Article
Rescuing Perishable Neuroanatomical Information from a Threatened Biodiversity Hotspot: Remote Field Methods for Brain Tissue Preservation Validated by Cytoarchitectonic Analysis, Immunohistochemistry, and X-Ray Microcomputed Tomography
PLoS ONE
(2016)
Abstract
Biodiversity hotspots, which harbor more endemic species than elsewhere on Earth, are
increasingly threatened. There is a need to accelerate collection efforts in these regions
before threatened or endangered species become extinct. The diverse geographical, ecological,
genetic, morphological, and behavioral data generated from the on-site collection of
an individual specimen are useful for many scientific purposes. However, traditional methods
for specimen preparation in the field do not permit researchers to retrieve neuroanatomical
data, disregarding potentially useful data for increasing our understanding of brain
diversity. These data have helped clarify brain evolution, deciphered relationships between
structure and function, and revealed constraints and selective pressures that provide context
about the evolution of complex behavior. Here, we report our field-testing of two commonly
used laboratory-based techniques for brain preservation while on a collecting
expedition in the Congo Basin and Albertine Rift, two poorly known regions associated with
the Eastern Afromontane biodiversity hotspot. First, we found that transcardial perfusion fixation
and long-term brain storage, conducted in remote field conditions with no access to
cold storage laboratory equipment, had no observable impact on cytoarchitectural features
of lizard brain tissue when compared to lizard brain tissue processed under laboratory conditions. Second, field-perfused brain tissue subjected to prolonged post-fixation
remained readily compatible with subsequent immunohistochemical detection of neural
antigens, with immunostaining that was comparable to that of laboratory-perfused brain tissue.
Third, immersion-fixation of lizard brains, prepared under identical environmental conditions,
was readily compatible with subsequent iodine-enhanced X-ray microcomputed
tomography, which facilitated the non-destructive imaging of the intact brain within its skull.
In summary, we have validated multiple approaches to preserving intact lizard brains in
remote field conditions with limited access to supplies and a high degree of environmental
exposure. This protocol should serve as a malleable framework for researchers attempting
to rescue perishable and irreplaceable morphological and molecular data from regions of
disappearing biodiversity. Our approach can be harnessed to extend the numbers of species
being actively studied by the neuroscience community, by reducing some of the difficulty
associated with acquiring brains of animal species that are not readily available in
captivity.
Disciplines
Publication Date
Spring May 19, 2016
DOI
doi:10.1371/journal.pone.0155824
Citation Information
Daniel F Hughes, Ellen M. Walker, Paul M Gignac, Anais Martinez, et al.. "Rescuing Perishable Neuroanatomical Information from a Threatened Biodiversity Hotspot: Remote Field Methods for Brain Tissue Preservation Validated by Cytoarchitectonic Analysis, Immunohistochemistry, and X-Ray Microcomputed Tomography" PLoS ONE Vol. 11 Iss. 5 (2016) p. e0155824 Available at: http://works.bepress.com/arshad_m_khan/20/