Effects of early undernutrition and subsequent rehabilitation on acetylcholine levels in rat brain

Abstract

Summary. Early undernutrition, induced by feeding mothers a low protein (5%) diet during gestation and/or lactation, resulted in significant deficits in acetylcholine concentration in the rat brain, and these deficits were reversed by subsequent dietary rehabilitation.The key role of acetylcholine (ACh) as a neurotransmitter has now been well established 3. The concentration of ACh in the brain varies inversely with the functional activity of the brain. Thus, it is elevated in anaesthesia and sleep 4'5, in deep narcosis 6 and after the administration of CNS depressants 7. It is decreased in conditions associated with increased brain activity, for example convulsions, electrical stimulation and emotional excitement 4. The concentration of ACh in the rat brain increases with age up to 100 days or moreT,8; this increase coincides with the 'growth spurt' of the brain, and this is the time when the brain is more vulnerable to nutritional insults 9' 10. Neonatal undernutrition brought about by litter-size manipulation was not found to alter the concentration of ACh in the rat brain during the weaning period ~2. However, postweaning protein deficiency and also caloric restriction were found to decrease the ACh concentration. Neonatal undernutrition in the rat is also associated with significant deficits in brain DNA, lipids and neurotransmitter amines 9,1~It was therefore logical to investigate the effects of early undernutrition in rats, induced by maternal protein deficiency during gestation and/or lactation, and the subsequent dietary rehabilitation, on brain ACh levels. Adult female albino rats of proved fertility, weighing 180-200 g (bred at Haffkine Institute), were used for the experiments. They were divided into 3 groups, each of which received a different dietary regimen from the 1st day of conception. The control group (G+L +) was fed a 20% protein diet during gestation and lactation. The 2nd group (G+L -) was fed a 20% protein diet during gestation and a 5% protein diet during lactation. The 3rd group (G-L-) was fed a 5% protein diet during gestation and lactation. Water and diet were provided ad libitum to all the groups. The composition of the diet was essentially similar to that Effects of early undernutrition and subsequent dietary rehabilitation on ACh concentration in rat brain ~ DietaryBody weight Brain weight Brain acetylregimen (g) (g) choline (gg per g)

Behavioural Changes in Adult Rats Produced by Early Postnatal Maternal Deprivation and Treatment with Choline Chloride

“…Food deprivation in this time is also known to influence brain neurochemistry (Adlard and Dobbing, 1971;Shoemaker and Wurtman, 1973;Wiggins et al, 1984). In this connection the observed decreased brain acetylcholine content after early undernutrition (Kulkarni and Gaitonde, 1982) and psychosocial deprivation (Dörner et al, 1982) seems to be noteworthy. This deficit was corrected when undernourished animals were placed on a normal diet (Kulkarni and Gaitonde, 1982) suggesting that the synthesizing and storage capacities for this transmitter were not permanently damaged.…”

“…In this connection the observed decreased brain acetylcholine content after early undernutrition (Kulkarni and Gaitonde, 1982) and psychosocial deprivation (Dörner et al, 1982) seems to be noteworthy. This deficit was corrected when undernourished animals were placed on a normal diet (Kulkarni and Gaitonde, 1982) suggesting that the synthesizing and storage capacities for this transmitter were not permanently damaged. Zamenhof and van Marthens (1978) pointed out that not the final concentration of neurotransmitters in the mature brain but their temporary deficiency in a critical period of synaptogenesis is of importance.…”

Effects of early thiamin deficiency and subsequent rehabilitation on the cholinergic system in developing rat brain.

“…The whole brain including olfactory lobes was removed, processed further and ACh levels were estimated by frog rectus abdominus bioassay as described earlier (23,24). AChE activity was measured by the method of Ellman et al (25).…”