Determining the distribution of ion channels from experimental data

• Published in: ESAIM. Mathematical modelling and numerical analysis 2018-09, Vol.52 (5), p.2083-2107
• Main Authors: Bourgeron, Thibault, Conca, Carlos, Lecaros, Rodrigo
• Format: Article
• Language: English
• Subjects: CNG channel; ill-posed problem; integral equation; Integral equations; Inverse problems; Ion channels; Ions; Mathematical models; Mellin transform; Mellin transforms; Observability (systems); Spatial distribution
• ISSN: 0764-583X; 1290-3841
• DOI: 10.1051/m2an/2017062

The authors study an integral inverse problem arising in the biology of the olfactory system. The transduction of an odor into an electrical signal is accomplished by a depolarising influx of ions through cyclic-nucleotide-gated (CNG for short) channels on the cilium membrane. The inverse problem studied in this paper consists in finding the spatial distribution of the CNG channels from the measured transduce electrical signals. The Mellin transform allows us to write an explicit formula for its solution. Proving observability and continuity inequalities is then a question of estimating the Mellin transform of the kernel of this integral equation on vertical lines. New estimates using arguments in the spirit of the stationary phase method are proven and a numerical scheme is proposed to reconstruct the density of CNG channels from modeled current representing experimental data, for an approximated model. For the original model an identifiability and a non observability (in some weighted L2 spaces) results are proven.