title: Direction-selective circuitry in rat retina develops independently of GABAergic, cholinergic and action potential activity.
abstract: The ON-OFF direction selective ganglion cells (DSGCs) in the mammalian retina code image motion by responding much more strongly to movement in one direction. They do so by receiving inhibitory inputs selectively from a particular sector of processes of the overlapping starburst amacrine cells, a type of retinal interneuron. The mechanisms of establishment and regulation of this selective connection are unknown. Here, we report that in the rat retina, the morphology, physiology of the ON-OFF DSGCs and the circuitry for coding motion directions develop normally with pharmacological blockade of GABAergic, cholinergic activity and/or action potentials for over two weeks from birth. With recent results demonstrating light independent formation of the retinal DS circuitry, our results strongly suggest the formation of the circuitry, i.e., the connections between the second and third order neurons in the visual system, can be genetically programmed, although emergence of direction selectivity in the visual cortex appears to require visual experience.
authors.affiliation: State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Le
authors.initials: L
authors.lastname: Sun
authors.forename: Xu
authors.initials: X
authors.lastname: Han
authors.forename: Shigang
authors.initials: S
authors.lastname: He
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D001640:Bicuculline / Q000031:analogs & derivatives / Q000494:pharmacology; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D005260:Female; D058787:GABA-A Receptor Antagonists / Q000494:pharmacology; D008297:Male; D018722:Nicotinic Agonists / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000378:metabolism*; D026941:Sodium Channel Blockers / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D058787:GABA-A Receptor Antagonists; D018722:Nicotinic Agonists; D011725:Pyridines; D026941:Sodium Channel Blockers; C017069:bicuculline methiodide; D013779:Tetrodotoxin; D005680:gamma-Aminobutyric Acid; C082748:epibatidine; D000109:Acetylcholine; D001640:Bicuculline