Columnar architecture sculpted by GABA circuits in developing cat visual cortex.
The mammalian visual cortex is organized into columns. Here, we examine cortical influences upon developing visual afferents in the cat by altering intrinsic gamma-aminobutyric acid (GABA)-mediated inhibition with benzodiazepines. Local enhancement by agonist (diazepam) infusion did not perturb visual responsiveness, but did widen column spacing. An inverse agonist (DMCM) produced the opposite effect. Thus, intracortical inhibitory circuits shape the geometry of incoming thalamic arbors, suggesting that cortical columnar architecture depends on neuronal activity.
Hensch
Takao K
TK
Laboratory for Neuronal Circuit Development, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan. hensch@postman.riken
Stryker
Michael P
MP
D000818:Animals; D002243:Carbolines / Q000494:pharmacology; D002415:Cats; D003975:Diazepam / Q000494:pharmacology; D023882:Dominance, Ocular / Q000502:physiology*; D004594:Electrophysiology; D058785:GABA-A Receptor Agonists; D009433:Neural Inhibition; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation; D011963:Receptors, GABA-A / Q000502:physiology; D009435:Synaptic Transmission; D013788:Thalamus / Q000254:growth & development / Q000502:physiology; D014785:Vision, Ocular; D014793:Visual Cortex / Q000033:anatomy & histology / Q000254:growth & development* / Q000502:physiology*; D014795:Visual Pathways; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D002243:Carbolines; D058785:GABA-A Receptor Agonists; D011963:Receptors, GABA-A; C034818:methyl 6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate; D005680:gamma-Aminobutyric Acid; D003975:Diazepam