Table 1.
Index of the experimental details and results from a subset of published NOR studies testing the involvement of the rodent hippocampus and which a sample session exploration criterion was imposed.
| Species & Strain | Technique | Structure | Treatment | Lesion size/Time of Drug Administration | Arena | Criterion | Delay | Detailed Results | Reference | Summary of Findings |
|---|---|---|---|---|---|---|---|---|---|---|
| Rat Long-Evans | inactivation | HPC (dorsal) | NMDA antag, APV (4 sites) | pre-sample | square 0.6m × 0.6m | 30-s sample | 5-m | not diff from sham | [74] | not impaired |
| Rat Long-Evans | inactivation | HPC (dorsal) | NMDA antag, APV (4 sites) | pre-sample | square 0.6m × 0.6m | 30-s sample | 3-h | sig diff from sham | [74] | impaired |
| Mouse C57BL/6J | inactivation | HPC (dorsal) | muscimol | pre-sample | square 0.4m × 0.4m | 30-s sample | 24-h | sig diff from sham | [34] | impaired |
| Mouse C57BL/6J | inactivation | HPC (dorsal) | muscimol | post-sample | square 0.4m × 0.4m | 30-s sample | 24-h | sig diff from sham | [34] | impaired |
| Mouse C57BL/6J | inactivation | HPC (dorsal) | muscimol | pre-, post-sample & pretest | square 0.4m × 0.4m | 30-s sample | 24-h | sig diff from sham | [34] | impaired |
| Mouse C57BL/6J | inactivation | HPC (dorsal) | anisomycin | post-sample 0h and 2h | square 0.4m × 0.4m | 30-s sample | 24-h | sig diff from sham | [34] | impaired |
| Mouse C57BL/6J | inactivation | HPC (dorsal) | anisomycin | post-sample 2h only (control study) | square 0.4m × 0.4m | 30-s sample | 24-h | not sig diff from sham | [34] | not impaired |
| Mouse C57BL/6J | inactivation | HPC (dorsal) | muscimol | pre-test (control study) | novel context for test (square 0.2m × 0.2m) | 30-s sample | 24-h | not sig diff from sham - controls fail to prefer novel obj | [34] | not impaired |
| Mouse C57BL/6J | inactivation | HPC (dorsal) | Lidocaine (0.5 μl of 4%/side) | pre-sample | square 0.4m × 0.4m | 38-s sample | 5-m | not sig diff from sham | [35] | not impaired |
| Mouse C57BL/6J | inactivation | HPC (dorsal) | Lidocaine (0.5 μl of 4%/side) | pre-sample | square 0.4m × 0.4m | 38-s sample | 24-h | sig diff from sham | [35] | impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Partial: 58% | square 0.9m × 0.9m | 30-s sample | 10-s | not diff from sham - results differ if looking at first minute of test or 30-s exp. | [75] | not impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Partial: 58% | square 0.9m × 0.9m | 30-s sample | 1-m | not diff from sham | [75] | not impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Partial: 58% | square 0.9m × 0.9m | 30-s sample | 10-m | chance | [75] | impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Partial: 58% | square 0.9m × 0.9m | 30-s sample | 1-h | chance | [75] | impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Partial: 58% | square 0.9m × 0.9m | 30-s sample | 24-h | chance | [75] | impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Complete: 98% | square 0.9m × 0.9m | 30-s sample | 10-s | not diff from sham | [75] | not impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Complete: 98% | square 0.9m × 0.9m | 30-s sample | 1-m | not diff from sham | [75] | not impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Complete: 98% | square 0.9m × 0.9m | 30-s sample | 10-m | not diff from sham | [75] | not impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Complete: 98% | square 0.9m × 0.9m | 30-s sample | 1-h | not diff from sham | [75] | not impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Complete: 98% | square 0.9m × 0.9m | 30-s sample | 24-h | chance | [75] | impaired |
| Rat Pigmented DA | lesion | HPC | NMDA | Partial: average 58% | rectangle 0.5m × 0.9m | 40-s sample | 5-m | not diff from sham - HPC: 58% (40–93%) | [76] | not impaired |
| Rat Pigmented DA | lesion | HPC | NMDA | Partial: average 58% | rectangle 0.5m × 0.9m | 40-s sample | 3-h | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | HPC | NMDA | Partial: average 58% | rectangle 0.5m × 0.9m | 40-s sample | 24-h | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | PRH+HPC contra | NMDA | PRH: average 85% HPC: average 54% | rectangle 0.5m × 0.9m | 40-s sample | 5-m | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | PRH+HPC contra | NMDA | PRH: average 85% HPC: average 54% | rectangle 0.5m × 0.9m | 40-s sample | 3-h | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | PRH+HPC contra | NMDA | PRH: average 85% HPC: average 54% | rectangle 0.5m × 0.9m | 40-s sample | 24-h | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | PRH+HPC ipsi | NMDA | PRH: average 86% HPC: average 61% | rectangle 0.5m × 0.9m | 40-s sample | 5-m | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | PRH+HPC ipsi | NMDA | PRH: average 86% HPC: average 61% | rectangle 0.5m × 0.9m | 40-s sample | 3-h | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | PRH+HPC ipsi | NMDA | PRH: average 86% HPC: average 61% | rectangle 0.5m × 0.9m | 40-s sample | 24-h | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | mPFC+ HPC contra | NMDA | mPFC: average 74% HPC: average 57% | rectangle 0.5m × 0.9m | 40-s sample | 5-m | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | mPFC+ HPC contra | NMDA | mPFC: average 74% HPC: average 57% | rectangle 0.5m × 0.9m | 40-s sample | 3-h | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | mPFC+ HPC contra | NMDA | mPFC: average 74% HPC: average 57% | rectangle 0.5m × 0.9m | 40-s sample | 24-h | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | mPFC+ HPC ipsi | NMDA | mPFC: average 69% HPC: average 54% | rectangle 0.5m × 0.9m | 40-s sample | 5-m | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | mPFC+ HPC ipsi | NMDA | mPFC: average 69% HPC: average 54% | rectangle 0.5m × 0.9m | 40-s sample | 3-h | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | mPFC+ HPC ipsi | NMDA | mPFC: average 69% HPC: average 54% | rectangle 0.5m × 0.9m | 40-s sample | 24-h | not diff from sham | [76] | not impaired |
| Rat Pigmented DA | lesion | HPC | Radiofrequency | Fornix Complete: ~80% | square 1.0m × 1.0m | 25-s sample | 15-m | not sig diff from sham - sig diff DR based on 1st min of test | [21] | not impaired |
| Rat Long-Evans | lesion | HPC | Ibotenic acid | Complete: 89.8% | square 0.9m × 0.9m | 30-s sample | 10-s | not sig diff from sham | [55] | not impaired |
| Rat Long-Evans | lesion | HPC | Ibotenic acid | Complete: 89.8% | square 0.9m × 0.9m | 30-s sample | 1-m | not sig diff from sham | [55] | not impaired |
| Rat Long-Evans | lesion | HPC | Ibotenic acid | Complete: 89.8% | square 0.9m × 0.9m | 30-s sample | 10-m | sig diff from sham | [55] | impaired |
| Rat Long-Evans | lesion | HPC | Ibotenic acid | Complete: 89.8% | square 0.9m × 0.9m | 30-s sample | 1-h | sig diff from sham | [55] | impaired |
| Rat Long-Evans | lesion | HPC | Ibotenic acid | Complete: 89.8% | square 0.9m × 0.9m | 30-s sample | 24-h | sig diff from sham | [55] | impaired |
| Rat Long-Evans | lesion | HPC | Radiofrequency | Complete: 71.2% | square 0.9m × 0.9m | 30-s sample | 10-s | not sig diff from sham | [55] | not impaired |
| Rat Long-Evans | lesion | HPC | Radiofrequency | Complete: 71.2% | square 0.9m × 0.9m | 30-s sample | 1-m | not sig diff from sham | [55] | not impaired |
| Rat Long-Evans | lesion | HPC | Radiofrequency | Complete: 71.2% | square 0.9m × 0.9m | 30-s sample | 10-m | sig diff from sham | [55] | impaired |
| Rat Long-Evans | lesion | HPC | Radiofrequency | Complete: 71.2% | square 0.9m × 0.9m | 30-s sample | 1-h | sig diff from sham | [55] | impaired |
| Rat Long-Evans | lesion | HPC | Radiofrequency | Complete: 71.2% | square 0.9m × 0.9m | 30-s sample | 24-h | sig diff from sham | [55] | impaired |
| Rat Long-Evans | lesion | HPC | Radiofrequency | Fornix Complete: 100% | square 0.9m × 0.9m | 30-s sample | 10-s | not sig diff from sham | [55] | not impaired |
| Rat Long-Evans | lesion | HPC | Radiofrequency | Fornix Complete: 100% | square 0.9m × 0.9m | 30-s sample | 1-m | not sig diff from sham | [55] | not impaired |
| Rat Long-Evans | lesion | HPC | Radiofrequency | Fornix Complete: 100% | square 0.9m × 0.9m | 30-s sample | 10-m | not sig diff from sham | [55] | not impaired |
| Rat Long-Evans | lesion | HPC | Radiofrequency | Fornix Complete: 100% | square 0.9m × 0.9m | 30-s sample | 1-h | not sig diff from sham | [55] | not impaired |
| Rat Long-Evans | lesion | HPC | Radiofrequency | Fornix Complete: 100% | square 0.9m × 0.9m | 30-s sample | 24-h | not sig diff from sham | [55] | not impaired |
| Rat Pigmented DA | lesion | PRH+HPC | NMDA+ Radiofrequency | Extensive | square 1m × 1m | 20-s (3 sessions) | 15-m | sig diff from sham - failed to discrim on all 3 sessions | [77] | impaired |
| Rat Pigmented DA | lesion | PRH+HPC | NMDA+ Radiofrequency | Extensive | square 1m × 1m | 40-s (3 sessions) | 15-m | sig diff from sham - failed to discrim on 1st and 3rd sessions | [77] | impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Complete | Y-shaped arena | 25-s sample (or 3 min) | 15-m | not sig diff from sham | [22] | not impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Complete | Y-shaped arena | 25-s sample (or 3 min) | 1-h | not sig diff from sham | [22] | not impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Complete | Y-shaped arena | 25-s sample (or 3 min) | 24-h | not sig diff from sham | [22] | not impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Complete | Y-shaped arena | 25-s sample (or 3 min) | 48-h | not sig diff from sham | [22] | not impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Complete: >70% | square 1m × 1m | 40-s sample | 2-m | not sig diff from sham - DR’s = sham 0.63; HPC 0.6 | [78] | not impaired |
| Rat Lister hooded | lesion | HPC | Ibotenic acid | Complete: 85–100% | cylinder 0.8m diameter | 15-s sample | 2-m | not sig diff from sham | [79] | not impaired |
| Rat Lister hooded | lesion | HPC | NMDA (pre-train) | Extensive loss DG,CA3-1 | Y-shaped arena | 25-s sample | 0-s | not sig diff from sham | [19] | not impaired |
| Rat Lister hooded | lesion | HPC | NMDA (pre-train) | Extensive loss DG,CA3-1 | Y-shaped arena | 25-s sample | 15-m | not sig diff from sham | [19] | not impaired |
| Rat Lister hooded | lesion | HPC | NMDA (pre-train) | Extensive loss DG,CA3-1 | Y-shaped arena | 25-s sample | 1-h | not sig diff from sham | [19] | not impaired |
| Rat Lister hooded | lesion | HPC | NMDA (pre-train) | Extensive loss DG,CA3-1 | Y-shaped arena | 25-s sample | 24-h | not sig diff from sham | [19] | not impaired |
Note.
For a more complete review of rodent object recognition memory studies in which the role of medial temporal lobe structures has been tested, please see supplementary table S1. Abbreviations: HPC, hippocampus; antag, antagonist; diff, different; sig, significant; obj, object; PRH, perirhinal cortex; contra, contralateral; ipsi, ipsilateral; mPFC, medial prefrontal cortex; discrim, discriminate; exp, exploration; DR, discrimination ratio. Statistical analyses revealed no significant effect of lesion treatment, arena characteristics, or rodent strain, on hippocampal involvement in the NOR task.