ALTERATION OF EXTRACELLULAR MATRIX MOLECULES IN THE DEVELOPING MOUSE BRAINSTEM
01/29/2020
Ildikó Wéber1, András Birinyi1, Klara Matesz1
1 University of Debrecen, Department of Anatomy, Histology and Embryology, Debrecen, Hungary
The molecular and structural composition of the extracellular matrix (ECM) in the central nervous system undergoes profound transformation during embryonic development and early postnatal period of life. In our study, we wanted to follow the changes of different ECM molecules in the developing mouse brainstem by using histochemical probe for hyaluronic acid (HA), and antibodies against aggrecan, neurocan, versican, tenascin (TN-R) and hyaluronan and proteoglycan link protein (HAPLN1) molecules. Wisteria floribunda agglutinin (WFA) histochemistry was used for general marker of perineuronal net (PNN) as it binds to N-acetylgalactosamine residues of CSPG-glycosaminoglycan chains. We found that HA, neurocan and versican reactions appeared as diffuse staining in the neuropil at different embryonic stages. We could not find any aggrecan, WFA or HAPLN1 staining before birth. The PNNs -composed of aggrecan- were detected after birth in the reticular formation and in the vestibular and other brainstem nuclei. Postnatally WFA, aggrecan and HAPLN1 were restricted to the neuropil of some brainstem nuclei, in contrast to HA, neurocan and TN-R which were found throughout the brainstem. Our results demonstrated that ECM molecules occurred first in the neuropil of the brainstem at early stages of development. The formation of a definitive PNN is recognizable postnatally but it is well developed after two weeks. We found spatiotemporal differences concerning the distribution of different ECM molecules in the neuropil and in the perineuronal net in various parts and nuclei of the brainstem. The pattern of ECM expression may be related to different maturation processes (neurogenesis, synaptogenesis) in the neural circuits of the brainstem. Grant sponsor: OTKA K115471, MTA-TKI 11008