Perinatal undernutrition associated to experimental model of cerebral palsy increases adverse effects on chewing in young rats

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.

Perinatal anoxia associated with sensorimotor restriction causes muscle atrophy and microglial activation: Meta-analysis of preclinical studies with implications for cerebral palsy

Several experimental cerebral palsy models have been created to investigate cellular and molecular mechanisms involved in this condition and develop new therapeutic strategies. The model that has come closest to a motor phenotype similar to cerebral palsy is the one that combines perinatal anoxia with hindlimb sensorimotor restriction, as it induces visible changes at the peripheral and central levels. This systematic review with meta-analysis presents the impact of the cerebral palsy model that associates perinatal anoxia with hindlimb sensorimotor restriction on the nervous, muscular and skeletal systems. Studies with perinatal anoxia associated with sensorimotor restriction and which evaluated outcomes related to skeletal, muscle, or nervous tissue were recovered from the databases: Embase, PubMed, Scopus, and Web of Science. The methodological and quantitative assessment was performed after eligibility screening (PROSPERO - ID: CRD42023477770). After screening of 4,641 articles, 21 studies with a moderate quality of evidence were chosen to be included in this review and 11 articles were included in the meta-analysis. The results of the meta-analysis reported a significant reduction in the media area of the soleus muscle fibers, increased number of glia cells and glia/neuron index in the somatosensory cortex, increased microglial activation in the hippocampus, and no changes in the corpus callosum thickness or neuron cells. The combination of perinatal anoxia and sensorimotor restriction entails muscle deficits and excessive activation of glial cells in brain areas. These results contribute to a methodological refinement of cerebral palsy models and favor new studies proposed for methodological elucidation in animal experimentation.

Neonatal resveratrol treatment in cerebral palsy model recovers neurodevelopment impairments by restoring the skeletal muscle morphology and decreases microglial activation in the cerebellum

Cerebral Palsy (CP) is the main motor disorder in childhood resulting from damage to the developing brain. Treatment perspectives are required to reverse the primary damage caused by the early insult and consequently to recover motor skills. Resveratrol has been shown to act as neuroprotection with benefits to skeletal muscle. This study aimed to investigate the effects of neonatal resveratrol treatment on neurodevelopment, skeletal muscle morphology, and cerebellar damage in CP model. Wistar rat pups were allocated to four experimental groups (n = 15/group) according CP model and treatment: Control+Saline (CS), Control+Resveratrol (CR), CP + Saline (CPS), and CP + Resveratrol (CPR). CP model associated anoxia and sensorimotor restriction. CP group showed delay in the disappearance of the palmar grasp reflex (p < 0.0001) and delay in the appearance of reflexes of negative geotaxis (p = 0.01), and free-fall righting (p < 0.0001), reduced locomotor activity and motor coordination (p < 0.05) than CS group. These motor skills impairments were associated with a reduction in muscle weight (p < 0.001) and area and perimeter of soleus end extensor digitorum longus muscle fibers (p < 0.0001), changes in muscle fibers typing pattern (p < 0.05), and the cerebellum showed signs of neuroinflammation due to elevated density and percentage of activated microglia in the CPS group compared to CS group (p < 0.05). CP animals treated with resveratrol showed anticipation of the appearance of negative geotaxis and free-fall righting reflexes (p < 0.01), increased locomotor activity (p < 0.05), recovery muscle fiber types pattern (p < 0.05), and reversal of the increase in density and the percentage of activated microglia in the cerebellum (p < 0.01). Thus, we conclude that neonatal treatment with resveratrol can contribute to the recovery of the delay neurodevelopment resulting from experimental CP due to its action in restoring the skeletal muscle morphology and reducing neuroinflammation from cerebellum.

Resveratrol Reduces Neuroinflammation and Hippocampal Microglia Activation and Protects Against Impairment of Memory and Anxiety-Like Behavior in Experimental Cerebral Palsy

Cerebral palsy (CP) is a neurodevelopmental disorder characterized by motor and postural impairments. However, early brain injury can promote deleterious effects on the hippocampus, impairing memory. This study aims to investigate the effects of resveratrol treatment on memory, anxiety-like behavior, and neuroinflammation markers in rats with CP. Male Wistar rats were subjected to perinatal anoxia (P0-P1) and sensory-motor restriction (P2-P28). They were treated with resveratrol (10 mg/kg, 0.1 ml/100 g) or saline from P3-P21, being divided into four experimental groups: CS (n = 15), CR (n = 15), CPS (n = 15), and CPR (n = 15). They were evaluated in the tests of novel object recognition (NORT), T-Maze, Light-Dark Box (LDB), and Elevated Plus Maze (EPM). Compared to the CS group, the CPS group has demonstrated a reduced discrimination index on the NORT (p < 0.0001) and alternation on the T-Maze (p < 0.01). In addition, the CPS group showed an increase in permanence time on the dark side in LDB (p < 0.0001) and on the close arms of the EPM (p < 0.001). The CPR group demonstrated an increase in the object discrimination index (p < 0.001), on the alternation (p < 0.001), on the permanence time on the light side (p < 0.0001), and on the open arms (p < 0.001). The CPR group showed a reduction in gene expression of IL-6 (p = 0.0175) and TNF-α (p = 0.0007) and an increase in Creb-1 levels (p = 0.0020). The CPS group showed an increase in the activated microglia and a reduction in cell proliferation in the hippocampus, while CPR animals showed a reduction of activated microglia and an increase in cell proliferation. These results demonstrate promising effects of resveratrol in cerebral palsy behavior impairment through reduced neuroinflammation in the hippocampus.

Creatine supplementation increases postnatal growth and strength and prevents overexpression of pro-inflammatory interleukin 6 in the hippocampus in an experimental model of cerebral palsy

ABSTRACTObjectives: The aim of this study was thus to evaluate the effect of Cr supplementation on morphological changes and expression of pro-inflammatory cytokines in the hippocampus and on developmental parameters. Methods: Male Wistar rat pups were submitted to an experimental model of CP. Cr was administered via gavage from the 21st to the 28th postnatal day, and in water after the 28th, until the end of the experiment. Body weight (BW), food consumption (FC), muscle strength, and locomotion were evaluated. Expression of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α) were assessed in the hippocampus by quantitative real-time polymerase chain reaction. Iba1 immunoreactivity was assessed by immunocytochemistry in the hippocampal hilus. Results: Experimental CP caused increased density and activation of microglial cells, and overexpression of IL-6. The rats with CP also presented abnormal BW development and impairment of strength and locomotion. Cr supplementation was able to reverse the overexpression of IL-6 in the hippocampus and mitigate the impairments observed in BW, strength, and locomotion. Discussion: Future studies should evaluate other neurobiological characteristics, including changes in neural precursor cells and other cytokines, both pro- and anti-inflammatory.

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.

Motor deficits are associated with increased glial cell activation in the hypothalamus and cerebellum of young rats subjected to cerebral palsy

Cerebral palsy (CP) is a syndrome characterized by a wide range of sensory and motor damage, associated with behavioral and cognitive deficits. The aim of the present study was to investigate the potential of a model of CP using a combination of perinatal anoxia and sensorimotor restriction of hind paws to replicate motor, behavioral and neural deficits. A total of 30 of male Wistar rats were divided into Control (C, n = 15), and CP (CP, n = 15) groups. The potential of the CP model was assessed by evaluating food intake, the behavioral satiety sequence, performance on the CatWalk and parallel bars, muscle strength, and locomotor activity. The weight of the encephalon, soleus, and extensor digitorum longus (EDL) muscles, and the activation of glial cells (microglia and astrocytes) were also measured. The CP animals showed delayed satiety, impaired locomotion on the CatWalk and open field test, reduced muscle strength, and reduced motor coordination. CP also reduced the weight of the soleus and muscles, brain weight, liver weight, and quantity of fat in various parts of the body. There was also found to be an increase in astrocyte and microglia activation in the cerebellum and hypothalamus (arcuate nucleus, ARC) of animals subjected to CP.

Neonatal treatment with resveratrol decreases postural and strength impairments and improves mitochondrial function in the somatosensory cortex rats submitted to cerebral palsy

Cerebral palsy is a neurodevelopmental disease characterized by postural, motor, and cognitive disorders, being one of the main causes of physical and intellectual disability in childhood. To minimize functional impairments, the use of resveratrol as a therapeutic strategy is highlighted due to its neuroprotective and antioxidant effects in different regions of the brain. Thus, this study aimed to investigate the effects of neonatal treatment with resveratrol on postural development, motor function, oxidative balance, and mitochondrial biogenesis in the brain of rats submitted to a cerebral palsy model. Neonatal treatment with resveratrol attenuated deficits in somatic growth, postural development, and muscle strength in rats submitted to cerebral palsy. Related to oxidative balance, resveratrol in cerebral palsy decreased the levels of MDA and carbonyls. Related to mitochondrial biogenesis, was observed in animals with cerebral palsy treated with resveratrol, an increase in mRNA levels of TFAM, in association with the increase of citrate synthase activity. The data demonstrated a promising effect of neonatal resveratrol treatment, improving postural and muscle deficits induced by cerebral palsy. These findings were associated with improvements in oxidative balance and mitochondrial biogenesis in the brain of rats submitted to cerebral palsy.

Neonatal kaempferol exposure attenuates gait and strength deficits and prevents altered muscle phenotype in a rat model of cerebral palsy

Cerebral palsy (CP) is characterized by brain damage at a critical period of development of the central nervous system, and, as a result, motor, behavioural and learning deficits are observed in those affected. Flavonoids such as kaempferol have demonstrated potential anti-inflammatory and neuroprotective properties for neurological disorders. This study aimed to assess the effects of neonatal treatment with kaempferol on the body development, grip strength, gait performance and morphological and biochemical phenotype of skeletal muscle in rats subjected to a model of CP. The groups were formed by randomly allocating male Wistar rats after birth to four groups as follows: C = control treated with vehicle, K = control treated with kaempferol, CP = CP treated with vehicle and CPK = CP treated with kaempferol. The model of CP involved perinatal anoxia and sensorimotor restriction of the hind paws during infancy, from the second to the 28th day of postnatal life. Treatment with kaempferol (1 mg/kg) was performed intraperitoneally during the neonatal period. Body weight and length, muscle strength, gait kinetics and temporal and spatial parameters were evaluated in the offspring. On the 36th day of postnatal life, the animals were euthanized for soleus muscle dissection. The muscle fibre phenotype was assessed using the myofibrillar ATPase technique, and the muscle protein expression was measured using the Western blot technique. A reduction in the impact of CP on body phenotype was observed, and this also attenuated deficits in muscle strength and gait. Treatment also mitigated the impact on muscle phenotype by preventing a reduction in the proportion of oxidative fibres and in the histomorphometric parameters in the soleus muscle of rats in the CP group. The results demonstrate that neonatal treatment with kaempferol attenuated gait deficits and impaired muscle strength and muscle maturation in rats subjected to a model of CP.

Evidence for Quercetin as a Dietary Supplement for the Treatment of Cardio-Metabolic Diseases in Pregnancy: A Review in Rodent Models

Quercetin supplementation during pregnancy and lactation has been linked to a lower risk of maternal cardio-metabolic disorders such as gestational diabetes mellitus (GDM), dyslipidemia, preeclampsia, attenuation of malnutrition-related conditions, and gestational obesity in animal studies. Pre-clinical studies have shown that maternal supplementation with quercetin reduces cardio-metabolic diseases in dams and rodents’ offspring, emphasizing its role in modifying phenotypic plasticity. In this sense, it could be inferred that quercetin administration during pregnancy and lactation is a viable strategy for changing cardio-metabolic parameters throughout life. Epigenetic mechanisms affecting the AMP-activated protein kinase (AMPK), nuclear factor-kappa B (NF-κB), and phosphoinositide 3-kinase (PI3 K) pathways could be associated with these changes. To highlight these discoveries, this review outlines the understanding from animal studies investigations about quercetin supplementation and its capacity to prevent or decrease maternal and offspring cardio-metabolic illnesses and associated comorbidities.

Fibroblast growth factor 19 as a countermeasure to muscle and locomotion dysfunctions in experimental cerebral palsy

BACKGROUND

Cerebral palsy (CP) associates cerebral function damages with strong locomotor defects and premature sarcopenia. We previously showed that fibroblast growth factor 19 (FGF19) exerts hypertrophic effects on skeletal muscle and improves muscle mass and strength in mouse models with muscle atrophy. Facing the lack of therapeutics to treat locomotor dysfunctions in CP, we investigated whether FGF19 treatment could have beneficial effects in an experimental rat model of CP.

METHODS

Cerebral palsy was induced in male Wistar rat pups by perinatal anoxia immediately after birth and by sensorimotor restriction of hind paws maintained until Day 28. Daily subcutaneous injections with recombinant human FGF19 (0.1 mg/kg bw) were performed from Days 22 to 28. Locomotor activity and muscle strength were assessed before and after FGF19 treatment. At Day 29, motor coordination on rotarod and various musculoskeletal parameters (weight of tibia bone and of soleus and extensor digitorum longus (EDL) muscles; area of skeletal muscle fibres) were evaluated. In addition, expression of specific genes linked to human CP was measured in rat skeletal muscles.

RESULTS

Compared to controls, CP rats had reduced locomotion activity (-37.8% of distance travelled, P < 0.05), motor coordination (-88.9% latency of falls on rotarod, P < 0.05) and muscle strength (-25.1%, P < 0.05). These defects were associated with reduction in soleus (-51.5%, P < 0.05) and EDL (-42.5%, P < 0.05) weight, smaller area of muscle fibres, and with lower tibia weight (-38%, P < 0.05). In muscles from rats submitted to CP, changes in the expression levels of several genes related to muscle development and neuromuscular junctions were similar to those found in wrist muscle of children with CP (increased mRNA levels of Igfbp5, Kcnn3, Gdf8, and MyH4 and decreased expression of Myog, Ucp2 and Lpl). Compared with vehicle-treated CP rats, FGF19 administration improved locomotor activity (+53.2%, P < 0.05) and muscle strength (+25.7%, P < 0.05), and increased tibia weight (+13.8%, P < 0.05) and soleus and EDL muscle weight (+28.6% and +27.3%, respectively, P < 0.05). In addition, it reduced a number of very small fibres in both muscles (P < 0.05). Finally, gene expression analyses revealed that FGF19 might counteract the immature state of skeletal muscles induced by CP.

CONCLUSIONS

These results demonstrate that pharmacological intervention with recombinant FGF19 could restore musculoskeletal and locomotor dysfunction in an experimental CP model, suggesting that FGF19 may represent a potential therapeutic strategy to combat the locomotor disorders associated with CP.

Experimental cerebral palsy causes microstructural brain damage in areas associated to motor deficits but no spatial memory impairments in the developing rat

INTRODUCTION

Cerebral palsy (CP) is the major cause of motor and cognitive impairments during childhood. CP can result from direct or indirect structural injury to the developing brain. In this study, we aimed to describe brain damage and behavioural alterations during early adult life in a CP model using the combination of maternal inflammation, perinatal anoxia and postnatal sensorimotor restriction.

METHODS

Pregnant Wistar rats were injected intraperitoneally with 200 µg/kg LPS at embryonic days E18 and E19. Between 3 and 6 h after birth (postnatal day 0 - PND0), pups of both sexes were exposed to anoxia for 20 min. From postnatal day 2 to 21, hindlimbs of animals were immobilized for 16 h daily during their active phase. From PND40, locomotor and cognitive tests were performed using Rota-Rod, Ladder Walking and Morris water Maze. Ex-vivo MRI Diffusion Tensor Imaging (DTI) and Neurite Orientation Dispersion and Density Imaging (NODDI) were used to assess macro and microstructural damage and brain volume alterations induced by the model. Myelination and expression of neuronal, astroglial and microglial markers, as well as apoptotic cell death were evaluated by immunofluorescence.

RESULTS

CP animals showed decreased body weight, deficits in gross (rota-rod) and fine (ladder walking) motor tasks compared to Controls. No cognitive impairments were observed. Ex-vivo MRI showed decreased brain volumes and impaired microstructure in the cingulate gyrus and sensory cortex in CP brains. Histological analysis showed increased cell death, astrocytic reactivity and decreased thickness of the corpus callosum and altered myelination in CP animals. Hindlimb primary motor cortex analysis showed increased apoptosis in CP animals. Despite the increase in NeuN and GFAP, no differences between groups were observed as well as no co-localization with the apoptotic marker. However, an increase in Iba-1+ microglia with co-localization to cleaved caspase 3 was observed.

CONCLUSION

Our results suggest that experimental CP induces long-term brain microstructural alterations in myelinated structures, cell death in the hindlimb primary motor cortex and locomotor impairments. Such new evidence of brain damage could help to better understand CP pathophysiological mechanisms and guide further research for neuroprotective and neurorehabilitative strategies for CP patients.

A systematic review of neurogenesis in animal models of early brain damage: Implications for cerebral palsy

Brain damage during early life is the main factor in the development of cerebral palsy (CP), which is one of the leading neurodevelopmental disorders in childhood. Few studies, however, have focused on the mechanisms of cell proliferation, migration, and differentiation in the brain of individuals with CP. We thus conducted a systematic review of preclinical evidence of structural neurogenesis in early brain damage and the underlying mechanisms involved in the pathogenesis of CP. Studies were obtained from Embase, Pubmed, Scopus, and Web of Science. After screening 2329 studies, 29 studies, covering a total of 751 animals, were included. Prenatal models based on oxygen deprivation, inflammatory response and infection, postnatal models based on oxygen deprivation or hypoxic-ischemia, and intraventricular hemorrhage models showed varying neurogenesis responses according to the nature of the brain damage, the time period during which the brain injury occurred, proliferative capacity, pattern of migration, and differentiation profile in neurogenic niches. Results mainly from rodent studies suggest that prenatal brain damage impacts neurogenesis and curbs generation of neural stem cells, while postnatal models show increased proliferation of neural precursor cells, improper migration, and reduced survival of new neurons.

Early life fluoxetine treatment causes long-term lean phenotype in skeletal muscle of rats exposed to maternal lard-based high-fat diet

There is a concern about early life exposure to Selective Serotonin Reuptake Inhibitors (SSRI) in child development and motor system maturation. Little is known, however, about the interaction of environmental factors, such as maternal nutrition, associated with early exposure to SSRI. The increased maternal consumption of high-fat diets is worrisome and affects serotonin system development with repercussions in body phenotype. This study aimed to assess the short- and long-term effects of neonatal fluoxetine treatment on the body and skeletal muscle phenotype of rats exposed to a maternal lard-based high-fat (H) diet during the perinatal period. A maternal lard-based high-fat diet causes reduced birth weight, a short-term reduction in type IIA fibers in the soleus muscle, and in type IIB fibers in the Extensor Digitorum Longus (EDL) muscle, reducing Lactate Dehydrogenase (LDH) activity in both muscles. In the long-term, the soleus showed reduced muscle weight, smaller area and perimeter of muscle fibers, while the EDL muscle showed reduced Citrate Synthase (CS) activity in offspring from the rats on the maternal lard-based high-fat diet. Early-life exposure to fluoxetine reduced body weight and growth and reduced soleus weight and enzymatic activity in young rats. Exposure to neonatal fluoxetine in adult rats caused a decreased body mass index, less food intake, and reduced muscle weight with reduced CS and LDH activity. Neonatal fluoxetine in young rats exposed to a maternal lard-based high-fat diet caused reduced body weight and growth, reduced soleus weight as well as area and perimeter of type I muscle fibers. In adulthood, there was a reduction in food intake, increased proportion of IIA type fibers, reduced area and perimeter of type IIB, and reduction in levels of CS activity in EDL muscle. Neonatal fluoxetine treatment in rats exposed to a maternal lard-based, high-fat diet induces a reduction in muscle weight, an increase in the proportion of oxidative fibers and greater oxidative enzymatic activity in adulthood.

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.

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.