Memory retrieval involves recalling previously consolidated information, while memory extinction refers to the gradual weakening of such memories after recall. Stress and glucocorticoids influence the retrieval and extinction of memory. This study employed a passive avoidance task to examine the impact of acute mild stress and equivalent doses of exogenous corticosterone on fear memory retrieval and extinction in male mice.
View Article and Find Full Text PDFPurpose: The infralimbic (IL) subregion of the medial prefrontal cortex (mPFC) regulates the extinction of conditioned fear memory. Glucocorticoid and gamma-aminobutyric acid (GABA) receptors are expressed in the mPFC and are also critical in fear extinction. This study investigated the possible interactive effects of the glucocorticoids and GABAergic system in the IL on the regulation of fear extinction.
View Article and Find Full Text PDFConsuming coffee, a widely enjoyed beverage with caffeine, can impact the central nervous system and disturb sleep if taken too close to bedtime. Caffeine impacts sleep by slowing the onset, blocking adenosine receptors, lowering deep sleep levels, disrupting sleep patterns, and lessening rapid eye movement sleep. Although coffee can help with alertness in the morning, it may disturb sleep in the evening, particularly for individuals who are sensitive to caffeine.
View Article and Find Full Text PDFA widely consumed beverage, coffee has emerged as a potential protective natural agent against neurodegenerative diseases. This chapter explores the intricate mechanisms by which coffee and its bioactive compounds exert neuroprotective effects. The antioxidant properties of coffee polyphenols, such as chlorogenic acid and caffeic acid, mitigate oxidative stress and neuroinflammation.
View Article and Find Full Text PDFThis chapter thoroughly examines coffee's impact on cognitive function. It synthesizes research findings involving animals and humans, investigating coffee's influence on various memory and cognitive aspects, including short-term/working memory, long-term memory, attention, vigilance, executive functions, and processing speed. The chapter also discusses moderating factors, such as dose-response relationships, individual differences, age, and habitual consumption patterns, that influence the cognitive effects of coffee.
View Article and Find Full Text PDFCaffeine, the main psychoactive component in coffee, has garnered significant attention for its potential impact on the most prevalent mental health conditions like anxiety and depression. This chapter comprehensively examines the neurobiological effects of caffeine, its influence on anxiety and depression, and relevant clinical studies. Caffeine exerts its psychostimulant effects primarily through antagonizing adenosine receptors, modulating neurotransmitter systems, and influencing intracellular calcium signaling in the brain.
View Article and Find Full Text PDFPurpose: Levothyroxine (LEV) monotherapy cannot completely improve cognitive and behavioral impairments induced by hypothyroidism, whereas a combination therapy of exercise and LEV may ameliorate these deficits. This study aimed to determine the effects of mild-intensity forced exercise and LEV treatment on the anxiety profile and cognitive functions in male offspring of hypothyroid dams.
Method: Twenty-four female rats (mothers) were randomly divided into sham (healthy) and hypothyroidism groups and then placed with male rats to mate.
The neuropeptide relaxin-3 and its cognate receptor, relaxin family peptide-3 receptors (RXFP3), have been implicated in modulating learning and memory processes, but their specific roles remain unclear. This study utilized behavioral and molecular approaches to investigate the effects of putatively reversible blockade of RXFP3 in the ventral dentate gyrus (vDG) of the hippocampus on spatial and fear memory formation in rats. Male Wistar rats received bilateral vDG cannula implantation and injections of the RXFP3 antagonist, R3(BΔ23-27)R/I5 (400 ng/0.
View Article and Find Full Text PDFDyslipidemia poses a significant risk to cardiovascular health in both diabetic and non-diabetic individuals. Therefore, it is crucial to normalize lipid homeostasis in order to prevent or minimize complications associated with dyslipidemia. However, pharmacological interventions for controlling lipid metabolism often come with adverse effects.
View Article and Find Full Text PDFGlucocorticoid administration, before or after fear memory reactivation, impairs subsequent fear memory expression, but the underlying mechanisms are not well understood. The present study examined the role of basolateral amygdala (BLA) β-adrenoceptors in the effects of intra-BLA corticosterone injection on fear memory in rats. Bilateral cannulae were implanted in the BLA of Wistar male rats.
View Article and Find Full Text PDFAutism is a neurobehavioral disease that induces cognitive and behavioral alterations, usually accompanied by oxidative stress in the brain. Crocus sativus (saffron) and its active ingredient, crocin, have potent antioxidative effects that may benefit autistic behaviors. This study aimed to determine the effects of saffron extract and crocin against brain oxidative stress and behavioral, motor, and cognitive deficits in an animal model of autism in male offspring rats.
View Article and Find Full Text PDFHumans have lived in a dynamic environment fraught with potential dangers for thousands of years. While fear and stress were crucial for the survival of our ancestors, today, they are mostly considered harmful factors, threatening both our physical and mental health. Trauma is a highly stressful, often life-threatening event or a series of events, such as sexual assault, war, natural disasters, burns, and car accidents.
View Article and Find Full Text PDFGlucocorticoid receptors (GRs) of the basolateral amygdala (BLA) play an important role in memory reconsolidation. The present study investigated the role of the BLA GRs in the late reconsolidation of fear memory using an inhibitory avoidance (IA) task in male Wistar rats. Stainless steel cannulae were implanted bilaterally into the BLA of the rats.
View Article and Find Full Text PDFReconsolidation is an active process induced following the reactivation of previously consolidated memories. Recent studies suggest brain corticosteroid receptors may participate in the modulation of fear memory reconsolidation. Glucocorticoid receptors (GRs), with 10-fold lower affinity than mineralocorticoid receptors (MRs), are mainly occupied during the peak of the circadian rhythm, and after stress, so they probably have a more critical role than MRs in memory phases during stressful situations.
View Article and Find Full Text PDFThis study investigated the interactive effect of glucocorticoid and β-adrenoceptors in the infralimbic (IL) cortex on the acquisition and consolidation of fear extinction in rats' auditory fear conditioning (AFC) task. On day 1, rats underwent habituation for 9 min (12 tones, 10 s, 4 kHz, 80 dB, without footshock). On day 2 (conditioning), rats received 3 mild electrical footshocks (US; 2 s, 0.
View Article and Find Full Text PDFPhysiol Behav
June 2023
The extinction of auditory fear conditioning (AFC) refers to reducing the fear responses induced following repeated presentation of a conditioned stimulus (tone) in the absence of an unconditioned stimulus (electric foot shock). Glucocorticoid receptors (GRs) play an important role in extinction, but the underlying neurobiological mechanisms are unclear. This study aimed to investigate the interaction between glucocorticoids and β-adrenoceptors of the infra-limbic cortex (IL) in regulating the acquisition and consolidation of fear memory extinction in rats.
View Article and Find Full Text PDFThe human microbiome comprises the genomes of the microbiota that live on and within humans, such as protozoa, archaea, eukaryotes, viruses, and most bacteria. Gastrointestinal disorders such as inflammatory bowel disease, colon cancer, celiac disease, and irritable bowel syndrome can all be triggered by a change in gut flora. The alteration of the gut microbiota (also known as "gut dysbiosis") is affected by host genetics, nutrition, antibiotics, and inflammation, and it is associated with the development of inflammatory bowel disease (IBD).
View Article and Find Full Text PDFBackground: MicroRNAs (miRNAs) are non-coding, endogenous, single-stranded, small (21-25 nucleotides) RNAs. Various target genes at the post-transcriptional stage are modulated by miRNAs that are involved in the regulation of a variety of biological processes such as embryonic development, differentiation, proliferation, apoptosis, inflammation, and metabolic homeostasis. Abnormal miRNA expression is strongly associated with the pathogenesis of multiple common human diseases including cardiovascular diseases, cancer, hepatitis, and metabolic diseases.
View Article and Find Full Text PDFPost-traumatic stress disorder (PTSD) arises after tremendous traumatic experiences. Recently, we have reported that morphine has time-dependent protective effects against behavioral and morphological deficits in the single prolonged stress (SPS) as an experimental model of PTSD in adult male rats. To find the mechanisms underlying the protective effects of morphine against SPS-induced PTSD-like symptoms, the present study investigated the interaction between morphine and hypothalamic-pituitary-adrenal (HPA) axis and beta - adrenergic system, which crucially involved in the stress response, on PTSD-like symptoms in male rats.
View Article and Find Full Text PDFPost-traumatic stress disorder (PTSD) arises after an individual has experienced a major traumatic event. Recent evidence suggests that acute morphine treatment may serve as a strategy to reduce PTSD development. In the present study, we investigated the time-dependent effects of morphine on behavioral and morphological deficits induced by the single prolonged stress (SPS), an experimental model of PTSD, in adult male rats.
View Article and Find Full Text PDFThe infralimbic (IL) cortex of the medial prefrontal cortex plays an important role in the extinction of fear memory. Also, it has been showed that both brain glucocorticoid and dopamine receptors are involved in many processes such as fear extinction that drive learning and memory; however, the interaction of these receptors in the IL cortex remains unclear. We examined a putative interaction between the effects of glucocorticoid and dopamine receptors stimulation in the IL cortex on fear memory extinction in an auditory fear conditioning paradigm in male rats.
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