Summers T R, Hunter A L, Summers C H
Department of Biology, University of South Dakota, Vermillion 57069-3290, USA.
Brain Res. 1997 Sep 5;767(2):272-8. doi: 10.1016/s0006-8993(97)00604-5.
Central monoamines display a variety of activation patterns in different social groups, and among males and females. We addressed three social conditions for female lizards of the species Anolis carolinensis: Isolated, paired with a mate, and in a group of 5 competing for one mate. Among those in a group, only 1 or 2 females exhibited recrudescing ovaries. Individuals paired with a mate (for one month) exhibited ovarian growth, isolated animals (initial controls) had quiescent ovaries. Reproductively dominant females had significantly greater telencephalic 5-HIAA, and serotonergic activation, as indicated by the ratio of 5-HIAA to 5-HT. Telencephalic HVA as well as the HVA/DA ratio were also significantly greater in dominant females compared to all other groups. In contrast, serotonergic activation in brainstem was elevated in subordinate females only. These results suggest that serotonergic activation in telencephalon, found only in dominant females, not in other reproductively active females, is a function of the unique social role of a dominant female, possibly combining submissive behaviors toward a male with dominance over other females and competition for access to that male. Dopaminergic activation in telencephalon, also found only in dominant females, may be related to aggressive interactions with other females. Activation of serotonin in brainstem, found in this study in subordinate females and previously in males [C.H. Summers and N. Greenberg, Activation of central biogenic amines following aggressive interaction in male lizards, Anolis carolinensis, Brain Behav. Evol., 45 (1995) 339-349], may be associated with subordinate social status. Monoamines, involved in social behaviors, appear to be regionally specialized for dominant and subordinate social roles, in males [C.H. Summers and N. Greenberg, Activation of central biogenic amines following aggressive interaction in male lizards, Anolis carolinensis, Brain Behav. Evol., 45 (1995) 339-349][T.R. Summers, E.T. Larson, A.L. Hunter, K.J. Renner, N. Greenberg and C.H. Summers, Amygdalar serotonin mediates long-term social roles following aggressive interaction, Soc. Neurosci. Abs., 22 (1996) 1147] and females. Dominant females exhibit unique social position, behavior and monoamine profile whereas subordinate females and males have a similar serotonergic response in this species.
中枢单胺类物质在不同社会群体以及雄性和雌性个体中表现出多种激活模式。我们研究了卡罗来纳安乐蜥雌性个体的三种社会条件：隔离状态、与配偶配对以及处于5只竞争1只配偶的群体中。在群体中的个体里，只有1或2只雌性个体的卵巢出现复发现象。与配偶配对（一个月）的个体卵巢生长，处于隔离状态的动物（初始对照组）卵巢静止。繁殖上占优势的雌性个体的端脑5-羟吲哚乙酸（5-HIAA）以及血清素能激活水平显著更高，这通过5-HIAA与5-羟色胺（5-HT）的比值来表示。与所有其他组相比，占优势雌性个体的端脑高香草酸（HVA）以及HVA/多巴胺（DA）比值也显著更高。相比之下，仅从属雌性个体的脑干血清素能激活水平升高。这些结果表明，仅在占优势雌性个体而非其他繁殖活跃雌性个体中发现的端脑血清素能激活，是占优势雌性个体独特社会角色的一种功能，可能是将对雄性的顺从行为与对其他雌性的支配以及竞争接近该雄性的机会结合在一起。同样仅在占优势雌性个体中发现的端脑多巴胺能激活，可能与与其他雌性的攻击性行为相互作用有关。本研究在从属雌性个体中发现且之前在雄性个体中也发现过的脑干血清素激活现象[C.H.萨默斯和N.格林伯格，雄性卡罗来纳安乐蜥攻击性行为后中枢生物胺的激活，《脑行为与进化》，45（1995）339 - 349]，可能与从属社会地位相关。参与社会行为的单胺类物质，在雄性[C.H.萨默斯和N.格林伯格，雄性卡罗来纳安乐蜥攻击性行为后中枢生物胺的激活，《脑行为与进化》，45（1995）339 - 349][T.R.萨默斯、E.T.拉尔森、A.L.亨特、K.J.伦纳、N.格林伯格和C.H.萨默斯，杏仁核血清素在攻击性行为后介导长期社会角色，《社会神经科学摘要》，22（1996）1147]和雌性个体中似乎在区域上专门用于占优势和从属社会角色。占优势雌性个体表现出独特的社会地位、行为和单胺类物质特征，而在该物种中，从属雌性个体和雄性个体具有相似的血清素能反应。
