Neuroscience research
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Neuroscience research · Dec 2009
Radiological and histological changes following cerebral venous sinus thrombosis in a rat model.
Cerebral venous sinus thrombosis (CVST) is an important cause of stroke in young especially after pregnancy. We induced CVST in rat by topical application of ferric chloride over the exposed superior sagittal sinus (SSS) and pathological changes were monitored on days 1, 2 and 7. Thrombus weight was estimated and H&E staining was performed for comparison with MRI data. ⋯ On histological evaluation, neuronal necrosis and cellular infiltration were observed in cortical region after thrombosis. The early decrease in ADC could be attributed to cytotoxic edema that precedes vasogenic edema indicated by normalization of ADC and a decreased T2 hyper intensity. In conclusion, ferric chloride induced CVST in the rat produces cytotoxic edema in early stage followed by vasogenic edema which is related to recanalization of the superior sagittal sinus.
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Neuroscience research · Dec 2009
Vasopressin and sympathetic systems mediate the cardiovascular effects of the GABAergic system in the bed nucleus of the stria terminalis.
The bed nucleus of the stria terminalis (BST) is an important part of the limbic system. It has been shown that chemical stimulation of the BST elicited cardiovascular depressive and bradycardic responses. It was also demonstrated that GABA is present in the BST, though its role in cardiovascular control is not yet understood. ⋯ This suggests that the sympathetic system is involved in the bradycardic effect of GABA. On the other hand, administration (i.v.) of a selective vasopressin V(1) receptor antagonist abolished the pressor effect of BMI, which indicates that the GABAergic system of the BST decreases the arterial pressure via tonic inhibition of vasopressin release. In summary, we demonstrated, for the first time, that GABA exerts its influence in the BST through the activation of GABA(A), but not GABA(B), receptors that, in turn, tonically inhibit vasopressin release and sympathetic outflow to the heart.