Taste recognition memory is evident in rodents because the initial neophobia to novel tastes attenuates across exposures as the taste becomes familiar and safe. This attenuation of taste neophobia ...(AN) is context-dependent and an auditory background change could induce the recovery of the neophobic response. The AN auditory context-dependency requires the hippocampal integrity but the neurochemical mechanisms underlying the interaction with the taste memory circuit remain unexplored. We have applied pharmacological intervention by 6-hidroxydopamine (6-OHDA) hippocampal lesion for assessing the role of catecholamines in the hippocampal system to Wistar rats that drank a novel 3% vinegar solution for several consecutive days. Additionally, we manipulated the auditory background as a context that could either change or remain constant across all the drinking sessions. We found that a disruption of the context-dependent AN was induced by intracerebral administration of 6-OHDA targeted to the ventral CA1 hippocampus (vCA1). We conclude that the ability of the auditory context to modulate taste recognition memory involves the catecholaminergic activity in the ventral hippocampal circuit for the proper acquisition of safe taste memory.
Adolescent binge alcohol drinking is a serious health concern contributing to adult alcohol abuse often associated with anxiety disorders. We have used adolescent intermittent ethanol (AIE) ...administration as a model of binge drinking in rats in order to explore its long-term effect on the basolateral amygdala (BLA) responsiveness to alcohol and anxiety-like behavior. AIE increased the number of BLA c-Fos positive cells in adult Wistar rats and anxiety-like behavior assessed by the open field test (OFT). Additionally, in adult female rats receiving AIE BLA over expression of miR-182 was found. Therefore, our results indicate that alcohol consumption during adolescence can lead to enduring changes in anxiety-like behavior and BLA susceptibility to alcohol that may be mediated by sex-dependent epigenetic changes. These results contribute to understanding the mechanisms involved in the development of alcohol use disorders (AUD) and anxiety-related disorders.
•Adolescent alcohol exposure leads to heightened BLA activation in adulthood, suggesting increased sensitivity to alcohol.•AIE results in elevated anxiety-related behavior in adulthood, possibly mediated by BLA hyperactivation.•Female rats exposed to AIE exhibit overexpression of miR-182 in the BLA.•Dysregulation of miR-182 in the BLA during AIE may contribute to long-term alterations in brain function and behavior.
Previous work on the effect of aging on spontaneous object recognition (SOR) memory tasks in rats has yielded controversial results. Although the results at long-retention intervals are consistent, ...conflicting results have been reported at shorter delays. We have assessed the potential relevance of the type of object used in the performance of aged rats in SOR tasks. Using standard objects, 24-mo-old rats did not exhibit retention impairment at a 1-h delay. At this retention interval no differences between young and old rats were found in a high-similarity SOR task, but aged rats exhibited deficits when clearly different complex forms were applied.
We have investigated the effect of protein kinase Mzeta (PKMzeta) inhibition in the basolateral amygdala (BLA) upon the retention of a nonspatial learned active avoidance response and conditioned ...taste-aversion (CTA) acquisition in rats. ZIP (10 nmol/muL) injected into the BLA 24 h after training impaired retention of a learned avoidance-jumping response assessed 7 d later when compared with control groups injected with scrambled-ZIP. Nevertheless, a retraining session applied 24 h later indicated no differences between the groups. Additionally, a similar ZIP injection into the BLA during the conditioned stimulus-unconditioned stimulus (CS-US) interval attenuated CTA acquisition. These findings support the BLA PKMzeta role in various forms of memory.
Gut microbiota has been linked to infant neurodevelopment. Here, an association between infant composite cognition and gut microbiota composition is established as soon as 6 months. Higher diversity ...and evenness characterize microbial communities of infants with composite cognition above (Inf-aboveCC) versus below (Inf-belowCC) median values. Metaproteomic and metabolomic analyses establish an association between microbial histidine ammonia lyase and infant histidine metabolome with cognition. Fecal transplantation from Inf-aboveCC versus Inf-belowCC donors into germ-free mice shows that memory, assessed by a novel object recognition test, is a transmissible trait. Furthermore, Inf-aboveCC mice are enriched in species belonging to Phocaeicola, as well as Bacteroides and Bifidobacterium, previously linked to cognition. Finally, Inf-aboveCC mice show lower fecal histidine and urocanate:histidine and urocanate:glutamate ratios in the perirhinal cortex compared to Inf-belowCC mice. Overall, these findings reveal a causative role of gut microbiota on infant cognition, pointing at the modulation of histidine metabolite levels as a potential underlying mechanism.
•LHb lesions delayed consummatory extinction in a task with sucrose as reward.•LHb lesions delayed instrumental extinction in a task with food pellets as reward.•LHb lesions did not affect ethanol ...consumption in a 2 h preference test (2%–24%).•LHb lesions did not affect ethanol consumption in a 24 h preference test (24%).
This study analyzed the effects of LHb lesions on appetitive extinction and alcohol consumption. Eighteen male Wistar rats received neurochemical lesions of the LHb (quinolinic acid) and 12 received a vehicle infusion (PBS). In a runway instrumental task, rats received acquisition (12 pellets/trial, 6 trials/session, 10 sessions) and extinction training (5 sessions). In a consummatory task, rats had daily access to 32% sucrose (5 min, 10 sessions) followed by access to water (5 sessions). Then, animals received 2 h preference tests with escalating alcohol concentrations (2%–24%), followed by two 24 h preference tests with 24% alcohol. Relative to Shams, LHb lesions delayed extinction, as indicated by lower response latencies (instrumental task) and higher fluid consumption (consummatory task). LHb lesions did not affect alcohol consumption regardless of alcohol concentration or test duration. The LHb modulates appetitive extinction and needs to be considered as part of the brain circuit underlying reward loss.
BACKGROUNDAdolescence in mammals is a period marked by increased novelty-seeking and enhanced responsiveness to the stressful properties of novel stimuli. Despite the need to taste potentially toxic ...novel foods during the adolescent growth spurt, there has been little study of taste neophobia and its attenuation.METHODFour experiments were carried out to compare taste neophobia and related memory processes in male and female adolescent (PND28) and adult (PND70) Wistar rats. Experiments 1 and 2 evaluated attenuation of taste neophobia to cider vinegar (3%) and sodium saccharin (0.1%) solutions were evaluated. Additionally, to test the role of memory in neophobia during adolescence, latent inhibition of taste aversion and object recognition memory were assessed in Experiment 3 and Experiment 4, respectively.RESULTSAdolescent and adult rats exhibited taste neophobia to the saccharin solution but adolescent rats required more exposure trials than adults to recognize the vinegar solution as safe. Both groups exhibited similar latent inhibition of taste aversion and object recognition memory. No sex effect was significant.CONCLUSIONSContrary to the accepted view associating adolescence with reduced neophobia, adolescent rats exhibited taste neophobia which even increased when sour tastes were encountered.
•Providing only explicit choice may increase young children’s vegetable intake.•Sensory specific satiation has no effect on young children’s vegetable consumption.•Context familiarity might be ...crucial for unveiling the choice-effect.
One hundred and fifty children between 4 and 6years old were studied to examine the effect of providing them with a choice of vegetables on their vegetable consumption. Offering vegetable choice was expected to increase the children’s vegetable intake due to increased personal autonomy. The option for the children to choose the vegetables to ingest was varied across three different conditions. Within the discrete choice condition (DCC), children could choose the target vegetable at the beginning of the meal; within the continued discrete choice plus variety condition (CDCP), children were exposed to a variety of vegetables (zucchini and green beans), so that they could choose the target vegetable whenever they made a bite during the whole meal. Within the no-choice condition (NCC), children were alternately exposed to only one kind of vegetable, so that no choice possibility was provided. The choice conditions (CDCP and DCC) were associated with higher vegetable intake, in comparison to the no-choice control condition (NCC). No significant differences were found between the DCC and the CDCP regarding participants’ total vegetable intake. These results demonstrate the enhancing effect of providing choice to increase vegetable intake in young children. A higher degree of personal control and consequent level of intrinsic motivation is hypothesized to underlie the effect of choice availability.
Choline is an essential nutrient that plays a role in the synthesis of the phospholipid membrane, critical for cell functions, and it is the major source of methyl donors relevant for epigenetic ...modifications of the genome ....
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