Skip to main content
    • Aa
    • Aa

The role of GABA in modulating the Xenopus electroretinogram

  • Arsaell Arnarsson (a1) and Thor Eysteinsson (a1)

We have recorded the electroretinogram (ERG) from the superfused eyecup of the Xenopus retina in order to assess the effects of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), and its agonists and antagonists, on individual ERG components. We found that GABA (0.5–10 mM) reduced the amplitudes of both the b- and d-waves of the Xenopus ERG. The GABA uptake blocker nipecotic acid (1 mM) had similar effects on b- and d-waves. GABA at 5 mM and 10 mM also caused an increase in the a-wave. The GABA antagonist picrotoxin (0.1–2 mM) and the GABA/a antagonist bicuculline (0.2 mM) both increased the amplitude of the b- and d-waves of the ERG. The GABA/b agonist baclofen (0.3 mM) reduced the amplitude of the ERG b-wave, enhanced the amplitude of the a-wave, and slightly reduced the amplitude and increased the peak time of the d-wave. The GABA/b antagonists phaclofen and saclofen had no reliable effects on the Xenopus ERG. Glutamate analogs known to affect specific types of retinal neurons were applied to modify the retinal circuitry and then the effects of GABA and its antagonists were examined under these modified conditions. 2-amino-4-phosphonobutyric acid (APB) increased the d-wave, and blocked the b-wave and the effect of GABA on the ERG, but not the antagonist-induced increase in the d-wave. KYN blocked the antagonist-induced increase in the b-wave, while GABA increases the amplitude of the b-wave if the d-wave has been removed by prior superfusion with kynurenic acid (KYN). N-methyl-DL-aspartate (NMDLA), which acts only in the proximal retina, reduced the amplitude of the ERG and blocked the effect of GABA and the antagonist-induced increase in ERG b- and d-waves amplitude. These results suggest that GABAergic mechanisms related to both A and B receptor types can influence the amplitude and light sensitivity of all the components of the Xenopus ERG. Since GABA is found in greatest abundance in the proximal retina, and B type of receptors are present almost exclusively there, the data suggests that most of the effects of GABA agonists and antagonists observed are dependent on proximal retinal mechanisms, and that there are separate mechanisms in the proximal retina related to the b- and the d-waves.

Linked references
Hide All

This list contains references from the content that can be linked to their source. For a full set of references and notes please see the PDF or HTML where available.

M.S. Arkin & R.F. Miller (1987). Subtle action of 2-amino-4-phosphonobutyriate (APB) on the Off pathway in the mudpuppy retina. Brain Research 426, 142148.

D. Attwell , P. Mobbs , M. Tessier-Lavigne & M. Wilson (1987). Neurotransmitter-induced currents in retinal bipolar cells of the axolotl, ambystoma mexicanum. Journal of Physiology 387, 125161.

J. Bormann (1988). Electrophysiology of GABAA & GABAB receptor subtypes. Trends in Neurosciences 11, 112116.

C. Brandon , D. M.-K. Lam , Y. Y.T. Su & J.-Y. Wu (1980). Immuno-cytochemical localization of GABA neurons in the rabbit and frog retina. Brain Research Bulletin (Suppl.) 5, 2129.

P.A. Coleman , S.C. Massey & R.F. Miller (1986). Kynurenic acid distinguishes kainate and quisqualate receptors in the vertebrate retina. Brain Research 381, 172175.

E. Dick & R.F. Miller (1985). Extracellular K+-activity changes related to electroretinogram components I: Amphibian (I-type) retinas. Journal of General Physiology 85, 911931.

I. Gottlob , L. Wundsch & F.K. Tuppy (1988). The rabbit electroretinogram: Effect of GABA and its antagonists. Vision Research 28, 203210.

J.G. Hollyfield , M.E. Rayborn , P.V. Sarthy & D.M.K. Lam (1979). The emergence, localization, and maturation of neurotransmitter systems during development of the retina in Xenopus laevis: I gamma-aminobutyric acid. Journal of Comparative Neurology 188, 587598.

J. Lerma , O. Herreras , A.S. Herranz , D. Munoz & R.M. del Rio (1984). In vivo effects of nipecotic acid on levels of extracellular GABA and taurine, and hippocampal excitability. Neuropharmacology 23, 595598.

G. Maguire , B. Maple , P. Lukasiewicz & F. Werblin (1989). GABA type B receptor modulation of L-type calcium channel current at bipolar cell terminals in the retina of the tiger salamander. Proceedings of the National Academy of Sciences of the U.S.A. 86, 1014410147.

S.C. Massey , D.A. Redburn , & M.L.J. Crawford (1983). The effects of 2-amino-4-phosphonobutyric acid (APB) on the ERG and ganglion cell discharge of rabbit retina. Vision Research 23, 16071613.

R.F. Miller & M.M. Slaughter (1986). Excitatory amino acid receptors of the retina: Diversity of subtypes and conductance mechanisms. Trends in Neuroscience 9, 211218.

J.L. Mosinger , K.M. Studholme & S. Yazulla (1986). Immunocyto-chemical localization of GABA in the retina: A species comparison. Experimental Eye Research 42, 631644.

F. Naarendorp & P.A. Sieving (1991). The scotopic threshold response of the cat ERG is suppressed selectively by GABA and glycine. Vision Research 31, 115.

M.M. Slaughter & R.F. Miller (1981). 2-Amino-4-phosphonobutyric acid: An new pharmacological tool for retinal research. Science 211, 182185.

M.M. Slaughter & R.F. Miller (1983 b). An excitatory amino acid antagonist blocks cone input to sign-conserving synapse. Science 219, 1230.

M.M. Slaughter & R.F. Miller (1983 c). Bipolar cells in the mudpuppy use an EAA neurotransmitter. Nature 303, 537538.

R. Stockton & M.M. Slaughter (1989). The b-wave of the electroretinogram: A reflection of ON-bipolar cell activity. Journal of General Physiology 93, 101122.

S. Stone & P. Witkovsky (1984). The actions of gamma-aminobutyric acid, glycine, and their antagonists upon horizontal cells of the Xenopus retina. Journal of Physiology 353, 249264.

N. Tian & M.M. Slaughter (1994). Pharmacology of the GABA/B receptor in amphibian retina. Brain Research 660, 267274.

P. Witkovsky , S. Stone & H. Ripps (1985). Pharmacological modification of the light-induced responses of Müller (glial) cells in the amphibian retina. Brain Research 328, 111120.

S.M. Wu (1986). Effects of GABA on cones and bipolar cells of the tiger salamanda retina. Brain Research 365, 7077.

C.Y. Yang & S. Yazulla (1988). Localization of putative GABAergic neurons in the larval tiger salamander retina by immunocytochemical and autoradiographic methods. Journal of Comparative Neurology 277, 96108.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Visual Neuroscience
  • ISSN: 0952-5238
  • EISSN: 1469-8714
  • URL: /core/journals/visual-neuroscience
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 5 *
Loading metrics...

Abstract views

Total abstract views: 96 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 21st September 2017. This data will be updated every 24 hours.