Interaction between ?-amyloid protein and the ?7 nicotinic acetylcholine receptor in cholinergic, gabaergic and calcium-binding proteins-containing neurons in the septum-diagonal band complex of the rat

• Autores: Alicia Gonzalo Ruiz, Juan Arévalo Serrano
• Localización: European Journal of anatomy, ISSN-e 1136-4890, Vol. 10, Nº. 3, 2006, págs. 127-142
• Idioma: inglés
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• Resumen

  • The effects of intracerebral injection of the beta-amyloid protein (A?1-40) on the ?7 subtype of nicotinic acetylcoline receptor protein (nAChR) in neurons of the septum-diagonal band (MS-nDBB) complex were studied in rats. Focal deposition of A? in the retrosplenial cortex resulted in a selective reduction in the number of ?7nAChR-immunoreactive cells in different parts of the MS-nDBB complex, especially in the horizontal nucleus of the diagonal band of Broca (HDB). The analysis revealed a significant decrease of 37.27% in the number of ?7nAChR-immunoreactive cells in the HDB ipsilateral to the A?-injected side as compared to the corresponding hemisphere of non-treated control animals, and a reduction of 31.55% was observed in the HDB ipsilateral to the A?-injected side as compared to the contralateral HDB, which corresponds to the control (PBS)-injected side. A significant reduction (up to 20%) of ?7nAChR-containing neurons was also found in the medial septal nucleus when compared with the corresponding hemisphere in non-treated control animals. The results also revealed that ?7nAChR-positive immunoreactivity is highly localized within cytoplasmic granules in cholinergic neurons and in a small subset of putative GABAergic cells of the MS-nDBB complex. In conclusion, these findings suggest an interaction of A?1-40 with the ?7nAChR, which may contribute to impairments in cholinergic and GABAergic transmission in the MS-nDBB complex.