Variability in Behavioral Phenotypes after Forced Swimming-Induced Stress in Rats Is Associated with Expression of the Glucocorticoid Receptor, Nurr1, and IL-1β in the Hippocampus

The Effect of Administering Forest Honey to Rats Exposed to Physical Stress on Corticosteroid Levels, Folliculogenesis and the Number of Corpus Luteum

Livestock that has stress releases glucocorticoids in response to it, and it causes inhibition of the hypothalamus-pituitary-gonadal axis (HPG) signaling pathway so that it reduces reproductive efficiency. Forest honey can reduce corticosteroid levels as a stress response from physical stress induction which is expected to increase reproductive efficiency including folliculogenesis and the formation of the corpus luteum. This study aims to determine the effect of forest honey on rats (Rattus novergicus) exposed to physical stress on corticosteroid levels, folliculogenesis, and the number of corpus luteum. This study is an experimental laboratory one using 32 rats which were divided into 4 treatment groups; control positive (C) treated with physical stress, treatment 1 (T1) treated with physical stress + honey 2 g/rat/day PO, treatment 2 (T2) treated with physical stress + honey 4 g/rat/day PO and treatment 3 (T3) treated with physical stress + honey 6 g/rat/day PO. All treatments were carried out for 14 days. The results showed that T1 had the lowest corticosteroid level compared to all treatment groups and the corticosteroid level of this group was significantly different (p <0.05) compared to that of C and T3. The folliculogenesis profile showed that the number of primary secondary, tertiary, and Graafian follicles of group T1 was significantly different (p<0.05) compared to that of C, T2, and T3. In terms of the number of corpus luteum, it showed that T1 had the highest number of corpus luteum, and the number of corpus luteum in this group was significantly different (p<0.05) from that of C, T2, and T3. It can be concluded that the administration of forest honey at a dose of 2g/rat/day could reduce corticosteroid levels, improve the folliculogenesis profile, and increase the number of corpus luteum in rats exposed to physical stress. The use of forest honey could reduce corticosteroid levels as a stress response from physical stress induction which was expected to increase reproductive efficiency.

Mechanisms of NURR1 Regulation: Consequences for Its Biological Activity and Involvement in Pathology

NURR1 (Nuclear receptor-related 1 protein or NR4A2) is a nuclear protein receptor transcription factor with an essential role in the development, regulation, and maintenance of dopaminergic neurons and mediates the response to stressful stimuli during the perinatal period in mammalian brain development. The dysregulation of NURR1 activity may play a role in various diseases, including the onset and progression of neurodegenerative diseases, and several other pathologies. NURR1 is regulated by multiple mechanisms, among which phosphorylation by kinases or SUMOylation are the best characterized. Both post-translational modifications can regulate the activity of NURR1, affecting its stability and transcriptional activity. Other non-post-translational regulatory mechanisms include changes in its subcellular distribution or interaction with other protein partners by heterodimerization, also affecting its transcription activity. Here, we summarize the currently known regulatory mechanisms of NURR1 and provide a brief overview of its participation in pathological alterations.

Maternal stress and vulnerability to depression: coping and maternal care strategies and its consequences on adolescent offspring

Depressive mothers often find mother-child interaction to be challenging. Maternal stress may further impair mother-child attachment, which may increase the risk of negative developmental consequences. We used rats with different vulnerability to depressive-like behavior (Wistar and Kyoto) to investigate the impact of stress (maternal separation-MS) on maternal behavior and adolescent offspring cognition. MS in Kyoto dams increased pup-contact, resulting in higher oxytocin levels and lower anxiety-like behavior after weaning, while worsening their adolescent offspring cognitive behavior. Whereas MS in Wistar dams elicited higher quality of pup-directed behavior, increasing brain-derived neurotrophic factor (BDNF) in the offspring, which seems to have prevented a negative impact on cognition. Hypothalamic oxytocin seems to affect the salience of the social environment cues (negatively for Kyoto) leading to different coping strategies. Our findings highlight the importance of contextual and individual factors in the understanding of the oxytocin role in modulating maternal behavior and stress regulatory processes.