Early weaning leads to disruption of homeostatic and hedonic eating behaviors and modulates serotonin (5HT) and dopamine (DA) systems in male adult rats

Early Life Stress and the Onset of Obesity: Proof of MicroRNAs’ Involvement Through Modulation of Serotonin and Dopamine Systems’ Homeostasis

“…On the other hand, we have been able to associate the EW with changes in gene expression of several components of the 5HT system in male and female rats, such as SERT, 5HT1B, and 5HT2C in hypothalamus and brainstem. Based on the patterns of expression in the brainstem and response to fenfluramine, we suggested a hypofunction of the serotonergic system in the EW animals ( Tavares et al, 2019 , 2020a , b ). All these changes in the 5-HT system were accompanied by alterations on feeding behavior, which indicate that the 5HT system control of feeding behavior can be modulated by ELS, which can be directly linked to the onset of obesity.…”

“…The MS also modulates the DA system in other brain areas, such as PLC, NAcc, and striatum, changing the density of immunoreactive fibers of TH, and the mRNA expression of DRD2, DRD1, and DRD5 (Majcher-Maślanka et al, 2017). On the other hand, EW increases DRD1 mRNA expression in the hypothalamus and brainstem and DRD2 in the brainstem of middle-aged male rats (Tavares et al, 2020b). In all of these studies, disrupted patterns on feeding behavior are observed, indicating that alterations in the dopaminergic system can be one of the underlying mechanisms that lead to behavioral disorders.…”

“…Regarding the dopaminergic system, the DRD1 and DRD2 actively participate in the regulation of food intake, especially with regard to palatable foods, as these are related to the food reward system ( Meguid et al, 2000 ; Berridge et al, 2009 ; Volkow et al, 2011 ). Changes in this reward system are linked to eating behavior disorders, with changes in the activity of DRD1 and DRD2 being observed in humans and animals ( Guo et al, 2014 ; Rivera et al, 2015 ; Gaiser et al, 2016 ; de Souza et al, 2018 ; Romanova et al, 2018 ; Tavares et al, 2020b ). In addition, both receptors are modulated by ELS ( de Souza et al, 2018 ; Tavares et al, 2020b ).…”

“…Changes in this reward system are linked to eating behavior disorders, with changes in the activity of DRD1 and DRD2 being observed in humans and animals ( Guo et al, 2014 ; Rivera et al, 2015 ; Gaiser et al, 2016 ; de Souza et al, 2018 ; Romanova et al, 2018 ; Tavares et al, 2020b ). In addition, both receptors are modulated by ELS ( de Souza et al, 2018 ; Tavares et al, 2020b ). Interestingly, we observed that miR-504 targets both DRD1 and DRD2, with their expression being altered by ELS ( Zhang et al, 2015 ).…”

Psychological and neurobiological mechanisms underlying the decline of maternal behavior

“…The "helicopter mom" phenomenon is no stranger to many of our readers and may reflect the failure of the mother to actively adjust her caregiving behaviors. On the other hand, weaning too early or deprivation of maternal care too early is known to cause various physical and psychological problems, including increased corticosterone secretion, dysregulation of feeding behavior, increased anxiety and stress responses in the young animals when they become adults (Kikusui et al, 2019;Tavares et al, 2020). Human children who experience maternal deprivation or neglect are also at greater risk to develop psychiatric illnesses in the future (Agid et al, 1999).…”