ABSTRACT
Glutamate uptake into synaptic vesicles in nerve terminals is a pivotal step in glutamate synaptic transmission. Glutamate is the major excitatory neurotransmitter and, as such, the vesicular glutamate transporter (VGLUT) responsible for this uptake is involved in a variety of nervous system functions and various types of pathophysiology. As yet, no VGLUT-specific, membrane-permeable agents have been developed to affect neuronal function in intact neurons, although two potent VGLUTspecific inhibitors are known. These compounds contain diazo and highly charged sulfonic acid groups, rendering them membrane-impermeable and potentially cytotoxic. In an effort to eliminate these undesirable properties, we have developed two novel agents, Brilliant Yellow analogs 1 and 2, which are free of these two groups. We show here that these agents retain highly VGLUT-selective inhibitory activity, despite their reduction in potency, and exhibit no significant cellular toxicity. Potential use of this molecular modification is discussed.
Subject(s)
Azo Compounds/chemistry , Azo Compounds/metabolism , Benzenesulfonates/chemistry , Benzenesulfonates/metabolism , Vesicular Glutamate Transport Proteins/analysis , Vesicular Glutamate Transport Proteins/metabolism , Animals , Brain/metabolism , Brain Chemistry/physiology , PC12 Cells , Rats , Synaptic Vesicles/chemistry , Synaptic Vesicles/metabolismABSTRACT
All-trans retinoic acid induces functional and structural plasticity of synapses in human cortical circuits through the engagement of the spine apparatus.
Subject(s)
Neuronal Plasticity , Synapses , Animals , Dendritic Spines , Humans , Mice , Neurons , TretinoinABSTRACT
Long-lasting forms of synaptic plasticity such as synaptic scaling are critically dependent on transcription. Activity-dependent transcriptional dynamics in neurons, however, remain incompletely characterized because most previous efforts relied on measurement of steady-state mRNAs. Here, we use nascent RNA sequencing to profile transcriptional dynamics of primary neuron cultures undergoing network activity shifts. We find pervasive transcriptional changes, in which â¼45% of expressed genes respond to network activity shifts. We further link retinoic acid-induced 1 (RAI1), the Smith-Magenis syndrome gene, to the transcriptional program driven by reduced network activity. Remarkable agreement among nascent transcriptomes, dynamic chromatin occupancy of RAI1, and electrophysiological properties of Rai1-deficient neurons demonstrates the essential roles of RAI1 in suppressing synaptic upscaling in the naive network, while promoting upscaling triggered by activity silencing. These results highlight the utility of bona fide transcription profiling to discover mechanisms of activity-dependent chromatin remodeling that underlie normal and pathological synaptic plasticity.