title: The Isotropic Fractionator as a Tool for Quantitative Analysis in Central Nervous System Diseases.
abstract: One major aim in quantitative and translational neuroscience is to achieve a precise and fast neuronal counting method to work on high throughput scale to obtain reliable results. Here, we tested the isotropic fractionator (IF) method for evaluating neuronal and non-neuronal cell loss in different models of central nervous system (CNS) pathologies. Sprague-Dawley rats underwent: (i) ischemic brain damage; (ii) intraperitoneal injection with kainic acid (KA) to induce epileptic seizures; and (iii) monolateral striatal injection with quinolinic acid (QA) mimicking human Huntington's disease. All specimens were processed for IF method and cell loss assessed. Hippocampus from KA-treated rats and striatum from QA-treated rats were carefully dissected using a dissection microscope and a rat brain matrix. Ischemic rat brains slices were first processed for TTC staining and then for IF. In the ischemic group the cell loss corresponded to the neuronal loss suggesting that hypoxia primarily affects neurons. Combining IF with TTC staining we could correlate the volume of lesion to the neuronal loss; by IF, we could assess that neuronal loss also occurs contralaterally to the ischemic side. In the epileptic group we observed a reduction of neuronal cells in treated rats, but also evaluated the changes in the number of non-neuronal cells in response to the hippocampal damage. In the QA model, there was a robust reduction of neuronal cells on ipsilateral striatum. This neuronal cell loss was not related to a drastic change in the total number of cells, being overcome by the increase in non-neuronal cells, thus suggesting that excitotoxic damage in the striatum strongly activates inflammation and glial proliferation. We concluded that the IF method could represent a simple and reliable quantitative technique to evaluate the effects of experimental lesions mimicking human diseases, and to consider the neuroprotective/anti-inflammatory effects of different treatments in the whole brain and also in discrete regions of interest, with the potential to investigate non-neuronal alterations. Moreover, IF could be used in addition or in substitution to classical stereological techniques or TTC staining used so far, since it is fast, precise and easily combined with complex molecular analysis.
authors.affiliation: Neuroscience Institute Cavalieri Ottolenghi, Department of Neuroscience, University of Turin Turin, Italy.
authors.forename: Ivan E
authors.initials: IE
authors.lastname: Repetto
authors.affiliation: Neuroscience Institute Cavalieri Ottolenghi, Department of Neuroscience, University of Turin Turin, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Monti
authors.affiliation: Neuroscience Institute Cavalieri Ottolenghi, Department of Neuroscience, University of Turin Turin, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Tropiano
authors.affiliation: Child Study Center, Yale School of Medicine, New Haven CT, USA.
authors.forename: Simone
authors.initials: S
authors.lastname: Tomasi
authors.affiliation: Neuroscience Institute Cavalieri Ottolenghi, Department of Neuroscience, University of Turin Turin, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Arbini
authors.affiliation: Federal University of Rio de Janeiro Medical School, Macaé Campus Rio de Janeiro, Brazil.
authors.forename: Carlos-Humberto
authors.initials: CH
authors.lastname: Andrade-Moraes
authors.affiliation: Institute of Biomedical Sciences, Federal University of Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Roberto
authors.initials: R
authors.lastname: Lent
authors.affiliation: Neuroscience Institute Cavalieri Ottolenghi, Department of Neuroscience, University of Turin Turin, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Vercelli
keywords: cerebral ischemia; epilepsy; isotropic fractionator; neuroprotection; striatal lesion