Topography of Striate-Extrastriate Connections in Neonatally Enucleated Rats
Figure 2
Topography of striate-extrastriate connections in normal and enucleated rats. (a) Diagram of the distribution of callosal connections and visual areas in lateral striate cortex of normal rats. The border of V1 is outlined in black; callosal pattern is indicated in grey, while acallosal areas are indicated in white. The diagram summarizes previous studies (see references in text) of the overall topographic organization of V1 and some visual areas in lateral extrastriate cortex (area 18a). Cortical regions representing upper, lower, nasal and temporal portions of the visual field are indicated by U, L, N, and T, respectively. RL: rostrolateral, AL: anterolateral, LM: lateromedial, LI: laterointermediate, LL: laterolateral, PL: posterolateral, and P: posterior. Modified from [31]. (b) Data from a normal rat (case C21) that received injections of GB (green dot) and RB (red dot) in V1. Cells labeled with either RB or GB are indicated by small red or green dots, respectively. Approximate location of the border of visual areas in area 18a is indicated by thin black lines. (c) Data from an enucleated rat (case M4e9) that received injections of RB (red dot) and BDA (black dot) in V1. BDA-labeled fields are indicated in black. The laterality index for each tracer injection in (b) and (c) is indicated. Insets in (b) and (c) show labeled fields in the dLGN. Callosal patterns, as well as striate projection fields in medial extrastriate cortex are not represented in (b) and (c). Inset in (a) indicates orientation, A: anterior, L: lateral. Scale bars = 1.0 mm.
