Retrograde inhibition by a specific subset of interpeduncular a5 nicotinic neurons regulates nicotine preference.

Translational profiling of specific populations in the MHb-IPN circuit allow identification of neurons in the relatively uncharacterized circuit. Here we use bac Cre drivers to direct expression of a Cre-iducible EGFP-tagged ribosomal protein to access translating mRNAs. We describe unique and complementary subsets of Chrna5 cells with differential response to nicotine treatment. Overall design: Polysome-bound mRNAs from TRAP IPs were compared to whole tissue mRNAs for baseline profiling. To determine nicotine-regulated genes, mRNAs from TRAP IPs from saccharin-treated mice were compared to IPs from nicotine-treated mice. For IPN, BAC Cre driver mice were crossed with Cre-inducible TRAP mice to generate double trangenic bacTRAP mice, while single transgenic bacTRAP mice were used for the MHb. Data was collected from ChAT neurons in the MHb and frm Chrna5, Amigo1 and Epyc neurons in the IPN. We collected at least 3 replicates per condition, with the exception of nicotine-treated IPN cells from Epyc-Cre mice and nicotine-treated MHb ChAT cells, which were collected in duplicate. Males and females were pooled for each sample unless otherwise indicated.