Neuropeptide Y modulates calcium channels in hamster submandibular ganglion neurons

Endoh, Takayuki; Nobushima, Hiromi; Tazaki, Masakazu

doi:10.1016/j.neures.2012.05.002

Cited by 2 publications

(1 citation statement)

References 45 publications

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“…In fact, NPY was reported to decrease depolarization-evoked increase in [Ca 2+ ] i by inhibiting voltage-dependent Ca 2+ channels. This effect was reported in a variety of neuronal cell types such as dorsal root ganglion neurons ( Bleakman et al., 1991 ), hippocampal neurons ( Bleakman et al., 1992 ), submandibular ganglion neurons ( Endoh et al., 2012 ), and hypothalamic arcuate nucleus neurons ( Sun and Miller, 1999 ). Moreover, the activation of Y 1 receptors has been associated with inhibition of neurotransmitter release ( Bitran et al., 1999 ; Hastings et al., 2004 ; Wang, 2005 ), though the opposite behavior can be found depending on the neurotransmitter or cell type ( Hastings et al., 2001 ).…”

Section: Discussionmentioning

confidence: 85%

Activation of Neuropeptide Y Receptors Modulates Retinal Ganglion Cell Physiology and Exerts Neuroprotective Actions In Vitro

et al. 2015

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Neuropeptide Y (NPY) is expressed in mammalian retina but the location and potential modulatory effects of NPY receptor activation remain largely unknown. Retinal ganglion cell (RGC) death is a hallmark of several retinal degenerative diseases, particularly glaucoma. Using purified RGCs and ex vivo rat retinal preparations, we have measured RGC intracellular free calcium concentration ([Ca2+]i) and RGC spiking activity, respectively. We found that NPY attenuated the increase in the [Ca2+]i triggered by glutamate mainly via Y1 receptor activation. Moreover, (Leu31, Pro34)−NPY, a Y1/Y5 receptor agonist, increased the initial burst response of OFF-type RGCs, although no effect was observed on RGC spontaneous spiking activity. The Y1 receptor activation was also able to directly modulate RGC responses by attenuating the NMDA-induced increase in RGC spiking activity. These results suggest that Y1 receptor activation, at the level of inner or outer plexiform layers, leads to modulation of RGC receptive field properties. Using in vitro cultures of rat retinal explants exposed to NMDA, we found that NPY pretreatment prevented NMDA-induced cell death. However, in an animal model of retinal ischemia-reperfusion injury, pretreatment with NPY or (Leu31, Pro34)−NPY was not able to prevent apoptosis or rescue RGCs. In conclusion, we found modulatory effects of NPY application that for the first time were detected at the level of RGCs. However, further studies are needed to evaluate whether NPY neuroprotective actions detected in retinal explants can be translated into animal models of retinal degenerative diseases.

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