title: Field potentials evoked in the avian optic tectum by diffuse and punctiform luminous stimuli.
abstract: An investigation was made of the slow field potentials evoked in the pigeon optic tectum by visual stimulation. Diffuse illumination of the retina produces a polyphasic response which is negative-going in the surface layers and reverses polarity at 200--400 micron. It is suggested that this response reflects activity in radially disposed nerve cells. Local stimulation, produced by punctiform (small-spot) stimuli, results in a negative-going response in the superficial tectum, paired with a smaller and less widely distributed positive-going wave in the deeper layers. It is suggested that this response involves both radial neurones and the tangential neurones ramifying in layers c and d of the SGFS.
mesh_terms: D000818:Animals; D010856:Columbidae; D005071:Evoked Potentials; D010775:Photic Stimulation; D012160:Retina / Q000502:physiology; D013477:Superior Colliculi / Q000502:physiology*; D014794:Visual Fields