Neural excitability, synaptic transmission and neuron-glia interactions
Author: Ana Paula Sieben Samek | email: anapsieben1@campus.fmed.uba.ar
Ana Paula Sieben Samek 1°, Javier Fotti 1°, Agustina Stahl 1°, Verónica Risso 1°, Lorena Rela 1°
1° Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Universidad de Buenos Aires y CONICET
Olfactory nerve regeneration after toxic damage is associated with increased density and reactivity of myeloid cells along the afferent olfactory pathway. Whether the reactivity and proliferation of these cells contribute with regeneration remains controversial. Here we evaluated whether minocycline, a modified tetracycline that inhibits proliferation and reactivity of myeloid cells, has an effect on the rate of regeneration of the damaged olfactory epithelium. We treated C57BL/6 mice with the olfatotoxin methimazole (75 mg/kg) and 2 days later half the animals received minocycline (0.25 mg/ml in drinking water) or regular water during 2 weeks. We found that minocycline significantly increased the degree of recovery of olfactory epithelium thickness (38% by week 1 and 10% by week 2 after damage). This improvement was not reflected in the proportion of mature neurons produced during regeneration at the observed time points. However, the minocycline treatment produced a larger proportion of immature neurons during early regeneration and a smaller proportion of immature neurons during late regeneration (p=0.0468 and p=0.006, post-hoc tests after significant interaction in 2-way ANOVA). These results indicate that minocycline is a modulator of olfactory nerve regeneration. A more detailed time course analysis of regeneration including additional cell identity markers will shed light on the dynamics of this modulation.