Coping with the experience of frustration throughout life: Sex- and age-specific effects of early life stress on the susceptibility to reward devaluation.

Early life stress may lead to lifelong impairments in psychophysiological functions, including emotional and reward systems. Unpredicted decrease in reward magnitude generates a negative emotional state (frustration) that may be involved with susceptibility to psychiatric disorders. We evaluated, in adolescents and adult rats of both sexes, whether maternal separation (MS) alters the ability to cope with an unexpected reduction of reward later in life.

Acrobatic training prevents learning impairments and astrocyte remodeling in the hippocampus of rats undergoing chronic cerebral hypoperfusion: sex-specific benefits.

Background: Chronic cerebral hypoperfusion (CCH) leads to memory and learning impairments associated with degeneration and gliosis in the hippocampus. Treatment with physical exercise carries different therapeutic benefits for each sex. We investigated the effects of acrobatic training on astrocyte remodeling in the CA1 and CA3 subfields of the hippocampus and spatial memory impairment in male and female rats at different stages of the two-vessel occlusion (2VO) model.

Routine regularity during a global pandemic: Impact on mental health outcomes and influence of chronotype.

Among the public health recommendations for supporting mental health during the COVID-19 pandemic, many strategies had an impact on biological rhythms, like sleep hygiene, physical exercise and healthy eating habits. Considering the known relationship between circadian organization and mental health, our aim was to test the association between behavioral regularity and mental health, and its interaction with chronotype, in a large sample surveyed in Brazil. We collected longitudinal data using online questionnaires that assessed sociodemographic characteristics, behavioral routines, mental health (PHQ-9, GAD-7, WHO-5 scales), and chronotype estimation based on midpoint of sleep on free days - MSF (μMCTQ), in a sample of 1390 participants (81% females).

Aversive memory reactivation: A possible role for delta oscillations in the hippocampus-amygdala circuit.

Memory labilization, the process by which memories become susceptible to update, is essential for memory reconsolidation and has been a target for novel therapies for traumatic memory-associated disorders. Maternal separation (MS) in male rats produced memories resistant to labilization in adulthood. Based on previous results, we hypothesized that temporal desynchronization between the dorsal hippocampus (DHc) and the basolateral amygdala (BLA), during memory retrieval, could be responsible for this impairment.

Absence-like Seizures, Cortical Oscillations Abnormalities and Decreased Anxiety-like Behavior in Wistar Audiogenic Rats with Cortical Microgyria.

Wistar Audiogenic Rats (WAR) is an inbred rodent strain susceptible to acute auditory stimulation-induced seizures. However, spontaneous epileptic seizures (SES) and their associated electroencephalogram (EEG) abnormalities have not been reported in WAR kindled animals. The same is true for naïve WARs (without sound-induced seizures).

Effects of acrobatic training on spatial memory and astrocytic scar in CA1 subfield of hippocampus after chronic cerebral hypoperfusion in male and female rats.

Chronic cerebral hypoperfusion leads to neuronal loss in the hippocampus and spatial memory impairments. Physical exercise is known to prevent cognitive deficits in animal models; and there is evidence of sex differences in behavioral neuroprotective approaches. The aim of present study was to investigate the effects of acrobatic training in male and female rats submitted to chronic cerebral hypoperfusion.

Effects of Early Life Adversities upon Memory Processes and Cognition in Rodent Models.

Exposure to stressors in early postnatal life induces long-lasting modifications in brain function. This plasticity, an essential characteristic of the brain that enables adaptation to the environment, may also induce impairments in some psychophysiological functions, including learning and memory. Early life stress (ELS) has long-term effects on the hypothalamic-pituitary-adrenal axis response to stressors, and has been reported to lead to neuroinflammation, altered levels of neurotrophic factors, modifications in neurogenesis and synaptic plasticity, with changes in neurotransmitter systems and network functioning.

Olive oil-rich diet during pregnancy/lactation attenuated the early life stress effects on depressive-like behavior and altered energy metabolism in the dorsal hippocampus in a sex-specific manner.

Methods: Pregnant Wistar rats received diets enriched in soybean oil (SO) or OO during gestation/lactation. At birth, litters were subdivided into MS or intact groups. After weaning, the pups received standard chow until adulthood, when they were subjected to behavioral tasks.

Effects of acute seizures on cell proliferation, synaptic plasticity and long-term behavior in adult zebrafish.

Acute seizures may cause permanent brain damage depending on the severity. The pilocarpine animal model has been broadly used to study the acute effects of seizures on neurogenesis and plasticity processes and the resulting epileptogenesis. Likewise, zebrafish is a good model to study neurogenesis and plasticity processes even in adulthood.

Pre- and early postnatal enriched environmental experiences prevent neonatal hypoxia-ischemia late neurodegeneration via metabolic and neuroplastic mechanisms.

Prenatal and early postnatal periods are important for brain development and neural function. Neonatal insults such as hypoxia-ischemia (HI) causes prolonged neural and metabolic dysregulation, affecting central nervous system maturation. There is evidence that brain hypometabolism could increase the risk of adult-onset neurodegenerative diseases.

Consumption of a palatable diet rich in simple sugars during development impairs memory of different degrees of emotionality and changes hippocampal plasticity according to the age of the rats.

We investigated the effect of a chronic palatable diet rich in simple sugars on memory of different degrees of emotionality in male adult rats, and on hippocampal plasticity markers in different stages of development. On postnatal day (PND) 21, 45 male Wistar rats were divided in two groups, according to their diet: (1-Control) receiving standard lab chow or (2-Palatable Diet) receiving both standard chow plus palatable diet ad libitum. At PND 60, behavioral tests were performed to investigate memory in distinct tasks.

Neurometabolic effects of sweetened solution intake during adolescence related to depressive-like phenotype in rats.

Objective: Exposure to artificial sweeteners, such as aspartame, during childhood and adolescence has been increasing in recent years. However, the safe use of aspartame has been questioned owing to its potentially harmful effects on the developing brain. The aim of this study was to test whether the chronic consumption of aspartame during adolescence leads to a depressive-like phenotype and to investigate the possible mechanisms underlying these behavioral changes.

Resilience and Vulnerability to Trauma: Early Life Interventions Modulate Aversive Memory Reconsolidation in the Dorsal Hippocampus.

Early life experiences program lifelong responses to stress. In agreement, resilience and vulnerability to psychopathologies, such as posttraumatic stress disorder (PTSD), have been suggested to depend on the early background. New therapies have targeted memory reconsolidation as a strategy to modify the emotional valence of traumatic memories.

Neonatal handling impairs intradimensional shift and alters plasticity markers in the medial prefrontal cortex of adult rats.

Stress response can be modulated by neonatal/childhood events. Neonatal handling (NH) is an animal model in which the animals are subjected to brief separations from the dam during the first days of life, and it leads to lower emotionality and behavioral changes in adulthood. The aim of this study was to observe if early events, such as (NH), may program associative learning and behavioral flexibility in adult male rats and if these changes could be related to altered neurochemistry in the medial prefrontal cortex (mPFC).

Swimming exercise before and during pregnancy: Promising preventive approach to impact offspring´s health.

Several environmental factors affect child development, such as the intrauterine environment during the embryonic and fetal development and early postnatal environment provided by maternal behavior. Although mechanistic effects of maternal exercise on offspring health improvement are not yet completely understood, the number of reports published demonstrating the positive influence of maternal exercise have increase. Herein, we addressed issues related to early postnatal environment provided by maternal behavior and early developmental physical landmarks, sensorimotor reflexes, and motor movements ontogeny.

Short post-weaning social isolation induces long-term changes in the dopaminergic system and increases susceptibility to psychostimulants in female rats.

Childhood and adolescence are sensitive periods of development, marked by high brain maturation and plasticity. Exposure to early life stress, such as social isolation, is able to prompt changes in sensitive brain circuitries, essentially in the mesolimbic dopaminergic system and increase the risk for addictive behaviors later in life. Post-weaning social isolation can stimulate the consumption of rewarding substances, like drugs of abuse and palatable foods.

Neonatal interventions differently affect maternal care quality and have sexually dimorphic developmental effects on corticosterone secretion.

Neonatal handling (H) and maternal separation (MS) both induce changes in maternal care, but the contribution of these changes to the behavioral and neurochemical outcomes of the offspring remains unclear, as studies often find opposite results concerning the frequency of maternal behaviors, particularly in the MS paradigm. In this study, behavior displayed by H, MS and non-handled (NH) Wistar rat dams were observed during the first 10days after birth. A tentative assessment of the quality of maternal care was made, using a previously reported score that reflects behavior fragmentation and inconsistency.

Neonatal handling causes impulsive behavior and decreased pharmacological response to methylphenidate in male adult wistar rats.

Neonatal handling has an impact on adult behavior of experimental animals and is associated with rapid and increased palatable food ingestion, impaired behavioral flexibility, and fearless behavior to novel environments. These symptoms are characteristic features of impulsive trait, being controlled by the medial prefrontal cortex (mPFC). Impulsive behavior is a key component of many psychiatric disorders such as attention deficit hyperactivity disorder (ADHD), manic behavior, and schizophrenia.

Mitochondrial and Oxidative Stress Aspects in Hippocampus of Rats Submitted to Dietary n-3 Polyunsaturated Fatty Acid Deficiency After Exposure to Early Stress.

Chronic dietary long-chain polyunsaturated fatty acids (PUFAs) deficiency may lead to changes in cortex and hippocampus neuronal membrane phospholipids, and may be linked to impaired central nervous system function. Particularly docosahexaenoic acid deficiency appears to be involved in neuropsychiatric disorders. On the other hand, adverse events early in life may also profoundly affect brain development, leading to long-lasting effects on neurophysiology, neurobiology and behavior.

Contextual fear conditioning in maternal separated rats: the amygdala as a site for alterations.

The first 2 weeks of life are a critical period for neural development in rats. Repeated long-term separation from the dam is considered to be one of the most potent stressors to which rat pups can be exposed, and permanently modifies neurobiological and behavioral parameters. Prolonged periods of maternal separation (MS) usually increase stress reactivity during adulthood, and enhance anxiety-like behavior.