Perforated patch-clamp recording of mouse olfactory sensory neurons in intact neuroepithelium: functional analysis of neurons expressing an identified odorant receptor
Analyzing the physiological responses of olfactory sensory neurons (OSN) when
stimulated with specific ligands is critical to understand the basis of
olfactory-driven behaviors and their modulation. These coding properties depend
heavily on the initial interaction between odor molecules and the olfactory
receptor (OR) expressed in the OSNs. The identity, specificity and ligand
spectrum of the expressed OR are critical. The probability to find the ligand of
the OR expressed in an OSN chosen randomly within the epithelium is very low. To
address this challenge, this protocol uses genetically tagged mice expressing the
fluorescent protein GFP under the control of the promoter of defined ORs. OSNs
are located in a tight and organized epithelium lining the nasal cavity, with
neighboring cells influencing their maturation and function. Here we describe a
method to isolate an intact olfactory epithelium and record through patch-clamp
recordings the properties of OSNs expressing defined odorant receptors. The
protocol allows one to characterize OSN membrane properties while keeping the
influence of the neighboring tissue. Analysis of patch-clamp results yields a
precise quantification of ligand/OR interactions, transduction pathways and
pharmacology, OSNs’ coding properties and their modulation at the membrane level.