Pre- and postsynaptic localization of RC3/neurogranin in the adult rat spinal cord: An immunohistochemical study

Abstract

RC3 (neurogranin; BICKS) is a neuron-specific calmodulin-binding protein kinase C substrate. Thus far, immunohistochemical studies on the localization of RC3 revealed its presence in all neuronal phenotypes, which were restricted to specific areas in the neostriatum, the neocortex, and the hippocampus. RC3 was mostly found in cell bodies and dendrites, with some infrequent presence in axonal profiles, i.e. in the internal capsule. Until now, RC3 expression was reported to be absent in the adult rat spinal cord. RC3 might, however, act as an intermediate of protein kinase C-mediated signaling pathways during synaptic development and plasticity. We hypothesized a role for this 78-amino-acid protein in dendritic plasticity occurring after spinal cord injury. To our surprise, an immunohistological analysis of the uninjured adult rat spinal cord revealed the presence of RC3-positive cell bodies and dendrites in specific regions in the gray matter. Interestingly, axon-containing structures, such as the dorsal and ventral corticospinal tract, were also found to be RC3-positive. This axonal labeling was confirmed by preembedding electron microscopy. In conclusion, we demonstrate here that RC3 is present in the adult rat spinal cord in pre- and postsynaptic structures.

Phenotypic diversity and expression of GABAergic inhibitory interneurons during postnatal development in lumbar spinal cord of glutamic acid decarboxylase 67–green fluorescent protein mice

“…Neurogranin is a PKC substrate with a spinal distribution localized primarily in the dorsal horn (Houben et al, 2000). Neurogranin has been implicated in dendritic plasticity in other CNS regions but its function in the spinal cord is unknown (Houben et al, 2000).…”

“…Neurogranin has been implicated in dendritic plasticity in other CNS regions but its function in the spinal cord is unknown (Houben et al, 2000). Since the distribution of neurogranin is similar to GFP, we looked for overlap.…”

Calcium dynamics are altered in cortical neurons lacking the calmodulin‐binding protein RC3

“…Cultures were immunostained with antibodies to microtubule‐associated protein‐2 (MAP‐2, Boehringer Mannheim, Indianapolis, IN, USA), glial fibrillary acidic protein (GFAP, Boehringer Mannheim), γ‐aminobutyric acid (GABA; DiaSorin, Stillwater, MN, USA) or RC3 (1 : 10 000 diluted polyclonal RC3 antibody 9701, Houben et al ., 2000) and visualized using Hoffman or brightfield optics. The immunohistochemical protocol followed methods published previously (Gruol & Crimi, 1988).…”

Neurogranin, a link between calcium/calmodulin and protein kinase C signaling in synaptic plasticity

“…The term ''soluble'' is sometimes confused with ''cytoplasmic or cytosolic,'' although it merely reflects the protein behavior during extraction and not its adscription to any intracellular location. Using specific antibodies, it was soon realized that Ng localizes in the neuronal soma and dendrites (9,71) and is very rarely observed in axons (71,72). Considering its small size, soluble character, and high intracellular levels, it seems reasonable to think that additional mechanisms would be involved in maintaining its somatodendritic confinement.…”