Both the medial diencephalon and retrosplenial cortex are vital for human episodic memory as well as spatial memory in rodents. Spatial navigation requires memory representations of landmarks and other navigation cues. Selective neuronal degeneration in the retrosplenial. Optogenetic reactivation of memory ensembles in the. Todd a functional circuit for the retrieval of remote cued fear memory. Anterior to the splenium, the lesions were largely complete, except in two cases where there was some granular cortex sparing one bilateral.
Retrosplenial cortical neurons encode navigational cues. Although some human studies do suggest that hippocampus is involved with spatial memory i. We combine neuroanatomical tracing studies, optical and electrophysiological mapping of retrosplenial cortex inputs and outputs, and opto and. Perhaps more importantly, medial temporal structures involved in memory receive anterior thalamic input directly via the cingulate bundle and indirectly through a relay in the. Aggleton1 1school of psychology, cardiff university, cardiff cf10 3at, united kingdom. For example, the existence of a connection between two brain regions ascertains that information transfer can occur. The contribution of the mammillary bodies, the mammillothalamic tract, anterior thalamic nuclei and retrosplenial cortex to different aspects of recognition memory i. Complimentary roles of the hippocampus and retrosplenial. Novel neuroscience techniques must be combined with welldesigned behavioural. To better characterize the role of the rsc, we tested its involvement in the formation and retrieval of memory for trace fear conditioning, a task that. The retrosplenial cortex rsc is anatomically positioned between limbic areas important for memory formation, such as the hippocampus hpc and the anterior thalamus, and cortical regions along the dorsal stream known to contribute importantly to longterm spatial representation, such as the posterior parietal cortex. To test retrograde amnesia, rats were trained with twoarm place discrimination in a radial maze 4 wk and 1 d before surgery with a different arm pair, respectively. They propose that it achieves this function through. C coronal reconstructions showing the case with the minimal black and the maximal black and gray areas extent of retrosplenial cortex damage.
Functional integrity of the retrosplenial cortex is. The retrosplenial cortex rsc plays an important role in memory and spatial navigation. The retrosplenial cortex rsc is anatomically positioned between limbic areas important for memory formation, such as the hippocampus hpc and the anterior thalamus, and cortical regions along the dorsal stream known to contribute importantly. A novel role for the rat retrosplenial cortex in cognitive control andrew j. Retrosplenial cortex and its role in spatial cognition anna. Corticohippocampal systems involved in memory and cognition. Situated at the crossroads between the hippocampal formation and many neocortical areas, it has attracted much attention especially for its involvement in cognition vann et al. Sep 18, 2012 discussion of brodmanns description of the retrosplenial cortex. Activity was recorded from single neurons in the retrosplenial cortex during performance of an operant foodprocuring behavior in two groups of rats. However, it is unclear whether rsc representations of permanence are a purely spatial phenomenon or whether they extend into behavioral and conceptual domains. A novel role for the rat retrosplenial cortex in cognitive. Howard thought that episodic memory involves more than simply. Functional integrity of the retrosplenial cortex is essential.
Abstract spatial navigation requires memory representations of landmarks and other navigation cues. The method of loci loci being latin for places is a strategy of memory enhancement which uses visualizations of familiar spatial environments in order to enhance the recall of information. Rsc lesions impair performance in spatial memory tasks sutherland et al. When tagged cells in rsc where later reactivated optogenetically in a novel context. What is the function of the human retrosplenial cortex. Retrosplenial cortical contributions to anterograde and. Neuron activity in the retrosplenial cortex of the rat at.
Retrosplenial cortex rsc is highly responsive to landmarks in the environment that remain fixed in a permanent location, and this has been linked with its known involvement in scene and spatial processing. The retrosplenial cortex rsc is a cortical area in the brain, located posteriorly towards the back and comprising brodmann areas 29 and 30. Spatial memory engram in the mouse retrosplenial cortex. Complimentary roles of the hippocampus and retrosplenial cortex in behavioral context discrimination david m. Since the early 1990s, a growing body of evidence has implicated the. The retrosplenial cortex rsc comprises the entire posterior cingulate cortex in rodents vogt and peters 1981 and is one of the largest cortical areas in the rat. Aug 15, 2017 sparse orthogonal coding is a key feature of hippocampal neural activity, which is believed to increase episodic memory capacity and to assist in navigation. Complex cognitive functions, such as learning and memory, arise from the interaction of multiple brain regions that comprise. The hippocampus is involved in processing path distance in novel. The method of loci is also known as the memory journey, memory palace, or mind palace technique. Lesions to retrosplenial cortex in humans produce profound impairments in episodic memory, and in rodents, to a variety of spatial and conditioning tasks. Area 29 retrosplenial cingulate cortex area 29 area retrolimbica granularis anatomical parts. The retrosplenial cortex and longterm spatial memory. Photomicrographs of a coronal section immunostained for nissl from a sham control a and from a case with a midsized retrosplenial lesion b.
The retrosplenial cortex rsc is a crucial transit region between the hippocampus and cingulate cortex and has been implicated in spatial navigation and memory. Similarly, rats with rsc damage remain capable of detecting novel. Location and extent of retrosplenial cortex lesions. To test retrograde amnesia, rats were trained with twoarm place discrimination in a radial maze 4 wk and 1 d before surgery with a different arm pair. Discussion of brodmanns description of the retrosplenial cortex. Together with colleagues in experimental psychology we study the circuitry and function of genetically identified neuronal populations in the retrosplenial cortex during associative memory tasks. A connectome is a comprehensive description of the network elements and connections that form the brain sporns et al.
Rodent studies suggest the region is important for using surrounding visual cues to carry out these tasks. By contrast retrosplenial cortex only tracked the distance to the goal in. The role of the amygdala, retrosplenial cortex, and medial prefrontal cortex in trace fear extinction and reconsolidation by janine l. In the retention test 1 wk after surgery, both lesion groups showed temporally. The retrosplenial cortex rsc is positioned at the interface between cortical. Such clear and comprehensive knowledge of anatomical connections lies at the basis of understanding network functions crick and koch, 2003. The classic dorsal stream areas, such as the intraparietal sulcus corresponding to area lip in the. The cingulate cortex includes the entire cingulate gyrus, which lies immediately above the corpus callosum, and the continuation of this in the cingulate sulcus. The retrosplenial region brodmanns area 26, 29 and 30 of cingulate gyrus can be divided into three parts. Report spatial memory engram in the mouse retrosplenial cortex highlights d longitudinal cfos imaging reveals retrosplenial spatial memory engrams in mice d engrams become progressively more stable with learning and are maintained over weeks d the degree of memory retention is related to the stability of the engrams authors.
The retrosplenial cortex is involved in the formation of. To embed the entire object, paste this html in website. Effective episodic memory, navigation and future thinking all require the ability to integrate and manipulate different. Contributions of retrosplenial cortex to associative learning and memory. Retrosplenial cortex indexes stability beyond the spatial.
Retrosplenial cortex an overview sciencedirect topics. The thesis described in the book combines the powerof neuroscience tools with those from cognitive and computer scienceto grapple with this universally recognized puzzle of the mind andbrain. The degree of memory retention is related to the stability of the engrams, highlighting a possible mechanism for memory consolidation. Anterograde and retrograde amnesia of place discrimination in. Thus, accumulating evidence points to an important role for retrosplenial cortex in the hippocampalneocortical interplay that supports formation and retrieval of spatialepisodic memories.
We combine neuroanatomical tracing studies, optical and electrophysiological mapping of retrosplenial cortex inputs and outputs, and opto and chemogenetic circuit manipulations in behavioural studies. The retrosplenial cortex rsc is known to play a role in the retrieval of context memory, but its involvement in memory formation and consolidation is unclear. The key anatomical and functional relationships of the retrosplenial cortex. Bucci department of psychological and brain sciences, dartmouth college, hanover, nh, usa. Retrosplenial cortex is required for the retrieval of remote memory. At the same time, these groups showed no significant difference in the percentages of neurons. Neurobiology of cingulate cortex and limbic thalamus. Consistent with this, substantial behavioral evidence indicates that rsc is essential for consolidating andor retrieving contextual and spatial memories. Kaboodvand n12, backman l1, nyberg l 234, salami a12. Preoperatively, monkeys learned 300 objectinplace scene discriminations. The retrosplenial cortex rsc is anatomically positioned between limbic. The retrosplenial cortex rsc is one of the largest cortical areas in rodents, and is subdivided in two main regions, a29 and a30, according to their cytoarchitectural organization and connectivities. This method is a mnemonic device adopted in ancient roman and greek rhetorical treatises in the anonymous. Immediateearly gene imaging can visualise retrosplenial neural ensembles.
Contributions of retrosplenial cortex to associative. The retrosplenial cortex rsc surgeries n 16 consistently produced marked cell loss and extensive gliosis throughout almost the entire retrosplenial cortex. The regions name refers to its anatomical location immediately behind the splenium of the corpus callosum in primates, although in rodents it is located more towards the brain surface and is relatively larger. It shares functional similarities with the hippocampus, including the presence of place fields and lesioninduced impairments in spatial navigation, and the rsc is an important source of visualspatial input to the hippocampus. Retrosplenial cortex has a timedependent role in memory for visual stimuli matthew y. Among its various connections, rsc receives input from visuospatial cortical sensory areas and has strong reciprocal connections with visual cortex areas 17 and 18b, cingulate cortex, and multiple parahippocampal. The retrosplenial cortex rsc is reciprocally connected with the hippocampus and various parahippocampal cortical regions, suggesting that rsc is wellpositioned to contribute to hippocampaldependent memory. The hippocampal formation sends dense projections to retrosplenial granular cortex a and b and fewer projections to the. Retrosplenial cortex and its role in spatial cognition. Role of retrosplenial cortex in processing stressrelated context. Since the early 1990s, a growing body of evidence has implicated the rsc variously in spatial memory, navigation. Review article retrosplenial cortex and longterm memory. Optogenetic reactivation of memory ensembles in the retrosplenial. Kwapis the university of wisconsinmilwaukee, 20 under the supervision of professor fred j.
Contributions of retrosplenial cortex to associative learning. The engrams become progressively more stable with learning and are maintained over several weeks. Retrosplenial cortex rsc has fallen within the scope of memory research for at least 40 years and yet as vann et al. Illustrated anatomical parts with images from eanatomy and descriptions of anatomical structures. Molecular mechanisms of memory consolidation, reconsolidation, and persistence. In one study on the effects of selective granular retrosplenial cortex lesions in rats, the researcher found that damage to the retrosplenial cortex led to impaired spatial learning abilities. Retrosplenial cortex is a polymodal region that has been implicated in crossmodal integration, specifically when performance requires either the switching between or association of different types of spatial cues cooper and mizumori, 1999. Fusters memory in the cerebral cortex is a brilliant exampleof an integrative, neural theory of memory by one of the pioneers ofmemory physiology. The retrosplenial cortex rsc is anatomically positioned between limbic areas important for memory formation, such as the hippocampus hpc and the anterior thalamus, and cortical regions along the dorsal stream known to contribute.
A comprehensive reference on the structure and functions of cingulate cortex and its associated thalamic nuclei, utilizing an integrated approach covering anatomy, physiology, pharmacology, behavior, and clinical neuroscience to explore these regions of the brain. The retrosplenial cortex rsc is reciprocally connected with the. Retrosplenial cortex and cuespecific learning and memory. This study provides the first causal evidence that rsc in macaque monkeys is crucial for postoperative retention of preoperatively and postoperatively acquired memories. Spatial navigation requires memory representations of landmarks and other. Neuron activity in the retrosplenial cortex of the rat at the.
To link to this page, paste this link in email, im or document. Selective neuronal degeneration in the retrosplenial cortex. A memory gateway between the cortical default mode network and the medial temporal lobe. Retrograde and anterograde amnesic effects of excitotoxic lesions of the rat retrosplenial cortex rs and hippocampus hpc were investigated. In addition, historical and theoretical perspectives. Findings are provided for the rat, rabbit, cat, monkey, and human brains.
However, very little is known about the functional activity of each rsc subdivision during the execution of complex cognitive tasks. Highfrequency stimulation of these ensembles in the retrosplenial cortex 1 day after learning produced a recent memory with features normally observed in consolidated remote memories, including higher engagement of neocortical areas during retrieval, contextual generalization, and decreased hippocampal dependence. Anterograde and retrograde amnesia of place discrimination. The retrosplenial cortex is also linked to memory and navigation. This article is from frontiers in human neuroscience, volume 8. Research a novel role for the rat retrosplenial cortex in cognitive control andrew j. Helmstetter a wealth of research has outlined the neural circuits responsible for the consolidation. To link to the entire object, paste this link in email, im or document. The retrosplenial cortex receives input from the subiculum and projects to the anterior thalamus, thus providing an alternative route between hippocampus and thalamus.
Hippocampal and retrosplenial goal distance coding after long. The current investigation examined verbal memory in idiopathic nondementia parkinsons disease and the significance of the left entorhinal cortex and left entorhinal retrosplenial. Primate retrosplenial cortex rsc is important for memory but patient neuropathologies are diffuse so its key contributions to memory remain elusive. The role of the amygdala, retrosplenial cortex, and medial. The rsc is a relatively large, polymodal midline structure that extends 8 mm along the rostrocaudal axis of the rat brain figure 1. Overall, our results provide novel evidence that rsc constitutes a. In humans, fmri studies implicate the retrosplenial cortex in a wide range of cognitive functions including episodic memory, navigation, imagining future events and processing scenes more generally. Here, we used a wellestablished fear learning protocol that. Sparse orthogonal coding is a key feature of hippocampal neural activity, which is believed to increase episodic memory capacity and to assist in navigation. Tulving, however, argued that episodic memory is a uniquely human ability, and howard sought to challenge this idea by demonstrating that rodents possess the capacity of episodic memory and.