A developmental profile of the levels of calcium pumps in chick cerebellum

Abstract

The functional expression and distribution of intracellular ATPase (sarco(endo)plasmic reticulum Ca 2+ -ATPase: SER-CA) and plasma membrane Ca 2+ -ATPase (PMCA) was analyzed in the developing chick cerebellum. The activity and Ca 2+ uptake increase with development for both ATPases.However, the protein content increases with the stage of development only for SERCA, remaining constant for PMCA. Immunohistochemical assays showed that the ontogenesis of these ATPases goes along with definite stages of cerebellum histogenesis, and is complete at hatching. The SERCA is mainly distributed in Purkinje neurons, whereas the PMCA seems to be expressed initially in climbing fibers, shifting to soma and spiny branchlets of Purkinje cells at late embryonic stages. Granule cells express both ATPases according to their degree of maturity, whereas only PMCA is present in cerebellar glomeruli. These pumps are present in deep nuclei and the choroid plexus, although in this latter tissue their expression declines with development. The spatio-temporal distribution of SERCA and PMCA must be closely related to their association with the development of specific cells and processes of the chick cerebellum.

Developmental distribution of plasma membrane Ca2+‐ATPase isoforms in chick cerebellum

“…In fact, the expression of PMCA isoforms appeared in Purkinje cells, the only output of information from cerebellum, from its morphogenesis and neurite extension (E15 stage). These cells are also enriched in several other proteins involved in the regulation of intracellular Ca 2ϩ as calbindin and parvalbumin (Bastianelli, 2003) or the SERCA2 calcium pump (Plessers et al, 1991;Sepulveda et al, 2004Sepulveda et al, , 2005. The restricted distribution of PMCA1 and 3 and the broad expression of PMCA2 in the Purkinje cells could be related to the establishment of different synapse types on the Purkinje cell.…”

“…The presence and expression levels of PMCA isoforms were analyzed in chick cerebellum at different stages of development, according to Sepulveda et al (2005). Cerebellar membrane vesicles (MV) were used from chick embryos and hatchlings (P0) and the proteins were identified by Western blot with specific antibodies (Fig.…”

Plasma membrane Ca2+-ATPases: Targets of oxidative stress in brain aging and neurodegeneration

“…Coincidently, PMCA levels are up-regulated during the maturation of hippocampal neurons [87] and in neuroblastoma cells undergoing differentiation [88] . Analysis of PMCA expression profile in the developing brain shows that distinct PMCA subtypes are expressed at different levels in various brain regions, with a noticeably higher expression in cellular compartments characterized by a greater number of synapses, suggesting a key role of the PMCAs in synaptogenesis and in the maturation of neuronal electrophysiological properties [89][90][91] .…”

Ontogênese de conexinas no cerebelo.

“…Na ICCL, encontram-se principalmente células de Purkinje e precursores de células gliais (Kordes et al, 2005). Em E12, as células de Purkinje começam a formar as primeiras sinapses do córtex cerebelar (Sepúlveda, 2005). Nesse estágio, a camada granular interna (IGL, internal granular layer) começa a se formar na região inferior da ICCL.…”

“…Da região inferior da EGL, as células granulares iniciam um processo de migração radial na ML primitiva e IGL até alcançarem sua posição final. No percurso da EGL para a IGL, as células granulares passam por diversas mudanças morfológicas e deixam para trás os processos que formarão as fibras paralelas (Luckner e tal, 2001;Sepúlveda, 2005).…”