Trend towards varying combinatorial centromere association in morphologically identical clusters in Purkinje neurons.

Neurons with similar morphology and neurotransmitter content located at a specific brain region may be part of the same or functionally separate networks. To address the question whether morphologically similar neurons have similar structural architecture at the chromosomal level, we studied Purkinje neurons in the cerebellum. Previous studies have shown that in Purkinje neurons centromeres of several chromosomes form clusters and that the number and size of these clusters remain stable in the adult brain. We examined whether the same set of centromeres form clusters in all the Purkinje neurons. Fluorescent in situ hybridization (FISH) with chromosome-specific para-centromeric probes provided an indirect evidence for a trend towards varying contributions from different chromosomes forming the centromeric clusters in adjacent Purkinje neurons. The results of the study indicate that the individual Purkinje neurons are likely unique in inter-chromosomal spatial associations.