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Strauch C, Manahan-Vaughan D. Orchestration of Hippocampal Information Encoding by the Piriform Cortex. Cereb Cortex 2020; 30:135-147. [PMID: 31220213 PMCID: PMC7029697 DOI: 10.1093/cercor/bhz077] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/08/2019] [Accepted: 03/18/2019] [Indexed: 01/03/2023] Open
Abstract
The hippocampus utilizes olfactospatial information to encode sensory experience by means of synaptic plasticity. Odor exposure is also a potent impetus for hippocampus-dependent memory retrieval. Here, we explored to what extent the piriform cortex directly impacts upon hippocampal information processing and storage. In behaving rats, test-pulse stimulation of the anterior piriform cortex (aPC) evoked field potentials in the dentate gyrus (DG). Patterned stimulation of the aPC triggered both long-term potentiation (LTP > 24 h) and short-term depression (STD), in a frequency-dependent manner. Dual stimulation of the aPC and perforant path demonstrated subordination of the aPC response, which was nonetheless completely distinct in profile to perforant path-induced DG plasticity. Correspondingly, patterned aPC stimulation resulted in somatic immediate early gene expression in the DG that did not overlap with responses elicited by perforant path stimulation. Our results support that the piriform cortex engages in specific control of hippocampal information processing and encoding. This process may underlie the unique role of olfactory cues in information encoding and retrieval of hippocampus-dependent associative memories.
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Affiliation(s)
- Christina Strauch
- Department of Neurophysiology, Medical Faculty
- International Graduate School for Neuroscience, Ruhr University Bochum, Universitaetsstr. Bochum, Germany
| | - Denise Manahan-Vaughan
- Department of Neurophysiology, Medical Faculty
- International Graduate School for Neuroscience, Ruhr University Bochum, Universitaetsstr. Bochum, Germany
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Strauch C, Manahan-Vaughan D. In the Piriform Cortex, the Primary Impetus for Information Encoding through Synaptic Plasticity Is Provided by Descending Rather than Ascending Olfactory Inputs. Cereb Cortex 2019; 28:764-776. [PMID: 29186359 DOI: 10.1093/cercor/bhx315] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Indexed: 12/27/2022] Open
Abstract
Information encoding by means of persistent changes in synaptic strength supports long-term information storage and memory in structures such as the hippocampus. In the piriform cortex (PC), that engages in the processing of associative memory, only short-term synaptic plasticity has been described to date, both in vitro and in anesthetized rodents in vivo. Whether the PC maintains changes in synaptic strength for longer periods of time is unknown: Such a property would indicate that it can serve as a repository for long-term memories. Here, we report that in freely behaving animals, frequency-dependent synaptic plasticity does not occur in the anterior PC (aPC) following patterned stimulation of the olfactory bulb (OB). Naris closure changed action potential properties of aPC neurons and enabled expression of long-term potentiation (LTP) by OB stimulation, indicating that an intrinsic ability to express synaptic plasticity is present. Odor discrimination and categorization in the aPC is supported by descending inputs from the orbitofrontal cortex (OFC). Here, OFC stimulation resulted in LTP (>4 h), suggesting that this structure plays an important role in promoting information encoding through synaptic plasticity in the aPC. These persistent changes in synaptic strength are likely to comprise a means through which long-term memories are encoded and/or retained in the PC.
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Affiliation(s)
- Christina Strauch
- Department of Neurophysiology, Medical Faculty.,International Graduate School for Neuroscience, Ruhr University Bochum, Universitaetsstr. 150, 44780 Bochum, Germany
| | - Denise Manahan-Vaughan
- Department of Neurophysiology, Medical Faculty.,International Graduate School for Neuroscience, Ruhr University Bochum, Universitaetsstr. 150, 44780 Bochum, Germany
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Manrique C, Migliorati M, Gilbert V, Brezun JM, Chaillan FA, Truchet B, Khrestchatisky M, Guiraudie-Capraz G, Roman FS. Dynamic expression of the polysialyltransferase in adult rat hippocampus performing an olfactory associative task. Hippocampus 2014; 24:979-89. [DOI: 10.1002/hipo.22284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 04/07/2014] [Accepted: 04/09/2014] [Indexed: 01/16/2023]
Affiliation(s)
| | | | - Valérie Gilbert
- Aix Marseille Université, CNRS; FR 3512 13331 Marseille France
| | | | | | - Bruno Truchet
- Aix Marseille Université, CNRS; UMR 7291 13331 Marseille France
| | | | | | - François S. Roman
- Aix Marseille Université, CNRS, NICN; UMR 7259 13344 Marseille France
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Linster C, Menon AV, Singh CY, Wilson DA. Odor-specific habituation arises from interaction of afferent synaptic adaptation and intrinsic synaptic potentiation in olfactory cortex. Learn Mem 2009; 16:452-9. [PMID: 19553383 DOI: 10.1101/lm.1403509] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Segmentation of target odorants from background odorants is a fundamental computational requirement for the olfactory system and is thought to be behaviorally mediated by olfactory habituation memory. Data from our laboratory have shown that odor-specific adaptation in piriform neurons, mediated at least partially by synaptic adaptation between the olfactory bulb outputs and piriform cortex pyramidal cells, is highly odor specific, while that observed at the synaptic level is specific only to certain odor features. Behavioral data show that odor habituation memory at short time constants corresponding to synaptic adaptation is also highly odor specific and is blocked by the same pharmacological agents as synaptic adaptation. Using previously developed computational models of the olfactory system we show here how synaptic adaptation and potentiation interact to create the observed specificity of response adaptation. The model analyzes the mechanisms underlying the odor specificity of habituation, the dependence on functioning cholinergic modulation, and makes predictions about connectivity to and within the piriform neural network. Predictions made by the model for the role of cholinergic modulation are supported by behavioral results.
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Affiliation(s)
- Christiane Linster
- Computational Physiology Laboratory, Neurobiology and Behavior, Cornell University, Ithaca, New York 14853, USA.
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The genomic determinants of alcohol preference in mice. Mamm Genome 2008; 19:352-65. [PMID: 18563486 DOI: 10.1007/s00335-008-9115-z] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Accepted: 05/14/2008] [Indexed: 02/06/2023]
Abstract
Searches for the identity of genes that influence the levels of alcohol consumption by humans and other animals have often been driven by presupposition of the importance of particular gene products in determining positively or negatively reinforcing effects of ethanol. We have taken an unbiased approach and performed a meta-analysis across three types of mouse populations to correlate brain gene expression with levels of alcohol intake. Our studies, using filtering procedures based on QTL analysis, produced a list of eight candidate genes with highly heritable expression, which could explain a significant amount of the variance in alcohol preference in mice. Using the Allen Brain Atlas for gene expression, we noted that the candidate genes' expression was localized to the olfactory and limbic areas as well as to the orbitofrontal cortex. Informatics techniques and pathway analysis illustrated the role of the candidate genes in neuronal migration, differentiation, and synaptic remodeling. The importance of olfactory cues, learning and memory formation (Pavlovian conditioning), and cortical executive function, for regulating alcohol intake by animals (including humans), is discussed.
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Davis CD, Jones FL, Derrick BE. Novel environments enhance the induction and maintenance of long-term potentiation in the dentate gyrus. J Neurosci 2005; 24:6497-506. [PMID: 15269260 PMCID: PMC6729872 DOI: 10.1523/jneurosci.4970-03.2004] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The induction of long-term potentiation (LTP) in the hippocampal formation can be modulated by different behavioral states. However, few studies have addressed modulation of LTP during behavioral states in which the animal is likely acquiring new information. Here, we demonstrate that both the induction and the longevity of LTP in the dentate gyrus are enhanced when LTP is induced during the initial exploration of a novel environment. These effects are independent from locomotor activity, changes in brain temperature, and theta rhythm. Previous exposure to the novel environment attenuated this enhancement, suggesting that the effects of novelty habituate with familiarity. LTP longevity also was enhanced when induced in familiar environments containing novel objects. Together, these data indicate that both LTP induction and maintenance are enhanced when LTP is induced while rats investigate novel stimuli. We suggest that novelty initiates a transition of the hippocampal formation to a mode that is particularly conducive to synaptic plasticity, a process that could allow for new learning while preserving the stability of previously stored information. In addition, LTP induced in novel environments elicited a sustained late LTP. This suggests that a single synaptic population can display distinct profiles of LTP maintenance and that this depends on the animal's behavioral state during its induction. Furthermore, the duration of LTP enhanced by novelty parallels the time period during which the hippocampal formation is thought necessary for memory, consistent with the view that dentate LTP is of a duration sufficient to sustain memory in the hippocampal formation.
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Affiliation(s)
- Cyndy D Davis
- Department of Biology and Cajal Neuroscience Research Center, The University of Texas at San Antonio, San Antonio, Texas 78249-0662, USA
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Roman FS, Truchet B, Chaillan FA, Marchetti E, Soumireu-Mourat B. Olfactory Associative Discrimination: A Model for Studying Modifications of Synaptic Efficacy in Neuronal Networks Supporting Long-term Memory. Rev Neurosci 2004; 15:1-17. [PMID: 15046196 DOI: 10.1515/revneuro.2004.15.1.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This review summarizes research that correlates behavioral performance and cellular physiology leading to modifications in the neuronal networks supporting long-term memory in the mammalian brain. Rats were trained in an olfactory associative discrimination task in which natural odors were replaced by mimetic olfactory stimulations. Olfactory learning induced synaptic modifications that affected behavioral performance along the central olfactory pathways. Starting with an early increase in monosynaptic efficacy in the dentate gyrus on the first session, a polysynaptic modification appeared later on in this hippocampal network, when rats began to make associations between cues and rewards. Therefore, only when rats made consistent associations did a long-term potentiation in the synapses of the piriform cortex pyramidal neurons appear. These modifications may correspond to the long-term storage of the meaning of the cue-reward association in a specific cortical area. Based on these cumulative results, a hypothesis is proposed to account for how, when, and where synaptic modifications in neural networks are required to constitute long-term memory.
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Affiliation(s)
- François S Roman
- Laboratoire de Neurobiologie des Comportements, UMR 6149 CNRS, Université de Provence, Faculté des Sciences de St Jérôme, Marseille, France.
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Kramár EA, Lynch G. Developmental and regional differences in the consolidation of long-term potentiation. Neuroscience 2003; 118:387-98. [PMID: 12699775 DOI: 10.1016/s0306-4522(02)00916-8] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The alpha5beta1 integrin is present in high concentrations in the apical dendrites of pyramidal neurons in adult rats but is virtually absent in the basal dendrites. Moreover, alpha5beta1 does not appear in apical dendritic branches until the third post-natal week. Given that integrins contribute to the consolidation of synaptic plasticity, these results raise the possibility of developmental and regional differences in the stability of long-term potentiation (LTP). The present study tested this point using a LTP reversal paradigm in field CA1 of hippocampal slices. In accord with earlier reports, low-frequency afferent stimulation (5 Hz) introduced 30 s after theta burst stimulation (TBS) completely reversed LTP but was ineffective 30 min and 60 min later in slices from adult rats. The same low-frequency trains caused a partial reversal of LTP when applied 30 and 60 min post-TBS in slices from 21-day-old rats and a complete reversal at all time points in slices from 10-day-old rats. LTP in the basal dendrites of adult rats did not fully consolidate; i.e. potentiation was partially reversed by low-frequency stimulation even after delays of 30 or 60 min. Moreover, spaced (10 min) applications of 5- Hz pulses beginning at 30 min post-TBS completely erased LTP. The reversal effect in both apical and basal dendrites was blocked by N-methyl-D-aspartic acid receptor antagonists but an integrin antagonist had differential effects across the two dendritic domains. These results constitute evidence that the stability of LTP increases with age in the apical dendrites but remains incomplete even in adulthood in the basal dendrites. The possibilities that the developmental and regional variations in LTP consolidation are correlated with integrin expression and linked to different types of memory processing are discussed.
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Affiliation(s)
- E A Kramár
- Department of Psychiatry and Human Behavior, 101 Theory Drive, #250 Research Park, University of California, Irvine, CA 92612-1695, USA.
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Potential Health Effects of Odor from Animal Operations, Wastewater Treatment, and Recycling of Byproducts. J Agromedicine 2000. [DOI: 10.1300/j096v07n01_02] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Stewart LS. Brief communication; differential effects of a physiologically patterned low-intensity agent on the formation of an olfactory memory trace. Int J Neurosci 2000; 103:19-23. [PMID: 10938559 DOI: 10.3109/00207450009003248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Male rats were exposed to a low-intensity (300-500 nT) electromagnetic (EM) field designed to simulate primed burst potentiation (PB) for 30 min preceding a one-trial olfactory learning task involving two brief encounters with a juvenile rat during a baseline (reference) and an experimental (EM) trial. The amount of time spent engaged in behaviors defining social investigation (i.e., sniffing, grooming) during the second encounter of the experimental trial was significantly elevated in adult rats receiving continuous EM stimulation prior to the initial encounter. These results support the hypothesis that LTP-like stimulation disrupts the acquisition of a learning task if the stimulus is delivered before training.
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Affiliation(s)
- L S Stewart
- Behavioral Neuroscience Laboratory, Department of Biology, Laurentian University, Sudbury, Ontario Canada P3E 2C6.
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Roman FS, Truchet B, Marchetti E, Chaillan FA, Soumireu-Mourat B. Correlations between electrophysiological observations of synaptic plasticity modifications and behavioral performance in mammals. Prog Neurobiol 1999; 58:61-87. [PMID: 10321797 DOI: 10.1016/s0301-0082(98)00076-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Within the past century it has been well established that most mature neurons lose their ability to divide. Since then, it has been assumed that behavioral performance leads to synaptic changes in the brain. The existence of these potential changes has been demonstrated in numerous experiments, and different mechanisms contributing to synaptic plasticity have been discovered. Many structures involved in different types of learning have now been identified. This article reviews the different methods used with mammals to detect electrophysiological modifications in synaptic plasticity following behavior. Evidence of long-term potentiation and long-term depression has been found in the hippocampus and cerebellum, respectively, and empirical data has been used to correlate these mechanisms with specific learning performance. Similar observations were made recently in the septum and amygdala. These phenomena seem to be involved in maintaining the performance in the cortical areas of the brain. Ongoing attempts to find the relationship between behavioral performance and modifications in synaptic efficacy allow to speculate upon the dynamics of cellular mechanisms that contribute to the ability of mammals to modify wide neuronal networks in the brain during their life.
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Affiliation(s)
- F S Roman
- Laboratoire de Neurobiologie des Comportements, UMR 6562 CNRS, Université de Provence, IBHOP Traverse Charles Susini, Marseille, France
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Chaillan FA, Roman FS, Soumireu-Mourat B. [Olfactory training: memory systems in the rats]. COMPTES RENDUS DE L'ACADEMIE DES SCIENCES. SERIE III, SCIENCES DE LA VIE 1998; 321:157-61. [PMID: 9759334 DOI: 10.1016/s0764-4469(97)89815-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- F A Chaillan
- Laboratoire de neurobiologie intégrative et adaptative, UMR 6562 CNRS, Equipe neurobiologie des comportements, université de Provence/CNRS, IBHOP, Marseille, France
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