Pyrazole carbodithiolate-driven iterative RAFT single-additions.

In this Communication, we comprehensively investigated substituent effects relevant to iterative reversible activation fragmentation chain transfer (RAFT) single unit monomer insertion (SUMI) reactions. Through the use of the pyrazole carbodithiolate (PCDT) "Z-group" as the chain transfer component in RAFT SUMI, we show the importance of "Z-group" effects and its interplay with "R-group" (the carbon-centred radical precursor) effects. We also expanded the scope of RAFT SUMI to new monomer types and sequences thereof. As such, the C-S bond dissocation/reformation steps were found to be crucial factors in SUMI, and it was found that general substituent effects must be wholistically examined for every step of this reaction. This stands in contrast with conventional knowledge of RAFT polymerisation, where the main consideration is often centred around the propagation stage, i.e., the key C-C bond formation step. Indeed, contrary to SUMI, the latter characteristic was observed in the analogous alternating copolymerisation.

Microglia promote maladaptive plasticity in autonomic circuitry after spinal cord injury in mice.

Robust structural remodeling and synaptic plasticity occurs within spinal autonomic circuitry after severe high-level spinal cord injury (SCI). As a result, normally innocuous visceral or somatic stimuli elicit uncontrolled activation of spinal sympathetic reflexes that contribute to systemic disease and organ-specific pathology. How hyperexcitable sympathetic circuitry forms is unknown, but local cues from neighboring glia likely help mold these maladaptive neuronal networks. Here, we used a mouse model of SCI to show that microglia surrounded active glutamatergic interneurons and subsequently coordinated multi-segmental excitatory synaptogenesis and expansion of sympathetic networks that control immune, neuroendocrine, and cardiovascular functions. Depleting microglia during critical periods of circuit remodeling after SCI prevented maladaptive synaptic and structural plasticity in autonomic networks, decreased the frequency and severity of autonomic dysreflexia, and prevented SCI-induced immunosuppression. Forced turnover of microglia in microglia-depleted mice restored structural and functional indices of pathological dysautonomia, providing further evidence that microglia are key effectors of autonomic plasticity. Additional data show that microglia-dependent autonomic plasticity required expression of triggering receptor expressed on myeloid cells 2 (Trem2) and α2δ-1-dependent synaptogenesis. These data suggest that microglia are primary effectors of autonomic neuroplasticity and dysautonomia after SCI in mice. Manipulating microglia may be a strategy to limit autonomic complications after SCI or other forms of neurologic disease.