The subunits forming the nAChRs constitute a multigene family. In the molecular studies of the subunits as well as in the functional studies of the receptors, the constant consideration of this fact allows a better understanding of the observed phenomenons. I tried to reconstruct the integrity of this family concept.
My phD work can be arranged according two major pathways, developed in parallel.
On one hand, I analyzed the sequence of nicotinic receptors subunits. I studied the phylogenetic relationships between subunit coding genes, using their sequences but also their structure. During this work I developed a database on internet, which contains the sequences of the ligand-gated ion channel subunits. The subunit subfamilies defined according to the phylogenetic reconstruction are congruent with the receptor groups formed from functional criteria (anatomical, biochemical and pharmacological). Then, I performed a prediction of the secondary structure of a typical nAChR subunit. I used for that the 3rd generation algorithms. I incorporated other data into this prediction, either predicted (topology, solvant accessibility) or experimentally determined (binding site, MIR), in order to draw a 2D representation of the prototypic subunit.
On the other hand, I examined the relations between the distributions of
the different neuronal subunits in the rodent brain. I observed this
distribution in the embryonic and adult rat and also in transgenic mice
lacking particular nAChR subunit. This work allowed to map the
expression of the 
6 subunit, which was still unknown. I found that
this subunit is highly expressed in the catecholaminergic cells of the
brain, which indicate a putative role in the nicotinic transmission at
these anatomical levels. In order to further explore the roles of
6, I blocked its expression in vivo with antisense
oligonucleotides. This experiment reveals that an involvement of the
6 subunit in the nicotine-induced locomotor activity.