Combined effects of mutations in loop C and the loop D-E-G triangle on neonicotinoid interactions with Drosophila Dα1/chicken β2 hybrid nAChRs.

Neonicotinoid insecticides interact with the orthosteric sites of nicotinic acetylcholine receptors (nAChRs) formed at the interfaces of (a) two adjacent α subunits and (b) α and non-α subunits. However, little is known of the detailed contributions of these two orthosteric sites to neonicotinoid actions. We therefore applied voltage-clamp electrophysiology to the Dα1/chicken β2 hybrid nAChR expressed in Xenopus laevis oocytes to explore the agonist actions of imidacloprid and thiacloprid on wild type receptors and following binding site mutations.

Caffeine improves contrast sensitivity of freely moving rats.

Caffeine (1, 3, 7-trimethylxanthine) is a well-known central nervous system stimulant that affects various brain functions such as attention, memory and sensation. However, it remains unclear whether and how caffeine modulates visual ability such as contrast sensitivity (CS) and the CS-spatial frequency (SF) relationship. To investigate these points, we tested the effects of caffeine on the perceptual CS of rats under three SF conditions.