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

Abstract

As several other factors, nutritional deficiency and sensory input hyperactivation can influence the mammalian brain development. This work investigated the effects of repeated episodes of early peripheral electrostimulation (PE), associated or not with early malnutrition, on cortical spreading depression (CSD) propagation. From postnatal days 7-28, well-nourished and malnourished Wistar rat pups (whose mothers were fed a 23 and 8% protein diet, respectively) received daily sessions of repetitive PE (2 or 60 Hz-square-wave pulses, 1.5 ms duration, 10-40 V intensity), delivered by two electrodes attached to the left paws. At postnatal days 35-45, under anesthesia, KCl-elicited spreading depression was monitored at two cortical points of both hemispheres. In the well-nourished rats, 2 Hz, but not 60 Hz PE was associated with slower spreading depression propagation in the hemisphere contralateral to the stimulated body-side, as compared to the ipsilateral hemisphere. In the malnourished rats, this effect was found for both 2 and 60 Hz stimulation frequencies. In the sham-stimulated controls, which received similar paw-electrodes, but were not stimulated, no inter-hemispheric spreading depression differences were seen. The results indicate an impairing effect of early PE on spreading depression propagation, which is frequency-dependent and can be influenced by the animal's nutritional status. Data raise the question whether brain plasticity changes consequent to the interaction between sensory input activation and malnutrition would be involved in the here described spreading depression effects.

Early vibrissae removal facilitates cortical spreading depression propagation in the brain of well‐nourished and malnourished developing rats

“…If this hypothesis has merit, then one should predict that sensory manipulations on the opposite direction (i.e., peripheral sensory activation instead of suppression) would lead to CSD propagation changes that would be contrary (i.e., decrease in CSD propagation velocity) to the presently reported increased CSD propagation. In fact, this has actually been observed by Monte‐Silva et al (2007). These authors submitted developing rats to daily sessions of repetitive peripheral electrical stimulation of the left paws delivered by two electrodes attached to them.…”

The Impairing Effect of Acute Ethanol on Spreading Depression is Antagonized by Astaxanthin in Rats of 2 Young‐Adult Ages

“…These conditions include nutritional, metabolic, environmental, hormonal, and pharmacological factors. Some of these conditions facilitate CSD, as for example malnutrition (Rocha‐de‐Melo et al., ), hypoglycemia (Costa‐Cruz et al., ), and γ‐aminobutyric acid (GABA)‐enhancing drugs (Guedes et al., ), while others like serotoninergic drugs (Amâncio‐dos‐Santos et al., ), hypernutrition (Rocha‐de‐Melo et al., ), aging (Guedes et al., ), and peripheral afferent stimulation (Monte‐Silva et al., ) impair CSD.…”

Propagation of spreading depression inversely correlates with cortical myelin content

“…Nevertheless, first indications that myelin may affect CSD derive from nutritional studies: Malnutrition of young rats was shown to cause dysmyelination within the CNS 39. Interestingly, malnourished rats early in life displayed greater CSD velocities than well‐nourished control animals 40. It was thus speculated that deficient myelination may account for this observation, but other causalities such as altered cell‐packing density, neuron‐to‐glia ratio, or synaptic neurotransmitters were also envisaged.…”