Animals communicate information within their environments via visual, chemical, auditory, and/or tactile modalities. The use of each modalityis generally linked to particular brain regions, but it is not yet known whe...Animals communicate information within their environments via visual, chemical, auditory, and/or tactile modalities. The use of each modalityis generally linked to particular brain regions, but it is not yet known whether the cellular morphology of neurons in these regions has evolved in association with the relative use of a modality.We investigated relationships between the behavioral use of communication modalities and neural morphologies in six lizard species. Two of these species （Anolis carol# nensis and Leiocephalus carinatus） primarily use visual signals to communicate with conspecifics and detect potential prey, and two （Aspidoscelis gularis and Scincella lateralis） communicate and forage primarily using chemical signals. Two other species （Hemidactylus turcicus and Sceloporus olivaceus） use both visual and chemical signals. For each species, we performed beha- vioral observations and quantified rates of visual and chemical behaviors. We then cryosectioned brain tissues from 9-10 males of each species and measured the soma size and density of neurons in two brain regions associated with visual behaviors （the lat- eral geniculate nucleus and the nucleus rotundus） and one region associated with chemical behaviors （the nucleus sphericus）. With analyses conducted in a phylogenetic context, we found that species that performed higher rates of visual displays had a denser lateral geniculate nucleus, and species that used a higher proportion of chemical displays had larger somas in the nucleus sphericus. These relationships suggest that neural morphologies in the brain have evolved convergently in species with similar communication behaviors .展开更多
基金We thank the members of the Johnson Lab at Trinity University for assistance in the field and labor- atory - particularly Bonnie Kircher, Alisa Dill, Michelle Ob- emdorf, Adam Silva, Taren Blackmon, Jordan Bush, McKen- zie Quinn, EUee Cook, Grayam Sailor-Tynes, and Collin Shinkle. We also thank David Ribble, Troy Murphy, Jimmy Roberts, Kevin McIntyre, and three reviewers for comments on an earlier version of this work, and Kevin McIntyre and Kimberly Phillips for statistical advice. This work was funded by a Sigma Xi GIAR （to C.D.R.）, a Trinity University Mind Science Foundation grant （to C.D.R.）, Trinity University＇s HHMI and Biology Summer Undergraduate Research Fel- lowships （to C.D.R.）, Texas Ecolab, and the National Science Foundation （IOS 1257021 to M.A.J.）. All procedures were approved by Trinity University＇s Animal Research Committee （protocol # 050213_MAJ2）.
文摘Animals communicate information within their environments via visual, chemical, auditory, and/or tactile modalities. The use of each modalityis generally linked to particular brain regions, but it is not yet known whether the cellular morphology of neurons in these regions has evolved in association with the relative use of a modality.We investigated relationships between the behavioral use of communication modalities and neural morphologies in six lizard species. Two of these species （Anolis carol# nensis and Leiocephalus carinatus） primarily use visual signals to communicate with conspecifics and detect potential prey, and two （Aspidoscelis gularis and Scincella lateralis） communicate and forage primarily using chemical signals. Two other species （Hemidactylus turcicus and Sceloporus olivaceus） use both visual and chemical signals. For each species, we performed beha- vioral observations and quantified rates of visual and chemical behaviors. We then cryosectioned brain tissues from 9-10 males of each species and measured the soma size and density of neurons in two brain regions associated with visual behaviors （the lat- eral geniculate nucleus and the nucleus rotundus） and one region associated with chemical behaviors （the nucleus sphericus）. With analyses conducted in a phylogenetic context, we found that species that performed higher rates of visual displays had a denser lateral geniculate nucleus, and species that used a higher proportion of chemical displays had larger somas in the nucleus sphericus. These relationships suggest that neural morphologies in the brain have evolved convergently in species with similar communication behaviors .
