Glycine potentiates the NMDA response in cultured mouse brain neurons

Transmitters mediating 'fast' synaptic processes in the vertebrate central nervous system are commonly placed in two separate categories that are believed to exhibit no interaction at the receptor level. The 'inhibitory transmitters' (such as glycine and GABA) are considered to act only on receptors mediating a chloride conductance increase, whereas 'excitatory transmitters' (such as L-glutamate) are considered to activate receptors mediating a cationic conductance increase. The best known excitatory receptor is that specifically activated by N-methyl-D-aspartate (NMDA) which has recently been characterized at the single channel level. The response activated by NMDA agonists is unique in that it exhibits a voltage-dependent Mg block. We report here that this response exhibits another remarkable property: it is dramatically potentiated by glycine. This potentiation is not mediated by the inhibitory strychnine-sensitive glycine receptor, and is detected at a glycine concentration as low as 10 nM. The potentiation can be observed in outside-out patches as an increase in the frequency of opening of the channels activated by NMDA agonists. Thus, in addition to its role as an inhibitory transmitter, glycine may facilitate excitatory transmission in the brain through an allosteric activation of the NMDA receptor.     

Epithelial cell processes in the development of the secondary palate in the mouse.

Ultrastructural studies of palatal shelves of Tuck A mice embryos aged 12.25-14.25 days show discontinuities of the epithelial basement membrane traversed by epithelial cell processes before the onset of midline degenerative changes.     

Surface area and effect of drying temperature related to dry weight of jejunal tissue in rat

Zusammenfassung Es werden Gleichungen angeführt, die eine Abschätzung der Oberfläche des Rattenjejunums aus Trockengewichtsbestimmungen erlauben. Sollte sich eine Trocknung des Gewebes bei Temperaturen über 100°C als unmöglich erweisen, ist anzuraten, eine Trocknung bei 80°C für nicht weniger als 48 h oder Gefriertrocknung über Nacht auszuführen; hierbei werden gleiche Resultate erzielt.