THE EFFECT OF CENTRAL ASIAN COBRA VENOM ON THE VESTIBULAR COMPENSATION AND REGENERATION OF NEURON

Unilateral Labyrinthectomy (UL) causes a syndrome of oculomotor, postural,
and autonomic system disorders which diminish over time in a process of behavioral recovery known
as vestibular compensation. Many studies have been done on the vestibular compensation after
unilateral labyrinthectomy (UL) and regeneration of nerve cells, but the mechanism of vestibular
compensation and regeneration nerve cells are not well known. The aim of this research was to study
the effect of cobra venom on the vestibular compensation and regeneration of nerve cells of vestibular
nuclei after damage of vestibular apparatus.
Materials & Methods: The present experimental study was carried out on 20 adult male albino rat’s
weight 230±30 gr. At first, the rats were randomly divided into dual groups include; Normal, UL and,
UL with NOX. Electrophysiological and histhochemically experiments were carried out on these
groups. For electrophysiology assessment of paraventricular and supraoptic nuclei of hypothalamus
were stimulated bipolar with high frequency stimulus 50 and 100 HZ during one second. The electrical
activity of membrane cells of bilateral Dieters’ neurons on the form of titanic potanseation and
depression were recorded. The end of electrophysiological experiment the brain stem rats were
removed and put into solution of 5% neutral formalin for assessment of ca2 depended acidic
phosphates and after 48 hours for assessment of morphology was performed.
Results: The increasing of inhibitory and excitatory reactions of Dieters’ neurons at early stage of
vestibular compensation following NOX injection reaching the norm at late stage was revealed. In
histochemical study after unilateral labyrenthectomy decrease in the activity of ca2-dependent acidic
phosphates and chromotholysis, swelling of neurons were observed. The neurons look like
degeneration pattern. But in the unilateral labyrinthectomy with NOX group, shape of cells was
polygonal and smooth surface with high granulation. The pattern of cells was like norm cells.
Conclusion: The cobra venom not only causes acceleration of vestibular compensation, but also
causes regeneration of damage side of lateral vestibular nucleus neurons