Biomaterial Database

Pharmacological modulation of on and off ganglion cells in the cat retina. 1984

J Bolz, and H Wässle, and P Thier

We studied the effects of 2-amino-4-phosphonobutyric acid and 2-amino-4-phosphonovaleric acid, which are antagonists to excitatory amino acids, on brisk-sustained(X) and brisk-transient(Y) ganglion cells in the cat retina. The ganglion cells were recorded extracellularly with a multibarreled electrode in the intact eye in vivo and drugs were applied iontophoretically. We found contrasting effects of 2-amino-4-phosphonobutyric acid and 2-amino-4-phosphonovaleric acid on ON- and OFF-centre cells irrespective of the brisk-sustained(X)/brisk-transient(Y) dichotomy. The maintained discharge and the light response of ON-centre cells decreased during 2-amino-4-phosphonobutyric acid and 2-amino-4-phosphonovaleric acid application, whereas the maintained discharge of OFF-centre cells increased. The light response of OFF-centre cells was not significantly affected. 2-Amino-4-phosphonovaleric acid was generally less potent than 2-amino-4-phosphonobutyric acid. It was shown in the mudpuppy retina [Slaughter and Miller (1981) Science, N.Y. 211, 182-185; Slaughter and Miller (1981) Invest. ophthal. Vis. Sci. 20, 44] that 2-amino-4-phosphonobutyric and 2-amino-4-phosphonovaleric acid selectively block the response of ON-bipolar cells. Assuming that these drugs act on the same synaptic sites in the cat retina, one expects a block of ON-centre ganglion cells. Moreover, the drug response of OFF-centre ganglion cells is then consistent with Sterling's hypothesis [Sterling (1983) A. Rev. Neurosci. 6, 149-185] that OFF-ganglion cells receive a direct inhibitory input from ON-bipolars. For some period 19 out of 108 cells responded to 2-amino-4-phosphonobutyric acid and 2-amino-4-phosphonovaleric acid in an opposite way to that described above: ON-centre cells increased and OFF-centre cells decreased their maintained discharge. It is proposed that this "reverse response" may be mediated by autoreceptors to excitatory amino acids or due to different receptor sites triggering antagonistic response mechanisms.

UI	MeSH Term	Description	Entries
D007478	Iontophoresis	Therapeutic introduction of ions of soluble salts into tissues by means of electric current. In medical literature it is commonly used to indicate the process of increasing the penetration of drugs into surface tissues by the application of electric current. It has nothing to do with ION EXCHANGE; AIR IONIZATION nor PHONOPHORESIS, none of which requires current.	Iontophoreses
D012160	Retina	The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.	Ora Serrata
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D000613	Aminobutyrates	Derivatives of BUTYRIC ACID that contain one or more amino groups attached to the aliphatic structure. Included under this heading are a broad variety of acid forms, salts, esters, and amides that include the aminobutryrate structure.	Aminobutyric Acids,Aminobutyric Acid,Acid, Aminobutyric,Acids, Aminobutyric
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012165	Retinal Ganglion Cells	Neurons of the innermost layer of the retina, the internal plexiform layer. They are of variable sizes and shapes, and their axons project via the OPTIC NERVE to the brain. A small subset of these cells act as photoreceptors with projections to the SUPRACHIASMATIC NUCLEUS, the center for regulating CIRCADIAN RHYTHM.	Cell, Retinal Ganglion,Cells, Retinal Ganglion,Ganglion Cell, Retinal,Ganglion Cells, Retinal,Retinal Ganglion Cell
D014633	Valine	A branched-chain essential amino acid that has stimulant activity. It promotes muscle growth and tissue repair. It is a precursor in the penicillin biosynthetic pathway.	L-Valine,L Valine
D015763	2-Amino-5-phosphonovalerate	The D-enantiomer is a potent and specific antagonist of NMDA glutamate receptors (RECEPTORS, N-METHYL-D-ASPARTATE). The L form is inactive at NMDA receptors but may affect the AP4 (2-amino-4-phosphonobutyrate; APB) excitatory amino acid receptors.	2-Amino-5-phosphonopentanoic Acid,2-Amino-5-phosphonovaleric Acid,2-APV,2-Amino-5-phosphonopentanoate,5-Phosphononorvaline,d-APV,dl-APV,2 Amino 5 phosphonopentanoate,2 Amino 5 phosphonopentanoic Acid,2 Amino 5 phosphonovalerate,2 Amino 5 phosphonovaleric Acid,5 Phosphononorvaline