The rhesus monkey hippocampus critically contributes to scene memory retrieval, but not new learning
| Autor: | Sean Froudist-Walsh, Jul Lea Shamy, Kathy L. Murphy, Mark G. Baxter, Tess L. Veuthey, Philip G. F. Browning, Paula L. Croxson, Charles R.E. Wilson |
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| Rok vydání: | 2018 |
| Předmět: |
Male
0301 basic medicine N-Methylaspartate Anterograde amnesia Amnesia Hippocampus Hippocampal formation Lesion 03 medical and health sciences 0302 clinical medicine Visual memory medicine Animals Learning Episodic memory Research Articles 030304 developmental biology 0303 health sciences Critical structure Recall General Neuroscience Retrograde amnesia medicine.disease Macaca mulatta 030104 developmental biology Mental Recall Amnesia Retrograde Female medicine.symptom Psychology Neuroscience 030217 neurology & neurosurgery |
| DOI: | 10.1101/288407 |
| Popis: | Humans can recall a large number of memories years after the initial events. Patients with amnesia often have lesions to the hippocampus, but human lesions are imprecise, making it difficult to identify the anatomy underlying memory impairments. Rodent studies enable great precision in hippocampal manipulations, but not investigation of many interleaved memories. Thus it is not known how lesions restricted to the hippocampus affect the retrieval of multiple sequentially encoded memories. Furthermore, disagreement exists as to whether hippocampal inactivations lead to temporally graded or ungraded amnesia, which could be a consequence of differences between rodent and human studies. In the current study, rhesus monkeys of both sexes received either bilateral neurotoxic hippocampal lesions or remained unoperated controls and were tested on recognition and new learning of visual object-in-place scenes. Monkeys with hippocampal lesions were significantly impaired at remembering scenes that were encoded before the lesion. We did not observe any temporal gradient effect of the lesion on memory recognition, with recent and remote memories being equally affected by the lesion. Monkeys with hippocampal lesions showed no deficits in learning new scenes. Thus, the hippocampus, like other cortical regions, may be engaged in the acquisition and storage of new memories, but the role of the damaged hippocampus can be taken over by spared hippocampal tissue or extra-hippocampal regions following a lesion. These findings illustrate the utility of experimental paradigms for studying retrograde and anterograde amnesia that make use of the capacity of nonhuman primates to rapidly acquire many distinct visual memories.SIGNIFICANCE STATEMENT Recalling old memories, creating new memories, and the process by which memories transition from temporary to permanent storage all may rely on the hippocampus. Whether the hippocampus is necessary for encoding and retrieval of multiple related visual memories in primates is not known. Monkeys that learned many visual memory problems before precise lesions of the hippocampus were impaired at recalling those memories after hippocampal damage regardless of when the memories were formed, but could learn new memory problems at a normal rate. This suggests the hippocampus is normally vital for retrieval of complex visual memories regardless of their age, and also points to the importance of investigating mechanisms by which memories may be acquired in the presence of hippocampal damage. |
| Databáze: | OpenAIRE |
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