Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2012 Jul;236(1):131-40.
doi: 10.1016/j.expneurol.2012.04.008. Epub 2012 Apr 19.

Ontogeny of Lafora bodies and neurocytoskeleton changes in Laforin-deficient mice

Affiliations

Ontogeny of Lafora bodies and neurocytoskeleton changes in Laforin-deficient mice

Jesús Machado-Salas et al. Exp Neurol. 2012 Jul.

Abstract

Lafora disease (LD) is an autosomal recessive, always fatal progressive myoclonus epilepsy with rapid cognitive and neurologic deterioration. One of the pathological hallmarks of LD is the presence of cytoplasmic PAS+polyglucosan inclusions called Lafora bodies (LBs). Current clinical and neuropathological views consider LBs to be the cause of neurological derangement of patients. A systematic study of the ontogeny and structural features of the LBs has not been done in the past. Therefore, we undertook a detailed microscopic analysis of the neuropile of a Laforin-deficient (epm2a-/-) mouse model. Wild type and epm2a-/- mice were sacrificed at different ages and their encephalon processed for light microscopy. Luxol-fast-blue, PAS, Bielschowski techniques, as well as immunocytochemistry (TUNEL, Caspase-3, Apaf-1, Cytochrome-C and Neurofilament L antibodies) were used. Young null mice (11 days old) showed necrotic neuronal death in the absence of LBs. Both cell death and LBs showed a progressive increment in size and number with age. Type I LBs emerged at two weeks of age and were distributed in somata and neurites. Type II LBs appeared around the second month of age and always showed a complex architecture and restricted to neuronal somata. Their number was considerably less than type I LBs. Bielschowski method showed neurofibrillary degeneration and senile-like plaques. These changes were more prominent in the hippocampus and ventral pons. Neurofibrillary tangles were already present in 11 days-old experimental animals, whereas senile-like plaques appeared around the third to fourth month of life. The encephalon of null mice was not uniformly affected: Diencephalic structures were spared, whereas cerebral cortex, basal ganglia, pons, hippocampus and cerebellum were notoriously affected. This uneven distribution was present even within the same structure, i.e., hippocampal sectors. Of special relevance, was the observation of the presence of immunoreactivity to neurofilament L on the external rim of type II LBs. Perhaps, type II LB is not the end point of a metabolic abnormality. Instead, we suggest that type II LB is a highly specialized structural and functional entity that emerges as a neuronal response to major carbohydrate metabolism impairment. Early necrotic cell death, neurocytoskeleton derangement, different structural and probably functional profiles for both forms of LBs, a potential relationship between the external rim of the LB type II and the cytoskeleton and an uneven distribution of these abnormalities indicate that LD is both a complex neurodegenerative disease and a glycogen metabolism disorder. Our findings are critical for future studies on disease mechanisms and therapies for LD. Interestingly, the neurodegenerative changes observed in this LD model can also be useful for understanding the process of dementia.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Cell death in very young laforin-deficient mouse. Panoramic views of the cerebral cortex (A), hippocampus (B) and cerebellum (C) from 11 days old laforin-deficient mouse. Notice the presence of collapsed and intensively stained (“dark”) neuronal cytoplasm (white arrows) and the absence of PAS+ inclusions. PS-Cerebral cortex pial surface; CA3-Hippocampal sector; ML-Cerebellum molecular layer; GL-Granule cell layer. PAS stain. Scale bar: A, B and C: 100 μm.
Figure 2
Figure 2
Ontogeny of Lafora bodies. (A–C) null mouse cerebral cortex showing progressive increment of LBs from early to late age (A-11 days old; B-9 months old; C 16-months old, laforin-deficient mouse). PAS+ reaction observed in A corresponds to blood vessels wall (arrows). In an older animal B, some LBs are seen in several cortical layers. Interestingly, abundant LBs appear as subpial conglomerates (arrows). Prominent number of PAS + inclusions are seen in the cerebral cortex from a 16 months old null mouse (C arrows). A similarly progressive deposit of LBs was observed in many other central nervous system structures. LBs were very prominent in the granule cell layer of cerebellum, as shown in a 26-months-old null mouse (D). Also, notice an intense PAS reaction within Purkinje cells cytoplasm (arrows). (PS-Cerebral cortex pial surface; GL-Granule cell layer; ML-Molecular layer). PAS stain. Scale bar A, C-100 μm; B- 40 μm; D –60 μm.
Figure 3
Figure 3
It appears that the final structural and molecular impact, triggered by lack of laforin is not uniform throughout the nervous system. (A) Illustrates a moderate deposit of LBs in hippocampus CA2 sector and a well-preserved neuropile. (B) Illustrates an advanced loss of the cytoarchitecture of the closely related CA4 sector with a prominent accumulation of PAS+ inclusions (A and B- 20-month-old null mouse). (C, D) depict a similar contrast between contiguous anatomic structures. In (C), the pontine periaqueductal grey matter, at the level of the VI cranial nerve nucleus shows a minimum amount of LBs. However, the dorsolateral pons, at the level of the vestibular nucleus, depicts an intense reaction to PAS stain (C, D- 9 month old mouse). (PAGM- Periaqueductal Grey Matter; VI- VI Cranial Nerve Nucleus; VN- Vestibular Nucleus; ML- Midline). PAS stain. Scale bar: A 75 μm; B 60 μm; C and D 150 μm.
Figure 4
Figure 4
Lafora bodies: Distribution and forms. (A, B) show the widely scattered type I LBs. They can be seen inside neurites (A, double arrow) as well as intrasomatic (B). They are more abundant in the neuropile and display different size and shape. The second type (Van Hoof’s Type II) are complex ring-like structures, limited in number and always restricted to an intracytoplasmic location (C, arrows). Notice the strong similarities between null mouse type II LBs (C) and an equivalent LB from a patient with LD (D). A, B, C- Nerve cells from the pontine reticular nucleus (Magnocellular). D- LD Human cerebral cortex. PAS stain. Scale bar: A- 20 μm; B- 10 μm; C- 30 μm; D- 15 μm.
Figure 5
Figure 5
Even though some diencephalic nuclei did not show a noticeable impact due to lack of laforin, most null mice structures showed a variable involvement. (A, B) depict a delicate but widespread deposit of LBs in the neuropile of the striatum and the septal nucleus respectively. By far, most of these polyglucosan inclusions are made of Type I LBs. On the other hand, the ventral part of the pons of experimental animals was characterized by massive deposits of polyglucosans (C, D), creating notorious alterations of the myelo- and cythoarchitectonics of the ventral tegmental region and a mosaic-like appearance. (A-D) 9 months old null mouse. PAS stain. Scale bar A, C- 160 μm; B, D- 75 μm.
Figure 6
Figure 6
(A) A prominent argyrophillic and collapsed nerve cell (long arrow) is observed in the ventral pons surrounded by normal neurons (short arrows), in an 11-day old null mouse. (B) Neuropile from a 9-month-old null mouse showing several neurons displaying somatodendritic distortion. One of them is fully collapsed (long arrow). Notice an abnormally large neurite displaying a “corkscrew” argyrophillic pattern (short arrow). (C) A notoriously dilated neuron (arrow) with a translucent cytoplasmic area corresponding to a LB. The remaining dark cytoplasmic content includes a distorted cytoskeleton and nucleus. Around it, many grossly argyrophillic neurites show an unorderly arrangement (20-month-old laforin-deficient mouse). (D) Multiple “negative images” of type I LBs (oval) and LBs type II (square) can be seen. Thick argyrophilic bands are contained in neurites and somata. A moderate argyrophilia is evident in the external ring of type II LBs (inset) 20 months old null mouse, ventral pons. Bielschowski method. Scale bar: A, B and C- 50 μm; D- 100 μm.
Figure 7
Figure 7
Two LBs type II are present in a nerve cell from the pontine reticular nucleus, pars magnocellularis. A centrally located nucleus separates them. 20 month-old null mouse. Bielschowski method. Scale bar: 30 μm
Figure 8
Figure 8
Presence of Neurofilament L in the external rim of LBs. (A) a ring-like structure eventually identified as type II LB, shows an intense immunoreaction to neurofilament L surrounding its “empty” core. (B) When a green filter was used, an “spheroidal” or punctuated appearance was unveiled, emphasizing their individuality. (C) Occasionally, we observe a nerve cell containing two of these immunoreactive rings. Even though the diameter is different, their structural resemblance is high. Notice a peripherally displaced and collapsed nucleus (arrow). (D) Another example of immunoreaction to neurofilament L within a type II LB, contained in an apparently normal superior colliculus neuron. (A, B, C) Cortical neurons. Antineurofilament L immunostaining. Scale bar: A, B- 10 μm. C, D- 20 μm.
Figure 9
Figure 9
Type II Lafora Body, a simple reservoir or highly specialized metabolic machinery? The punctated immunoreactive structures forming a ring-like intracytoplasmic structure (A), perfectly fit into the external rim of a type II LB, as seen with PAS stain (B). In (C), a large neuron from the ventral pons displays a LB II containing darkly stained structures as revealed by Bielschowski method. (IC- Inner core; ER- External rim; N- Nucleus). (A, C) Laforin-deficient mouse cerebral cortex and ventral pons, respectively. (B) LD Human cerebral cortex. Scale bar: A, B- 5 μm; C- 10 μm.

Similar articles

Cited by

References

    1. Adler D, Horoupian DS, Towfighi J, Gandolfi A, Suzuki K. Status marmoratus and Bielschowsky bodies. A report of two cases and review of the literature. Acta Neuropathol. 1982;56:75–77. - PubMed
    1. Antal M. Lafora bodies in the retina of various animals. J Fr Ophtalmol. 1982;5:615–620. - PubMed
    1. Bielschowski M. Beitrage zur Histopathologie der Ganglienzelle. J Psychol Neurol (Lpz) 1912;18:513–521.
    1. Carden MJ, Trojanowski JQ, Schleapfer WW, Lee VMY. Two-stage expression of neurofilament polypeptides during rat neurogénesis with early establishment of adult phosphorylation. J Neurosci. 1987;7:3489–3504. - PMC - PubMed
    1. Cavanagh JB. Corpora-amylacea and the family of polyglucosan diseases. Brain Res Brain Res Rev. 1999;29:265–295. - PubMed

Publication types

MeSH terms

Substances