Perirhinal Cortex and its Neighbours in the Medial Temporal Lobe: Contributions to Memory and Perception

2005 ◽  
Vol 58 (3-4b) ◽  
pp. 378-396 ◽  
Author(s):  
Elisabeth A. Murray ◽  
Kim S. Graham ◽  
David Gaffan
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Nonhuman Primates ◽  
Species Differences ◽  
Perirhinal Cortex ◽  
Future Research ◽  
Special Issue ◽  
Functional Entity

As promised in the Introduction, this Special Issue presents several recurring themes concerning the perirhinal cortex and its neighbours within the medial temporal lobe (MTL). First, although orthodoxy insists that the diverse constituents of the MTL operate as a single functional entity, several papers presented here challenge that idea, although some defend it. Second, although many experts hold that the MTL subserves memory but not perception, several papers presented here point to a role for certain MTL structures in both. Third, although some researchers have invoked “species differences” to account for discrepant findings, several papers presented here document a striking convergence of findings in humans, nonhuman primates, and rodents. We close this Special Issue by high-lighting these recurring themes, acknowledging discrepant findings and pointing to future research that might resolve some current controversies.

scholarly journals The Contribution of the Human Medial Temporal Lobe to Perception: Bridging the Gap between Animal and Human Studies

2005 ◽  
Vol 58 (3-4b) ◽  
pp. 300-325 ◽  
Author(s):  
Andy C. H. Lee ◽  
Morgan D. Barense ◽  
Kim S. Graham
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Nonhuman Primates ◽  
Declarative Memory ◽  
Object Perception ◽  
Perirhinal Cortex ◽  
Higher Order ◽  
Human Studies ◽  
Memory Processes ◽  
Current Article

The medial temporal lobe (MTL) has been considered traditionally to subserve declarative memory processes only. Recent studies in nonhuman primates suggest, however, that the MTL may also be critical to higher order perceptual processes, with the hippocampus and perirhinal cortex being involved in scene and object perception, respectively. The current article reviews the human neuropsychological literature to determine whether there is any evidence to suggest that these same views may apply to the human MTL. Although the majority of existing studies report intact perception following MTL damage in human amnesics, there have been recent studies that suggest that when scene and object perception are assessed systematically, signifi-cant impairments in perception become apparent. These findings have important implications for current mnemonic theories of human MTL function and our understanding of human amnesia as a result of MTL lesions.

scholarly journals Tau pathology in the medial temporal lobe of athletes with chronic traumatic encephalopathy: a chronic effects of neurotrauma consortium study

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Christy M. Kelley ◽  
Sylvia E. Perez ◽  
Elliott J. Mufson
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Chronic Traumatic Encephalopathy ◽  
Stage Iv ◽  
Perirhinal Cortex ◽  
Stage Ii ◽  
Stage Iii ◽  
Dystrophic Neurites ◽  
Tau Pathology ◽  
African American Athletes

AbstractChronic traumatic encephalopathy (CTE) is a progressive neurodegenerative condition associated with repetitive traumatic brain injury (rTBI) seen in contact-sport athletes and military personnel. The medial temporal lobe (MTL; i.e., hippocampus, subiculum, and entorhinal and perirhinal cortices) memory circuit displays tau lesions during the pathological progression of CTE. We examined MTL tissue obtained from 40 male Caucasian and African American athletes who received a postmortem CTE neuropathological diagnosis defined as stage II, III, or IV. Sections were immunolabeled using an early (AT8) or a late (TauC3) marker for pathological tau and for amyloid beta (Aβ) species (6E10, Aβ1–42 and thioflavin S). Stereological analysis revealed that stage III had significantly less AT8-positive neurons and dystrophic neurites than stage IV in all MTL regions except hippocampal subfield CA3, whereas significantly more AT8-positive neurons, dystrophic neurites, and neurite clusters were found in the perirhinal cortex, entorhinal cortex, hippocampal CA1, and subiculum of CTE stage III compared with stage II. TauC3-positive pathology was significantly higher in the perirhinal and subicular cortex of stage IV compared to stage III and the perirhinal cortex of stage III compared to stage II. AT8-positive neurite clusters were observed in stages III and IV, but virtually absent in stage II. When observed, Aβ pathology appeared as amyloid precursor protein (APP)/Aβ (6E10)-positive diffuse plaques independent of region. Thioflavine S labeling, did not reveal evidence for fibril or neuritic pathology associated with plaques, confirming a diffuse, non-cored plaque phenotype in CTE. Total number of AT8-positive profiles correlated with age at death, age at symptom onset, and time from retirement to death. There was no association between AT8-positive tau pathology and age sport began, years played, or retirement age, and no difference between CTE stage and the highest level of sport played. In summary, our findings demonstrate different tau profiles in the MTL across CTE stages, proffering CA3 tau pathology and MTL dystrophic neurite clusters as possible markers for the transition between early (II) and late (III/IV) stages, while highlighting CTE as a progressive noncommunicative tauopathy.

scholarly journals Autobiographical Memory Retrieval and Hippocampal Activation as a Function of Repetition and the Passage of Time

2007 ◽  
Vol 2007 ◽  
pp. 1-14 ◽  
Author(s):  
Lynn Nadel ◽  
Jenna Campbell ◽  
Lee Ryan
Keyword(s):  
Autobiographical Memory ◽  
Temporal Lobe ◽  
Memory Retrieval ◽  
Medial Temporal Lobe ◽  
Perirhinal Cortex ◽  
Brain Regions ◽  
Long Term Memory ◽  
Memory Traces ◽  
Multiple Trace Theory

Multiple trace theory (MTT) predicts that hippocampal memory traces expand and strengthen as a function of repeated memory retrievals. We tested this hypothesis utilizing fMRI, comparing the effect of memory retrieval versus the mere passage of time on hippocampal activation. While undergoing fMRI scanning, participants retrieved remote autobiographical memories that had been previously retrieved either one month earlier, two days earlier, or multiple times during the preceding month. Behavioral analyses revealed that the number and consistency of memory details retrieved increased with multiple retrievals but not with the passage of time. While all three retrieval conditions activated a similar set of brain regions normally associated with autobiographical memory retrieval including medial temporal lobe structures, hippocampal activation did not change as a function of either multiple retrievals or the passage of time. However, activation in other brain regions, including the precuneus, lateral prefrontal cortex, parietal cortex, lateral temporal lobe, and perirhinal cortex increased after multiple retrievals, but was not influenced by the passage of time. These results have important implications for existing theories of long-term memory consolidation.

scholarly journals Age-related alterations in prelimbic cortical neuron Arc expression vary by behavioral state and cortical layer

2020 ◽  
Author(s):  
Abbi R. Hernandez ◽  
Leah M. Truckenbrod ◽  
Maya E. Barrett ◽  
Katelyn N. Lubke ◽  
Benjamin J. Clark ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Cortical Neuron ◽  
Long Range ◽  
Temporal Lobe ◽  
Cortical Neurons ◽  
Medial Temporal Lobe ◽  
Perirhinal Cortex ◽  
Early Gene ◽  
Projection Neurons ◽  
Age Related

AbstractPrefrontal cortical and medial temporal lobe connectivity is critical for higher cognitive functions that decline in older adults. Likewise, these cortical areas are among the first to show anatomical, functional, and biochemical alterations in advanced age. The prelimbic subregion of the prefrontal cortex and the perirhinal cortex of the medial temporal lobe are densely reciprocally connected and well-characterized as undergoing age-related neurobiological changes that correlate with behavioral impairment. Despite this fact, it remains to be determined how changes within these brain regions manifest as alterations in their functional connectivity. In our previous work, we observed an increased probability of age-related dysfunction for perirhinal cortical neurons that projected to the prefrontal cortex in old rats compared to neurons that were not identified as projection neurons. The current study was designed to investigate the extent to which aged prelimbic cortical neurons also had altered patterns of Arc expression during behavior, and if this was more evident in those cells that had long-range projections to the perirhinal cortex. The expression patterns of the immediate-early gene Arc were quantified in behaviorally characterized rats that also received the retrograde tracer cholera toxin B (CTB) in the perirhinal cortex to identify projection neurons to this region. As in our previous work, the current study found that CTB+ cells were more active than those that did not have the tracer. Moreover, there were age-related reductions in prelimbic cortical neuron Arc expression that correlated with a reduced ability of aged rats to multitask. Unlike the perirhinal cortex, however, the age-related reduction in Arc expression was equally likely in CTB+ and CTB− negative cells. Thus, the selective vulnerability of neurons with long-range projections to dysfunction in old age may be a unique feature of the perirhinal cortex. Together, these observations identify a mechanism involving prelimbic-perirhinal cortical circuit disruption in cognitive aging.

scholarly journals 'Online' integration of sensory and fear memories in the rat medial temporal lobe

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Francesca S Wong ◽  
R Fred Westbrook ◽  
Nathan M Holmes
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Perirhinal Cortex ◽  
Fear Memory ◽  
Sensory Preconditioning ◽  
Memory Network ◽  
Stage 1 ◽  
Memory Rats

How does a stimulus never associated with danger become frightening? The present study addressed this question using a sensory preconditioning task with rats. In this task, rats integrate a sound-light memory formed in stage 1 with a light-danger memory formed in stage 2, as they show fear when tested with the sound in stage 3. Here we show that this integration occurs ‘online’ during stage 2: when activity in the region that consolidated the sound-light memory (perirhinal cortex) was inhibited during formation of the light-danger memory, rats no longer showed fear when tested with the sound but continued to fear the light. Thus, fear that accrues to a stimulus paired with danger simultaneously spreads to its past associates, thereby roping those associates into a fear memory network.

scholarly journals Path Integration Deficits during Linear Locomotion after Human Medial Temporal Lobectomy

2004 ◽  
Vol 16 (4) ◽  
pp. 510-520 ◽  
Author(s):  
John W. Philbeck ◽  
Marlene Behrmann ◽  
Lucien Levy ◽  
Samuel J. Potolicchio ◽  
Anthony J. Caputy
Keyword(s):  
Temporal Lobe ◽  
Path Integration ◽  
Medial Temporal Lobe ◽  
Right Hemisphere ◽  
Functional Neuroimaging ◽  
Hippocampal Formation ◽  
Angular Acceleration ◽  
Temporal Lobectomy ◽  
Future Research ◽  
Anterior Portion

Animal navigation studies have implicated structures in and around the hippocampal formation as crucial in performing path integration (a method of determining one's position by monitoring internally generated self-motion signals). Less is known about the role of these structures for human path integration. We tested path integration in patients who had undergone left or right medial temporal lobectomy as therapy for epilepsy. This procedure removed approximately 50% of the anterior portion of the hippocampus, as well as the amygdala and lateral temporal lobe. Participants attempted to walk without vision to a previously viewed target 2–6 m distant. Patients with right, but not left, hemisphere lesions exhibited both a decrease in the consistency of path integration and a systematic underregistration of linear displacement (and/or velocity) during walking. Moreover, the deficits were observable even when there were virtually no angular acceleration vestibular signals. The results suggest that structures in the medial temporal lobe participate in human path integration when individuals walk along linear paths and that this is so to a greater extent in right hemisphere structures than left. This information is relevant for future research investigating the neural substrates of navigation, not only in humans (e.g., functional neuroimaging and neuropsychological studies), but also in rodents and other animals.

scholarly journals High-resolution fMRI of Content-sensitive Subsequent Memory Responses in Human Medial Temporal Lobe

2010 ◽  
Vol 22 (1) ◽  
pp. 156-173 ◽  
Author(s):  
Alison R. Preston ◽  
Aaron M. Bornstein ◽  
J. Benjamin Hutchinson ◽  
Meghan E. Gaare ◽  
Gary H. Glover ◽  
...  
Keyword(s):  
High Resolution ◽  
Dentate Gyrus ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Functional Neuroimaging ◽  
Perirhinal Cortex ◽  
Memory Effects ◽  
Long Term Memory ◽  
Memory Strength ◽  
Parahippocampal Cortex

The essential role of the medial temporal lobe (MTL) in long-term memory for individual events is well established, yet important questions remain regarding the mnemonic functions of the component structures that constitute the region. Within the hippocampus, recent functional neuroimaging findings suggest that formation of new memories depends on the dentate gyrus and the CA3 field, whereas the contribution of the subiculum may be limited to retrieval. During encoding, it has been further hypothesized that structures within MTL cortex contribute to encoding in a content-sensitive manner, whereas hippocampal structures may contribute to encoding in a more domain-general manner. In the current experiment, high-resolution fMRI techniques were utilized to assess novelty and subsequent memory effects in MTL subregions for two classes of stimuli—faces and scenes. During scanning, participants performed an incidental encoding (target detection) task with novel and repeated faces and scenes. Subsequent recognition memory was indexed for the novel stimuli encountered during scanning. Analyses revealed voxels sensitive to both novel faces and novel scenes in all MTL regions. However, similar percentages of voxels were sensitive to novel faces and scenes in perirhinal cortex, entorhinal cortex, and a combined region comprising the dentate gyrus, CA2, and CA3, whereas parahippocampal cortex, CA1, and subiculum demonstrated greater sensitivity to novel scene stimuli. Paralleling these findings, subsequent memory effects in perirhinal cortex were observed for both faces and scenes, with the magnitude of encoding activation being related to later memory strength, as indexed by a graded response tracking recognition confidence, whereas subsequent memory effects were scene-selective in parahippocampal cortex. Within the hippocampus, encoding activation in the subiculum correlated with subsequent memory for both stimulus classes, with the magnitude of encoding activation varying in a graded manner with later memory strength. Collectively, these findings suggest a gradient of content sensitivity from posterior (parahippocampal) to anterior (perirhinal) MTL cortex, with MTL cortical regions differentially contributing to successful encoding based on event content. In contrast to recent suggestions, the present data further indicate that the subiculum may contribute to successful encoding irrespective of event content.

The Roles of Perirhinal Cortex, Postrhinal Cortex, and the Fornix in Memory for Objects, Contexts, and Events in the Rat

2005 ◽  
Vol 58 (3-4b) ◽  
pp. 202-217 ◽  
Author(s):  
M. J. Eacott ◽  
E. A. Gaffan
Keyword(s):  
Learning And Memory ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Perirhinal Cortex ◽  
Memory System ◽  
Strong Connectivity ◽  
Postrhinal Cortex ◽  
Cortical Regions ◽  
Combining Information

Investigation of the anatomical substructure of the medial temporal lobe has revealed a number of highly interconnected areas, which has led some to propose that the region operates as a unitary memory system. However, here we outline the results of a number of studies from our laboratories, which investigate the contributions of the rat's perirhinal cortex and postrhinal cortex to memory, concentrating particularly on their respective roles in memory for objects. By contrasting patterns of impairment and spared abilities on a number of related tasks, we suggest that perirhinal cortex and postrhinal cortex make distinctive contributions to learning and memory: for example, that postrhinal cortex is important in learning about within-scene position and context. We also provide evidence that despite the strong connectivity between these cortical regions and the hippocampus, the hippocampus, as evidenced by lesions of the fornix, has a distinct function of its own—combining information about objects, positions, and contexts.

scholarly journals The Medial Temporal Lobe Supports Mnemonic Discrimination For Event Duration

2020 ◽  
Author(s):  
Nathan M. Muncy ◽  
C. Brock Kirwan
Keyword(s):  
Temporal Lobe ◽  
Stimulus Duration ◽  
Medial Temporal Lobe ◽  
Discrimination Task ◽  
Temporal Discrimination ◽  
Perirhinal Cortex ◽  
Event Duration ◽  
Similar Information ◽  
Integral Role ◽  
Over Time

AbstractTime has an integral role in episodic memory and previous work has implicated the medial temporal lobe in both representing time and discriminating between similar information. Here we developed a novel paradigm to test mnemonic discrimination for temporal duration, as previous work has largely focused on order or maintaining information over time. Thirty-five healthy, young adults completed a continuous-recognition, temporal discrimination task in which participants were tasked with detecting a change in stimulus duration on the order of 0.5 seconds. Whole-brain high-resolution fMRI data were acquired. Behavioral results indicate that participants were successful at detecting whether or not the stimulus duration changed. Further, fMRI analyses revealed that the left entorhinal and perirhinal cortices were differentially involved in encoding and retrieval, respectively. These findings support the notion of the entorhinal cortex being involved in the encoding of temporal context information as well as the perirhinal cortex representing the conjunction of item and context during retrieval.

Sign in / Sign up

Export Citation Format

Share Document