Microiontophoresis combined with extracellular spike recording is an excellent method for investigating local neuropharmacological effects under in vivo conditions. However, its application has recently become relatively rare in neuroscience research. Now, we aimed to revisit microiontophoresis and demonstrate that it provides valuable data about the pharmacophysiology of neurons and local neuronal networks, in vivo. Extracellular recordings were performed through the central recording channel of multibarrel carbon-fiber microelectrodes in the CA1 pyramidal layer of the hippocampus of anesthetized rats, while N-methyl-D-aspartate (NMDA) was locally administrated by means of microiontophoresis through the surrounding micropipettes of the microelectrode. Various separation procedures were used to distinguish putative pyramidal cells and interneurons. Quality of separation was verified by electrophysiological parameters. After the delivery of NMDA in the vicinity of the examined neurons, firing rate of putative pyramidal cells was increased with a significantly higher grade then that of putative interneurons. The present results in line with previous data indicate that pyramidal cells are more responsive to pharmacological manipulation through NMDA receptors, also confirming the reliability of the separation of different types of neurons in in vivo microiontophoretic experiments.
Authors:T. Abonyi, S. Tömösközi, M. Budai, Sz. Gergely, É. Scholz, D. Lásztity, and R. Lásztity
The proteins that form gluten of a winter wheat cultivar, Ukrainka (HMW-GS composition 1, 7+8, 5+10) grown in Hungary and harvested in the year 2006, was investigated during grain development. The formation of gluten, its protein fractions and composition of polymeric fraction, were followed starting at the 12
day after anthesis (DAA) to the 52
.Gluten formation was first observed (manual method of determination) only 20–25 days after anthesis and its quantity increased rapidly during the next period of grain development. The gluten was separated to a fraction extractable with SDS-phosphate buffer and another fraction, unextractable by this buffer. An increase in the ratio of unextractable polymeric protein (UPP)/soluble protein fraction was observed during grain development. As expected, gliadin was the main component of the soluble fraction and glutenin that of the insoluble one. HMW monomers were detected in unreduced fractions in small quantities only until 30
DAA. RP-HPLC of reduced gluten fractions showed a slight increase of the ratio HMW/LMW with days after anthesis.An increase of relative viscosity of gluten solutions during grain development was also observed as a sign of polymerization of glutenin subunits and consequently an increase in average molecular weight of glutenin.