Effects of Neurokinin-1 Receptor Inhibition on Anxiety Behavior in Neonatal Rats Selectively Bred for an Infantile Affective Trait

Interest in understanding the etiology and developing new treatments for anxiety disorders in children and adolescents has led to recent studies of neurotransmitters not traditionally associated with neural pathways for fear and anxiety. The binding of the neurotransmitter substance P (SP) to its neurokinin-1 (NK1) receptor may be a crucial component in mediating the anxiety response. While previous studies using rodent models have documented the anxiolytic effects of SP antagonists, the role of individual differences in affective temperament has not yet been examined in studies of drug response. This study used intracerebroventricular injections of the NK1 antagonist Spantide II at concentrations of 10 and 100 pmol to examine the consequences of blocking the SP-NK1 pathway in high and low line rats selectively bred for high or low levels of ultrasonic distress calls after a brief maternal separation. Affective temperament was a significant factor in determining drug response. Spantide II resulted in a significant reduction of distress calls in subjects in the high anxiety line, while low line subjects with low anxiety were resistant to the drug. These data indicate that the SP-NK1 pathway could be an important therapeutic target for the treatment of various stress disorders, but drug response might be influenced by the individual’s state anxiety or history of chronic stress.

Eating as a motivated behavior:modulatory effect of high fat diets on energy homeostasis,reward processing and neuroinflammation

Eating is a basic motivated behavior that provides fuel for the body and supports brain function.To ensure survival,the brain’s feeding circuits are tuned to monitor peripheral energy balance and promote food-seeking behavior when energy stores are low.The brain’s bias toward a positive energy state,which is necessary to ensure adequate nutrition during times of food scarcity,is evolutionarily conserved across mammalian species and is likely to drive overeating in the presence of a palatable,energy-dense diet.Animal models of diet-induced overeating have played a vital role in investigating how the drive to consume palatable food may override the homeostatic processes that serve to maintain energy balance.These animal models have provided valuable insights into the neurobiological mechanisms underlying homeostatic and non-homeostatic eating,motivation and food reward,and the development of obesity and related comorbidities.Here,we provide a brief review of this literature and discuss how diet-induced inflammation in the central nervous system impacts the neural control of food intake and regulation of body weight.The connection between diet and the immune system provides an exciting new direction for the study of ingestive behavior and the pathophysiology of obesity.

Density-induced social stress alters oxytocin and vasopressin activities in the brain of a small rodent species

It is known that social stress could alter oxytocin(OT)and arginine-vasopressin(AVP)expression in specific regions of brains which regulate the aggressive behavior of small rodents,but the effects of density-induced social stress are still unknown.Brandt’s voles(Lasiopodomys brandtii)are small herbivores in the grassland of China,but the underlying neurological mechanism of population regulation is still unknown.We tested the effects of housing density of Brandt’s voles on OT/AVP system with physical contact(allowing aggression)and without physical contact(not allowing aggression)under laboratory conditions.Then,we tested the effects of paired-aggression(no density effect)of Brandt’s voles on OT/AVP system under laboratory conditions.We hypothesized that high density would increase aggression among animals which would then increase AVP but reduce OT in brains of animals.Our results showed that high housing density induced more aggressive behavior.We found high-densityinduced social stress(with or without physical contact)and direct aggression significantly increased expression of mRNA and protein of AVP and its receptor,but decreased expression of mRNA and protein of OT and its receptor in specific brain regions of voles.The results suggest that density-dependent change of OT/AVP systems may play a significant role in the population regulation of small rodents by altering density-dependent aggressive behavior.

哺乳动物成体神经元的再生:内、外环境因子的作用(英文)

哺乳动物成体神经元的再生现象是最近三十年才被科学家们所认识并逐渐接受的。随着科研方法与实验技术的发展 ,在成年哺乳动物的一些特定脑区 ,比如海马齿状回 (Dentategyrusofthehippocampus)、室下区(Subventricularzone)和杏仁核 (Amygdala)中发现了新生细胞。研究表明 ,内外环境因子可影响成体神经元的再生。具体表现在环境多样性、自主活动、有益社会交往、短日光照、化学刺激以及诸如 5 -羟色胺和脑源性神经营养因子等神经递质水平的增加 ,都会促进新生细胞的增生或存活。而负面社会交往及应激激素皮质酮对成体神经元的再生有抑制和降低作用。研究还表明 ,根据种和性别的差异 ,类脂醇激素对成体神经元的再生起到促进或抑制作用。

单配制啮齿动物PairBond形成的神经调节机制(英文)

单配制啮齿动物社会结构的神经生物学原理可以通过实验室研究Socialbonding而获得。在本文中,我们探讨了如何利用单配制的草原田鼠(Microtusochrogaster)作为研究模型揭示pairbond形成的神经调控机制。我们进而探讨了单配制与多配制田鼠之间神经解剖学的差异以及神经化学物质的调节是怎样影响pairbond的。本篇综述还讨论了与pairbond形成有关的神经化学系统之间的相互影响以及pairbond形成过程中的两性差异。最后,我们预测了这一研究领域的未来研究方向以及研究socialbonding的神经调控对人类健康的重要性。