In the present study, we
investigated the spatiotemporal expression of KCC2 in mouse cerebella, particularly focusing on Purkinje cells (PCs). First, we confirmed the fundamental expression profiles of KCC2 in the cerebellum, i.e. neuron-specific expression, Selleck LY2109761 somatodendritic distribution, and postnatal upregulation. We also found preferential recruitment to climbing fiber (CF) synapses during the second and third postnatal weeks, when perisomatic innervation in PCs switches from CFs to basket cell axons (BAs) and also when single winner CFs translocate from somata to dendrites. In parallel with this synaptic recruitment, the intracellular distribution shifted from a diffuse cytoplasmic to a predominantly cell surface pattern. In adult PCs, CF synapse-associated accumulation was Navitoclax obscured. Instead, significantly high expression was noted on the surface of PC dendrites in the superficial two-thirds of the molecular layer, in which stellate cells reside and project axons to innervate PC dendrites. Thus, the somatodendritic distribution in PCs is regulated in relation to particular inputs
or input zones. During development, timed recruitment of KCC2 to CF synapses will augment inhibitory GABAergic actions by incoming BAs, promoting the CF-to-BA switchover in perisomatic PC innervation. In adulthood, enriched KCC2 expression at the stellate cell-targeting territory of PC dendrites might help in maintaining intracellular Cl− homeostasis and the polarity of GABAA receptor-mediated
not responses upon sustained activity of this interneuron. “
“Cellular prion protein (PrPC) is widely expressed in the brain. Although the precise role of PrPC remains uncertain, it has been proposed to be a pivotal modulator of neuroplasticity events by regulating the glutamatergic and serotonergic systems. Here we report the existence of neurochemical and functional interactions between PrPC and the dopaminergic system. PrPC was found to co-localize with dopaminergic neurons and in dopaminergic synapses in the striatum. Furthermore, the genetic deletion of PrPC down-regulated dopamine D1 receptors and DARPP-32 density in the striatum and decreased dopamine levels in the prefrontal cortex of mice. This indicates that PrPC affects the homeostasis of the dopaminergic system by interfering differently in different brain areas with dopamine synthesis, content, receptor density and signaling pathways. This interaction between PrPC and the dopaminergic system prompts the hypotheses that the dopaminergic system may be implicated in some pathological features of prion-related diseases and, conversely, that PrPC may play a role in dopamine-associated brain disorders. “
“This review focuses on the plasticity of the regulation of a particular neuroendocrine transducer cell, the melanotrope cell in the pituitary pars intermedia of the amphibian Xenopus laevis.