MORPHOFUNCTIONAL PROPERTIES OF MICROTUBULE ULTRASTRUCUTURE AND MAP2 PROTEIN
PHOSPHORYLATION IN HIPPOCAMPAL NEURONES OF RATS WITH PREDISPOSITION TO AUDIOGENIC EPILEPSY
E. N. Bezgina,1 D. A. Moshkov,1, 2 S. N. Yechikhov,1
T. A. Savina,1 S. V. Kamenev,1 E. D. Morenkov,3 T. G. Shchipakina 1
1 Institite of Theoretical and Experimental Biophysics RAS, Pushchino,
2 Chair of Histology, Pushchino State University, and
3 Chair of Higher Nervous Activity, Moscow State University, Russia;
e-mail: cellpath@mail.cytspb.rssi.ru
It has been shown that modification of microtubule (MT) ultrastructure are accompanied by functional changes in
microtubule-associated protein MAP2 in the hippocampus of Krushinsky-Molodkina rats (KM), which are prone to autogenic seizures.
The morphogenetic analysis revealed that contrary to Wistar rats, which are insensitive to sound stimulation, in KM the middle length of
microtubule fragments in the apical dendrites of pyramidal neurons in ÑÀÇ hippocampal area was reduced. Using immunoblot and
autoradiography methods, we found that the level of MAP2 and the rate of its cAMP- and Ca2+-calmodulin-dependent
phosphorylation were increased in hippocampus of KM, in comparison with Wistar rats. Daily repeated so-und stimulation for 20 days
(audiogenic kindling) induced a further decrease in length of MT fragments, and an increase of their density in the proximal part of apical
dendrites of KM. Moreover, audiogenic kindling in-duced additional increase in MAP2 phosphorylation state, but did not change the level
of MAP2 in KM hippocampus. We suppose that the obtained alteration of MAP2 phosphorylation state exerted influence on kinetic
parameters of microtubule assembly, serving as part of genetically determined predisposition of KM to audiogenic epilepsy.
Key words: audiogenic seizures, microtubule, hippocampus, MAP2 phosphorylation
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