BALB/c and C57 strains of mice.

10 MATERIALS AND METHODS HOLE BOARD TEST Hole board apparatus Lister R G (1987) Wooden box painted black, 40 x 40 x 26 cm Floor is 7 cm above the surface 4 peripheral holes 4 central holes Exploratory behaviour, anxiety Total time 3 min Count central and peripheral head dips

11 MATERIALS AND METHODS OPEN FIELD TEST The open field apparatus measure 72 x 72 cm with 36 cm walls The lines divided the floor into sixteen 18 x 18 cm squares. A central square (18 cm x 18 cm) was drawn in the middle of the open field Total test time 5 min Line cross, centre square frequency, rearing Open field apparatus Brown, Corey, & Moore, 1999

12 MATERIALS AND METHODS ELEVATED PLUS-MAZE TEST Elevated plus maze apparatus Lister R G (1987) Raised to 45 cm above the floor Two open arms & two closed arms (45 cm by 5 cm) Anxiety Mice were placed in the central square of the Plus- Maze facing an open arm Total test time: 5 min Time in open and closed arms was recorded

13 MATERIALS AND METHODS T MAZE TEST Open wooden T-maze with a moveable wooden block or doors which can be used to deny access to parts of the maze T-maze apparatus Robert Deacons&J Nicholas P Rawlins; 2006 Sample- restrain mouse for 30 seconds Remove barriers Put mouse again (choice)

14 MATERIALS AND METHODS PUZZLE BOX TEST Box 73 cm by 28 cm by 27.5 cm Puzzle box apparatus Divided by a removable barrier into a smaller dark goal box & larger brightly lit Underpass at the barrier location Day 1: Training (3 trials each 2 min) Day 2: Burrowing puzzle (3 trials each 4 min) Day 3: Plug puzzle (3 trials each 4 min) Time to find entrance & to enter into dark box were recorded Galsworthy et al., 2002

15 STATISTICAL ANALYSIS Mean ± standard error of mean Data was analyzed using Statview Bar graphs, figures used Non-parametric test Mann Witney Significance levels were set at P< 0.05

16 RESULTS ELEVATED PLUS MAZE OPEN FIELD PUZZLE BOX HOLE BOARD

17 20 %time in open arms %time in open arms average Balbc average C57BL

18 SCORE OPEN FIELD TEST C57 50 Balb 0 Line cross freq Center square freq Rearing freq stretch attent freq urination defecation

19 OPEN FIELD Series1 Series2

20 C57 Balb BALB D2 C57 D Line cross freqcenter square freq Rearing freq stretch attent freq urination defecation

21 Open field C57 Balb BALB D2 C57 D2

22 T1Time to enter in to dark box T2Time to enter in to dark box T3Time to enter in to dark box Cell Mean 120 Interaction Bar Plot for Day 1 puzzle Effect: Category for Day 1 puzzle * Group Error Bars: ± 1 Standard Error(s) Balbc C Cell

23 Cell Mean Interaction Bar Plot for day3 blocked trials Effect: Category for day3 blocked trials * Group Error Bars: ± 1 Standard Error(s) Balbc C X1 to enter Cell X2 to enter

24 Perpheral dips: balbc Perpheral dips: CBJ Central: balbc Central: CBJ Cell Mean HOLE BOARD central dips 18 Cell Bar Chart Grouping Variable(s): Group Error Bars: ± 1 Standard Error(s)

25 ELEVATED PLUS MAZE DISCUSSION Non significant relationship in: 1. Time spent in open arms 2. Head dips 3. Faecal boli 4. Rearing OPEN FIELD Generally C57/b showed less anxiety as compared to Balb/C mice but the difference was non significant

26 Discussion contd. PUZZLE BOX Day and trial analysis was done for each mouse and for the 2 groups A significant difference between the 2 groups was observed in the time to enter after the dark box after an obstacle had been placed on the entrance P=0.02 ANOVA for blocked trials revealed a significant difference between the time to remove the obstacle and enter into the dark box.

27 HOLE BOARD On average C57B mice showed less anxiety by having a greater overall average of central dips as compared with Balb/C mice but the relationship was non-significant. By analysing the EPM results and Hole Board test Balb/C mice showed greater anxiety than C57/B.

28 Thank you all