However, different conclusions were reached concerning the ratio of synchronous to asynchronous mTOR inhibitor release (synchronicity ratio) and its dependence on the identity of the postsynaptic target cell. Whereas Daw et al. (2009) and Karson et al. (2009) suggested that the synchronicity ratio is independent of the identity of the postsynaptic target cell, Ali and Todorova report that this ratio is larger for synapses formed between

CCK-interneurons than for synapses between CCK-interneurons and pyramidal neurons. Accordingly, they suggest that factors governing asynchronous GABA release are synapse-specific and determined in part by the postsynaptic target. Alternatively, these divergent results may be explained by differences in experimental conditions (room versus physiological temperature, number of presynaptic action potentials, current-clamp versus voltage-clamp recording, and/or age of the animals) and the methods used to quantify asynchronous release. Despite these differences, all three papers unequivocally demonstrate asynchronous release at interneuron-interneuron synapses. Asynchronous transmitter release and modulation of synaptic transmission by presynaptic CB1 receptors are hallmarks of the function of synapses formed by CCK-interneurons. How are these two properties interrelated? Ali & Todorova (2010) found that the CB1 receptor inverse agonist AM-251 increased the synchronicity ZD1839 purchase ratio, whereas the

endocannabinoid anandamide decreased it. This finding raises the interesting possibility that synchronous and asynchronous release are differentially affected during DSI. Whether other presynaptic receptors on the terminals of CCK-interneurons have similar effects needs to be determined. Furthermore, filipin the computational significance of asynchronous GABA release in principal neuron-interneuron networks remains to be elucidated. Ali & Todorova (2010)

suggest that asynchronous GABA release modulates the time windows of inhibition, thereby controlling spike timing among local circuit interneurons. “
“This revised Figure 2A corrects the time-points listed for the studies by Kippin et al . (2005), Tanaka et al. (2007) and Tropepe et al. (1997) in the published paper of Hamilton et al. (2013). The authors apologize for any inconvenience caused by this error. “
“Brain plasticity is a double-edged sword. It allows for individuals to learn and adapt to their environment, but peculiarities may also alter the brain and contribute to maladaptive outcomes. Here, in the very interesting study conducted by Frey and colleagues, the authors used measures derived from event-related potentials (ERPs) to assess visuo-spatial maps within the visual cortex in youths with autism spectrum disorders (ASD) and controls. Based on the observation that some individuals with ASD tend to not fixate on a target (i.e. they exhibit off-center fixations), Frey and colleagues hypothesized that this fixation pattern would impact the development of the visual cortex.