Table 1.
Histological expression (mRNA and receptor protein) of P2 receptors in the cochlear partition
Subtype | Species | Age | Target | Method | Findings | References |
---|---|---|---|---|---|---|
IHC | ||||||
P2 | Guinea pig | Adult | Receptor | Fluorescence imaging | P2 receptors localized at the apical membrane | [4] |
P2X | Guinea pig | N/A | Receptor | Fluorescence imaging | P2X ionotropic channels localized at the endolymphatic surface | [5] |
P2X2 | Rat | E12-Adult | mRNA | In situ hybridization | Positive for P10–P12 | [6] |
Rat | Adult | Receptor | Immunohistochemistry | Negative | [7] | |
Mouse | N/A | Receptor | Immunohistochemistry | Negative | [8] | |
Guinea pig | Adult | Receptor | Immunohistochemistry | Positive at stereocilia | [9] | |
P2X3 | Rat | E16-Adult | Receptor | Immunohistochemistry | Negative | [10] |
Mouse | E18-Adult | Receptor | Immunohistochemistry | Slightly positive for E18 | [11] | |
P2X7 | Rat | E14-Adult | Receptor | Immunohistochemistry | Positive for P0–P6 | [12] |
SGN (type I) | ||||||
P2 | Guinea pig | Adult | Receptor | Autoradiography | Positive | [13] |
P2X1–P2X6 | Rat | Adult | Receptor | Immunohistochemistry | All positive, strongest in P2X2 | [14] |
P2X1 | Rat | E12-Adult | mRNA | In situ hybridization | Positive for E16–P6 | [15] |
P2X2 | Mouse | N/A | Receptor | Immunohistochemistry | Positive | [8] |
Rat | P7-Adult | Receptor | Immunohistochemistry | All positive, strongest at synaptic region under IHC | [16] | |
Guinea pig | Adult | Receptor | Immunohistochemistry | Positive at postsynaptic membrane under IHC | [9] | |
mRNA | RT-PCR | P2X2–2 is the dominant splice variant | ||||
Rat | E16-Adult | Receptor | Immunohistochemistry | Positive, stronger at the synaptic region for E19–P6 | [7] | |
Rat | Adult | mRNA | In situ RT-PCR | Positive for a subpopulation of SGNs | [17] | |
mRNA | RT-PCR | Identification of the third isoform, P2X2-3 | ||||
Rat | E12-Adult | mRNA | In situ hybridization | Positive for E16-Adult, maximum at P8-P12 | [6] | |
P2X3 | Rat | E16-Adult | Receptor | Immunohistochemistry | Neuron body: positive for E16–P14 | [10] |
Afferent fibers: positive for E18–P4 | ||||||
Mouse | E18-Adult | Receptor | Immunohistochemistry | Positive (body and fibers) for E18–P6 | [11] | |
P2X7 | Rat | E14-Adult | Receptor | Immunohistochemistry | Positive in neuron body for E18-Adult | [12] |
Positive at synaptic region under IHC for P0-Adult |