Mechanisms of Pyrethroid Insecticide-Induced Stimulation of Calcium Influx in Neocortical Neurons

Abstract

Pyrethroid insecticides bind to voltage-gated sodium channels (VGSCs) and modify their gating kinetics, thereby disrupting neuronal function. Pyrethroids have also been reported to alter the function of other channel types, including activation of voltage-gated calcium channels. Therefore, the present study compared the ability of 11 structurally diverse pyrethroids to evoke Ca 2ϩ influx in primary cultures of mouse neocortical neurons. Nine pyrethroids (tefluthrin, deltamethrin, -cyhalothrin, ␤-cyfluthrin, esfenvalerate, S-bioallethrin, fenpropathrin, cypermethrin, and bifenthrin) produced concentration-dependent elevations in intracellular calcium concentration (

Deltamethrin Increases Neurite Outgrowth in Cortical Neurons through Endogenous BDNF/TrkB Pathways

“…We also found previously that DM produced a prolonged increase in intracellular calcium concentrations (Ihara et al, 2012). CM induces calcium influx into neocortical neurons less potently than DM, while PM has no effect (Cao et al, 2011). These results suggest that the ability to induce calcium influx into neurons, probably via L-VDCC, is necessary for increasing neurite outgrowth.…”

Evidence for dose-additive effects of a type II pyrethroid mixture. In vitro assessment

“…activation of many neural pathways and processes decrease motor activity). Recently, Cao et al (2011aCao et al ( , 2011b) evaluated directly at the primary molecular target the potency and efficacy of the same 11 pyrethroids determining the sodium (Na þ ) influx in cerebrocortical neuron cultures. The results demonstrated that they stimulate TTX-sensitive Na þ influx in primary cultures of cerebrocortical neurons with differing potencies and efficacies.…”

Nanomolar Bifenthrin Alters Synchronous Ca2+Oscillations and Cortical Neuron Development Independent of Sodium Channel Activity

“…The University of California Davis Animal Use and Care Committee approved this study, and animal experiments were conducted in accordance with the guidelines of the Animal Use and Care of the National Institutes of Health. Cortical neurons were dissociated from the cortex from C57Bl/6J mouse pups at postnatal day 0 to 1 as described previously (Cao et al, 2011b). The dissociated neurons were maintained in Neurobasal complete medium (Neurobasal medium supplemented with NS21 (Chen, et al, 2010), 0.5 mM L-glutamine, and HEPES) with 5% fetal bovine serum.…”