Interactions between medial preoptic area, nucleus accumbens, and ventral pallidum in the control of mammalian maternal behavior

本研究探讨了动物母性行为控制中特异性和非特异性动机系统之间的相互作用。本研究将探讨下丘脑内侧视前区（MPOA）与伏隔核-腹侧白斑回路（NA-VP回路）在母性行为中的相互作用。先前的研究表明，MPOA神经回路参与了母性行为的调节。相反，其他研究表明，NA-VP回路是非特异性动机系统的一部分：该回路的活动似乎调节了生物体对各种生物重要刺激的反应。有人提出，当NA-VP的输出由MPOA神经元驱动时，生物体的母性动机就会增加[如果NA-VP电路的输出由另一种特定的动机系统（例如饥饿）驱动，那么行为反应的类型就会相应改变]。该研究将采用的方法包括：(a)颅内注射药物以改变NA-VP回路内的活性；(b)将研究破坏MPOA和NA-VP之间的通讯对产妇行为的影响；(c)将进行神经解剖程序，以确定关键神经回路的化学组成。据预测，从MPOA到NA-VP的连接允许婴儿刺激激活VP神经元，并且那些增加VP活性的处理将促进，而那些抑制VP活性的处理将破坏母亲的行为。这种类型的基础研究很重要，因为它采用了一种系统级的方法来研究动机的神经生物学，解释了大脑如何运作来控制核心的社会动机——母性反应。重要的是，最近的功能磁共振成像研究表明，我们强调的许多在低等动物中很重要的大脑区域，在人类母亲处理婴儿线索时也很活跃。

The proposed research explores the interaction between specific and nonspecific motivational systems in the control of maternal behavior in animals. It will explore the interactions between the medial preoptic area (MPOA) of the hypothalamus and the nucleus accumbens-ventral pallidal circuit [NA-VP circuit] in maternal behavior. Previous research has shown the specific involvement of MPOA neural circuits in the regulation of maternal behavior. In contrast, other research has indicated that the NA-VP circuit is part of a nonspecific motivational system: activity across this circuit appears to regulate an organism's responsiveness to a wide variety of biologically significant stimuli. It is proposed that when the output of the NA-VP is driven by MPOA neurons, the organism's maternal motivation is increased [if output of the NA-VP circuit were to be driven by another specific motivational system (hunger, for example), then the type of behavioral reactivity would change accordingly]. The methods that will be employed in the proposed study include: (a) intracranial injections of drugs to alter activity within the NA-VP circuit; (b) the effects of disrupting communication between MPOA and NA-VP on maternal behavior will be examined; (c) neuroanatomical procedures to define the chemical makeup of the critical neural circuits will be performed. It is predicted that connections from the MPOA to NA-VP allow infant stimuli to activate VP neurons, and that those treatments which increase VP activity will facilitate, and those that depress VP activity will disrupt, maternal behavior. This type of basic research is important because it takes a systems level approach to the neurobiology of motivation, explaning how the brain operates to control a core social motivation - maternal responsiveness. Importantly, recent fMRI work indicates that many of the brain regions we emphasize that are important in lower animals are also active in human mothers attending to infant cues.