Developmental and cell type‐specific expression of the neuronal marker NeuN in the murine cerebellum

Abstract

NeuN is a 46/48-kD nuclear protein antigen used widely to identify postmitotic neurons in both research and diagnostics. It is expressed by neurons throughout the nervous system of a variety of species, including birds, rodents, and man (Mullen et al. [1992] Development 116:201-211). When we sought to use NeuN to follow the developmental progression of murine cerebellar interneurons, we observed that expression of this antigen in the cerebellum was restricted to granule neurons and a small population of cells present in the lower molecular layer of the adult cerebellum. In an attempt to identify these cells, we combined immunostaining for NeuN with a panel of cell type-specific markers to unambiguously identify neurons that express NeuN in the adult and developing cerebellum. In contrast to postmitotic granule neurons, NeuN was not expressed by any other immunocytochemically identified cerebellar interneurons, which comprised basket and stellate cells, Golgi neurons, unipolar brush cells, and Lugaro cells. NeuN-positive cells in the molecular layer failed to express any cell type-specific markers tested. They may represent ectopic granule cells; alternatively, they may represent a hitherto unknown population of cerebellar cells. In vitro experiments suggest that NeuN expression is related closely to granule cell axogenesis. This approach also revealed that the level of NeuN expression could be modulated by chronically depolarizing these cells. Thus, whereas NeuN expression per se is a reliable marker of proliferative capacity, levels of NeuN expression may also be indicative of the physiological status of a postmitotic neuron.

Are cyclooxygenase-2 and nitric oxide involved in the dyskinesia of Parkinson's disease induced byl-DOPA?

“…COX2-positive labelling co-localized with immunoreactivity for NeuN (figure 1a-e), a 46/48 kD neuronal nuclear protein antigen widely used to identify neurons [65,66].…”

Different Types of Cerebellar GABAergic Interneurons Originate from a Common Pool of Multipotent Progenitor Cells

“…Their phenotypes were determined on the basis of several criteria, including (1) morphological features, (2) expression of type-specific markers, (3) morphometric parameters (e.g., cell body size), and (4) position in the host cortical layers or deep nuclei. The different types of GABAergic interneurons were identified according to the expression pattern of a set of distinctive markers and assigned to different categories: deep nuclei interneurons [NeuN/calretinin (Bastianelli, 2003;Weyer and Schilling, 2003)]; granular layer interneurons for Golgi [mGluR2/Pax-2 Grimaldi and Rossi, 2006)] and Lugaro cells [calretinin (Dino et al, 1999;Bastianelli, 2003)]; and molecular layer interneurons for basket and stellate cells [parvalbumin (Celio, 1990)]. Except for rare elements ectopically positioned in the white matter (see below and Fig.…”

“…Among the markers applied to distinguish between these types in adult rats, we found that NeuN labels the nucleus and perikaryal cytoplasm of virtually all nuclear neurons (Figs. 2 A, 3C,D) (Mullen et al, 1992;Weyer and Schilling, 2003). In contrast, SMI32 and calretinin identify two primarily nonoverlapping neuronal subsets (of a sample of 1310 neurons, only 27 were double labeled): the former marker decorates large polygonal neurons (Figs.…”

Prolonged Glial Expression of Sox4 in the CNS Leads to Architectural Cerebellar Defects and Ataxia

“…6 B, G), which marks the fraction of differentiating granule cells on their way from the external cell layer into deeper layers of the cerebellum (Weyer and Schilling, 2003). This was similarly observed in transgenic and wild-type cerebella.…”

“…This was similarly observed in transgenic and wild-type cerebella. Differentiating and differentiated granule cells in deeper layers of wild-type cerebella express high levels of NeuN (Weyer and Schilling, 2003). NeuN immunoreactivity in deeper regions was also observed in transgenic cerebella, arguing that granule cells differentiate in this genotype despite the obvious absence of an orderly internal granule cell layer (Fig.…”