Long-term effects of Preweaning environmental impoverishment on neurobehavioral and neurocognitive outcomes in Sprague Dawley rats: An early environmental stress model

Developmental stress, including low socioeconomic status (SES), can induce dysregulation of the hypothalamic-pituitary-adrenal axis and result in long-term changes in stress reactivity. Children in lower SES conditions often experience more stress than those in other SES groups. There are multiple model systems of early environmental stress (EES), one of which is reduced cage bedding. Here we tested the effects of both prenatal and lactational EES in rats on a range of long-term behavioral and cognitive outcomes. There were persistent reductions in body weight in the EES rats in both sexes. The behavioral results showed no effects on learning and memory using tests of spatial learning or cognitive flexibility in the Morris water maze, egocentric learning in the Cincinnati water maze, or working memory in the radial-arm maze. There were no effects on basic open-field activity, elevated zero-maze, or forced swim test, but EES rats had reduced time in the dark side of the light/dark test. When rats were drug challenged in the open-field with d-amphetamine or MK-801, there were no differential responses to d-amphetamine, but the EES group under responded compared with the drug-induced hyperactivity in the control group in both males and females. The objective was to establish a developmental stress model that induced cognitive deficits and to the extent that this method did not cause such effects it was not the model we sought. However, the data showed several long-term effects of EES, including the reduced response to the irreversible NMDA antagonist MK-801. This effect merits further investigation.

The influence of maternal diet on offspring's gut microbiota in early life

BACKGROUND

The influence of maternal diet on offspring's health is an area of study that is linked to epigenetics. Maternal diet contributes to determining the health status of offspring and maternally linked mechanisms and is a global health challenge that requires attention. The impact of gut microbiota on host metabolism and offspring health is still not established.

OBJECTIVE

In this review, we intend to discuss the evidence on the impact of maternal diet and the health of offspring gut microbiota. The paper focuses on the gut microbiome of animal models. It captures the maternal diet and its influence on the offspring's gut microbiota, behavior that is supported by cell experimental results. Both inflammation and immune status of offspring induced by maternal diet are discussed. Finally, this review used predicted biological pathways involved in maternal diet and offspring health, and the influence of maternal diet on gut microbiota and offspring behavior. Obesity, diabetes, asthma and allergies, and neurodegenerative disorders and prospects for maternal diet, and microbiota and offspring health were discussed.

CONCLUSION

The review was able to gather that a high-fat diet during pregnancy created a long-lasting metabolic signature on the infant's innate immune system, altering inflammation in the offspring microbiota, which predisposed offspring to obesity and metabolic diseases in adulthood.

Influence of maternal high-fat diet on offspring's locomotor activity during anxiety-related behavioral tests: A systematic review

The aim of this review was to summarize and discuss the impact of a maternal high-fat diet on the locomotor activity of offspring during anxiety-related behavioral tests. A search was performed in the LILACS, Web of Science, SCOPUS and PUMBED databases, using the following inclusion criteria: studies in which rodent dams were submitted to a high-fat diet during gestation and/or lactation and in which the locomotor activity parameters of offspring were evaluated during an anxiety-related test. Twenty-three articles met these criteria and were included. Most studies, 14 out of 23, found that a maternal high-fat diet did not alter offspring locomotor activity. Six articles found that a maternal high-fat diet increased the locomotor activity of offspring, while three found decreased locomotion. This effect may be associated with the initial response to the test and the fact that it was the first day of exposure to the apparatus.

Maternal immune suppression during pregnancy does not prevent abnormal behavior in offspring

BACKGROUND

Offspring of hypertensive disorders of pregnancy are at an increased risk of developing neurodevelopmental and neurobehavioral disorders compared to offspring from non-affected pregnancies. Using rodent models of Preeclampsia (PreE; new onset of hypertension after 20 weeks gestation) and HELLP (hemolysis, elevated liver enzymes, and low platelets), we studied the behavioral outcome of their offspring in adolescence.

METHODS

A subset of dams received Orencia, a T-cell activation inhibitor, as T cells have been associated with the induction of hypertension and inflammation during pregnancy. We hypothesized that offspring from hypertensive dams would experience adverse behavioral outcomes in social, cognitive, locomotor, and anxiety tests, and offspring from dams treated with Orencia would demonstrate less adverse behaviors.

RESULTS

Male offspring of PreE + Orencia dams (p < 0.05) and female offspring from HELLP + Orencia dams (p < 0.05) spent more time playing compared to normal pregnant offspring. All offspring from hypertensive and Orencia-treated dams performed worse on the Barnes Maze test compared to normal pregnant. We also measured adult (postnatal day > 60) myelin basic protein (MBP) and NeuN expression in both the prefrontal cortex and hippocampus. In the hippocampus and prefrontal cortex, there was no difference in expression of either MBP or NeuN in all groups regardless of sex.

CONCLUSION

The results from this study suggest that offspring of hypertensive disorders of pregnancy have behavioral changes, specifically cognitive differences. This study has shown that there is a sex dependent difference in offspring neurobehavioral development, influenced in part by the type of hypertensive disorder of pregnancy, and alterations in the maternal immune system.

Preeclampsia as a possible risk factor for memory impairment, anxiety- and depressive-like behavior in offspring

RATIONALE

Preeclampsia is a condition that can affect the health in offspring at adult life. The effect on several systems has been described, but less is known about its effect on neuropsychiatric disorders at early ages.

OBJECTIVE

Evaluate the possible relationship of preeclampsia with development of anxiety- and depressive-like behavior, as well as memory impairments in male and female early adolescent offspring from preeclamptic mice.

METHODS

Thirty pregnant females were divided into control group receiving vehicle, and preeclampsia group receiving L-NAME in drinking water at a dose of 60 mg/Kg from day 10 of pregnancy until delivery. Offspring was weaned and sexed at 4 weeks after birth. Each group was evaluated using the elevated plus maze test (anxiety- like response), tail suspension test (depressive-like behavior) and the recognition of novel objects test (recognition memory), in addition to the open field test was performance to corroborate their motor activity and validate our results.

RESULTS

We found that preeclampsia produces behavioral alterations in offspring, and this effect is dependent on sex. The male offspring from preeclampsia showed an enhancement in the time that mice spend in the close arms in the elevated plus maze test, and longer immobility time in the tail suspension test, compared to the offspring from healthy pregnancies. On the other hand, female offspring from preeclampsia showed a lower percentage of recognition in the memory test compared to offspring from normal pregnancy.

CONCLUSIONS

These results suggest that preeclampsia predisposes early adolescent young male offspring to develop anxiety- and depressive-like behavior as well as memory impairment in early adolescent young female offspring.

Effects of maternal mild hyperglycemia associated with snack intake on offspring metabolism and behavior across the lifespan

The increasing prevalence of diabetes is of particular concern in women of childbearing age because of the short and long-term consequences of maternal diabetes for the health of the offspring, such as a greater risk of developing metabolic impairments and cognitive deficits. In addition, maternal diet during pregnancy and lactation might contribute to preventing or ameliorating adverse offspring outcomes. Recently, we described that access to snacks exacerbates glucose intolerance in mildly hyperglycemic pregnant dams. Therefore, we hypothesized that these offspring would show greater impairment in metabolic and behavioral outcomes across the lifespan. Neonatal STZ treatment was employed to induce maternal mild hyperglycemia in females. After mating, normo- and hyperglycemic dams were given access either to standard chow or standard show plus snacks. Male and female offspring were evaluated on postnatal days (PND) 30, 90, and 360. Offspring behavior was assessed in the marble burying task, the open-field test, the elevated-plus maze, and sucrose preference. Glucose tolerance and morphometric analyses were also carried out. Maternal hyperglycemia increased body weight and fat deposition only on PND 30, while retroperitoneal fat deposition was reduced in the offspring of snack-fed dams. However, maternal snack intake reduced offspring body weight and length on PND 90. Fasting glucose was increased in females born to hyperglycemic, snack-fed dams on PND 90. Glucose clearance was altered by both maternal conditions in male offspring on PND 30, however, this sex difference was reversed on PND 90, with maternal hyperglycemia impairing glucose clearance only in females. In addition, maternal hyperglycemia reduced anxiety-like behavior in female offspring on PND 30, especially in the offspring of snack-fed dams, while maternal snack intake reduced sucrose preference in both males and females in adulthood. These results suggest that the effects of maternal hyperglycemia during pregnancy and lactation on offspring outcomes were not exacerbated by snack intake. Although additive effects of the two maternal conditions were hypothesized, the absence of such effects could be related to the mild maternal hyperglycemia induced by STZ treatment even when combined with snack intake. While maternal hyperglycemia alone impaired some offspring outcomes, its association with snack intake did not aggravate those impairments but rather resulted in outcomes more similar to those of offspring born to normoglycemic dams. Finally, females were found to be more susceptible to both the effects of maternal hyperglycemia and snack intake on metabolism and behavior.

Distinct alterations in motor & reward seeking behavior are dependent on the gestational age of exposure to LPS-induced maternal immune activation

The dopaminergic system is involved in motivation, reward and the associated motor activities. Mesodiencephalic dopaminergic neurons in the ventral tegmental area (VTA) regulate motivation and reward, whereas those in the substantia nigra (SN) are essential for motor control. Defective VTA dopaminergic transmission has been implicated in schizophrenia, drug addiction and depression whereas dopaminergic neurons in the SN are lost in Parkinson's disease. Maternal immune activation (MIA) leading to in utero inflammation has been proposed to be a risk factor for these disorders, yet it is unclear how this stimulus can lead to the diverse disturbances in dopaminergic-driven behaviors that emerge at different stages of life in affected offspring. Here we report that gestational age is a critical determinant of the subsequent alterations in dopaminergic-driven behavior in rat offspring exposed to lipopolysaccharide (LPS)-induced MIA. Behavioral analysis revealed that MIA on gestational day 16 but not gestational day 12 resulted in biphasic impairments in motor behavior. Specifically, motor impairments were evident in early life, which were resolved by adolescence, but subsequently re-emerged in adulthood. In contrast, reward seeking behaviors were altered in offspring exposed MIA on gestational day 12. These changes were not due to a loss of dopaminergic neurons per se in the postnatal period, suggesting that they reflect functional changes in dopaminergic systems. This highlights that gestational age may be a key determinant of how MIA leads to distinct alterations in dopaminergic-driven behavior across the lifespan of affected offspring.