EFFECT OF SWIMMING TRAINING ON COGNITIVE FUNCTION IN SCOPOLAMINE INDUCED DEMENTIA IN MICE.

ABSTRACT

The present study investigated the effects of a 2-week swimming exercise on scopolamine-induced dementia in a mice model. Thirty-two mice, were randomly divided into four groups (8 rats in each). Group A served as control without exercise and received saline only; Group B served as induced control and receive a single dose of scopolamine (1 mg/kg, i.p.) only on the last day; group C mice were subjected to short-term exercise (swimming) + single dose of scopolamine (1 mg/kg, i.p.) on the last day; while group D were subjected to short-term exercise (swimming) only. In the neuro-behavioural study, it was revealed that swimming exercise prevented memory impairment and anxiety level in group C when compared with group B. Acetylcholinesterase (AchE) activity was significantly increased in the group B when compared with group A. However, swimming prevented the observed increase in AchE activity in group B when compared with swimming + scopolamine treated group. Adenosine deaminase activity was significantly increased in the scopolamine treated group when compared with the control, and swimming prevented the increase when compared with group C. Results of nitric oxide showed that there was no significant difference among the groups while that of superoxide dismutase and catalase showed a significant decrease in scopolamine treated group when compared with control group, while swimming caused a significant increase when compared with group C. Furthermore, the MDA level increased in the scopolamine treated group but swimming prevented the significant increase when compared with swimming + scopolamine group. In conclusion, swimming exercise served as a neuroprotective measure against scopolamine-induced dementia in mice model.

Table of Contents

CERTIFICATION ...................................................................................................................... i

APPROVAL PAGE ................................................................................................................... ii

DEDICATION ......................................................................................................................... iii

ACKNOWLEDGEMENT ........................................................................................................ iv

LIST OF FIGURES ................................................................................................... vii

LIST OF PLATES ................................................................................................. viii

LIST OF TABLES .................................................................................................... ix

ABSTRACT ............................................................................................................................... x

CHAPTER ONE ........................................................................................................................ 1

1.0 INTRODUCTION .......................................................................................................... 1

1.2 OVERALL AIM ............................................................................................................. 5

1.3 SPECIFIC OBJECTIVE ................................................................................................. 5

1.4 JUSTIFICATION OF STUDY ....................................................................................... 5

CHAPTER TWO ....................................................................................................................... 6

2.0 Literature Review................................................................................................................. 6

2.1 Exercise/Physical Activity ................................................................................................... 6

2.1.1 Swimming ......................................................................................................................... 7

2.1.1.1 Significance of Swimming ............................................................................................. 7

2.2 Human Brain ........................................................................................................................ 7

2. 2.1 HINDBRAIN ................................................................................................................... 8

2.2.2Cerebellum ....................................................................................................................... 10

2.2.3MIDBRAIN (MESENCEPHALON) ............................................................................... 11

2.2.4FOREBRAIN(PROSENCEPHALON) ........................................................................... 11

2.2.5Cerebrum.......................................................................................................................... 13

2.3 Y MAZE ............................................................................................................................ 13

2.4 OPEN FIELD ..................................................................................................................... 14

2.5 ACETYLCHOLINE .......................................................................................................... 14

2.6 NITRIC OXIDE ................................................................................................................. 15

2.7ANTIOXIDANTS............................................................................................................... 15

2.8 SCOPOLAMINE ............................................................................................................... 16

CHAPTER THREE ................................................................................................................. 18

3.0 MATERIALS AND METHOD ......................................................................................... 18

vi

3.1 MATERIALS ..................................................................................................................... 18

3.2 METHODS ........................................................................................................................ 18

3.2.1 Experimental Animals .................................................................................................... 18

3.2.2 Experimental Protocol .................................................................................................... 18

3.2.3 EXERCISE PROTOCOL ............................................................................................... 19

3.3 BEHAVIOURAL STUDY ................................................................................................ 19

3.3.1 Y-MAZE TEST .............................................................................................................. 19

3.3.2 OPEN FIELD .................................................................................................................. 20

3.4 PREPARATION OF TISSUE HOMOGENATES ............................................................ 20

3.4.1 ISOLATION AND HOMOGENIZATION OF TISSUE HOMOGENATE .................. 20

3.5 BIOCHEMICAL ASSAY .................................................................................................. 24

3.5.1 ACETYLCHOLINESTERASE (AChE) ENZYMATIC ACTIVITY ............................ 24

3.5.2 ADENOSINE DEAMINASE ACTIVITY (ADA) ......................................................... 25

3.5.3 NITRIC OXIDE ASSAY ................................................................................................ 25

3.5.4 LIPID PEROXIDATION................................................................................................ 26

3.5.5 TOTAL THIOL (TSH) CONTENT................................................................................ 26

3.5.6 NON-PROTEIN THIOL (NPSH) CONTENT ............................................................... 27

3.5.7 CATALASE .................................................................................................................... 28

3.5.8 SUPEROXIDE DISMUTASE (SOD) ACTIVITY ........................................................ 29

3.6 STATISTICAL ANALYSIS ............................................................................................. 30

CHAPTER FOUR .................................................................................................................... 31

4.0 RESULTS ......................................................................................................................... 31

4.1 Effect of swimming exercise on some neurobehavioural parameters .......................... 31

4.2 Effect of swimming exercise on some key enzymes associated with brain function ... 34

CHAPTER FIVE ..................................................................................................................... 44

5.0 DISCUSSION ............................................................................................................... 44

CONTRIBUTION TO KNOWLEDGE ................................................................................... 48

REFERENCES ........................................................................................................................ 49

APPENDIX .............................................................................................................................. 58

vii

LIST OF FIGURES PAGES Figure 2.1 Anatomy of the brain 9

Figure 4.1: Effect of swimming exercise on spatial working memory in

scopolamine-induced dementia in mice as assessed by Y-maze test 32

Figure 4.2: Effect of swimming exercise on brain acetylcholinesterase

(AChE) activity in scopolamine-induced dementia in mice model 35

Figure 4.3: Effect of swimming exercise on brain adenosine deaminase

(ADA) activity in scopolamine-induced dementia in mice model 36

Figure 4.4: Effect of swimming exercise on brain nitric oxide (NO)

level in scopolamine-induced dementia in mice model 38

Figure 4.5: Effect of swimming exercise on brain malondialdehyde

(MDA) level in scopolamine-induced dementia in mice model 39

Figure 4.6: Effect of swimming exercise on brain superoxide dismutase

(SOD) activity in scopolamine-induced dementia in mice model 40

Figure 4.7: Effect of swimming exercise on brain catalase activity in

scopolamine-induced dementia in mice model 41

Figure 4.8: Effect of swimming exercise on brain total protein thiol

(TSH) level in scopolamine-induced dementia in mice model 42

Figure 4.9: Effect of swimming exercise on brain non-protein thiol

(NPSH) level in scopolamine-induced dementia in mice model 43

viii

LIST OF PLATES PAGES

PLATE 1: Y Maze 22

PLATE 2: Open Field 23

ix

LIST OF TABLES PAGES

Table 1: Swimming Protocol With Training Time For 14 Days,

To Be Held From Monday To Friday. 21

Table 4.1: Effect of swimming exercise on locomotor function and

anxiety linked behaviours in scopolamine-induced dementia in mice

as assessed by open field test (OFT) 33