, 2010). The studies on subunit assembly of AMPA-type receptors and the study by Kumar et al. on kainate-type receptor subunit assembly are consistent with the subunit arrangement observed in the crystal structure of a the membrane-spanning,
tetrameric glutamate receptor (Das et al., 2010 and Sobolevsky et al., 2009) (see also Figure 1). Furthermore, recent results suggest that glutamate receptors of the AMPA-type assemble via a mechanism that involves initial ATD Selleckchem Gemcitabine dimer formation and, subsequently, a dimerization of dimers to form the tetrameric receptor, similar to the observations made by Kumar et al. (2009) for the GluR6/KA2 heterotetramer. Interestingly, the mechanism for subunit assembly of NMDA-type receptors could be different from those of AMPA- and kainate-type receptors (Farina et al., 2011; see also Karakas et al., 2011). The possibility of differences in
receptor assembly raises the potential of a striking variation in the domain organization of NMDA- versus AMPA- and kainate-type receptors, underscoring the need for more information on the fundamental process of glutamate receptor assembly. An undeniable axiom of science is that more detail always brings more questions; in this context, the findings presented by Kumar et al. certainly provide an exciting opportunity to think at a new level about questions related to glutamate receptor biogenesis. “
“The dynamics of synchronous activity MycoClean Mycoplasma Removal Kit in immature
and mature cortical networks are strikingly different. I-BET151 supplier In the neonate rat, much of the neocortical activity takes the form of “spindle bursts” (SBs; also termed “spontaneous activity transients” and “delta brushes”), which are self-organized, long-lasting (1–3 s) network events generated by both glutamatergic and GABAergic neurons (Minlebaev et al., 2007). So far, SBs have been mainly studied in the rat somatosensory and visual cortices (Khazipov et al., 2004, Mohns and Blumberg, 2010 and Colonnese et al., 2010), where they are present immediately after birth. During development, the SBs disappear within a very narrow time window, e.g., in the barrel cortex at around postnatal day (P) 8 and in the primary visual cortex at about P11, to be replaced by continuous oscillatory rhythms. A similar, most likely homologous, reorganization of gross network dynamics is also evident in humans. The highly discontinuous EEG patterns characteristic of preterm babies (Dreyfus-Brisac, 1962), which are largely attributable to the presence of spontaneous activity transients (Vanhatalo et al., 2002), give way to a more continuous EEG around the time of normal birth. Dating back to the classical work by Hubel and Wiesel in visual cortex, there is now overwhelming evidence pointing to a crucial role for precisely patterned neuronal activity in the formation of cortical connectivity.