Nutrition and Brain Function: A Multidisciplinary Virtual Symposium

Abstract

A few months ago, the Brazilian Society for Neuroscience and Behavior (SBNeC) promoted a "virtual symposium" (by Internet, under the coordination of R.C.A. Guedes) on "Nutrition and Brain Function". The discussions generated during that symposium originated the present text, which analyzes current topics on the theme, based on the multidisciplinary experience of the authors. The way the brain could be non-homogeneously affected by nutritional alterations, as well as questions like early malnutrition and the development of late obesity and hormone abnormalities were discussed. Also, topics like the role of essential fatty acids (EFAs) on brain development, increased seizure susceptibility and changes in different neurotransmitters and in cognitive performance in malnourished animals, as well as differences between overall changes in nutrient intake and excess or deficiency of specific nutrients (e.g. iodine deficiency) were analyzed. It was pointed out that different types of neurons, possibly in distinct brain structures, might be differently affected by nutritional manipulation, including not only lack-but also excess of nutrient intake. Such differences could help in explaining discrepancies between data on humans and in animals and so, could aid in determining the basic mechanisms underlying lesions or changes in brain function and behavior.

Favorable and unfavorable lactation modulates the effects of electrical stimulation on brain excitability: A spreading depression study in adult rats

“…Such brain weight oscillation probably resulted from the lesser/higher number and/or size of glial and neuronal cells, as well as from alterations in the events that cause neuronal maturation, which include reduction of processes such as dendritic development, synapse formation and myelination for malnourished rats (Morgane et al, 1993;Almeida et al, 2002). By the same logic, one can expect the opposite reaction for the overnourished animals.…”

Malnutrition and REM-sleep Deprivation Modulate in Rats the Impairment of Spreading Depression by a Single Sub-convulsing Dose of Pilocarpine

“…Regarding the possible mechanisms for the interaction, in the adult organism, between past malnutrition (early in life) and present sleep deprivation (at adulthood), no definitive conclusions are available yet. It is very likely that at least some of the longlasting structural-and neurotransmitter alterations consequent to early malnutrition (Morgane et al, 1978;1993;Guedes et al, 1996;Almeida et al, 2002) play a pivotal role in changing the brain responses to REM-sleep deprivation in adulthood.…”

“…Some of the neural effects of malnutrition are long-lasting ar\d can be observed in adulthood. Changes in the number and size of nerve cells, as well as modifications in myelination, in synaptic architecture and in neurotransmitter availability and effectiveness consequent to malnutrition, are frequently mentioned as the main causes of the behavioral and electrophysiological alterations observed in early malnourished humans and laboratory animals (Morgane et al, 1978;1993;Guedes et al, 1996;Almeida et al 2002). In the rat, malnutrition has been shown to facilitate the induction of seizures by electroconvulsive shock {Stern et al, 1974) and also to increase the propagation rateofSD (deLucaeffl/.,1977;Guedes£'frt/,, 1987;1992;Rocha-De-Melo and Guedes, 1997).…”

Manipulation of rat litter size during suckling influences cortical spreading depression after weaning and at adulthood

“…During this early period, nutritional deficiency can alter brain structure and function (Morgane et al 1978(Morgane et al , 1993Almeida et al 2002) and this effect can last until adulthood (Rocha-de-Melo and Guedes 1997. It is already well known that malnutritioninduced neural effects are much more severe when the nutritional disorders coincide with the so-called "brain growth spurt" which corresponds to the highest rate of neurogenesis and neuronal migration during development.…”