Early-life malnutrition role in memory, emotional behavior and motor impairments in early brain lesions with potential for neurodevelopmental disorders: a systematic review with meta-analysis.

OBJECTIVES: The present study aims to evaluate the impact of early exposure to brain injury and malnutrition on episodic memory and behavior. METHODS: For this, a systematic review was carried out in the Medline/Pubmed, Web of Science, Scopus, and LILACS databases with no year or language restrictions. RESULTS: Initially, 1759 studies were detected. After screening, 53 studies remained to be read in full. The meta-analysis demonstrated that exposure to double insults worsens episodic recognition memory but does not affect spatial memory. Early exposure to low-protein diets has been demonstrated to aggravate locomotor and masticatory sequelae. Furthermore, it reduces the weight of the soleus muscle and the muscle fibers of the masseter and digastric muscles. Early exposure to high-fat diets promotes an increase in oxidative stress and inflammation in the brain, increasing anxiety- and depression-like behavior and reducing locomotion. DISCUSSION: Epigenetic modifications were noted in the hippocampus, hypothalamus, and prefrontal cortex depending on the type of dietetic exposure in early life. These findings demonstrate the impact of the double insult on regions involved in cognitive and behavioral processes. Additional studies are essential to understand the real impact of the double insults in the critical period.

Neonatal kaempferol exposure attenuates impact of cerebral palsy model on neuromotor development, cell proliferation, microglia activation, and antioxidant enzyme expression in the hippocampus of rats.

OBJECTIVES: This study aims to assess the effect of neonatal treatment with kaempferol on neuromotor development, proliferation of neural precursor cells, the microglia profile, and antioxidant enzyme gene expression in the hippocampus. METHODS: A rat model of cerebral palsy was established using perinatal anoxia and sensorimotor restriction of hindlimbs during infancy. Kaempferol (1 mg/ kg) was intraperitoneally administered during the neonatal period. RESULTS: Neonatal treatment with kaempferol reduces the impact of the cerebral palsy model on reflex ontogeny and on the maturation of physical features. Impairment of locomotor activity development and motor coordination was found to be attenuated by kaempferol treatment during the neonatal period in rats exposed to cerebral palsy. Neonatal treatment of kaempferol in cerebral palsy rats prevents a substantial reduction in the number of neural precursor cells in the dentate gyrus of the hippocampus, an activated microglia profile, and increased proliferation of microglia in the sub-granular zone and in the granular cell layer. Neonatal treatment with kaempferol increases gene expression of superoxide dismutase and catalase in the hippocampus of rats submitted to the cerebral palsy model. DISCUSSION: Kaempferol attenuates the impact of cerebral palsy on neuromotor behavior development, preventing altered hippocampal microglia activation and mitigating impaired cell proliferation in a neurogenic niche in these rats. Neonatal treatment with kaempferol also increases antioxidant defense gene expression in the hippocampus of rats submitted to the cerebral palsy model.

Effects of riboflavin in the treatment of brain damage caused by oxygen deprivation: an integrative systematic review.

Brain oxygen deprivation causes morphological damage involved in the formation of serious pathological conditions such as stroke and cerebral palsy. Therapeutic methods for post-hypoxia/anoxia injuries are limited and still have deficiencies in terms of safety and efficacy. Recently, clinical studies of stroke have reported the use of drugs containing riboflavin for post-injury clinical rehabilitation, however, the effects of vitamin B2 on exposure to cerebral oxygen deprivation are not completely elucidated. This review aimed to investigate the potential antioxidant, anti-inflammatory and neuroprotective effects of riboflavin in cerebral hypoxia/anoxia. After a systematic search, 21 articles were selected, 8 preclinical and 12 clinical studies, and 1 translational study. Most preclinical studies used B2 alone in models of hypoxia in rodents, with doses of 1-20 mg/kg (in vivo) and 0.5-5 µM (in vitro). Together, these works suggested greater regulation of lipid peroxidation and apoptosis and an increase in neurotrophins, locomotion, and cognition after treatment. In contrast, several human studies have administered riboflavin (5 mg) in combination with other Krebs cycle metabolites, except one study, which used only B2 (20 mg). A reduction in lactic acidosis and recovery of sensorimotor functions was observed in children after treatment with B2, while adults and the elderly showed a reduction in infarct volume and cognitive rehabilitation. Based on findings from preclinical and clinical studies, we conclude that the use of riboflavin alone or in combination acts beneficially in correcting the underlying brain damage caused by hypoxia/anoxia and its inflammatory, oxidative, and behavioral impairments.

Neonatal treatment with fluoxetine alters locomotor activity and the cortical glial/neuron index in rats with cerebral palsy.

Cerebral palsy (CP) is characterized by motor disorders, including deficits in locomotor activity, coordination, and balance. Selective serotonin reuptake inhibitors have been shown to play an important role in brain plasticity. This study investigates the effect of neonatal treatment using fluoxetine on locomotor activity and histomorphometric parameters of the primary somatosensory cortex (S1) in rats submitted to an experimental model of CP. CP was found to reduce bodyweight and locomotion parameters and also to increase the glia/neuron index in the S1. Administration of fluoxetine 10 mg/kg reduced bodyweight, impaired locomotor activity parameters, and increased the number of glial cells and the glia/neuron ratio in the S1 in rats with CP. However, treatment with fluoxetine 5 mg/kg was not found to be associated with adverse effects on locomotor activity and seems to improve histomorphometric parameters by way of minor changes in the S1 in animals with CP. These results thus indicate that experimental CP, in combination with the use of a high dose of fluoxetine (10 mg/kg), impairs locomotor and histomorphometric parameters in the S1, while treatment with a low dose of fluoxetine (5 mg/kg) averts the negative outcomes associated with a high dose of fluoxetine in relation to these parameters but produces no protective effect.

Treatment with the essential amino acid L-tryptophan reduces masticatory impairments in experimental cerebral palsy.

Purpose Children with cerebral palsy (CP) often exhibit difficulties in feeding resulting from deficits in chewing. This study investigates the therapeutic potential of L-tryptophan (TRI) to reduce deficits in chewing in rats subjected to an experimental model of CP.Methods A total of 80 Wistar albino rats were used. Pups were randomly assigned to 4 experimental groups: Control Saline, Control TRI, CP Saline, and CP TRI groups. The experimental model of CP was based on the combination of perinatal anoxia associated with postnatal sensorimotor restriction of the hind limbs. TRI was administered subcutaneously during the lactation period. Anatomical and behavioral parameters were evaluated during maturation, including body weight gain, food intake, chewing movements, relative weight and the distribution of the types of masseter muscle fibers.Results The induction of CP limited body weight gain, decreased food intake and led to impairment in the morphological and functional parameters of chewing. Moreover, for a comparable amount of food ingested, CP TRI animals grew the most. In addition, supplementation with TRI improved the number of chewing movements, and increased the weight and proportion of type IIB fibers of the masseter in rats subjected to CP.Conclusion These results demonstrate that experimental CP impaired the development of mastication and that TRI supplementation increased masticatory maturation in animals subjected to CP.

Neonatal fluoxetine exposure delays reflex ontogeny, somatic development, and food intake similarly in male and female rats.

Serotonin (5-HT) acts as a neuromodulator and plays a critical role in brain development. Changes in 5-HT signaling during the perinatal period can affect neural development and may result in behavioral changes in adulthood; however, further investigations are necessary including both sexes to study possible differences. Thus, the aim of this study was to investigate the impact of neonatal treatment with fluoxetine on the development of male and female offspring. The animals were divided into four groups according to sex and treatment. The experimental groups received fluoxetine at 10 mg·kg-1 (1 µL/g of body weight (bw)) and the animals of control group received saline solution 0.9% (1 µL/g of bw) from postnatal days 1-21. In the neonatal period, reflex ontogeny, somatic development, physical features, and food intake were recorded. In the postnatal period (until day 31) bw and post-weaning food intake were recorded. Chronic administration of fluoxetine in the neonatal period caused a delay in the reflex ontogeny and somatic development, as well as reduction of lactation, post-weaning bw, and post-weaning food intake in rats. No difference was found between the sexes. These changes reaffirm that serotonin plays an important role in regulating the plasticity of the brain during the early development period, but without sex differences.

Does l-Tryptophan supplementation reduce chewing deficits in an experimental model of cerebral palsy?

Children with cerebral palsy commonly present with feeding difficulties that result from multiple orofacial sequelae, especially deficits in mastication. A previous study demonstrated that perinatal protein undernutrition accentuated the chewing impact in an experimental model of cerebral palsy. Therefore, the present study investigated whether nutritional manipulation reversed or minimized the chewing sequelae in cerebral palsy. We emphasized the relevance of evaluating the therapeutic potential of nutrients, especially tryptophan supplementation, to reduce the chewing deficits that are typical of this syndrome. Clarification of the role of nutrients may help in the development of new treatment strategies for these children.

Selective serotonin reuptake inhibitors affect structure, function and metabolism of skeletal muscle: A systematic review.

Selective Serotonin Reuptake Inhibitors (SSRIs) may have side effects, such as stiffness, tremors and altered tonic activity, as well as an increased risk of developing insulin resistance and diabetes mellitus. However, little is known about the structural, functional and metabolic changes of skeletal muscle after administration of SSRIs. The aim of this systematic review was to explore and discuss the effects of SSRIs on skeletal muscle properties described in human and rodent studies. A systematic search of PUBMED, SCOPUS, and WEB OF SCIENCE was performed. The inclusion criteria were intervention studies in humans and rodents that analysed the effects of SSRIs on skeletal muscle properties. The research found a total of six human studies, including two randomized controlled trials, one non-randomized controlled trial, one uncontrolled before-after study and two case reports, and six preclinical studies in rodents. Overall, the studies in humans and rodents showed altered electrical activity in skeletal muscle function, assessed through electromyography (EMG) and needle EMG in response to chronic treatment or local injection with SSRIs. In addition, rodent studies reported that SSRIs may exert effects on muscle weight, the number of myocytes and the cross-sectional area of skeletal muscle fibre. The results showed effects in energy metabolism associated with chronic SSRI use, reporting altered levels of glycogen synthase activity, acetyl-CoA carboxylase phosphorylation, citrate synthase activity, and protein kinase B Ser phosphorylation. Moreover, changes in insulin signalling and glucose uptake were documented. In this context, we concluded based on human and rodent studies that SSRIs affect electrical muscle activity, structural properties and energy metabolism in skeletal muscle tissue. However, these changes varied according to pre-existing metabolic and functional conditions in the rodents and humans.

Peripheral and Central Glucocorticoid Signaling Contributes to Positive Energy Balance in Rats.

The obesity epidemic has been the target of several studies to understand its etiology. The pathophysiological processes that take to obesity generally relate to the rupture of energy balance. This imbalance can result from environmental and/or endogenous events. Among the endogenous events, the hypothalamic-pituitary-adrenal axis, which promotes stress response via glucocorticoid activity, is considered a modulator of energy balance. However, it remains controversial whether the increase in plasma levels of glucocorticoids results in a positive or negative energy balance. Furthermore, there are no studies comparing different routes of administration of glucocorticoids in this context. Here, we investigated the effects of intraperitoneal (i.p.) or intracerebroventricular (i.c.v.) administration of a specific agonist for glucocorticoid receptors on food intake and energy expenditure in rats. Sixty-day old rats were treated with i.p. or i.c.v. dexamethasone. Food intake and satiety were evaluated, as well as locomotor activity in order to determine energy expenditure. Both i.p. and i.c.v. dexamethasone increased food intake and decreased energy expenditure. Moreover, i.c.v. dexamethasone delayed the onset of satiety. Together, these results confirm that central glucocorticoid signaling promotes a positive energy balance and supports the role of the glucocorticoid system as the underlying cause of psychological stress-induced obesity.