CoChat
Sign Up
Cited by 92Primate Behavior and EcologyEvolution and Paleontology StudiesNeurogenesis and neuroplasticity mechanisms

Cellular scaling rules of insectivore brains.

Open access
Sarko, Diana·2009·Frontiers in Neuroanatomy
DOI 10.3389/neuro.05.008.2009PMC PMC2713736
Open this paper in CoChat — free accountOpen PDF

Abstract

Insectivores represent extremes in mammalian body size and brain size, retaining various "primitive" morphological characteristics, and some species of Insectivora are thought to share similarities with small-bodied ancestral eutherians. This raises the possibility that insectivore brains differ from other taxa, including rodents and primates, in cellular scaling properties. Here we examine the cellular scaling rules for insectivore brains and demonstrate that insectivore scaling rules overlap somewhat with those for rodents and primates such that the insectivore cortex shares scaling rules with rodents (increasing faster in size than in numbers of neurons), but the insectivore cerebellum shares scaling rules with primates (increasing isometrically). Brain structures pooled as "remaining areas" appear to scale similarly across all three mammalian orders with respect to numbers of neurons, and the numbers of non-neurons appear to scale similarly across all brain structures for all three orders. Therefore, common scaling rules exist, to different extents, between insectivore, rodent, and primate brain regions, and it is hypothesized that insectivores represent the common aspects of each order. The olfactory bulbs of insectivores, however, offer a noteworthy exception in that neuronal density increases linearly with increasing structure mass. This implies that the average neuronal cell size decreases with increasing olfactory bulb mass in order to accommodate greater neuronal density, and represents the first documentation of a brain structure gaining neurons at a greater rate than mass. This might allow insectivore brains to concentrate more neurons within the olfactory bulbs without a prohibitively large and metabolically costly increase in structure mass.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.3389/neuro.05.008.2009

Cites

49 of 50 references verified1 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • In mammals, the pallium accounts for most of total brain volume, but the cerebellum houses a large majority of brain neurons.

    “This markedly contrasts with the situation found in mammals, in which the pallium accounts for most of total brain volume, but the cerebellum houses a large majority of brain neurons (32–39)”

    From Birds have primate-like numbers of neurons in the forebrain (2016) · cites this paper as [34]

    The Results section ('Relative distribution of mass and neurons across brain structures'; page unavailable) reports that the cerebellum contains an average of 64.6% of neurons in the five insectivore species studied. It reports the combined cerebral cortex and hippocampus as 33–48% of brain mass, but does not establish that the pallium accounts for most brain volume across mammals. (LLM, conf=0.85)

    Experimental — accuracy not yet measured

  • Like in mammals, the proportion of nonneuronal cells is very small in the cerebellum, varying between 12% and 19% in songbirds and between 14% and 19% in parrots, but, in contrast to mammals, nonneuronal cells also constitute a minor cellular fraction in the telencephalon, representing 21-40% of cells in songbirds and 31-43% of cells in parrots.

    “Like in mammals (32–39, 46), the proportion of nonneuronal cells is very small in the cerebellum, varying between 12% and 19% in songbirds and between 14% and 19% in parrots, but, in contrast to mammals, nonneuronal cells also constitute a minor cellular fraction in the telencephalon, representing 21–40% of cells in songbirds and 31–43% of cells in parrots”

    From Birds have primate-like numbers of neurons in the forebrain (2016) · cites this paper as [34]

  • Brain metabolism is not necessarily related to whole body metabolism in any determining way; any apparent relationship might be coincidental and dependent on the rate with which brain size scales as a function of its number of neurons.

    “the scaling of brain metabolism as a function of total numbers of neurons opens the possibility that brain metabolism is not necessarily related to whole body metabolism in any determining way; any apparent relationship might be coincidental, and dependent on the rate with which brain size scales as a function of its number of neurons, which we have shown to vary across mammalian orders [24], [25]”

    From Scaling of Brain Metabolism with a Fixed Energy Budget per Neuron: Implications for Neuronal Activity, Plasticity and Evolution (2011) · cites this paper as [41]

  • There is no uniform scaling of neuronal density with brain size.

    “However, it has now been demonstrated that there is no uniform scaling of neuronal density with brain size [24], [25], [41], which invalidates the previous estimate”

    From Scaling of Brain Metabolism with a Fixed Energy Budget per Neuron: Implications for Neuronal Activity, Plasticity and Evolution (2011) · cites this paper as [41]

  • The previous estimate that average energy use per neuron increases with brain size is invalidated.

    “However, it has now been demonstrated that there is no uniform scaling of neuronal density with brain size [24], [25], [41], which invalidates the previous estimate”

    From Scaling of Brain Metabolism with a Fixed Energy Budget per Neuron: Implications for Neuronal Activity, Plasticity and Evolution (2011) · cites this paper as [41]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Stephan H. Baron G. Frahm H. D. (1991). Insectivora. In Comparative Brain Research in Mammals, Vol. 1 New York, NY, Springer-Verlag

Cited by

Sorted by citations

Related

Authors
Sarko, D.
Affiliations
Vanderbilt University (US)
Corresponding author
Sarko, Diana
ORCID
Sarko, Diana
Venue
Frontiers in Neuroanatomy
Publisher
Frontiers Media SA
Published
2009
Volume
3
Pages
8-8
ISSN
1662-5129 (ISSN-L)
DOI
10.3389/neuro.05.008.2009
PMC
PMC2713736
OpenAlex
W2054236829
Cited by
92
References
48
Citations by year
2025: 2 · 2024: 1 · 2023: 2 · 2022: 2 · 2021: 8 · 2020: 4 · 2019: 2 · 2018: 4 · 2017: 5 · 2016: 8 · 2015: 7 · 2014: 16 · 2013: 6 · 2012: 11
FWCI
10.88
Type
journal article
Language
en
Open access
Licence
cc-by
Locations
  • Frontiers in Neuroanatomy (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
  • UpSpace Institutional Repository (University of Pretoria) (submittedVersion, cc-by)
Funders
  • National Science Foundation (0844743)
  • Conselho Nacional de Desenvolvimento Científico e Tecnológico
  • Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro
  • National Institutes of Health
  • National Eye Institute (R01EY002686)
  • National Institute of Neurological Disorders and Stroke (R01NS016446)
  • National Institute of Dental and Craniofacial Research (R21DE014739)
Topics
  • Social Sciences › Psychology › Social Psychology › Primate Behavior and Ecology
  • Physical Sciences › Earth and Planetary Sciences › Paleontology › Evolution and Paleontology Studies
  • Life Sciences › Neuroscience › Developmental Neuroscience › Neurogenesis and neuroplasticity mechanisms
Keywords
brain scaling, neuronal density, brain mass, olfactory bulb, cerebellum, cerebral cortex, rodent brain, primate brain, brain evolution, body size

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review