A Neural Circuit Analysis of Visual Recognition Memory: Role of Perirhinal, Medial, and Lateral Entorhinal Cortex

Abstract

Using a continuous recognition memory procedure for visual object information, we sequentially presented rats with eight novel objects and four repeated objects (chosen from the 8). These were selected from 120 different three-dimensional objects of varying sizes, shapes, textures, and degree of brightness. Repeated objects had lags ranging from 0 to 4 (from 0 to 4 different objects between the first and repeated presentation). An object was presented on one side of a long table divided in half by an opaque Plexiglas guillotine door, and the latency between opening the door and the rat moving the object was measured. The first presentation of an object resulted in reinforcement, but repeated presentations did not result in a reinforcement. After completion of acquisition training (significantly longer latencies for repeated presentation compared with the first presentation of an object), rats received lesions of the perirhinal, medial, or lateral entorhinal cortex or served as sham operated controls. On the basis of postsurgery testing and additional tests, the results indicated that rats with perirhinal cortex lesions had a sustained impairment in performing the task. There were no sustained deficits with medial or lateral entorhinal cortex lesions. The data suggest that recognition memory for visual object information is mediated primarily by the perirhinal cortex but not by the medial or lateral entorhinal cortex.

Interaction between Perirhinal and Medial Prefrontal Cortex Is Required for Temporal Order But Not Recognition Memory for Objects in Rats

“…Rats receiving lidocaine infusions into the Prh failed to direct more exploration at novel objects than familiar objects, yet did not exhibit any grossly observable behavioral abnormalities or altered overall amounts of object exploration. This pattern of behavior suggests that Prh inactivation specifically blocked capacity for familiarity discrimination, which agrees with other demonstrations of impairments after permanent Prh lesions in similar spontaneous object recognition tasks (Ennaceur et al, 1996;Aggleton et al, 1997;Ennaceur and Aggleton, 1997;Bussey et al, 1999;Liu and Bilkey, 2001;Mumby et al, 2002) and in reinforced tests of object recognition memory (Mumby and Pinel, 1994;Kesner et al, 2001;Murray and Richmond, 2001). The basis for impaired familiarity discrimination in the present study cannot be determined but could relate to the hypothesized role of the Prh in either object recognition memory per se (i.e., the ability to remember that an object has been previously encountered), object identification (i.e., the ability to perceive diverse object features as an integrated whole distinct from other similar objects) or both (Murray and Richmond, 2001).…”

Neural Correlates of Novel Object and Novel Location Recognition Behavior in the Mouse Anterior Cingulate Cortex

“…Evidence for hippocampal involvement in object recognition has been reported, although it is unclear whether the evidence is attributable to the length of the delay to test (Clark et al 2000;Hammond et al 2004) or when the lesions are performed relative to the initial encounter (Gaskin et al 2003). For both scenarios it was proposed that extrahippocampal structures, such as the perirhinal cortex, mediate the behavior in the absence of the hippocampus, a possibility that is supported by lesion data (Kesner et al 2001).…”

Improved Long-Term Potentiation and Memory in Young Tau-P301L Transgenic Mice before Onset of Hyperphosphorylation and Tauopathy

“…Recent studies demonstrate that the delay length determines hippocampal involvement (Hammond et al, 2004), and this is crucial for object recognition at a longer delay (hours), similar to what we studied here. However, we do acknowledge that associated structures like perirhinal and postrhinal cortex may influence ORT performance (Bussey et al, 1999;Kesner et al, 2001), and alterations in these brain regions could contribute to the changes observed in the young tau-P301L mice.…”