Coevolution of generalist feeding ecologies and gyrencephalic mushroom bodies in insects

Sarah M. Farris, Nathan S. Roberts

Research output: Contribution to journalArticle

98 Citations (Scopus)

Abstract

Here we demonstrate the independent acquisition of strikingly similar brain architectures across divergent insect taxa and even across phyla under similar adaptive pressures. Convoluted cortical gyri-like structures characterize the mushroom body calyces in the brains of certain species of insects; we have investigated in detail the cellular and ecological correlates of this morphology in the Scarabaeidae (scarab beetles). "Gyrencephalic" mushroom bodies with increased surface area and volume of calycal synaptic neuropils and increased intrinsic neuron number characterize only those species belonging to generalist plant-feeding subfamilies, whereas significantly smaller "lissencephalic" mushroom bodies are found in more specialist dung-feeding scarab beetles. Such changes are not unique to scarabs or herbivores, because the mushroom bodies of predatory beetles display similar morphological disparities in generalists vs. specialists. We also show that gyrencephalic mushroom bodies in generalist scarabs are not associated with an increase in the size of their primary input neuropil, the antennal lobe, or in the number of antennal lobe glomeruli but rather with an apparent increase in the density of calycal microglomeruli and the acquisition of calycal subpartitions. These differences suggest changes in calyx circuitry facilitating the increased demands on processing capability and flexibility imposed by the evolution of a generalist feeding ecology.

Original languageEnglish
Pages (from-to)17394-17399
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume102
Issue number48
DOIs
StatePublished - 29 Nov 2005

Fingerprint

Mushroom Bodies
Ecology
Insects
Beetles
Neuropil
Herbivory
Brain
Neurons
Pressure

Keywords

  • Afferent
  • Behavior
  • Carnivore
  • Sociality

Cite this

@article{e4b28bbfbbdb4d28a0f6de262960d1df,
title = "Coevolution of generalist feeding ecologies and gyrencephalic mushroom bodies in insects",
abstract = "Here we demonstrate the independent acquisition of strikingly similar brain architectures across divergent insect taxa and even across phyla under similar adaptive pressures. Convoluted cortical gyri-like structures characterize the mushroom body calyces in the brains of certain species of insects; we have investigated in detail the cellular and ecological correlates of this morphology in the Scarabaeidae (scarab beetles). {"}Gyrencephalic{"} mushroom bodies with increased surface area and volume of calycal synaptic neuropils and increased intrinsic neuron number characterize only those species belonging to generalist plant-feeding subfamilies, whereas significantly smaller {"}lissencephalic{"} mushroom bodies are found in more specialist dung-feeding scarab beetles. Such changes are not unique to scarabs or herbivores, because the mushroom bodies of predatory beetles display similar morphological disparities in generalists vs. specialists. We also show that gyrencephalic mushroom bodies in generalist scarabs are not associated with an increase in the size of their primary input neuropil, the antennal lobe, or in the number of antennal lobe glomeruli but rather with an apparent increase in the density of calycal microglomeruli and the acquisition of calycal subpartitions. These differences suggest changes in calyx circuitry facilitating the increased demands on processing capability and flexibility imposed by the evolution of a generalist feeding ecology.",
keywords = "Afferent, Behavior, Carnivore, Sociality",
author = "Farris, {Sarah M.} and Roberts, {Nathan S.}",
year = "2005",
month = "11",
day = "29",
doi = "10.1073/pnas.0508430102",
language = "English",
volume = "102",
pages = "17394--17399",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
number = "48",

}

TY - JOUR

T1 - Coevolution of generalist feeding ecologies and gyrencephalic mushroom bodies in insects

AU - Farris, Sarah M.

AU - Roberts, Nathan S.

PY - 2005/11/29

Y1 - 2005/11/29

N2 - Here we demonstrate the independent acquisition of strikingly similar brain architectures across divergent insect taxa and even across phyla under similar adaptive pressures. Convoluted cortical gyri-like structures characterize the mushroom body calyces in the brains of certain species of insects; we have investigated in detail the cellular and ecological correlates of this morphology in the Scarabaeidae (scarab beetles). "Gyrencephalic" mushroom bodies with increased surface area and volume of calycal synaptic neuropils and increased intrinsic neuron number characterize only those species belonging to generalist plant-feeding subfamilies, whereas significantly smaller "lissencephalic" mushroom bodies are found in more specialist dung-feeding scarab beetles. Such changes are not unique to scarabs or herbivores, because the mushroom bodies of predatory beetles display similar morphological disparities in generalists vs. specialists. We also show that gyrencephalic mushroom bodies in generalist scarabs are not associated with an increase in the size of their primary input neuropil, the antennal lobe, or in the number of antennal lobe glomeruli but rather with an apparent increase in the density of calycal microglomeruli and the acquisition of calycal subpartitions. These differences suggest changes in calyx circuitry facilitating the increased demands on processing capability and flexibility imposed by the evolution of a generalist feeding ecology.

AB - Here we demonstrate the independent acquisition of strikingly similar brain architectures across divergent insect taxa and even across phyla under similar adaptive pressures. Convoluted cortical gyri-like structures characterize the mushroom body calyces in the brains of certain species of insects; we have investigated in detail the cellular and ecological correlates of this morphology in the Scarabaeidae (scarab beetles). "Gyrencephalic" mushroom bodies with increased surface area and volume of calycal synaptic neuropils and increased intrinsic neuron number characterize only those species belonging to generalist plant-feeding subfamilies, whereas significantly smaller "lissencephalic" mushroom bodies are found in more specialist dung-feeding scarab beetles. Such changes are not unique to scarabs or herbivores, because the mushroom bodies of predatory beetles display similar morphological disparities in generalists vs. specialists. We also show that gyrencephalic mushroom bodies in generalist scarabs are not associated with an increase in the size of their primary input neuropil, the antennal lobe, or in the number of antennal lobe glomeruli but rather with an apparent increase in the density of calycal microglomeruli and the acquisition of calycal subpartitions. These differences suggest changes in calyx circuitry facilitating the increased demands on processing capability and flexibility imposed by the evolution of a generalist feeding ecology.

KW - Afferent

KW - Behavior

KW - Carnivore

KW - Sociality

UR - http://www.scopus.com/inward/record.url?scp=28444467744&partnerID=8YFLogxK

U2 - 10.1073/pnas.0508430102

DO - 10.1073/pnas.0508430102

M3 - Article

C2 - 16293692

AN - SCOPUS:28444467744

VL - 102

SP - 17394

EP - 17399

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 48

ER -