Regional Variation in Receptive Field Properties of Tectal Neurons in Pigeons

Abstract

The present study provides the first electrophysiological evidence for dorsoventral variation in the receptive field properties of tectal cells in pigeons. According to their receptive field organization, visual response properties and laminar locations, 95 tectal neurons recorded in the present study could be categorized into two groups: (1) Fifty-five DL-neurons were recorded in the dorsal, dorso-lateral, lateral and ventro-lateral tectum and characterized by an excitatory receptive field surrounded by an inhibitory receptive field. Most of them almost equally responded to white and black objects, but did not respond to switch-on and -off of a light spot. (2) Forty VC-neurons were recorded in the ventral tectum and characterized by an excitatory receptive field alone. Their responses to switch-on of a light spot and to a white object were significantly stronger than those to light-off and to a black object, respectively. DL-neurons preferred higher velocity, whereas VC-neurons preferred lower velocity. The recording sites of 53 of 95 cells (56%) examined were marked with pontamine sky blue, showing that DL-neurons were located in tectal layers I–IV, predominantly in layer II, whereas VC-neurons were mainly concentrated in sublayer IIc. The receptive fields of VC-neurons were located within the rostroventral visual field possibly corresponding to the red field of the pigeon retina, suggesting that they might be associated with visual food-foraging behaviors.

Visual object categorization in birds and primates: Integrating behavioral, neurobiological, and computational evidence within a “general process” framework

“…The receptive fields of many neurons in the tectum have a centersurround structure similar to that shown by LGN neurons (Frost, Scilley, & Wong, 1981;Gu, Wang, & Wang, 2000;Jassik-Gerschenfeld & Guichard, 1972). Li, Xiao, and Wang (2007) found that the receptive fields of neurons in the nucleus isthmus, a structure that has reciprocal connections with the tectum, are constructed by feedforward convergence of tectal receptive fields, as proposed by the hierarchical model of Wiesel (1962, 1968).…”

Comparisons of Visual Properties between Tectal and Thalamic Neurons with Overlapping Receptive Fields in the Pigeon

“…Most OPT cells are characterized by ERF without an inhibitory surround, whereas the majority of tectal cells paired with the OPT cells possess a concentrically organized ERF and IRF. It appears that ERFs of OPT cells are organized similarly to those of visual cells in the ventral tectum [Gu et al, 2000]. Generally speaking, ERFs in OPT cells are larger in dimensions than those of tectal cells.…”

“…Some recording sites were marked with dye. Under deep anesthesia, the brain was removed and histologically processed for microscopic observation [Gu et al, 2000].…”

“…Though extensive electrophysiological studies in birds have been performed separately on the receptive field organization and visual responses of tectal [Jassik-Gerschenfeld and Guichard, 1972;Hughes and Pearlman, 1974;Frost and Di Franco, 1976;Frost and Nakayama, 1983;Frost et al, 1990;Schmidt et al, 1999;Gu et al, 2000;Sun et al, 2002] and OPT cells [Britto et al, 1975;Jassik-Gerschenfeld et al, 1976;Pateromichelakis, 1981], the physiological differences between both visual centers remain unclear. Particularly, comparisons are lacking between the visual properties of tectal cells and those of OPT cells, both of which receive information from the same region of the visual field.…”

Functional investigation of neural circuits in larval zebrafish

“…Exploration of the different responses encoded along the dorso-ventral axis of the tectal PVL appears only sporadically in the literature (Gu et al, 2000;Lim et al, 2010), and never in larval zebrafish. In this study, auditory responses were relatively weak and sparsely distributed in ventral areas of the PVL.…”