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Pereno G.l.,National University of Cordoba | Pereno G.l.,Institute Investigaciones Medicas Mercedes y Martin Ferreyra | Beltramino C.A.,National University of Cordoba | Beltramino C.A.,Institute Investigaciones Medicas Mercedes y Martin Ferreyra
Brain Research | Year: 2010

Repeated seizures induce permanent alterations of the brain in experimental models and patients with intractable temporal lobe epilepsy (TLE), which is a common form of epilepsy in humans. Together with cell loss and gliosis in many brain regions, synaptic reorganization is observed principally in the hippocampus. However, in the amygdala this synaptic reorganization has been not studied. The changes in Zn density, synaptophysin and MAP2 as markers of reactive synaptogenesis in medial extended amygdala induced by kainic acid (KA) as a model of TLE was studied. Adult male rats (n = 6) were perfused at 10 days, 1, 2, 3 and 4 months after KA i.p. injection (9 mg/kg). Controls were injected with saline. The brains were processed by the Timm's method to reveal synaptic Zn and analyzed by densitometry. Immunohistochemistry was used to reveal synaptophysin and MAP2 expression. A two-way ANOVA was used for statistics, with a P < 0.05 as a significance limit. Normal dark staining was seen in all medial extended amygdala subdivisions of control animals. At 10 days post KA injection a dramatic loss of staining was observed. A slow but steady recovery of Zn density can be followed in the 4 month period studied. Parallel, from 10 days to 2 months stronger synaptophysin expression could be observed, whereas MAP2 expression increased from 1 month with peak levels at 3-4 months. The results suggest that a process of sprouting exists in surviving neurons of medial extended amygdala after status epilepticus and that these neurons might be an evidence of a reactive synaptogenesis process. © 2010.


Pereno G.L.,National University of Cordoba | Pereno G.L.,Institute Investigaciones Medicas Mercedes y Martin Ferreyra | Balaszczuk V.,Institute Investigaciones Medicas Mercedes y Martin Ferreyra | Beltramino C.A.,National University of Cordoba | Beltramino C.A.,Institute Investigaciones Medicas Mercedes y Martin Ferreyra
Experimental and Toxicologic Pathology | Year: 2012

Previously we have demonstrated that medial nucleus of the amygdala, which is part of medial extended amygdala, is damaged by status epilepticus induced by kainic acid (KA) and this neurodegeneration was prevents by estrogen replacement. The medial bed nucleus of stria terminalis (BSTM) also belong to medial extended amygdala and it is uncertain whether the gonadal hormones are protective or not against this neurotoxicity in the BSTM.Here we show that a single i.p. injection of KA (9. mg/kg) induces neurodegeneration in the subnuclei of the BSTM of rats with different degrees of intensity in males and females. A differential neuroprotective effect of the gonadal hormones was also observed.In diestrous rats, massive neuronal death similar to that in the ovariectomized females was detected. BSTM neurons of proestrous rats, like the ovariectomized treated with estrogen, were significantly less affected by the KA. Testosterone produced a mild neuroprotective action, but dihydrotestosterone did not protect. A similar pattern was observed in all male groups.This results show that estrogen protects BSTM neurons from KA neurotoxicity and androgens are partially neuroprotective; and probably this effect of androgens is due to conversion to estrogen. © 2010 Elsevier GmbH.


Pereno G.L.,National University of Cordoba | Balaszczuk V.,Institute Investigaciones Medicas Mercedes Y Martin Ferreyra | Beltramino C.A.,National University of Cordoba
Journal of Physiology and Biochemistry | Year: 2011

The olfactory accessory system is specialized in the detection of pheromones, being an afferent to medial extended amygdala. In spite of the fact that numerous phenotypes are found in these structures, in the current literature, there are no detailed descriptions about the phenotype of neurons in the vomeronasal system-medial extended amygdale after their activation by pheromonal stimuli. Using immunohistochemistry for fos and dual immunohistochemistry for fos and phenotypes, here we show that females have a greater number of activated neurons by the pheromonal stimulus. Likewise, a great colocalization of fos with GABA, calretinin, and calbindin was observed in the vomeronasal system-medial extended amygdala. These data suggest that in amygdaloid areas, neuronal excitability is controlled by GABAergic neurons that contain different calcium-binding proteins, indicating the important role of inhibitory control on the incoming sensory pheromonal and olfactory inputs controlled and processed by the vomeronasal system. © University of Navarra 2010.

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