Control of neuronal excitation-inhibition balance by BMP-SMAD1 signalling.

Throughout life, neuronal networks in the mammalian neocortex maintain a balance of excitation and inhibition, which is essential for neuronal computation. Deviations from a balanced state have been linked to neurodevelopmental disorders, and severe disruptions result in epilepsy. To maintain balance, neuronal microcircuits composed of excitatory and inhibitory neurons sense alterations in neural activity and adjust neuronal connectivity and function.

LTP of inhibition at PV interneuron output synapses requires developmental BMP signaling.

Parvalbumin (PV)-expressing interneurons (PV-INs) mediate well-timed inhibition of cortical principal neurons, and plasticity of these interneurons is involved in map remodeling of primary sensory cortices during critical periods of development. To assess whether bone morphogenetic protein (BMP) signaling contributes to the developmental acquisition of the synapse- and plasticity properties of PV-INs, we investigated conditional/conventional double KO mice of BMP-receptor 1a (BMPR1a; targeted to PV-INs) and 1b (BMPR1a/1b (c)DKO mice). We report that spike-timing dependent LTP at the synapse between PV-INs and principal neurons of layer 4 in the auditory cortex was absent, concomitant with a decreased paired-pulse ratio (PPR).

The Yin and Yang of Arnt2 in Activity-Dependent Transcription.

Spatiotemporal regulation of neuronal gene expression is essential for proper functioning of neuronal circuits. In this issue of Neuron, Sharma et al. (2019) discover a dual role for Arnt2-NcoR2 protein complexes in the activity-dependent regulation of neuronal transcriptomes.

Promotion of neurite outgrowth by rationally designed NGF-β binding peptide nanofibers.

Promotion of neurite outgrowth is an important limiting step for regeneration in nerve injury and depends strongly on the local expression of nerve growth factor (NGF). The rational design of bioactive materials is a promising approach for the development of novel therapeutic methods for nerve regeneration, and biomaterials capable of presenting NGF to nerve cells are especially suitable for this purpose. In this study, we show bioactive peptide amphiphile (PA) nanofibers capable of promoting neurite outgrowth by displaying high density binding epitopes for NGF.