Monocular Enucleation Induces Nuclear Localization of Calcium/Calmodulin-Dependent Protein Kinase IV in Cortical Interneurons of Adult Monkey Area V1

Abstract

Elevation of intracellular Ca2ϩ levels activates calcium/calmodulin-dependent protein kinase (CaMK) IV, which in turn plays an important role in neuroprotection and neuroplasticity. The possibility that CaMKIV is similarly involved in neocortical tissue has not been examined previously, especially with regard to the plastic nature of ocular dominance features in the primary visual cortex (area V1). We addressed this question by way of monocular enucleation (ME) to disrupt sensory input and examine CaMKIV expression changes in monkey area V1. Immunohistochemical staining of area V1 in normal infants showed a nuclear presence of CaMKIV, which did not changed after ME. However, a striking set of layer-and time-dependent changes in nuclear CaMKIV expression was observed in adult area V1 after ME. A strong increase in nuclear CaMKIV levels was evident in cortical layers II/III and VI after 1 d of ME and in layer IVC after 5 d of ME. These specific laminar changes persisted after 30 d of ME and, most notably, showed a columnar profile in which CaMKIV expression was linked to open-eye columns. Real-time quantitative reverse transcription-PCR and Western blot analysis showed that total amounts of CaMKIV mRNA and protein remained unchanged after ME, suggesting that a nuclear translocation may occur from the cytoplasm. Finally, double-label immunohistochemical staining with a pyramidal cell marker (SMI-32) showed that CaMKIV was absent in this subtype, whereas coincidental expression with GABA, parvalbumin, and calretinin, but not calbindin, showed its clear presence in a subset of interneurons. We propose that CaMKIV activity within diverse groups of cortical interneurons may play an important role in adaptive plastic reorganization of adult neocortical tissue.

Presbyacusis and calcium-binding protein immunoreactivity in the cochlear nucleus of BALB/c mice

“…For example, in the visual system, increased parvalbumin immunoreactivity following unilateral deafferentation was found (Schmidt-Kastner et al, 1992). After monocular visual blockade, there was a simultaneous increased expression of parvalbumin and calretinin in area IV but no change in calbindin expression in monkeys (Lalonde et al, 2004). Hippocampal, or motor neurons expressing calretinin were resistant to Ca2 + induced excitotoxicity, while those neurons without calretinin were more vulnerable (Mockel and Fischer, 1994;Terro et al, 1998).…”

Hippocampal Mek/Erk signaling mediates extinction of contextual freezing behavior

“…Quantification of immunostaining signals was performed separately for the CA1 hippocampal layers (stratum pyramidale and stratum radiatum) as described previously (Lalonde et al, 2004). Digital images were captured with a cooled color CCD camera (RTKE Diagnostic Instruments) and SPOT software for Macintosh.…”

Decreased Rhythmic GABAergic Septal Activity and Memory-Associated θ Oscillations after Hippocampal Amyloid-β Pathology in the Rat

“…In agreement with this, little if any loss of ChAT expression was observed after hippocampal A␤ injections, with an unexpected increase in septal parvalbumin immunoreactivity. Interestingly, GABAergic sprouting, ectopic neuropeptide Y expression, and an increase in calcium-binding protein immunoreactivity have already been characterized and interpreted as compensatory inhibitory mechanisms in various mouse models involving neuronal injury, epilepsy, and amyloid precursor protein (APP) overexpression (hAPPFAD mice) (Idrizbegovic et al, 2004;Lalonde et al, 2004;Palop et al, 2007) since they can attenuate neuronal overexcitation. This potential rescue process seems consistent with the transient upregulation of specific neurotransmitters observed in AD brains (Bell et al, 2003(Bell et al, , 2007.…”