Cholinergic, serotonergic and catecholaminergic neurons are not affected in Ts65Dn mice

Ts65DN mice were developed as a model of Down syndrome (DS); they are trisomic for the distal segment of chromosome 16 (MMU16), which contains genes syntenic with some of the genes located on the critical region of human chromosome 21 (HSA21). Since behavioral and neurochemical disturbances have been observed in this animal model, it seemed interesting to perform an immunohistochemical characterization of the main cholinergic, catecholaminergic and serotonergic nuclei. However, when the brains of Ts65Dn mice were compared with those of control littermates, no differences were found either in the morphology of the neurons of the three systems or in the number of immunoreactive cells. The results indicate that these systems are not affected by the triplication of some of the genes present on chromosome 16.