title: Expression of purinergic receptors in bipolar cells of the rat retina.
abstract: P2X receptors are ligand-gated ion channels which are activated by excitatory neurotransmitter ATP. Despite considerable evidence of signaling by extracellular nucleotides in other sensory systems, P2X receptors in the visual system have only rarely been studied, and almost nothing is known about their functional significance in the retina. To determine whether ATP plays a role in the modulation of vertical retinal signal pathways, we examined the expression of P2X receptor mRNA in freshly isolated bipolar cells of the rat retina (Brown Norway, P25) using the single-cell RT-PCR technique. Positive amplification signals were found in about 33% of the bipolar cells for P2X(3), P2X(4) and P2X(5) but not for P2X(7) mRNA. We conclude that at least a subpopulation of bipolar cells in the rat retina expresses ionotropic P2 receptors of the P2X type and that these possibly exert a neuromodulatory influence on information processing in the retina.
authors.affiliation: Department of Pathophysiology of Vision and Neuroophthalmology, Division of Experimental Ophthalmology, University Eye Hospital Tuebingen Roentgenweg 11, 72076, Tuebingen, Germany. thomas.wheeler-schilling@uni-tuebingen.de
authors.forename: T H
authors.initials: TH
authors.lastname: Wheeler-Schilling
authors.forename: K
authors.initials: K
authors.lastname: Marquordt
authors.forename: K
authors.initials: K
authors.lastname: Kohler
authors.forename: R
authors.initials: R
authors.lastname: Jabs
authors.forename: E
authors.initials: E
authors.lastname: Guenther
mesh_terms: D000818:Animals; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011914:Rats, Inbred BN; D018048:Receptors, Purinergic P2 / Q000235:genetics*; D058477:Receptors, Purinergic P2X3; D058848:Receptors, Purinergic P2X4; D058485:Receptors, Purinergic P2X5; D058486:Receptors, Purinergic P2X7; D012160:Retina / Q000166:cytology* / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
chemical_list: C546410:P2rx3 protein, rat; C548228:P2rx4 protein, rat; C546467:P2rx5 protein, rat; C546470:P2rx7 protein, rat; D012333:RNA, Messenger; D018048:Receptors, Purinergic P2; D058477:Receptors, Purinergic P2X3; D058848:Receptors, Purinergic P2X4; D058485:Receptors, Purinergic P2X5; D058486:Receptors, Purinergic P2X7