Changes in acetylcholinesterase activities in the developing and aging pig brain and hypophyses

Abstract

Changes in the activities of Acetylcholinesterase (AChE, E.C. 3117), the enzyme which catalyses the hydrolysis of Ach, thereby mediating in food and water intake, aggressive sexual behaviour and body development were studied in aging pig brains and hypophyses using 88 crossbred Large White pigs. Results from this study indicated highly significant (P<0.01) age effects in the pons, hippocampus, hypothalamus, cerebral cortex and medulla oblongata and to a lesser level (P<0.05) in the amygdala, midbrain and neurohypophysis. The pons was linearly negative with advancing age and AChE activities significantly (P<0.05) fell with increasing age from day old to 36 months. The amygdala on the other hand had very low AChE activities at birth (1.97) rising sharply by 551% to 10.48 at 10 months and falling sharply by 63% to 5.45 at 14 months and 3.87 at 36 months. The hippocampus witnessed a rise in AChE activity by 61% from day old to 14 months and a fall thereafter by 51% from 14 months to 36 months. The trends in the hypothalamus, mid brain, and neurohypophysis are also very similar to the other regions. AChE activity in the midbrain rose by 70% from day old to 18 months and fell thereafter by 58% to 36 months. Age effects were not significant in the adenohypophysis. From this study, it appears that the brain attains adulthood by 16 to 18 months and is in senescence by 30 months onwards. This decline in transmitter action and concentration in brain regions with advancing age points to the need for a closer look at the productivity indices of livestock at old age and the need to provide good quality nutrients and optimum micronutrients balance for better neuro-endocrine response and improved productivity with advancing age.

Keywords: brain regions, development, acetylcholinesterase, nutrition, hypophyses

International Journal of Agriculture and Rural Development Vol. 5 2004: 46-53