Neuregulin 3 promotes excitatory synapse formation on hippocampal interneurons.

Hippocampal GABAergic interneurons are crucial for cortical network function and have been implicated in psychiatric disorders. We show here that Neuregulin 3 (Nrg3), a relatively little investigated low-affinity ligand, is a functionally dominant interaction partner of ErbB4 in parvalbumin-positive (PV) interneurons. Nrg3 and ErbB4 are located pre- and postsynaptically, respectively, in excitatory synapses on PV interneurons Additionally, we show that ablation of Nrg3 results in a similar phenotype as the one described for ErbB4 ablation, including reduced excitatory synapse numbers on PV interneurons, altered short-term plasticity, and disinhibition of the hippocampal network.

Parvalbumin-Expressing GABAergic Neurons in Primary Motor Cortex Signal Reaching.

The control of targeted reaching is thought to be shaped by distinct subtypes of local GABAergic inhibitory neurons in primary forelimb motor cortex (M1). However, little is known about their action potential firing dynamics during reaching. To address this, we recorded the activity of parvalbumin-expressing (PV+) GABAergic neurons identified from a larger population of fast-spiking units and putative excitatory regular-spiking units in layer 5 of the mouse forelimb M1 during an M1-dependent, sensory-triggered reaching task.

Nanostimulation: manipulation of single neuron activity by juxtacellular current injection.

In the mammalian brain, many thousands of single-neuron recording studies have been performed but less than 10 single-cell stimulation studies. This paucity of single-cell stimulation data reflects a lack of easily applicable single-cell stimulation techniques. We provide a detailed description of the procedures involved in nanostimulation, a single-cell stimulation method derived from the juxtacellular labeling technique.

Behavioral detectability of single-cell stimulation in the ventral posterior medial nucleus of the thalamus.

In mammals, most sensory information passes through the thalamus before reaching cortex. In the rat whisker system, each macrovibrissa is represented by approximately 250 neurons in the ventral posterior medial nucleus (VPM) of the thalamus and approximately 10,000 neurons in a cortical barrel column. Here we quantify the sensory impact of individual thalamic neurons in the rat VPM.