Enhanced functional detection of synaptic calcium-permeable AMPA receptors using intracellular NASPM

Calcium-permeable AMPA-type glutamate receptors (CP-AMPARs) contribute to many forms of synaptic plasticity and pathology. They can be distinguished from GluA2-containing calcium-impermeable AMPARs by the inward rectification of their currents, which reflects voltage-dependent channel block by intracellular spermine. However, the efficacy of this weakly permeant blocker is differentially altered by the presence of AMPAR auxiliary subunits - including transmembrane AMPAR regulatory proteins, cornichons, and GSG1L - which are widely expressed in neurons and glia. This complicates the interpretation of rectification as a measure of CP-AMPAR expression. Here, we show that the inclusion of the spider toxin analog 1-naphthylacetyl spermine (NASPM) in the intracellular solution results in a complete block of GluA1-mediated outward currents irrespective of the type of associated auxiliary subunit. In neurons from GluA2-knockout mice expressing only CP-AMPARs, intracellular NASPM, unlike spermine, completely blocks outward synaptic currents. Thus, our results identify a functional measure of CP-AMPARs, that is unaffected by their auxiliary subunit content.

Targeted anthelminthic treatment of school children: effect of frequency of application on the intensity of Ascaris lumbricoides infection in children from rural Nigerian villages

A study to compare the effects of different frequencies of targeted chemotherapy with levamisole (Ketrax: JAGAL Pharma, Lagos, Zeneca Pharmaceuticals UK) as an action for the control of Ascaris lumbricoides was carried out in 3 communities in rural Oyo State, Nigeria. The targeted group comprised children, age 5 to 15 years, attending primary school within their village. Treatment was provided within the school with the assistance of the school teachers. Three frequencies of targeted treatment were offered. In one village targeted treatment was provided on 1 occasion in 1 year, in another village at two 6-monthly intervals and in the third village every 4 months. Prevalence and intensity (e.p.g.) of A. lumbricoides infection were determined immediately before and after the period of intervention using a modified Kato-Katz technique. In the villages which received treatment once and at 6-monthly intervals, a reduction in post-treatment intensity of A. lumbricoides was observed in the total population but this failed to attain statistical significance. In contrast, within the village which received 4-monthly targeted chemotherapy, a significant reduction in post-treatment intensity of A. lumbricoides was observed in the total population and in the targeted children. In general, reductions in the intensity of A lumbricoides after intervention were not particularly pronounced in untreated children (aged 0-4 years) even in the 4-monthly targeted village, whereas in untreated adults, reductions approached statistical significance in villages which received targeted treatment once and at 4-monthly intervals.