Mother's Day Special: Mom loves your nerve mechanism.

Learn about the latest progress in neuroscience ● click the blue word to pay attention to us ● happy mother's Day "mother's hand thread, wandering body jacket" expresses the greatness and selflessness of maternal love.when she was young, Mencius' mother moved many times in order to provide a better environment for her children to study, which led to the subsequent three moves.this is the greatness of maternal love.in order to know how the brain works in calf care behavior, researchers have made important progress in neurobiology of maternal behavior by using animal models in recent years.the maternal behaviors of rodents such as rats and mice mainly include licking their pups (the mother cleans the pups and helps defecate and urinate), grooming, retrieving, sniffing, nesting (to keep the pups in a warm environment), and breastfeeding, which is similar to human behavior.these seemingly simple behaviors are actually a complex process: the establishment of maternal behavior - the sensory information of maternal behavior is input to the brain center - the brain center reacts and outputs specific behaviors.01 the key brain area of maternal behavior - medial preoptic area The medial preoptic area of hypothalamus (MPOA), located near the third ventricle, is the key brain area for maternal behavior control. There are dopaminergic, GABAergic and glutamatergic neurons in this area, which express multiple receptors such as prolactin receptor, progesterone receptor and estrogen receptor, and are more closely related to paraventricular nucleus (PVN), arcuate nucleus, dorsal medial hypothalamic nucleus and VTA There were projections in three brain regions.studies have shown that about 75% of inhibitory neurons in this brain region are activated when the mice display maternal brilliance.it has been found that the neurons expressing estrogen receptor A (ESR1) regulate maternal behavior, while the MPOA brain region is highly enriched in the expression of ESR1.the role of ESR1 in maternal behavior was found through virus silencing. After reducing the expression of ESR1 in MPOA brain region, mice significantly prolonged the incubation time of mice taking back their mothers, and the licking behavior of mothers to their offspring was also reduced, that is to say, maternal behavior was affected.subsequently, Professor Lin Dayu of New York University School of medicine further found that chronic inhibition of the expression of ESR1 neurons in MPOA brain area reduced the number of times that female rats retrieved mice, which inhibited maternal behavior; light activated ESR1 expressing neurons promoted the behavior of female rats to retrieve their offspring.through calcium imaging fiber recording system, it was found that ESR1 neurons only increased in the specific maternal behavior of retrieval, which indicated that the ESR1 neurons in MPOA brain region specifically responded to the retrieval behavior.through anterograde virus tracing experiment, it was found that ESR1 neurons in MPOA brain area projected to VTA, and light activated mpoa-vta neural circuit could also promote mother rats to retrieve their offspring.in addition, other studies have found that prolactin receptor is also involved in this process. After specifically knocking out the prolactin receptor in MPOA neurons, adult female mice abandon their newborn babies, ignore them and no longer show maternal behavior.the research group of Xu Xiaohong, Shanghai Institute of neuroscience, Chinese Academy of Sciences, is one of the few research teams to study maternal behavior in China.the agogue related peptide (AgRP) neurons in the hypothalamic arcuate nucleus (ARC) can promote diet. They found that about 30% of the AgRP neurons project to the medial preoptic area and form inhibitory synaptic connections.light activated AgRP neurons projecting to the medial preoptic area significantly reduced the nesting behavior of female mice. In addition, it was found that although the retrieval behavior of female mice was not affected after eating for 24 hours, the nesting behavior was decreased. chronic inhibition of inhibitory neurons in medial preoptic area can also reduce nesting behavior and activate such neurons to promote nesting behavior. in addition to MPOA, the bed nucleus of the ventral stria terminalis (vbst) is also a key brain region in regulating maternal behavior. the ventral tegmental area (VTA) is the key reward brain area in dopamine reward system of maternal behavior. virus tracing experiments showed that MPOA neurons could project to VTA, and these neurons were activated in maternal behavior. MPOA integrates information from the sensory system and transmits it to the dopaminergic reward system. in addition, maternal behavior was impaired after VTA lesion. These results suggest that the midbrain dopamine system is involved in the regulation of maternal behavior. the researchers injected baclofen (a GABA-B receptor agonist) into the VTA brain region, which inhibited the behavior of the mother rats to retrieve their offspring. through calcium imaging fiber recording system, it was found that dopamine neurons in VTA area were activated more when maternal love was displayed. however, the injection of D1 / D2 receptor antagonist into NAC (nucleus accumbens) not only reduced the withdrawal behavior, but also reduced the licking behavior, but had no effect on lactation. this may be caused by two different types of neurons in NAC: dopamine receptor type 1 (D1) and dopamine receptor type 2 (D2). it was found that administration of D1 antagonist into NAC could significantly inhibit maternal behavior, but inhibition of D2 did not. in addition, high-dose D1 antagonist was injected into MPOA brain area to inhibit maternal behavior, while D1 agonist injection promoted maternal behavior. therefore, the midbrain dopamine system controls maternal behavior through the neural circuit (mpoa-vta) or dopamine release. at present, there are not many studies on neural regulation of maternal behavior, mainly focusing on MPOA, VTA, vbst and other brain regions. with the deepening of the research, we can know more about the mechanism of maternal love. References: 1. Prolactin action in the medium preferred area is necessary for postpartum materal nursing behavior. 2. SiRNA silencing of ester receptor - α expression spec fi call in medium reoptic area nerves abolishes materal care in female mie3. A hypobaric midbrain pathway essential for driving material Behaviors4.Medial preoptic area interactions with dopamine neural systems in the control of the onset and maintenance of maternal behavior in rats5. A Neural Circuit Driving Maternal Behaviors