Related Experiment Videos
Aluminium maltol-induced neurocytoskeletal changes in fetal rabbit midbrain in matrix culture
C D Hewitt1, M M Herman, M B Lopes
1Department of Pathology, University of Virginia Health Sciences Center, Charlottesville 22908.
Abstract:
We have developed a neuronal culture system to evaluate the neurotoxic effects of aluminium maltol on fetal rabbit midbrain sections containing the oculomotor nucleus. Cultures were treated with 5, 7, 9, 11, 13 and 15 mumol/l aluminium maltol or 39 and 45 mumol/l maltol (molal equivalents to 13 and 15 mumol/l aluminium maltol). Control cultures were maintained in nutrient medium alone. Silver-positive neuritic swellings and occasional perikaryal neurofibrillary tangles were observed in cultures treated with 11, 13 and 15 mumol/l aluminium maltol. The number of tangles (involved neurons) produced in aluminium maltol treated cultures were counted and compared to (untreated) controls. We observed a total of 3, 7 and 7% of involved neurons following treatment with 11, 13 and 15 mumol/l aluminium maltol respectively, and none in the control group. By immunohistochemistry, neurofibrillary tangles were immunoreactive with MAbs to phosphorylated (SMI-31), non-phosphorylated, phosphorylation dependent (SMI-32) and phosphorylation independent (SMI-33) epitopes of the high (-H) and middle (-M) molecular weight neurofilament subunits (NF-H/M). By contrast these lesions were nonreactive with MAbs recognizing tau, MAP2 or different beta-tubulin isotypes. The perikaryal tangles consisted of focal accumulations of 10 nm straight filaments by electron microscopy. These findings are in agreement with previous data from rabbit in vivo studies after the administration of aluminium maltol intravenously (Bertholf et al., 1989) or intraventricularly (Katsetos et al., 1990). Using this in vitro system, aluminium-induced neurofibrillary tangles can be consistently produced, and changes in the distribution of neurofilament proteins evaluated. These studies may aid in the assessment of the possible role of aluminium in the aetiology of human neurodegenerative disorders.
Insights
Researchers created a neuronal culture to study aluminium maltol neurotoxicity. This system successfully produced aluminium-induced neurofibrillary tangles in rabbit brain cells, aiding research into neurodegenerative disorders.
Area of Science:
- Neuroscience
- Toxicology
- Cell Biology
Background:
- Aluminium exposure is linked to neurodegenerative diseases.
- Understanding the mechanisms of aluminium neurotoxicity is crucial.
- Previous in vivo studies suggest aluminium maltol induces neurofibrillary changes.
Purpose of the Study:
- To develop and validate an in vitro neuronal culture system for assessing aluminium maltol neurotoxicity.
- To characterize the formation and composition of aluminium-induced neurofibrillary tangles in a controlled neuronal environment.
- To investigate the role of neurofilament proteins in aluminium-induced pathology.
Main Methods:
- Primary neuronal cultures derived from fetal rabbit midbrain (oculomotor nucleus).
- Treatment with varying concentrations of aluminium maltol and maltol.
- Histopathological analysis using silver staining.
- Immunohistochemistry with antibodies against neurofilament subunits (SMI-31, SMI-32, SMI-33), tau, MAP2, and beta-tubulin.
- Electron microscopy to examine tangle ultrastructure.
Main Results:
- Aluminium maltol induced silver-positive neuritic swellings and neurofibrillary tangles in a dose-dependent manner (11-15 µmol/l).
- Tangles were immunoreactive with neurofilament subunit antibodies (NF-H/M) but not with tau or MAP2 antibodies.
- Electron microscopy revealed tangles composed of 10 nm straight filaments.
- The in vitro results align with previous in vivo findings.
Conclusions:
- The developed neuronal culture system reliably reproduces aluminium-induced neurofibrillary tangles in vitro.
- Neurofibrillary changes involve specific neurofilament protein alterations.
- This in vitro model is valuable for studying aluminium neurotoxicity and its potential role in human neurodegenerative disorders.