A maternal low-protein diet results in sex-specific differences in synaptophysin expression and milk fatty acid profiles in neonatal rats.

The developmental origins of health and disease hypothesis have highlighted the link between early life environment and long-term health outcomes in offspring. For example, maternal protein restriction during pregnancy and lactation can result in adverse metabolic and cognitive outcomes in offspring postnatal. Hence, in the present study, we assess whether an isocaloric low-protein diet (ILPD) affects the fatty acid profile in breast milk, the hippocampal synaptophysin (Syn) ratio, and the oxidative stress markers in the neonatal stage of male and female offspring.

Involvement of kinases in memory consolidation of inhibitory avoidance training.

The inhibitory avoidance (IA) task is a paradigm widely used to investigate the molecular and cellular mechanisms involved in the formation of long-term memory of aversive experiences. In this review, we discuss studies on different brain structures in rats associated with memory consolidation, such as the hippocampus, striatum, and amygdala, as well as some cortical areas, including the insular, cingulate, entorhinal, parietal and prefrontal cortex. These studies have shown that IA training triggers the release of neurotransmitters, hormones, growth factors, etc.

Intense training prevents the amnestic effect of inactivation of dorsomedial striatum and induces high resistance to extinction.

A large body of evidence has shown that treatments that interfere with memory consolidation become ineffective when animals are subjected to an intense learning experience; this effect has been observed after systemic and local administration of amnestic drugs into several brain areas, including the striatum. However, the effects of amnestic treatments on the process of extinction after intense training have not been studied. Previous research demonstrated increased spinogenesis in the dorsomedial striatum, but not in the dorsolateral striatum after intense training, indicating that the dorsomedial striatum is involved in the protective effect of intense training.

Steering the Microbiota-Gut-Brain Axis by Antibiotics to Model Neuro-Immune-Endocrine Disorders.

Background: Over the last century, animal models have been employed to study the gut-brain axis and its relationship with physiological processes, including those necessary for survival, such as food intake and thermoregulation; those involved in diseases, ranging from inflammation to obesity; and those concerning the development of neurodegenerative diseases and neuropsychiatric disorders, such as Alzheimer's disease and autism spectrum disorder, respectively.

Summary: The gut microbiota has been recognized in the last decade as an essential functional component of this axis. Many reports demonstrate that the gut microbiota influences the development of a vast array of physiological processes.

Hepatocyte ballooning and steatosis in early and late gestation without liver malfunction: Effects of low protein/high carbohydrate diet.

Pregnancy is a challenging metabolic and physiological condition. The aim of this study was to include a second demanding situation as a low protein/high carbohydrate diet (LPHCD) to characterize the histological and functional responses of the maternal liver. It is unknown how the maternal liver responds during early and late pregnancy to LPHCD intake.

Intense inhibitory avoidance training increases nuclear-phosphorylated glucocorticoid receptors in neurons of CA1 of hippocampus and ventral caudate putamen.

Corticosterone (CORT), the principal glucocorticoid in rodents, is released after stressful experiences such as training with high foot-shock intensities in the inhibitory avoidance task (IA). CORT reaches the glucocorticoid receptor (GR) located in almost all brain cells; the GR is subsequently phosphorylated at serine 232 (pGRser232). This has been reported as an indicator of ligand-dependent activation of the GR, as well as a requirement for its translocation into the nucleus for its transcription factor activity.

Dynamics of Dendritic Spines in Dorsal Striatum after Retrieval of Moderate and Strong Inhibitory Avoidance Learning.

In marked contrast to the ample literature showing that the dorsal striatum is engaged in memory consolidation, little is known about its involvement in memory retrieval. Recent findings demonstrated significant increments in dendritic spine density and mushroom spine counts in dorsal striatum after memory consolidation of moderate inhibitory avoidance (IA) training; further increments were found after strong training. Here, we provide evidence that in this region spine counts were also increased as a consequence of retrieval of moderate IA training, and even higher mushroom spine counts after retrieval of strong training; by contrast, there were fewer thin spines after retrieval.

Imbalance in cerebral protein homeostasis: Effects on memory consolidation.

The long-standing hypothesis that memory consolidation is dependent upon de novo protein synthesis is based primarily on the amnestic effects of systemic administration of protein synthesis inhibitors (PSIs). Early experiments on mice showed that PSIs produced interference with memory consolidation that was dependent on the doses of PSIs, on the interval between drug injection and training, and, importantly, on the degree and duration of protein synthesis inhibition in the brain. Surprisingly, there is a conspicuous lack of information regarding the relationship between the duration of protein synthesis inhibition produced by PSIs and memory consolidation in the rat, one of the species most widely used to study memory processes.

Morris water maze overtraining increases the density of thorny excrescences in the basal dendrites of CA3 pyramidal neurons.

The hippocampus plays a fundamental role in spatial learning and memory. Dentate gyrus (DG) granular neurons project mainly to proximal apical dendrites of neurons in the CA3 stratum lucidum and also, to some extent, to the basal dendrites of CA3 pyramidal cells in the stratum oriens. The terminal specializations of DG neurons are the mossy fibers (MF), and these huge axon terminals show expansion in the CA3 stratum oriens after the animals undergo overtraining in the Morris Water Maze task (MWM).

Inhibition of transcription and translation in dorsal hippocampus does not interfere with consolidation of memory of intense training.

Findings of several experiments indicate that many treatments that typically interfere with memory consolidation are ineffective in preventing or attenuating memory induced by intense training. As extensive evidence suggests that the consolidation of newly acquired memories requires gene expression and de novo protein synthesis the present study investigated whether intense training prevents consolidation impairment induced by blockers of mRNA and protein synthesis. Rats were given a single inhibitory training trial using a moderate (1.

Effects of anisomycin infusions into the dorsal striatum on memory consolidation of intense training and neurotransmitter activity.

The most influential hypothesis about the neurobiological basis of memory consolidation posits that this process is dependent upon de novo protein synthesis. Strong support for this proposition has been provided by a multitude of experiments showing that protein synthesis inhibitors (PSIs) interfere with consolidation. However, this hypothesis has been challenged by the results of studies showing that PSIs also produce a host of side effects that, by themselves, could account for their amnestic effects.

Inhibition of transcription and translation in the striatum after memory reactivation: Lack of evidence of reconsolidation.

It has been found that interference with neural activity after a consolidated memory is retrieved produces an amnestic state; this has been taken has indicative of destabilization of the memory trace that would have been produced by a process of reconsolidation (allowing for maintenance of the original trace). However, a growing body of evidence shows that this is not a reliable effect, and that it is dependent upon some experimental conditions, such as the age of the memory, memory reactivation procedures, the predictability of the reactivation stimulus, and strength of training. In some instances, where post-retrieval treatments induce a retention deficit (which would be suggestive of interference with reconsolidation), memory is rescued by simple passing of time or by repeated retention tests.

Mushroom spine dynamics in medium spiny neurons of dorsal striatum associated with memory of moderate and intense training.

A growing body of evidence indicates that treatments that typically impair memory consolidation become ineffective when animals are given intense training. This effect has been obtained by treatments interfering with the neural activity of several brain structures, including the dorsal striatum. The mechanisms that mediate this phenomenon are unknown.

Differential effects of spaced vs. massed training in long-term object-identity and object-location recognition memory.

Here we tested whether the well-known superiority of spaced training over massed training is equally evident in both object identity and object location recognition memory. We trained animals with objects placed in a variable or in a fixed location to produce a location-independent object identity memory or a location-dependent object representation. The training consisted of 5 trials that occurred either on one day (Massed) or over the course of 5 consecutive days (Spaced).

When are new hippocampal neurons, born in the adult brain, integrated into the network that processes spatial information?

Adult-born neurons in the dentate gyrus (DG) functionally integrate into the behaviorally relevant hippocampal networks, showing a specific Arc-expression response to spatial exploration when mature. However, it is not clear when, during the 4- to 6-week interval that is critical for survival and maturation of these neurons, this specific response develops. Therefore, we characterized Arc expression after spatial exploration or cage control conditions in adult-born neurons from rats that were injected with BrdU on one day and were sacrificed 1, 7, 15, 30, and 45 days post-BrdU injection (PBI).