Connectivity and network state-dependent recruitment of long-range VIP-GABAergic neurons in the mouse hippocampus
Ruggiero Francavilla, Vincent Villette, Xiao Luo, Simon Chamberland, Einer Muñoz-Pino, Olivier Camiré, Kristina Wagner, Viktor Kis, Peter Somogyi, Lisa Topolnik
Received: 6th July 18
GABAergic interneurons in the hippocampus provide for local and long-distance coordination of neurons in functionally connected areas. Vasoactive intestinal peptide-expressing (VIP+) interneurons occupy a distinct niche in circuitry as many of them specialize in innervating GABAergic cells, thus providing network disinhibition. In the CA1 hippocampus, VIP+ interneuron-selective cells target local interneurons. Here, we discovered a novel type of VIP+ neuron whose axon innervates CA1 and also projects to the subiculum (VIP-LRPs). VIP-LRPs showed specific molecular properties and targeted interneurons within the CA1 area but both interneurons and pyramidal cells within subiculum. They were interconnected through gap junctions but demonstrated sparse spike coupling in vitro. In awake mice, VIP-LRPs decreased their activity during theta-run epochs and were more active during quiet wakefulness but not coupled to sharp-wave ripples. Together, the data provide new evidence for VIP interneuron molecular diversity and functional specialization in controlling cell ensembles along the hippocampo-subicular axis.
Read in full at bioRxiv.
This is an abstract of a preprint hosted on an independent third party site. It has not been peer reviewed but is currently under consideration at Nature Communications.