新生儿期母子隔离与抚触刺激对成年后大鼠社会交往行为的影响

Effects of neonatal isolation and neonatal tactile stimulation on social behavior of adult rats

目的研究大鼠新生儿期母子隔离(NI)和新生儿期抚触刺激(NTS)对成年后社交行为,下丘脑室旁核(PVN)和视上核(SON)的催产素(OXT)、精氨酸后叶加压素(AVP)表达神经元数量的影响。方法将78只大鼠分到正常对照(SFR)组、母子隔离(NI)组、抚触刺激(NTS)组,于新生儿期进行相应干预,待大鼠成年后进行社会交往能力测试及神经元数量测定。结果大鼠新生儿期间的母子隔离对成年后的社交行为有不良影响,且这种行为改变在子代雌鼠的社会交往及同性社会交往时的缺陷更加明显。NI组雌鼠OXT免疫组化染色阳性神经元数量在PVN的大细胞区域显著下降,AVP免疫组化染色阳性神经元数量在PVN的大小细胞区域亦显著下降。新生儿期抚触刺激可部分逆转这些行为和分子上的变化。在雌鼠中PVN的OXT和AVP免疫组化染色阳性神经元数量与社交行为呈正相关(r^2=0.277,P=0.044;r^2=0.325,P=0.017)。结论新生儿期母子隔离和抚触刺激可能通过PVN的OXT/AVP系统,对雌鼠的社交行为产生长期影响。

Objective This study examined the impact of childhood neonatal isolation （NI） and neonatal tactile stimulation （NTS） on social behavior and oxytocin （OXT）/vasopressin （AVP） systems in hypothalamic paraventricular nucleus （PVN） and supraoptic nucleus （SON） of rats in adulthood. Methods 78 rats were randomly divided into standard facility rearing （ SFR）, NI and NTS groups. After receiving intervention according to neonatal period, social interaction test and immunohistochemical test were carried out in their adulthood. Results Childhood NI had negative effects on social interaction behavior in their adulthood, and the behavioral change was more obvious in female rats interacting to both sexes （female to male or female） , and in both sexes interacting between the same sex （male to male and female to female）. The results of immunohistochemical staining showed that in NI group, female rats had significant reductions in the number of OXT-immunopositive neurons in magnocellnlar region of PVN and in the AVP-immunopositive neurons in both magnocellular and parvocellular regions of PVN. The change in behavior and molecule was partially reversed in NTS group. Correlation analysis showed that in female rats, the numbers of OXT- and AVP-immunopositive neurons in PVN were positively correlated to the social interaction ability. Conclusion NI and NTS may have long-term impact on social interaction behavior in female rats through the OXT/AVP system in the PVN areas, which are known to be involved in social behavior in mammals.