Table 1.
Schedule of experimental phases.
Table 2.
Anatomical landmarks based on the rat brain atlas.
Fig 1.
Representative Lesion Symmetry Maps.
Top: scoring for a representative large bilateral lesion of a rat whose lesion met the inclusion criteria for behavioral analyses (≥50% of GC, and ≥70% of the GC “core”, containing a lesion). Bottom: scoring for a representative small bilateral lesion in a rat that did not meet the inclusion criteria, and was therefore removed from behavioral analyses. D: Dorsal to granular insular cortex. GI: Granular insular cortex. DI: Dysgranular insular cortex. AI: Agranular insular cortex, dorsal to the rhinal fissure. V: Ventral to the rhinal fissure. L: Lateral. M: Medial. Left and right hemispheres are shown for each representative map along with the resulting Symmetry Map (middle panel). Complete lesion to an area (one grid cell) is indicated in red and received a score of 1.0. Damage less than complete but at least half of the area is shown in orange and was given a score of 0.5. Less than half of the area with destruction, is shown in white and was given a score of 0. The anterior and posterior boundaries of traditionally defined GC are indicated by solid lines at 2.3 and 0.2 mm (AP relative to bregma). Medium-dashed lines show anterior and posterior boundaries of GC “core” at 1.8 and 0.6 mm (AP relative to bregma). The approximate center of GC is indicated with short-dashed lines at 1.2 mm (AP relative to bregma). Photomicrographs of the representative lesion maps are shown with labeled coordinates (in mm, relative to bregma) for each hemisphere. Arrowheads indicate lesion borders. Scale bar = 1 mm.
Fig 2.
Overlap Map for lesions of rats included in behavioral analyses.
Compiled Symmetry Maps of those rats meeting lesion criterion for behavioral analyses (left panel; ≥50% of GC and ≥70% of the GC “core” containing a lesion; n = 26) and lesions too small to be included in behavioral analyses (right panel; n = 3). The lesions for the included rats encompassed 91% of GC and 96% of GC “core” on average. The color key between the maps shows the average lesion score for the group in each cell by color. D: Dorsal to granular insular cortex. GI: Granular insular cortex. DI: Dysgranular insular cortex. AI: Agranular insular cortex, dorsal to the rhinal fissure. V: Ventral to the rhinal fissure. L: Lateral. M: Medial. Solid lines show anterior and posterior boundaries of the traditionally defined GC at 2.3 and 0.2 mm (AP relative to bregma). Medium-dashed lines indicate anterior and posterior boundaries of GC “core” at 1.8 and 0.6 mm (AP relative to bregma). Short-dashed lines indicate the approximate center of GC at 1.2 mm (AP relative to bregma).
Table 3.
Mean (SE) for presurgically conditioned taste aversion to NaCl.
Table 4.
Two-way ANOVAs for presurgically conditioned taste aversion to NaCl.
Fig 3.
Assessments of a postsurgically conditioned taste aversion to Maltrin.
(A) Left panel: Mean (±SE) of CS intake across groups for the first conditioning trial with plotted points indicating individual rats as a function of group. Right panel: Mean (±SE) of CS intake across groups for the second conditioning trial with symbols representing each rat within the group. (B)Taste/Water Ratios for each stimulus by group. A score of 1.0 (dashed line) indicates licking rates comparable to water; a score approaching 0 represents avoidance of the stimulus. The green arrow points to the CS concentration (5% Maltrin). (C) Mean (±SE) group preference scores during the 46-h two-bottle intake test, comparing CS intake to total intake. A score of 1.0 indicates total preference for the CS; a score of 0 indicates total avoidance of the CS. The dashed line at 0.5 represents equal intake of DW and CS. Symbols represent scores for individual animals within the respective groups.
Table 5.
Two-way ANOVAs for postsurgically conditioned taste aversion to Maltrin.
Table 6.
Three-way ANOVA for a postsurgically conditioned taste aversion to Maltrin in a brief-access test.
Table 7.
Two-way ANOVAs for a postsurgically conditioned taste aversion to Maltrin in a brief-access test.
Fig 4.
Mean (±SE) proportion correct as a function of stimulus concentration for sucrose (left), KCl (center), and quinine (right) sensitivity testing by group. The curves were fit to the data based on a 3-parameter logistic function (see Data Analysis).
Fig 5.
EC50 for sucrose, KCl and quinine.
Individual EC50 values for sucrose (left), KCl (center), and quinine (right). Means are indicated by the solid lines and dashed-lines are the ± SEs. Left panels are SHAM and right panels are GCX rats.
Table 8.
Two-way ANOVAs for detection testing.
Table 9.
Mean (SE) of curve parameters for detection testing within surgical groups.