Dental Public Health in Action: Delivering a domestic violence and abuse screening and identification training programme in North Staffordshire-based dental practices.

Domestic violence and abuse (DVA) is a significant public health problem both globally and in the UK. Dental professionals are aptly place to detect the signs of DVA and support patients to disclose DVA. However, dental professionals may lack confidence to identify and refer patients experiencing DVA; training needs in these areas were identified in Staffordshire. Glow DVA charity and the local Dental Public Health teams worked collaboratively to develop DVA training and resources specific to the needs to the dental team; these were provided to participating dental practices in the North-Staffordshire region. Feedback from the training was positive and the training was refined to better meet the needs of the dental team.mKey challenges included obtaining dental team buy in, securing funding for the continuation of the initiative and minimising the disruption to the dental team when attending training sessions or when managing a DVA disclosure. The implementation of the training highlighted the importance of DVA champions within the third sector organisations to develop and evolve the project, within dental practices to support implementation, and within the local Dental Public Health team to facilitate dental team buy-in and sustained engagement. Future plans include developing the patient-facing resources, finding ways to formally accredit dental teams for taking part in the DVA programme, and evaluating the impact of the training programme on DVA screening, identification and referral.

Optical measurements of presynaptic nicotinic effects.

We have used the styryl dye FM 2-10 to monitor changes in synaptic activity mediated by nicotinic acetylcholine receptors (AChRs) on cultured hippocampal neurons. We show that both 100 microM ACh and nicotine at 20 microM causes a significant increase in staining intensities of presynaptic boutons in the presence of 0.5 microM tetrodotoxin (TTX). This effect of nicotine is blocked by d-tubocurarine. Interestingly, nicotine also had a long-lasting effect on high potassium-induced staining of boutons. These results suggest that nicotine can have significant and sustained effects on synaptic efficacy in cultured hippocampal neurons.

N-methyl-D-aspartate receptor-induced proteolytic conversion of postsynaptic class C L-type calcium channels in hippocampal neurons.

Ca2+ influx controls multiple neuronal functions including neurotransmitter release, protein phosphorylation, gene expression, and synaptic plasticity. Brain L-type Ca2+ channels, which contain either alpha 1C or alpha 1D as their pore-forming subunits, are an important source of calcium entry into neurons. Alpha 1C exists in long and short forms, which are differentially phosphorylated, and C-terminal truncation of alpha 1C increases its activity approximately 4-fold in heterologous expression systems. Although most L-type calcium channels in brain are localized in the cell body and proximal dendrites, alpha 1C subunits in the hippocampus are also present in clusters along the dendrites of neurons. Examination by electron microscopy shows that these clusters of alpha 1C are localized in the postsynaptic membrane of excitatory synapses, which are known to contain glutamate receptors. Activation of N-methyl-D-aspartate (NMDA)-specific glutamate receptors induced the conversion of the long form of alpha 1C into the short form by proteolytic removal of the C terminus. Other classes of Ca2+ channel alpha1 subunits were unaffected. This proteolytic processing reaction required extracellular calcium and was blocked by inhibitors of the calcium-activated protease calpain, indicating that calcium entry through NMDA receptors activated proteolysis of alpha1C by calpain. Purified calpain catalyzed conversion of the long form of immunopurified alpha 1C to the short form in vitro, consistent with the hypothesis that calpain is responsible for processing of alpha 1C in hippocampal neurons. Our results suggest that NMDA receptor-induced processing of the postsynaptic class C L-type Ca2+ channel may persistently increase Ca2+ influx following intense synaptic activity and may influence Ca2+-dependent processes such as protein phosphorylation, synaptic plasticity, and gene expression.

Phosphorylation of presynaptic and postsynaptic calcium channels by cAMP-dependent protein kinase in hippocampal neurons.

Phosphorylation by cAMP-dependent protein kinase (PKA) and other second messenger-activated protein kinases modulates the activity of a variety of effector proteins including ion channels. Anti-peptide antibodies specific for the alpha 1 subunits of the class B, C or E calcium channels from rat brain specifically recognize a pair of polypeptides of 220 and 240 kDa, 200 and 220 kDa, and 240 and 250 kDa, respectively, in hippocampal slices in vitro. These calcium channels are localized predominantly on presynaptic and dendritic, somatic and dendritic, and somatic sites, respectively, in hippocampal neurons. Both size forms of alpha 1B and alpha 1E and the full-length form of alpha 1C are phosphorylated by PKA after solubilization and immunoprecipitation. Stimulation of PKA in intact hippocampal slices also induced phosphorylation of 25-50% of the PKA sites on class B N-type calcium channels, class C L-type calcium channels and class E calcium channels, as assessed by a back-phosphorylation method. Tetraethylammonium ion (TEA), which causes neuronal depolarization and promotes repetitive action potentials and neurotransmitter release by blocking potassium channels, also stimulated phosphorylation of class B, C and E alpha 1 subunits, suggesting that these three classes of channels are phosphorylated by PKA in response to endogenous electrical activity in the hippocampus. Regulation of calcium influx through these calcium channels by PKA may influence calcium-dependent processes within hippocampal neurons, including neurotransmitter release, calcium-activated enzymes and gene expression.