Department of Biology, Indiana University,1001 East Third Street, Bloomington, IN 47405, USA.
Horm Behav. 2011 Jun;60(1):12-21. doi: 10.1016/j.yhbeh.2011.01.012. Epub 2011 Feb 3.
Previous comparisons of territorial and gregarious finches (family Estrildidae) suggest the hypothesis that arginine vasotocin (VT) neurons in the medial bed nucleus of the stria terminalis (BSTm) and V(1a)-like receptors in the lateral septum (LS) promote flocking behavior. Consistent with this hypothesis, we now show that intraseptal infusions of a V(1a) antagonist in male zebra finches (Taeniopygia guttata) reduce gregariousness (preference for a group of 10 versus 2 conspecific males), but have no effect on the amount of time that subjects spend in close proximity to other birds ("contact time"). The antagonist also produces a profound increase in anxiety-like behavior, as exhibited by an increased latency to feed in a novelty-suppressed feeding test. Bilateral knockdown of VT production in the BSTm using LNA-modified antisense oligonucleotides likewise produces increases in anxiety-like behavior and a potent reduction in gregariousness, relative to subjects receiving scrambled oligonucleotides. The antisense oligonucleotides also produced a modest increase in contact time, irrespective of group size. Together, these combined experiments provide clear evidence that endogenous VT promotes preferences for larger flock sizes, and does so in a manner that is coupled to general anxiolysis. Given that homologous peptide circuitry of the BSTm-LS is found across all tetrapod vertebrate classes, these findings may be predictive for other highly gregarious species.
先前对领地性和群居性雀科鸟类（雀形目）的比较研究提出了这样一种假设，即终纹床核内侧部的精氨酸加压素（VT）神经元和外侧隔核（LS）中的 V1a 样受体促进了群居行为。与这一假设一致，我们现在表明，在雄性斑马雀（Taeniopygia guttata）的隔核内注射 V1a 拮抗剂会降低群居性（对 10 只同种雄性的偏好与对 2 只同种雄性的偏好），但对鸟类之间的近距离接触时间（“接触时间”）没有影响。该拮抗剂还会导致类似焦虑的行为明显增加，表现在新奇抑制性摄食试验中摄食潜伏期的增加。使用 LNA 修饰的反义寡核苷酸对 BSTm 中的 VT 产生进行双侧敲低，也会导致类似焦虑的行为增加和群居性显著降低，而接受乱序寡核苷酸的鸟类则不会。反义寡核苷酸也会导致接触时间略有增加，而与群体大小无关。综上所述，这些综合实验为内源性 VT 促进对更大群体大小的偏好提供了明确的证据，并且这种作用与一般的焦虑缓解有关。鉴于 BSTm-LS 的同源肽电路在所有四足脊椎动物类群中都有发现，这些发现可能对其他高度群居的物种具有预测性。
