Sexually dimorphic organization of open field behavior following moderate prenatal alcohol exposure

Unraveling the complex relationship between prenatal alcohol exposure, hippocampal LTP, and learning and memory

Prenatal alcohol exposure (PAE) has been extensively studied for its profound impact on neurodevelopment, synaptic plasticity, and cognitive outcomes. While PAE, particularly at moderate levels, has long-lasting cognitive implications for the exposed individuals, there remains a substantial gap in our understanding of the precise mechanisms underlying these deficits. This review provides a framework for comprehending the neurobiological basis of learning and memory processes that are negatively impacted by PAE. Sex differences, diverse PAE protocols, and the timing of exposure are explored as potential variables influencing the diverse outcomes of PAE on long-term potentiation (LTP). Additionally, potential interventions, both pharmacological and non-pharmacological, are reviewed, offering promising avenues for mitigating the detrimental effects of PAE on cognitive processes. While significant progress has been made, further research is required to enhance our understanding of how prenatal alcohol exposure affects neural plasticity and cognitive functions and to develop effective therapeutic interventions for those impacted. Ultimately, this work aims to advance the comprehension of the consequences of PAE on the brain and cognitive functions.

Impact of two different rodent diets on maternal ethanol consumption, serum ethanol concentration and pregnancy outcome measures

Recent studies report varying levels of ethanol consumption by rodents maintained on different commercially available laboratory diets. As varied ethanol consumption by dams may impact offspring outcome measures in prenatal ethanol exposure paradigms, we compared ethanol consumption by rats maintained on the Envigo 2920 diet, used in our vivarium, with an isocalorically equivalent PicoLab 5L0D diet used in some alcohol consumption studies. Compared to 5L0D diet, female rats maintained on 2920 diet consumed 14% less ethanol during daily 4-h drinking sessions prior to pregnancy and 28% less ethanol during gestation. Rat dams consuming 5L0D diet gained significantly less weight during pregnancy. However, their pup birth weights were significantly higher. A subsequent study revealed that hourly ethanol consumption was not different between diets during the first 2 h, but was significantly lower on 2920 diet at the end of the third and fourth hours. The mean serum ethanol concentration in 5L0D dams after the first 2 h of drinking was 46 mg/dL compared to 25 mg/dL in 2920 dams. Further, ethanol consumption at the 2-h blood sampling time point was more variable in 2920 dams compared to 5L0D dams. An in vitro analysis mixing each powdered diet with 5% ethanol in acidified saline revealed that a 2920 diet suspension adsorbed more aqueous medium than the 5L0D diet suspension. The total ethanol remaining in aqueous supernatant of 5L0D mixtures was nearly twice the amount of ethanol in supernatants of the 2920 mixtures. These results suggest that the 2920 diet expands to a greater extent in aqueous medium than the 5L0D diet. We speculate that increasing adsorption of water and ethanol by the 2920 diet may reduce or delay the amount of ethanol absorbed and may decrease serum ethanol concentration to a greater extent than would be predicted from the amount of ethanol consumed.

Cue polarization and representation in mouse home base behaviors

The nature of the representation guiding spatial navigation has been investigated extensively; however, most of this work has used behavioral tasks that involved learning the location of food reward or an escape platform. In contrast, relatively few studies have focused on the spatial representation of a home base, a ubiquitous feature of open-field behavior, and its ability to be encoded relative to environmental cues. The current set of experiments investigated acquisition and retention of the location of home base establishment. In general, proximal cues anchored the position of the home base during acquisition sessions across all four experiments. Although mice established a home base during retention sessions, previous experience did not influence its position during retention sessions. These observations demonstrate that stimulus control of home base position depends on access to proximal cues. Further work is needed to determine the extent that home base establishment may provide a framework to encode goal-directed spatial behaviors.