The neural circuits of monogamous behavior.

The interest in studying the neural circuits related to mating behavior and mate choice in monogamous species lies in the parallels found between human social structure and sexual behavior and that of other mammals that exhibit social monogamy, potentially expanding our understanding of human neurobiology and its underlying mechanisms. Extensive research has suggested that social monogamy, as opposed to non-monogamy in mammals, is a consequence of the neural encoding of sociosensory information from the sexual partner with an increased reward value. Thus, the reinforced value of the mate outweighs the reward value of mating with any other potential sexual partners. This mechanism reinforces the social relationship of a breeding pair, commonly defined as a pair bond. In addition to accentuated prosocial behaviors toward the partner, other characteristic behaviors may appear, such as territorial and partner guarding, selective aggression toward unfamiliar conspecifics, and biparental care. Concomitantly, social buffering and distress upon partner separation are also observed. The following work intends to overview and compare known neural and functional circuits that are related to mating and sexual behavior in monogamous mammals. We will particularly discuss reports on Cricetid rodents of the Microtus and Peromyscus genus, and New World primates (NWP), such as the Callicebinae subfamily of the titi monkey and the marmoset (Callithrix spp.). In addition, we will mention the main factors that modulate the neural circuits related to social monogamy and how that modulation may reflect phenotypic differences, ultimately creating the widely observed diversity in social behavior.

The vocal sac of Hylodidae (Amphibia, Anura): Phylogenetic and functional implications of a unique morphology.

Anuran vocal sacs are elastic chambers that recycle exhaled air during vocalizations and are present in males of most species of frogs. Most knowledge of the diversity of vocal sacs relates to external morphology; detailed information on internal anatomy is available for few groups of frogs. Frogs of the family Hylodidae, which is endemic to the Atlantic Forest of Brazil and adjacent Argentina and Paraguay, have three patterns of vocal sac morphology-that is, single, subgular; paired, lateral; and absent. The submandibular musculature and structure of the vocal sac mucosa (the internal wall of the vocal sac) of exemplar species of this family and relatives were studied. In contrast to previous accounts, we found that all species of Crossodactylus and Hylodes possess paired, lateral vocal sacs, with the internal mucosa of each sac being separate from the contralateral one. Unlike all other frogs for which data are available, the mucosa of the vocal sacs in these genera is not supported externally by the mm. intermandibularis and interhyoideus. Rather, the vocal sac mucosa projects through the musculature and is free in the submandibular lymphatic sac. The presence of paired, lateral vocal sacs, the internal separation of the sac mucosae, and their projection through the m. interhyoideus are synapomorphies of the family. Furthermore, the specific configuration of the m. interhyoideus allows asymmetric inflation of paired vocal sacs, a feature only reported in species of these diurnal, stream-dwelling frogs.

The Early Emergence of Temporal Reference in Mother-Child Multimodal Communication / Emergencia temprana de la referencia temporal en la comunicación multimodal entre madre-niño

The study longitudinally explores the early emergence of temporal reference to objects/events that are either present or absent in time while mothers and children use and combine pointing and verbal references. Over one year of observations and in five separate sessions, eight Spanish mothers and their one- and two-year-old babies were observed while performing daily routines at home. The results indicated that overall mothers and children used more verbs referring to the present frame than to the past and future frames. As compared with the production of utterances accompanied by pointing, children were more likely to produce present references in the young group and displaced references (mostly near past and near future) in the older group when utterances were produced without pointing. Mothers closely preceded or accompanied the children's verbal and gestural referential production to either immediate or displaced referents across ages, indicating that they systematically engage their children in talking about the present and especially about the future.

El estudio explora de forma longitudinal la aparición temprana de la referencia temporal de los objetos/eventos que están presentes o ausentes en el tiempo, mientras que las madres y los niños usan y combinan señales y referencias verbales. Más de un año de observaciones y en cinco sesiones separadas, ocho madres españolas y sus bebés de uno y dos años de edad se observaron en el desempeño de las rutinas diarias en el hogar. Los resultados indicaron que las madres en general y los niños utilizan más verbos que se refieren al marco actual que a las situaciones pasadas y futuras. En comparación con la producción de los enunciados acompañados de señalar, los niños eran más propensos a producir referencias presentes en el grupo de jóvenes y referencias desplazadas (en su mayoría cerca de pasado y futuro cercano) en el grupo de mayor edad cuando se produjeron declaraciones sin apuntar. Las madres más facilmente precedian o acompañaban de forma verbal y gestual la producción referencial de los niños ya sea a los referentes inmediatos o desplazadas en todas las edades, lo que indica que se dedican sistemáticamente a sus hijos en hablar sobre el presente y especialmente sobre el futuro.

Risks of multimodal signaling: bat predators attend to dynamic motion in frog sexual displays.

Many sexual displays contain multiple components that are received through a variety of sensory modalities. Primary and secondary signal components can interact to induce novel receiver responses and become targets of sexual selection as complex signals. However, predators can also use these complex signals for prey assessment, which may limit the evolution of elaborate sexual signals. We tested whether a multimodal sexual display of the male túngara frog (Physalaemus pustulosus) increases predation risk from the fringe-lipped bat (Trachops cirrhosus) when compared with a unimodal display. We gave bats a choice to attack one of two frog models: a model with a vocal sac moving in synchrony with a mating call (multisensory cue), or a control model with the call but no vocal sac movement (unimodal cue). Bats preferred to attack the model associated with the multimodal display. Furthermore, we determined that bats perceive the vocal sac using echolocation rather than visual cues. Our data illustrate the costs associated with multimodal signaling and that sexual and natural selection pressures on the same trait are not always mediated through the same sensory modalities. These data are important when considering the role of environmental fluctuations on signal evolution as different sensory modalities will be differentially affected.