Spreading depression is facilitated in adult rats previously submitted to short episodes of malnutrition during the lactation period

Abstract

Lactating rat dams were submitted to short episodes (1, 2 or 3 weeks) of nutritional restriction by receiving the "regional basic diet" (RBD, with 8% protein) of low-income human populations of Northeast Brazil. Their pups were then studied regarding the developmental effects on body and brain weights. When the rats reached adulthood, cortical susceptibility to the phenomenon of spreading depression (SD) was evaluated by performing electrophysiological recordings on the surface of the cerebral cortex. SD was elicited at 20-min intervals by applying 2% KCl for 1 min to a site on the frontal cortex and its occurrence was monitored at 2 sites in the parietal region by recording the electrocorticogram and the slow potential change of SD. When compared to control rats fed a commercial diet with 23% protein, early malnourished rats showed deficits in body and brain weights (10% to 60% and 3% to 15%, respectively), as well as increases in velocity of SD propagation (10% to 20%). These effects were directly related to the duration of maternal dietary restriction, with pups malnourished for 2 or 3 weeks presenting more intense weight and SD changes than those malnourished for 1 week. The effects of 1-week restrictions on SD were less evident in the pups malnourished during the second week of lactation and were more evident in pups receiving the RBD during the third week. The results indicate that short episodes of early malnutrition during the suckling period can affect body and brain development, as well as the cortical susceptibility to SD during adulthood. The data also suggest that the third week of lactation is the period during which the brain is most sensitive to malnutrition, concerning the effects on SD.

Nutrition-dependent influence of peripheral electrical stimulation during brain development on cortical spreading depression in weaned rats

“…Concerning nutritional deficiency, CSD-susceptibility was increased in rats malnourished early in life, as judged by its higher CSD velocities, in comparison to the well-nourished rats, confirming previous studies (Andrade et al 1990;Rocha-De-Melo and Guedes 1997;Santos Monteiro et al 2000;Amâncio-dosSantos et al 2006). Deficient myelination, increased brain cell packing density, altered neuron-to-glia ratio and synaptic neurotransmitters are the most suggested mechanisms to explain the effect of early malnutrition on cortical CSD (De Luca et al 1977;Rocha-DeMelo and Guedes 1997).…”

l-Glutamine supplementation during the lactation period facilitates cortical spreading depression in well-nourished and early-malnourished rats

“…Malnutrition facilitates CSD in the rat brain (De Luca et al 1977), and this condition has been extensively demonstrated in our laboratory (Guedes et al 1987;Andrade et al 1990;Rocha-de-Melo and Guedes 1997;Rocha-de-Melo et al 2006), and confirmed in the present study, as indexed by the CSD velocities in the naïve condition, which were higher in the malnourished group, as compared to the well-nourished one (see Fig. 3).…”

Effects of maternal undernutrition during lactation on aromatase, estrogen, and androgen receptors expression in rat testis at weaning

“…This study provides further evidence that early malnutrition can lead to endocrine disruption , Ramos et al 1997, Rocha de Melo & Guedes 1997, Teixeira et al 2002. The maternal nutritional state during lactation is equivalent and possibly even more important than that during gestation, as evidenced by a study from Léonhard et al (2003) that showed that the offspring whose dams were malnourished during lactation had more drastic consequences on gonadal development when compared with the offspring whose dams were malnourished only during pregnancy or during pregnancy and lactation.…”

“…Undernutrition is known to have a wide variety of effects on endocrine systems (Rocha de Melo & Guedes 1997, Cónsole et al 2001. Regarding the reproductive system, it has been shown that food restriction can inhibit both the maintenance and onset of reproductive capability (Desjardins & Lopez 1983).…”