251
|
Jouvenceau A, Dutar P. A role for the protein phosphatase 2B in altered hippocampal synaptic plasticity in the aged rat. ACTA ACUST UNITED AC 2006; 99:154-61. [PMID: 16442785 DOI: 10.1016/j.jphysparis.2005.12.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Synaptic plasticity following NMDA application on hippocampal slices from young (3-5 months) and aged (24-27 months) rats was compared. In young rats, NMDA (20 microM) induced opposite effects depending on the duration of the application. A short (1 min) or long (5 min) application induced a long-term depression of synaptic activity while a 3 min application induced a potentiation. In aged rats, however, NMDA application always induced depression, regardless of the duration. To identify mechanisms which could explain the difference observed between young and aged rats, we explored changes in NMDA receptor activation and changes in kinase/phosphatase balance. We first demonstrate that the potentiation present in slices from young rats was not restored in aged rats by exogenous application of the co-agonist of NMDA receptor d-serine (which compensates for the changes in NMDAR activation seen in aged rats). This suggested that alterations in synaptic plasticity activation mainly involve intracellular mechanisms. We next showed that the participation of the kinases PKA and CaMKII in the NMDA-induced potentiation in young rats is negligible. Finally, we determined the consequences of phosphatase inhibition in aged rats. Incubation of slices in okadaic acid (a PP1/PP2B antagonist) did not affect the depression induced by a 3min NMDA application in aged rats. The PP2B antagonist FK506 restored potentiation in aged rats (3 min NMDA application). In hippocampal neurons from aged rats, a depression is always observed, suggesting a preferential activation of PP2B by NMDA in these neurons.
Collapse
Affiliation(s)
- Anne Jouvenceau
- INSERM U549, Neurobiologie de la croissance et de la sénescence, 2 ter rue d'Alésia, 75014 Paris, France.
| | | |
Collapse
|
252
|
Alonso M, Bekinschtein P, Cammarota M, Vianna MRM, Izquierdo I, Medina JH. Endogenous BDNF is required for long-term memory formation in the rat parietal cortex. Learn Mem 2006; 12:504-10. [PMID: 16204202 PMCID: PMC1240062 DOI: 10.1101/lm.27305] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Information storage in the brain is a temporally graded process involving different memory phases as well as different structures in the mammalian brain. Cortical plasticity seems to be essential to store stable long-term memories, although little information is available at the moment regarding molecular and cellular events supporting memory consolidation in the neocortex. Brain-derived neurotrophic factor (BDNF) modulates both short-term synaptic function and activity-dependent synaptic plasticity in hippocampal and cortical neurons. We have recently demonstrated that endogenous BDNF in the hippocampus is involved in memory formation. Here we examined the role of BDNF in the parietal cortex (PCx) in short-term (STM) and long-term memory (LTM) formation of a one-trial fear-motivated learning task in rats. Bilateral infusions of function-blocking anti-BDNF antibody into the PCx impaired both STM and LTM retention scores and decreased the phosphorylation state of cAMP response element-binding protein (CREB). In contrast, intracortical administration of recombinant human BDNF facilitated LTM and increased CREB activation. Moreover, inhibitory avoidance training is associated with a rapid and transient increase in phospho-CREB/total CREB ratio in the PCx. Thus, our results indicate that endogenous BDNF is required for both STM and LTM formation of inhibitory avoidance learning, possibly involving CREB activation-dependent mechanisms. The present data support the idea that early sensory areas constitute important components of the networks subserving memory formation and that information processing in neocortex plays an important role in memory formation.
Collapse
Affiliation(s)
- Mariana Alonso
- Department of Neuroscience, Perception and Memory Laboratory, Pasteur Institute, Paris, France
| | | | | | | | | | | |
Collapse
|
253
|
Affiliation(s)
- Mohammad R Zarrindast
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
254
|
Ramírez-Amaya V, Vazdarjanova A, Mikhael D, Rosi S, Worley PF, Barnes CA. Spatial exploration-induced Arc mRNA and protein expression: evidence for selective, network-specific reactivation. J Neurosci 2005; 25:1761-8. [PMID: 15716412 PMCID: PMC6725922 DOI: 10.1523/jneurosci.4342-04.2005] [Citation(s) in RCA: 298] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The immediate-early gene Arc is transcribed in neurons that are part of stable neural networks activated during spatial exploratory behaviors. Arc protein has been demonstrated to regulate AMPA-type glutamate receptor trafficking by recruiting endosomal pathways, suggesting a direct role in synaptic plasticity. The purpose of the present study is to examine the fidelity of Arc mRNA translation and the temporal dynamics of behaviorally induced Arc protein expression after rats explore a novel environment. These experiments reveal two waves of Arc protein expression after a single exploration session. In the initial wave, virtually all cells that express Arc mRNA in the hippocampus and parietal cortex also express Arc protein, indicating, at a cellular level, that mRNA transcription and translation are closely correlated from 30 min to 2 h in hippocampal CA and parietal neurons. A second wave of protein expression spans the interval from 8 to 24 h and is also remarkably specific to cells active in the original behavior-induced network. This second wave is detected in a subset of the original active network and displays the novel property that the proportions of Arc-positive neurons become correlated among regions at 24 h. This suggests that the second expression wave is driven by network activity, and the stabilization of circuits reflecting behavioral experience may occur in temporally discrete phases, as memories become consolidated. This is the first demonstration of network-selective translational events consequent to spatial behavior and suggests a role for immediate-early genes in circuit-specific, late-phase synaptic biology.
Collapse
Affiliation(s)
- Victor Ramírez-Amaya
- Arizona Research Laboratories, Division of Neural Systems, Memory, and Aging, University of Arizona, Tucson, Arizona 85724-5115, USA
| | | | | | | | | | | |
Collapse
|
255
|
Duman CH, Duman RS. Neurobiology and treatment of anxiety: signal transduction and neural plasticity. Handb Exp Pharmacol 2005:305-34. [PMID: 16594263 DOI: 10.1007/3-540-28082-0_11] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The stress-dependence and chronic nature of anxiety disorders along with the anxiolytic effectiveness of antidepressant drugs suggests that neuronal plasticity may play a role in the pathophysiology of anxiety. Intracellular signaling pathways are known in many systems to be critical links in the cascades from surface signals to the molecular alterations that result in functional plasticity. Chronic antidepressant treatments can regulate intracellular signaling pathways and can induce molecular, cellular, and structural changes over time. These changes may be important to the anxiolytic effectiveness of these drugs. In addition, the signaling proteins implicated in the actions of chronic antidepressant action, such as cAMP response element binding protein (CREB), have also been implicated in conditioned fear and in anxiety. The cellular mechanisms underlying conditioned fear indicate roles for additional signaling pathways; however, less is known about such mechanisms in anxiety. The challenge to identify intracellular signaling pathways and related molecular and structural changes that are critical to the etiology and treatment of anxiety will further establish the importance of mechanisms of neuronal plasticity in functional outcome and improve treatment strategies.
Collapse
Affiliation(s)
- C H Duman
- Laboratory of Molecular Psychiatry, Departments of Psychiatry and Pharmacology, Yale University School of Medicine, 34 Park Street, New Haven CT, 06508, USA
| | | |
Collapse
|
256
|
Ulloor J, Datta S. Spatio-temporal activation of cyclic AMP response element-binding protein, activity-regulated cytoskeletal-associated protein and brain-derived nerve growth factor: a mechanism for pontine-wave generator activation-dependent two-way active-avoidance memory processing in the rat. J Neurochem 2005; 95:418-28. [PMID: 16190868 DOI: 10.1111/j.1471-4159.2005.03378.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The present study explored possible physiological and molecular mechanisms of pontine-wave (P-wave) generator activation-dependent memory processing in the rat using a two-way active-avoidance learning paradigm. The results show that learning training increased rapid eye movement sleep and activated brainstem cells in the P-wave generator. During this period, there was a time-dependent increase in phosphorylation of cAMP response element-binding protein (CREB) in the dorsal hippocampus and amygdala and increased synthesis of activity-regulated cytoskeletal-associated protein (Arc) in the dorsal hippocampus, amygdala, frontal cortex and occipital cortex. Learning training also increased synthesis of brain-derived nerve growth factor (BDNF) in the occipital cortex, amygdala and dorsal hippocampus at different time intervals. During this time, the levels of nerve growth factor did not change. The results also show that the increase in rapid eye movement sleep P-wave density during the post-training 3-h recording session is positively correlated with the increased levels of phosphorylated CREB, BDNF and Arc in the dorsal hippocampus. These results suggest that memory processing of two-way active-avoidance learning may involve excitation of P-wave-generating cells in the brainstem and increased expression of phosphorylated CREB, Arc and BDNF in a time-dependent manner in the forebrain. These dynamic changes in cellular and molecular features provide considerable insight into the mechanisms of the P-wave generator activation-dependent memory consolidation process.
Collapse
Affiliation(s)
- Jagadish Ulloor
- Sleep and Cognitive Neuroscience Laboratory, Department of Psychiatry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | | |
Collapse
|
257
|
Cammarota M, Bevilaqua LRM, Barros DM, Vianna MRM, Izquierdo LA, Medina JH, Izquierdo I. Retrieval and the extinction of memory. Cell Mol Neurobiol 2005; 25:465-74. [PMID: 16075375 DOI: 10.1007/s10571-005-4009-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2004] [Accepted: 08/03/2004] [Indexed: 11/28/2022]
Abstract
1. Memory is assessed by measuring retrieval which is often elicited by the solely presentation of the conditioned stimulus (CS). However, as known since Pavlov, presentation of the CS alone generates extinction. 2. One-trial avoidance (IA) is a much used conditioned fear paradigm in which the CS is the safe part of a training apparatus, the unconditioned stimulus (US) is a footshock and the conditioned response (CR) is to stay in the safe area. Retrieval of the memory for the step-down version of this task is measured in the absence of the US, as latency to step-down from the safe area (i.e., a platform). 3. Extinction of the IA response is installed at the moment of the first non-reinforced test session, as clearly shown by the fact that many drugs, including PKA, ERK and protein synthesis inhibitors as well as NMDA receptor antagonists, hinder extinction when infused into the hippocampus or the basolateral amygdala at the moment of the first test session but not later. 4. Some, but not all the molecular systems required for extinction are also activated by retrieval, further endorsing the hypothesis that although retrieval is necessary for the generation of extinction this last process constitutes a new learning secondary to the non-reinforced expression of the original trace.
Collapse
Affiliation(s)
- Martín Cammarota
- Centro de Memória, IPB, Pontificia Universidade Católica do Rio Grande do Sul (PUCRS), Av. Ipiranga 6690-2. Andar, 90610-000, Porto Alegre, RS, Brazil
| | | | | | | | | | | | | |
Collapse
|
258
|
Moyano S, Del Río J, Frechilla D. Acute and chronic effects of MDMA on molecular mechanisms implicated in memory formation in rat hippocampus: Surface expression of CaMKII and NMDA receptor subunits. Pharmacol Biochem Behav 2005; 82:190-9. [PMID: 16154187 DOI: 10.1016/j.pbb.2005.07.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Revised: 06/27/2005] [Accepted: 07/05/2005] [Indexed: 11/22/2022]
Abstract
Acute 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") treatment induces learning deficits in different animal models. In a passive avoidance learning task in rats, previous studies suggested a role for Ca2+/calmodulin-dependent protein kinase II (CaMKII) and N-methyl-D-aspartate (NMDA) receptors in the acute learning impairment. As cognitive deficits by "ecstasy" in humans have been only reported in frequent recreational users, we examined whether a repeated MDMA treatment could induce in rats lasting molecular changes related to memory consolidation of passive avoidance. In rats with a pronounced 5-HT depletion by MDMA, the effect of another drug challenge was also examined. The surface expression in the hippocampus of NMDA receptor subunits, the scaffolding postsynaptic density protein PSD-95, phosphorylated CaMKII and protein phosphatase 1 (PP1) was measured. In rats repeatedly treated with MDMA (10 mg/kg) twice daily for 4 consecutive days, hippocampal 5-HT levels were markedly reduced 1 week later. At this time, neither learning performance was affected nor changes in membrane levels of NMDA receptor subunits, PSD-95, CaMKII and PP1 were found. In these rats, however, another drug challenge produced a rapid reduction in PSD-95 immunoreactivity and prevented the learning-specific increase in the NMDA receptor NR1 subunit and phosphorylated CaMKII. The results show no lasting change in learning-associated molecular events after a neurotoxic MDMA treatment. This drug only produces transient effects on early molecular events involved in memory consolidation, which do not appear to depend on endogenous 5-HT levels.
Collapse
Affiliation(s)
- S Moyano
- Division of Neuroscience, Center for Applied Medical Research, School of Medicine, University of Navarra, Apartado 177, 31080-Pamplona, Spain
| | | | | |
Collapse
|
259
|
Lisman JE, Grace AA. The hippocampal-VTA loop: controlling the entry of information into long-term memory. Neuron 2005; 46:703-13. [PMID: 15924857 DOI: 10.1016/j.neuron.2005.05.002] [Citation(s) in RCA: 1351] [Impact Index Per Article: 71.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this article we develop the concept that the hippocampus and the midbrain dopaminergic neurons of the ventral tegmental area (VTA) form a functional loop. Activation of the loop begins when the hippocampus detects newly arrived information that is not already stored in its long-term memory. The resulting novelty signal is conveyed through the subiculum, accumbens, and ventral pallidum to the VTA where it contributes (along with salience and goal information) to the novelty-dependent firing of these cells. In the upward arm of the loop, dopamine (DA) is released within the hippocampus; this produces an enhancement of LTP and learning. These findings support a model whereby the hippocampal-VTA loop regulates the entry of information into long-term memory.
Collapse
Affiliation(s)
- John E Lisman
- Department of Biology, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, USA.
| | | |
Collapse
|
260
|
Runyan JD, Dash PK. Distinct prefrontal molecular mechanisms for information storage lasting seconds versus minutes. Learn Mem 2005; 12:232-8. [PMID: 15930501 PMCID: PMC1142450 DOI: 10.1101/lm.92405] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The prefrontal cortex (PFC) is known to actively hold information "online" for a period of seconds in working memory for guiding goal-directed behavior. It has been proposed that relevant information is stored in other brain regions, which is retrieved and held in working memory for subsequent assimilation by the PFC in order to guide behavior. It is uncertain whether PFC stores information outside the temporal limits of working memory. Here, we demonstrate that although enhanced cAMP-dependent protein kinase A (PKA) activity in the PFC is detrimental to working memory, it is required for performance in tasks involving conflicting representations when memory storage is needed for minutes. This study indicates that distinct molecular mechanisms within the PFC underlie information storage for seconds (working memory) and for minutes (short-term memory). In addition, our results demonstrate that short-term memory storage within the prefrontal cortex is required for guiding behavior in tasks with conflicts and provides a plausible mechanism by which the prefrontal cortex executes cognitive control.
Collapse
Affiliation(s)
- Jason D Runyan
- The Vivian L. Smith Center for Neurological Research, Department of Neurobiology and Anatomy, The University of Texas Medical School, Houston, Texas 77225, USA
| | | |
Collapse
|
261
|
Saha S, Datta S. Two-way active avoidance training-specific increases in phosphorylated cAMP response element-binding protein in the dorsal hippocampus, amygdala, and hypothalamus. Eur J Neurosci 2005; 21:3403-14. [PMID: 16026478 DOI: 10.1111/j.1460-9568.2005.04166.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Previous studies have demonstrated that the activation of pontine-wave (P-wave) generating cells in the brainstem during post-training rapid eye movement (REM) sleep is critical for the consolidation of memory for two-way active avoidance (TWAA) learning in the rat. Here, using immunocytochemistry, we investigated the spatio-temporal distribution of CREB phosphorylation within different parts of the dorsal hippocampus, amygdala, and hypothalamus following a session of TWAA training in the rat. We show that the TWAA training trials increased phosphorylation of CREB (p-CREB) in the dorsal hippocampus, amygdala, amygdalo-hippocampal junction (AHi), and hypothalamus. However, the time intervals leading to training-induced p-CREB activity were different for different regions of the brain. In the dorsal hippocampus, p-CREB activity was maximal at 90 min and this activity disappeared by 180 min. In the AHi, activity of the p-CREB peaked by 180 min and disappeared by 360 min. In the amygdala, the p-CREB activity peaked at 180 min and still remained higher than the control at the 360 min interval. In the hypothalamus, at 90 min p-CREB activity was present only in the ventromedial hypothalamus; however, by 180 min this p-CREB activity was also present in the dorsal hypothalamus, perifornical area, and lateral hypothalamus. By 360 min, p-CREB activity disappeared from the hypothalamus. This TWAA training trials-induced spatiotemporal characteristic of CREB phosphorylation, for the first time, suggests that REM sleep P-wave generator activation-dependent memory processing involves different parts of the dorsal hippocampus, amygdala, and hypothalamus.
Collapse
Affiliation(s)
- Subhash Saha
- Sleep and Cognitive Neuroscience Laboratory, Department of Psychiatry, and Program in Behavioural Neuroscience, Boston University School of Medicine, Building M-902, 715 Albany Street, Boston, MA 02118, USA
| | | |
Collapse
|
262
|
Countryman RA, Orlowski JD, Brightwell JJ, Oskowitz AZ, Colombo PJ. CREB phosphorylation and c-Fos expression in the hippocampus of rats during acquisition and recall of a socially transmitted food preference. Hippocampus 2005; 15:56-67. [PMID: 15390165 DOI: 10.1002/hipo.20030] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In the present study, phosphorylation of cAMP-response element binding protein (pCREB) and expression of c-Fos were measured in the dorsal and ventral hippocampus, as well as in a control region, the retrosplenial cortex, of rats following acquisition and recall of a socially transmitted food preference (STFP). Behavioral analyses revealed that STFP-trained rats showed a stronger preference for the demonstrated food than did rats in social-control or odor-control conditions. Rats in a social + odor control condition displayed an intermediate preference that was not significantly different from either STFP-trained rats or the social- or odor-controls. Immunocytochemical analyses revealed increased pCREB-immunoreactivity (ir) in the ventral hippocampus of STFP-trained rats in comparisons with rats in all three control conditions and increased pCREB-ir in the dorsal hippocampus in comparisons with the social- and odor-control conditions. In contrast, c-Fos-ir was greater in the dorsal hippocampus of STFP-trained rats in comparisons with all three control conditions and greater in the ventral hippocampus than rats in the social- and odor-control conditions. Comparisons of pCREB-ir and c-Fos-ir were made also between STFP-trained rats and social-controls following either acquisition or a 48-h recall test. c-Fos-ir was greater in STFP-trained rats after both acquisition and recall, whereas pCREB was greater after recall only. There were no differences in either c-Fos-ir or pCREB-ir in comparisons between trained and control rats in the retrosplenial cortex. The current results indicate that the activity of transcription factors in the hippocampus is related to both acquisition and retention of a socially transmitted food preference.
Collapse
Affiliation(s)
- Renee A Countryman
- Department of Psychology, Tulane University, New Orleans, Louisiana 70118, USA
| | | | | | | | | |
Collapse
|
263
|
Locatelli F, Romano A. Differential activity profile of cAMP-dependent protein kinase isoforms during long-term memory consolidation in the crab Chasmagnathus. Neurobiol Learn Mem 2005; 83:232-42. [PMID: 15820859 DOI: 10.1016/j.nlm.2005.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2004] [Revised: 01/13/2005] [Accepted: 01/19/2005] [Indexed: 11/30/2022]
Abstract
The isoforms of cAMP-dependent protein kinase (PKA) show distinct biochemical properties and subcellular localization, suggesting different physiological functions, and conferring the fine-tuning between the activation of cAMP-PKA cascade and the cellular response. The critical role of PKA in memory and synaptic plasticity has been extensively demonstrated both in vertebrates and invertebrates, but the role of PKA isoforms is a matter of debate. Here we present experimental data showing differential PKA activation profiles after two different experiences: an instance of associative contextual learning (context-signal learning) and a single exposure to a novel context, both in the learning and memory model of the crab Chasmagnathus. Differences were found in the temporal course of activation and in the involvement of PKA isoforms. We found increased PKA activity immediately and 6 h after context-signal training correlating with the critical periods during which pharmacological inhibition of PKA disrupts memory formation. In contrast, PKA activity increased immediately but not 6 h after single exposure to a novel context. The amounts of PKA I and PKA II holoenzymes were analyzed to determine changes in holoenzyme levels and/or differential activation induced by both experiences. Results indicate that context-induced PKA activation is at least in part due to PKA II, and that PKA activation 6 h after context-signal learning coincides with an increase in the total level of PKA I. Considering the higher sensitivity of PKA I to cAMP, its increment can account for the PKA activation found 6 h after training and is proposed as a novel mechanism providing the prolonged PKA activation during memory consolidation.
Collapse
Affiliation(s)
- Fernando Locatelli
- Laboratorio de Neurobiología de la Memoria, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina.
| | | |
Collapse
|
264
|
Kerr DS, Bevilaqua LRM, Bonini JS, Rossato JI, Köhler CA, Medina JH, Izquierdo I, Cammarota M. Angiotensin II blocks memory consolidation through an AT2 receptor-dependent mechanism. Psychopharmacology (Berl) 2005; 179:529-35. [PMID: 15551065 DOI: 10.1007/s00213-004-2074-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2004] [Accepted: 07/29/2004] [Indexed: 10/26/2022]
Abstract
RATIONALE AND OBJECTIVES Several studies suggest that the brain renin-angiotensin system is involved in memory consolidation. However, the participation of angiotensin II (AII) in this process is controversial. This is probably due to the fact that many of the studies carried out to elucidate this matter employed multitrial learning paradigms together with pretraining intracerebroventricular infusions, and therefore were unable to distinguish between consolidation and retrieval related events and lacked anatomical specificity. To circumvent this problem, we analyzed the role played in memory consolidation by AII using the hippocampal-dependent, one-trial, step-down inhibitory avoidance task (IA) in combination with stereotaxically localized intrahippocampal infusion of drugs. METHODS AND RESULTS Rats bilaterally implanted with infusion cannulae into the CA1 region of the dorsal hippocampus (CA1) were trained in IA and tested for memory retention 24 h later. We found that when infused into CA1 immediately or 30 min after training but not later, AII produced a dose-dependent amnesic effect without altering locomotor activity, exploratory behavior or anxiety state. The amnesic effect of AII was not mimicked by angiotensin IV (AIV) and was totally blocked by the AII-type 2 receptor (AT2) antagonist, PD123319, but not by the AII-type 1 receptor (AT1) antagonist, losartan. Importantly, when infused alone, neither PD123319 nor losartan produced any effect on memory retention. CONCLUSIONS Our data indicate that, when given into CA1, AII blocks memory formation through a mechanism involving activation of AT2 receptors; however, endogenous AII does not seem to participate in the consolidation of IA long-term memory.
Collapse
Affiliation(s)
- Daniel S Kerr
- Center for Memory Research, ICBS, Department of Biochemistry, Federal University of Rio Grande do Sul, Ramiro Barcelos 2600-Anexo, Porto Alegre, 90035-003, Brazil
| | | | | | | | | | | | | | | |
Collapse
|
265
|
Sun L, Wang X, Liu S, Wang Q, Wang J, Bennecib M, Gong CX, Sengupta A, Grundke-Iqbal I, Iqbal K. Bilateral injection of isoproterenol into hippocampus induces Alzheimer-like hyperphosphorylation of tau and spatial memory deficit in rat. FEBS Lett 2005; 579:251-8. [PMID: 15620722 DOI: 10.1016/j.febslet.2004.11.083] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Revised: 11/10/2004] [Accepted: 11/11/2004] [Indexed: 11/20/2022]
Abstract
The abnormal hyperphosphorylation of tau protein is one of the hallmarks of Alzheimer disease and other tauopathies; as yet the exact role of various tau kinases in this pathology is not fully understood. Here, we show that injection of isoproterenol, an activator of cAMP-dependent kinase (PKA), into rat hippocampus bilaterally results in the activation of PKA, calcium/calmodulin-dependent kinase II and cyclin-dependent kinase-5, inhibition of protein phosphatase-2A, hyperphosphorylation of tau at several Alzheimer-like epitopes and a disturbance of spatial memory retention 48 h after the drug injection. These findings suggest the involvement of PKA and PKA-mediated signaling pathway in the Alzheimer-like tau hyperphosphorylation and memory impairment.
Collapse
Affiliation(s)
- Li Sun
- Department of Pathophysiology, Institute of Neuroscience, Tongji Medical College, Huazhong University of Science and Technology, 13 Hang Kong Road, Wuhan 430030, PR China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
266
|
Wittmann BC, Schott BH, Guderian S, Frey JU, Heinze HJ, Düzel E. Reward-Related fMRI Activation of Dopaminergic Midbrain Is Associated with Enhanced Hippocampus- Dependent Long-Term Memory Formation. Neuron 2005; 45:459-67. [PMID: 15694331 DOI: 10.1016/j.neuron.2005.01.010] [Citation(s) in RCA: 481] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Revised: 12/22/2004] [Accepted: 01/07/2005] [Indexed: 11/20/2022]
Abstract
Long-term potentiation in the hippocampus can be enhanced and prolonged by dopaminergic inputs from midbrain structures such as the substantia nigra. This improved synaptic plasticity is hypothesized to be associated with better memory consolidation in the hippocampus. We used a condition that reliably elicits a dopaminergic response, reward anticipation, to study the relationship between activity of dopaminergic midbrain areas and hippocampal long-term memory in healthy adults. Pictures of object drawings that predicted monetary reward were associated with stronger fMRI activity in reward-related brain areas, including the substantia nigra, compared with non-reward-predicting pictures. Three weeks later, recollection and source memory were better for reward-predicting than for non-reward-predicting pictures. FMRI activity in the hippocampus and the midbrain was higher for reward-predicting pictures that were later recognized compared with later forgotten pictures. These data are consistent with the hypothesis that activation of dopaminergic midbrain regions enhances hippocampus-dependent memory formation, possibly by enhancing consolidation.
Collapse
Affiliation(s)
- Bianca C Wittmann
- Department of Neurology II and , Centre for Advanced Imaging, Otto von Guericke University, Leipziger Str. 44, 39120 Magdeburg, Germany
| | | | | | | | | | | |
Collapse
|
267
|
Colombo PJ. Learning-induced activation of transcription factors among multiple memory systems. Neurobiol Learn Mem 2005; 82:268-77. [PMID: 15464409 DOI: 10.1016/j.nlm.2004.07.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2004] [Revised: 07/21/2004] [Accepted: 07/22/2004] [Indexed: 11/17/2022]
Abstract
Experimental evidence for multiple memory systems grew initially from reports that integrity of the medial temporal lobes is necessary for some, but not all, types of memory formation. A primary inference from many studies of multiple memory systems is that they operate independently during encoding, storage, and retrieval of information. An accumulation of recent evidence, however, suggests that multiple memory systems may interact under some conditions. At the cellular level of analysis, it is accepted widely that protein synthesis is necessary for the formation of long-term memory and recent efforts have focused on the mechanisms by which learning-induced gene transcription and translation are regulated. The present review examines learning-induced activation of transcription factors among multiple memory systems. The results indicate that studies of transcriptional regulation, in conjunction with other experimental approaches, can provide complementary lines of evidence to further understanding of the extent to which multiple memory systems are independent or interactive.
Collapse
Affiliation(s)
- Paul J Colombo
- Department of Psychology, Tulane University, 6823 Saint Charles Avenue, New Orleans, LA, USA.
| |
Collapse
|
268
|
Seamans JK, Yang CR. The principal features and mechanisms of dopamine modulation in the prefrontal cortex. Prog Neurobiol 2005; 74:1-58. [PMID: 15381316 DOI: 10.1016/j.pneurobio.2004.05.006] [Citation(s) in RCA: 1101] [Impact Index Per Article: 57.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2003] [Accepted: 05/04/2004] [Indexed: 12/17/2022]
Abstract
Mesocortical [corrected] dopamine (DA) inputs to the prefrontal cortex (PFC) play a critical role in normal cognitive process and neuropsychiatic pathologies. This DA input regulates aspects of working memory function, planning and attention, and its dysfunctions may underlie positive and negative symptoms and cognitive deficits associated with schizophrenia. Despite intense research, there is still a lack of clear understanding of the basic principles of actions of DA in the PFC. In recent years, there has been considerable efforts by many groups to understand the cellular mechanisms of DA modulation of PFC neurons. However, the results of these efforts often lead to contradictions and controversies. One principal feature of DA that is agreed by most researchers is that DA is a neuromodulator and is clearly not an excitatory or inhibitory neurotransmitter. The present article aims to identify certain principles of DA mechanisms by drawing on published, as well as unpublished data from PFC and other CNS sites to shed light on aspects of DA neuromodulation and address some of the existing controversies. Eighteen key features about DA modulation have been identified. These points directly impact on the end result of DA neuromodulation, and in some cases explain why DA does not yield identical effects under all experimental conditions. It will become apparent that DA's actions in PFC are subtle and depend on a variety of factors that can no longer be ignored. Some of these key factors include distinct bell-shaped dose-response profiles of postsynaptic DA effects, different postsynaptic responses that are contingent on the duration of DA receptor stimulation, prolonged duration effects, bidirectional effects following activation of D1 and D2 classes of receptors and membrane potential state and history dependence of subsequent DA actions. It is hoped that these factors will be borne in mind in future research and as a result a more consistent picture of DA neuromodulation in the PFC will emerge. Based on these factors, a theory is proposed for DA's action in PFC. This theory suggests that DA acts to expand or contract the breadth of information held in working memory buffers in PFC networks.
Collapse
Affiliation(s)
- Jeremy K Seamans
- Department of Physiology, MUSC, 173 Ashley Avenue, Suite 403, Charleston, SC 29425, USA.
| | | |
Collapse
|
269
|
Cammarota M, Bevilaqua LRM, Köhler C, Medina JH, Izquierdo I. Learning twice is different from learning once and from learning more. Neuroscience 2005; 132:273-9. [PMID: 15802182 DOI: 10.1016/j.neuroscience.2005.01.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2005] [Indexed: 11/29/2022]
Abstract
The rat hippocampus plays a crucial role in the consolidation of a variety of memories, including that for a one trial inhibitory avoidance learning task in which stepping down from a platform is associated with a footshock. Here we show that this is the case regardless of the intensity of the footshock used and hence, of the strength of the learned response. However, additional learning produced by a second training session in this task does not involve the hippocampus but, instead, the striatum. Memory consolidation of the second trial requires glutamate alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate, N-methyl-D-aspartate and metabotropic receptors, activation of signaling pathways, gene expression and protein synthesis in the striatum, as are required in the hippocampus during memory consolidation of the first trial.
Collapse
Affiliation(s)
- M Cammarota
- Laboratorio de Neuroreceptores, Instituto de Biología Celular y Neurociencias Prof. Dr. Eduardo de Robertis, Facultad de Medicina, Universidad de Buenos Aires, Paraguay, Ciudad Autónoma de Buenos Aires CP 1121, Argentina
| | | | | | | | | |
Collapse
|
270
|
Bachmann CG, Bilang-Bleuel A, De Carli S, Linthorst ACE, Reul JMHM. The selective glucocorticoid receptor antagonist ORG 34116 decreases immobility time in the forced swim test and affects cAMP-responsive element-binding protein phosphorylation in rat brain. Neuroendocrinology 2005; 81:129-36. [PMID: 15970644 DOI: 10.1159/000086413] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2004] [Accepted: 03/07/2005] [Indexed: 01/22/2023]
Abstract
Glucocorticoid receptor (GR) antagonists can block the retention of the immobility response in the forced swimming test. Recently, we showed that forced swimming evokes a distinct spatiotemporal pattern of cAMP-responsive element-binding protein (CREB) phosphorylation in the dentate gyrus (DG) and neocortex. In the present study, we found that chronic treatment of rats with the selective GR antagonist ORG 34116 decreased the immobility time in the forced swim test, increased baseline levels of phosphorylated CREB (P-CREB) in the DG and neocortex and affected the forced swimming-induced changes in P-CREB levels in a time- and site-specific manner. Overall, we observed that, in control rats, forced swimming evoked increases in P-CREB levels in the DG and neocortex, whereas in ORG 34116-treated animals a major dephosphorylation of P-CREB was observed. These observations underscore an important role of GRs in the control of the phosphorylation state of CREB which seems to be of significance for the immobility response in the forced swim test and extend the molecular mechanism of action of GRs in the brain.
Collapse
Affiliation(s)
- Cornelius G Bachmann
- Max Planck Institute of Psychiatry, Section of Neuropsychopharmacology, Munich, Germany
| | | | | | | | | |
Collapse
|
271
|
Brightwell JJ, Smith CA, Countryman RA, Neve RL, Colombo PJ. Hippocampal overexpression of mutant creb blocks long-term, but not short-term memory for a socially transmitted food preference. Learn Mem 2005; 12:12-7. [PMID: 15687228 PMCID: PMC548490 DOI: 10.1101/lm.85005] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2004] [Accepted: 11/23/2004] [Indexed: 11/24/2022]
Abstract
Phosphorylation of the transcription factor CREB on Ser133 is implicated in the establishment of long-term memory for hippocampus-dependent tasks, including spatial learning and contextual fear conditioning. We reported previously that training on a hippocampus-dependent social transmission of food preference (STFP) task increases CREB phosphorylation in the hippocampus of trained rats in comparisons with controls. In the current study, we tested the hypothesis that CREB function is necessary for long-term memory for STFP using herpes simplex viral (HSV) vector-mediated gene transfer. Rats received intrahippocampal infusions of HSV-mCREB (a mutant form of CREB, in which Ser133 has been replaced with Ala), HSV-LacZ, or saline, and were trained 3 d later. Rats were tested for food preference (demonstrated vs. novel foods) immediately (short-term test) and 11 d (long-term test) after training. Rats in all treatment groups showed a significant preference for the demonstrated food at the short-term memory test. At the long-term memory test, however, the percentage of demonstrated food eaten by mCREB-treated rats was significantly less than that eaten by the LacZ- or saline-treated rats. Quantitative Western blotting confirmed that mCREB-infused rats had significantly more hippocampal CREB protein than controls during training. The present results show that hippocampal CREB function is necessary for long-term, but not short-term memory for STFP.
Collapse
|
272
|
Quevedo J, Vianna MRM, Roesler R, Martins MR, de-Paris F, Medina JH, Izquierdo I. Pretraining but not Preexposure to the Task Apparatus Prevents the Memory Impairment Induced by Blockade of Protein Synthesis, PKA or MAP Kinase in Rats. Neurochem Res 2005; 30:61-7. [PMID: 15756933 DOI: 10.1007/s11064-004-9686-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Adult male Wistar rats were trained and tested in a step-down inhibitory avoidance task (0.4 mA footshock, 24 h training-test interval). Fifteen minutes before or 0, 1.5 or 3 hours after training, animals received a 0.8 microl intrahippocampal infusion of the protein synthesis inhibitor anisomycin (80 microg), the PKA inhibitor Rp-cAMP (0.05 microg), the MAPK kinase inhibitor PD 098059 (50 microM solution) or vehicle (phosphate buffer in saline, pH 7.4). Anisomycin, Rp-cAMP and PD 098059 impaired retention test performance in animals injected at different times, prior and after training. Pretraining with a low footshock intensity (0.2 mA) 24 h before training prevented the amnestic effect of all drugs studied. However, simple preexposure to the inhibitory avoidance apparatus did not alter the amnestic effects of all drugs. The results suggest that memory processing requires hippocampal mechanisms dependent on protein synthesis, PKA and MAPK kinase at different times after training. These findings suggest that weak training must be sufficient to produce some lasting cellular expression of the experience so that the enhancement of consolidation of a previously acquired memory is not dependent on protein synthesis, PKA or MAPK.
Collapse
Affiliation(s)
- João Quevedo
- Laboratório de Neurociências, Universidade do Extremo Sul Catarinense, 88806-000 Criciúma, SC, Brazil.
| | | | | | | | | | | | | |
Collapse
|
273
|
Bevilaqua LR, Medina JH, Izquierdo I, Cammarota M. Memory consolidation induces N-methyl-d-aspartic acid-receptor- and Ca2+/calmodulin-dependent protein kinase II-dependent modifications in α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor properties. Neuroscience 2005; 136:397-403. [PMID: 16182449 DOI: 10.1016/j.neuroscience.2005.08.007] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2005] [Revised: 07/26/2005] [Accepted: 08/01/2005] [Indexed: 11/26/2022]
Abstract
The N-methyl-D-aspartic acid (NMDA) receptor-dependent activation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) is necessary for induction of the long-term potentiation of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor-mediated responses in the CA1 region of the hippocampus, a putative model for learning and memory. We analyzed the interplay among NMDA receptor, CaMKII and AMPA receptor during consolidation of the memory for an inhibitory avoidance learning task in the rat. Bilateral intra-CA1 infusion of the NMDA receptor antagonist D-(-)-2-amino-5-phosphonopentanoic acid (AP5) or of the CaMKII inhibitor 2-[N-(2-hydroxyethyl)]-N-(4-methoxybenzenesulfonyl)] amino-N-(4-chlorocinnamyl)-N-methylbenzylamine) (KN-93) immediately after step-down inhibitory avoidance training hindered memory consolidation. Learning of the avoidance response induced the NMDA receptor-dependent translocation of alphaCaMKII to a postsynaptic density-enriched fraction isolated from dorsal CA1 and the autophosphorylation of this kinase at Thr-286. Step-down inhibitory avoidance training increased the quantity of GluR1 and GluR2/3 AMPA receptor subunits and the phosphorylation of GluR1 at Ser-831 but not at Ser-845 in CA1 postsynaptic densities. The intra-CA1 infusion of KN-93 and AP5 blocked the increases in GluR1 and GluR2/3 levels and the phosphorylation of GluR1 brought on by step-down inhibitory avoidance training. Our data suggest that step-down inhibitory avoidance learning promotes the learning-specific and NMDA receptor-dependent activation of CaMKII in the CA1 region of the dorsal hippocampus and that this activation is necessary for phosphorylation and translocation of AMPA receptor to the postsynaptic densities, similarly to what happens during long-term potentiation.
Collapse
Affiliation(s)
- L R Bevilaqua
- Laboratorio de Neuroreceptores, Instituto de Biología Celular y Neurociencias Prof. Dr. Eduardo de Robertis, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155 3 Piso, Ciudad Autónoma de Buenos Aires, CP 1121 Argentina
| | | | | | | |
Collapse
|
274
|
Igaz LM, Bekinschtein P, Izquierdo I, Medina JH. One-trial aversive learning induces late changes in hippocampal CaMKIIα, Homer 1a, Syntaxin 1a and ERK2 protein levels. ACTA ACUST UNITED AC 2004; 132:1-12. [PMID: 15548423 DOI: 10.1016/j.molbrainres.2004.08.016] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2004] [Indexed: 11/25/2022]
Abstract
Most studies regarding altered gene expression after learning are performed using multi-trial tasks, which do not allow a clear discrimination of memory acquisition, consolidation and retrieval. We screened for candidate memory-modulated genes in the hippocampus at 3 and 24 h after one-trial inhibitory avoidance (IA) training, using a cDNA array containing 1176 genes. While 33 genes were modulated by training (respect to shocked-only animals), most of them were upregulated (27 genes) and only 6 were downregulated. To confirm and extend these findings, we performed RT-PCRs and analyzed differences in protein levels in rat hippocampus using immunoblot assays. We found several proteins upregulated 24 h after training: extracellular signal-regulated kinase ERK2, Ca2+/calmodulin-dependent protein kinase II alpha (CaMKIIalpha), Syntaxin 1a, c-fos and Homer 1a. The total level of none of these proteins were found to be altered when measured 3-h post-training. Several of the mRNAs corresponding to the upregulated proteins were changed at 3 h but not 24 h. Additionally, a number of other candidates were identified for the first time as modulated by learning. The results presented here suggest that single-trial tasks can expose previously unseen differences in dynamic regulation of gene expression after behavioral manipulations, both at the transcriptional and translational levels, and reveal a diversity of gene products modulated by this task, allowing deeper understanding of the molecular basis of memory formation.
Collapse
Affiliation(s)
- Lionel Müller Igaz
- Instituto de Biologia Celular y Neurociencias, Facultad de Medicina, UBA, Paraguay 2155, piso 3, 1121 Buenos Aires, Argentina
| | | | | | | |
Collapse
|
275
|
Quevedo J, Vianna MRM, Martins MR, Barichello T, Medina JH, Roesler R, Izquierdo I. Protein synthesis, PKA, and MAP kinase are differentially involved in short- and long-term memory in rats. Behav Brain Res 2004; 154:339-43. [PMID: 15313021 DOI: 10.1016/j.bbr.2004.03.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2003] [Revised: 02/09/2004] [Accepted: 03/03/2004] [Indexed: 11/19/2022]
Abstract
We studied the involvement of hippocampal protein synthesis-, PKA-, and MAP kinase-dependent processes in short- (STM) and long-term memory (LTM) for inhibitory avoidance task. Fifteen minutes before or immediately after training rats received intrahippocampal infusions of vehicle, the protein synthesis inhibitor anisomycin, the PKA inhibitor Rp-cAMPs or the MAPKK inhibitor PD098059. The results show that STM recruits PKA and MAPK, whereas, LTM depends on PKA activity and protein synthesis during the early post-training period.
Collapse
Affiliation(s)
- João Quevedo
- Laboratório de Neurotoxicologia, Universidade do Extremo Sul Catarinense, Av. Universitaria 1105, Criciúma 88806-000, SC, Brazil.
| | | | | | | | | | | | | |
Collapse
|
276
|
Barros DM, Carlis V, Maidana M, Silva ES, Baisch ALM, Ramirez MR, Izquierdo I. Interactions between anandamide-induced anterograde amnesia and post-training memory modulatory systems. Brain Res 2004; 1016:66-71. [PMID: 15234253 DOI: 10.1016/j.brainres.2004.04.067] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2004] [Indexed: 11/17/2022]
Abstract
Rats were bilaterally implanted with indwelling cannulae in the CA1 region of the dorsal hippocampus. After recovery from surgery, they were trained in a one-trial, step-down inhibitory avoidance task using a 0.5 mA foot shock. The animals received intrahippocampal infusions of either vehicle or anandamide (100 microM, 0.5 microl/side) 30 min before training. Then, either immediately post-training or 3 h later, they received infusions of saline, noradrenaline (0.5 microg/side), SKF 38393 (1.5 microg/side), oxotremorine (0.6 microg/side) or Sp-cAMPs (0.5 microg/side) also in the hippocampus. All animals were tested for retention 24-h post-training. Anandamide produced anterograde amnesia. Immediate, but not delayed, post-training treatment with Sp-cAMPs and noradrenaline reversed this effect. SKF 38393 and oxotremorine had no influence on the amnesia caused by anandamide either when given immediately or 3 h after training. The results suggest that the amnesic effect of anandamide is related to the known noradrenergic regulation of cAMP-dependent protein kinase (PKA) activity previously described in the hippocampus immediately after avoidance training, which is crucial to long-term memory (LTM) formation.
Collapse
Affiliation(s)
- Daniela Martí Barros
- Laboratório de Comportamento, Departamento de Ciências Fisiológicas, CENPRE, Fundação Universidade Federal do Rio Grande, Av Itália Km 8, 96201-900 Rio Grande, RS, Brazil.
| | | | | | | | | | | | | |
Collapse
|
277
|
Mele A, Avena M, Roullet P, De Leonibus E, Mandillo S, Sargolini F, Coccurello R, Oliverio A. Nucleus accumbens dopamine receptors in the consolidation of spatial memory. Behav Pharmacol 2004; 15:423-31. [PMID: 15343069 DOI: 10.1097/00008877-200409000-00017] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Nucleus accumbens dopamine is known to play an important role in motor activity and in behaviours governed by drugs and natural reinforcers, as well as in non-associative forms of learning. At the same time, activation of D1 and D2 dopamine receptors has been suggested to promote intracellular events related to neural plasticity. Therefore, in this study we wished to investigate the role of the two classes of dopamine receptors within the nucleus accumbens on the consolidation of spatial information. On day 1, CD1 male mice were placed in an open field containing five different objects and, immediately after three sessions of habituation, the animals were focally injected within the nucleus accumbens with either the D1 antagonist SCH 23390 (12.5, 25 or 50 ng/side), or the D2 antagonist sulpiride (25, 50, 75 or 100 ng/side). Twenty-four hours later the ability of mice to discriminate an object displacement was assessed. Both the D1 and the D2 antagonists impaired the ability of mice to detect the spatial change. If the highest doses of the two antagonists were injected 2 h after the end of the last of the habituation sessions, no effect was observed in the reactivity to spatial change examined 24 h later. These data demonstrate that activation of both D1 and D2 receptors within the accumbens is necessary in the early stages of the consolidation of spatial information. The data are discussed in terms of involvement of nucleus accumbens dopamine in information processing in the absence of explicit reinforcers.
Collapse
Affiliation(s)
- A Mele
- Dipartimento di Genetica e Biologia Molecolare, Università di Roma La Sapienza, Roma, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
278
|
Cammarota M, Barros DM, Vianna MRM, Bevilaqua LRM, Coitinho A, Szapiro G, Izquierdo LA, Medina JH, Izquierdo I. The transition from memory retrieval to extinction. AN ACAD BRAS CIENC 2004; 76:573-82. [PMID: 15334255 DOI: 10.1590/s0001-37652004000300011] [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: 11/22/2022] Open
Abstract
Memory is measured by measuring retrieval. Retrieval is often triggered by the conditioned stimulus (CS); however, as known since Pavlov, presentation of the CS alone generates extinction. One-trial avoidance (IA) is a much used conditioned fear paradigm in which the CS is the safe part of a training apparatus, the unconditioned stimulus (US) is a footshock and the conditioned response is to stay in the safe area. In IA, retrieval is measured without the US, as latency to step-down from the safe area (i.e., a platform). Extinction is installed at the moment of the first unreinforced test session, as clearly shown by the fact that many drugs, including PKA, ERK and protein synthesis inhibitors as well as NMDA receptor antagonists, hinder extinction when infused into the hippocampus or the basolateral amygdala at the moment of the first test session but not later. Some, but not all the molecular systems required for extinction are also activated by retrieval, further endorsing the hypothesis that although retrieval is behaviorally and biochemically necessary for the generation of extinction, this last process constitutes a new learning secondary to the unreinforced expression of the original trace.
Collapse
Affiliation(s)
- Martín Cammarota
- Centro de Memória, ICS, Departamento de Bioquímica, Universidade Federal Do Rio Grande Do Sul, 90035-003 Porto Alegre, RS, Brasil
| | | | | | | | | | | | | | | | | |
Collapse
|
279
|
Hogan MV, Wieraszko A. An increase in cAMP concentration in mouse hippocampal slices exposed to low-frequency and pulsed magnetic fields. Neurosci Lett 2004; 366:43-7. [PMID: 15265587 DOI: 10.1016/j.neulet.2004.05.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2004] [Revised: 05/06/2004] [Accepted: 05/06/2004] [Indexed: 10/26/2022]
Abstract
Our previous studies revealed that magnetic fields amplified evoked potentials recorded from mouse hippocampal slices. In search for the mechanism of this effect, we evaluated the concentration of cAMP in slices exposed to low-frequency and pulsed magnetic fields. Low-frequency magnetic fields of 15 mT applied at 0.16 Hz for 30 min enhanced the concentration of cAMP almost three-fold. The concentration of cAMP continued to rise through the first hour after turning magnetic fields off, reaching almost a four-fold increase, and then returned to control levels at the end of the second hour. Neither static magnetic fields nor magnetic fields applied with the frequency of 0.5 Hz had any effect on cAMP concentration. The increase in cAMP levels was dependent on the strength of the magnetic field and required the presence of extracellular calcium. A pulsed magnetic field applied with variable intensity (9-15 mT) and in cycles lasting from 5 to 20 min doubled the cAMP concentration. These results support our previous electrophysiological observations and provide biochemical correlates for their interpretation.
Collapse
Affiliation(s)
- Michael V Hogan
- Clinical Laboratory Sciences, College of Allied Health Professions, University of South Alabama, SHAC 2309, 1504 Springhill Avenue, Mobile, AL 36604, USA
| | | |
Collapse
|
280
|
Sato T, Tanaka KI, Ohnishi Y, Teramoto T, Irifune M, Nishikawa T. Inhibitory effects of group II mGluR-related drugs on memory performance in mice. Physiol Behav 2004; 80:747-58. [PMID: 14984810 DOI: 10.1016/j.physbeh.2003.12.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2003] [Revised: 12/19/2003] [Accepted: 12/22/2003] [Indexed: 11/24/2022]
Abstract
The cAMP/protein kinase A signaling pathway is negatively modulated by group II metabotropic glutamate receptors (mGluRs), and the cross-talk that occurs between these receptors may modulate learning and memory. To examine the relationship among cAMP/PKA-signaling pathway activity, group II mGluRs, and learning and memory, mice were trained to perform a step-through-type passive avoidance task, and 10 min before each avoidance trial the following drugs were injected intracisternally (i.cist.): vehicle (0.05% dimethylsulfoxide); a specific group II mGluR agonist, DCG-IV (1-50 ng/mouse); a specific group II mGluR antagonist, LY341495 (10-300 ng); a selective inhibitor of cAMP-specific phosphodiesterase, rolipram (100-1000 ng); an activator of adenylyl cyclase, forskolin (25-250 ng); a specific inhibitor of PKA, H-89 (150 or 300 ng) or; an activator of protein kinase C, phorbol 12-myristate 13-acetate (PMA 200 ng). DCG-IV (25 and 50 ng) or LY341495 (150 and 300 ng) reduced the latency in the avoidance task. The reduction of latency by DCG-IV was not observed in mice coinjected with DCG-IV (50 ng) together with rolipram (500 ng) or forskolin (25 ng). Conversely, coinjection of LY341495 with 100 or 1000 ng rolipram, or with 25 or 250 ng forskolin tended to potentiate the LY341495-induced shortening of latency. In addition, the reduction of latency by DCG-IV (50 ng) was not observed in mice coinjected with DCG-IV and PMA together. However, the reduction of latency by LY341495 (300 ng) was potentiated when the drug was coadministered with PMA. These results suggest that changes in the cAMP/PKA-signaling pathway, mediated by group II mGluRs, influence memory in the passive avoidance task, and that both the excessive activation and deactivation of this pathway may induce the impairment of learning and memory.
Collapse
Affiliation(s)
- Tomoaki Sato
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Sakuragaoka, Kagoshima 890-8544, Japan
| | | | | | | | | | | |
Collapse
|
281
|
Ahmed T, Frey S, Frey JU. Regulation of the phosphodiesterase PDE4B3-isotype during long-term potentiation in the area dentata in vivo. Neuroscience 2004; 124:857-67. [PMID: 15026126 DOI: 10.1016/j.neuroscience.2004.01.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2004] [Indexed: 11/28/2022]
Abstract
Hippocampal long-term potentiation (LTP) is the most prominent cellular model underlying learning and memory formation. However, which cellular processes are involved in maintaining LTP remains largely unknown. We have previously detailed temporal modulations of cyclic adenosine monophosphate (cAMP) and a cAMP-specific phosphodiesterase, PDE4B3, after LTP-induction and its maintenance in hippocampal area CA1 in vitro. To test whether other hippocampal sub-structures are characterised by similar mechanisms, tissue from the area dentata of freely moving rats was analysed at different LTP-time points. The tissue was fractionated into three components, where PDE4B-levels and cAMP-concentrations were measured. In contrast with data obtained in area CA1, we now detail an LTP-specific translational, but not transcriptional regulation of PDE4B3 within the first 8 h after tetanization and present spatio-temporal changes of PDE4B proteins and cAMP that is LTP-specific.
Collapse
Affiliation(s)
- T Ahmed
- Leibniz-Institute for Neurobiology, Department of Neurophysiology, Brenneckestrasse 6, D-39118 Magdeburg, Germany
| | | | | |
Collapse
|
282
|
Weeber EJ, Caldwell KK. Delay fear conditioning modifies phospholipase C-β1a signaling in the hippocampus and frontal cortex. Pharmacol Biochem Behav 2004; 78:155-64. [PMID: 15159145 DOI: 10.1016/j.pbb.2004.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2003] [Revised: 03/02/2004] [Accepted: 03/04/2004] [Indexed: 11/30/2022]
Abstract
The use of the single-trial fear conditioning paradigm allows for control over the exact moment when an animal is exposed to a learning event, making it possible to study both the initial neurobiological changes that are associated with learning and changes that take place over long periods of time. In the present study, we performed detailed analyses of the alterations in phosphatidylinositol-specific phospholipase C-beta1a (PLC-beta1a) levels and enzyme activities in subcellular fractions prepared from the hippocampal formation (HPF) and medial frontal cortex (MFC) 1, 3, 5, 7, 24, and 72 h following single-trial fear conditioning. We observed tissue- and time-dependent changes in both PLC-beta1a enzyme activity and anti-PLC-beta1a immunoreactivity in each subcellular fraction. Based on these observations, we hypothesize that changes in PLC-beta1a catalytic activity and subcellular distribution play important roles in neuronal signaling processes that are required for fear-conditioned learning and memory.
Collapse
Affiliation(s)
- Edwin J Weeber
- Department of Neurosciences, MSC08 4740, University of New Mexico, Albuquerque, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA
| | | |
Collapse
|
283
|
Das UN. Long-chain polyunsaturated fatty acids in memory formation and consolidation: further evidence and discussion. Nutrition 2004; 19:988-93. [PMID: 14624950 DOI: 10.1016/s0899-9007(03)00174-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Undurti N Das
- EFA Sciences LLC, Norwood, Massachusetts 02062, USA.
| |
Collapse
|
284
|
Abstract
One of the most significant challenges in neuroscience is to identify the cellular and molecular processes that underlie learning and memory formation. The past decade has seen remarkable progress in understanding changes that accompany certain forms of acquisition and recall, particularly those forms which require activation of afferent pathways in the hippocampus. This progress can be attributed to a number of factors including well-characterized animal models, well-defined probes for analysis of cell signaling events and changes in gene transcription, and technology which has allowed gene knockout and overexpression in cells and animals. Of the several animal models used in identifying the changes which accompany plasticity in synaptic connections, long-term potentiation (LTP) has received most attention, and although it is not yet clear whether the changes that underlie maintenance of LTP also underlie memory consolidation, significant advances have been made in understanding cell signaling events that contribute to this form of synaptic plasticity. In this review, emphasis is focused on analysis of changes that occur after learning, especially spatial learning, and LTP and the value of assessing these changes in parallel is discussed. The effect of different stressors on spatial learning/memory and LTP is emphasized, and the review concludes with a brief analysis of the contribution of studies, in which transgenic animals were used, to the literature on memory/learning and LTP.
Collapse
Affiliation(s)
- M A Lynch
- Trinity College Institute of Neuroscience, Department of Physiology, Trinity College, Dublin, Ireland.
| |
Collapse
|
285
|
Chang YC, Huang AM, Kuo YM, Wang ST, Chang YY, Huang CC. Febrile seizures impair memory and cAMP response-element binding protein activation. Ann Neurol 2004; 54:706-18. [PMID: 14681880 DOI: 10.1002/ana.10789] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The long-term effects of brief but repetitive febrile seizures (FS) on memory have not been as thoroughly investigated as the impact of single and prolonged seizure in the developing brain. Using a heated-air FS paradigm, we subjected male rat pups to one, three, or nine episodes of brief FS on days 10 to 12 postpartum. Neither hippocampal neuronal damage nor apoptosis was noted within 72 hours after FS, nor was there significant hippocampal neuronal loss, aberrant mossy fiber sprouting, or altered seizure threshold to pentylenetetrazol in any FS group at adulthood. The adult rats subjected to nine episodes of early-life FS, however, showed long-term memory deficits as assessed by the Morris water maze. They also exhibited impaired intermediate and long-term memory but spared short-term memory in the inhibitory avoidance task. Three hours after inhibitory avoidance training, phosphorylation of cAMP response-element binding (CREB) protein in the hippocampus was significantly lower in nine-FS-group rats than in controls. Furthermore, rolipram administration, which activated the cAMP-CREB signaling pathway by inhibiting phosphodiesterase type IV, reversed the long-term memory deficits in nine-FS-group rats by enhancing hippocampal CREB phosphorylation. These results raise concerns about the long-term cognitive consequences of even brief frequently repetitive FS during early brain development.
Collapse
Affiliation(s)
- Ying-Chao Chang
- Graduate Institute of Clinical Medicine and Department of Pediatrics, Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | | | | | | | | | | |
Collapse
|
286
|
Ramos BP, Birnbaum SG, Lindenmayer I, Newton SS, Duman RS, Arnsten AFT. Dysregulation of protein kinase a signaling in the aged prefrontal cortex: new strategy for treating age-related cognitive decline. Neuron 2004; 40:835-45. [PMID: 14622586 DOI: 10.1016/s0896-6273(03)00694-9] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Activation of the cAMP/protein kinase A (PKA) pathway has been proposed as a mechanism for improving age-related cognitive deficits based on studies of hippocampal function. However, normal aging also afflicts prefrontal cortical cognitive functioning. Here, we report that agents that increase PKA activity impair rather than improve prefrontal cortical function in aged rats and monkeys with prefrontal cortical deficits. Conversely, PKA inhibition ameliorates prefrontal cortical cognitive deficits. Western blot and immunohistochemical analyses of rat brain further indicate that the cAMP/PKA pathway becomes disinhibited in the prefrontal cortex with advancing age. These data demonstrate that PKA inhibition, rather than activation, is the appropriate strategy for restoring prefrontal cortical cognitive abilities in the elderly.
Collapse
Affiliation(s)
- Brian P Ramos
- Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | | | | | | | | | | |
Collapse
|
287
|
Mellott TJ, Williams CL, Meck WH, Blusztajn JK. Prenatal choline supplementation advances hippocampal development and enhances MAPK and CREB activation. FASEB J 2004; 18:545-7. [PMID: 14715695 DOI: 10.1096/fj.03-0877fje] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Choline is an essential nutrient for animals and humans. Previous studies showed that supplementing the maternal diet with choline during the second half of gestation in rats permanently enhances memory performance of the adult offspring. Here we show that prenatal choline supplementation causes a 3-day advancement in the ability of juvenile rats to use relational cues in a water maze task, indicating that the treatment accelerates hippocampal maturation. Moreover, phosphorylation and therefore activation of hippocampal mitogen-activated protein kinase (MAPK) and cAMP-response element binding protein (CREB) in response to stimulation by glutamate, N-methyl-D-aspartate, or depolarizing concentrations of K+ were increased by prenatal choline supplementation and reduced by prenatal choline deficiency. These data provide the first evidence that developmental plasticity of the hippocampal MAPK and CREB signaling pathways is controlled by the supply of a single essential nutrient, choline, during fetal development and point to these pathways as candidate mechanisms for the developmental and long-term cognitive enhancement induced by prenatal choline supplementation.
Collapse
Affiliation(s)
- Tiffany J Mellott
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | | | | | | |
Collapse
|
288
|
Martí Barros D, Ramirez MR, Dos Reis EA, Izquierdo I. Participation of hippocampal nicotinic receptors in acquisition, consolidation and retrieval of memory for one trial inhibitory avoidance in rats. Neuroscience 2004; 126:651-6. [PMID: 15183514 DOI: 10.1016/j.neuroscience.2004.03.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2004] [Indexed: 10/26/2022]
Abstract
One-trial step-down inhibitory avoidance in rats involves the activation of two separate memory types, a short-term system (STM) that lasts 3-6 h, and a long-term system (LTM) that takes 3-6 h to be formed and lasts for many days or even months. Here we investigate the effect of nicotinic receptor (nAChR) ligands infused bilaterally in the hippocampus on STM and LTM formation and on LTM retrieval of this task. Rats were implanted with chronic cannulae in the CA1 region of the dorsal hippocampus, trained using a 0.5 mA foot shock, and tested twice, first 1.5 h after training to measure STM, and again at 24 h to measure LTM. The drugs used were the nAChR antagonists, mecamylamine (1, 3 and 10 microg/side) and dihydro-beta-erythroidine (DHbetaE; 2, 6 and 18 microg/side) and the agonist, nicotine (0.6, 1 and 3 microg/side). They were given either 15 min before training, immediately after training or 15 min prior to LTM retrieval. Mecamylamine and DHbetaE impaired and nicotine enhanced STM, LTM and retrieval similarly. The results indicate that nAChRs in CA1 participate in the regulation of both STM and LTM formation, and on the retrieval of LTM.
Collapse
Affiliation(s)
- D Martí Barros
- Departamento de Ciências Fisiológicas, Fundação Universidade Federal de Rio Grande, Av. Itália Km 8, CEP 96.201-900, Rio Grande, RS, Brazil.
| | | | | | | |
Collapse
|
289
|
Igaz LM, Bekinschtein P, Vianna MMR, Izquierdo I, Medina JH. Gene expression during memory formation. Neurotox Res 2004; 6:189-204. [PMID: 15325958 DOI: 10.1007/bf03033221] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
For several decades, neuroscientists have provided many clues that point out the involvement of de novo gene expression during the formation of long-lasting forms of memory. However, information regarding the transcriptional response networks involved in memory formation has been scarce and fragmented. With the advent of genome-based technologies, combined with more classical approaches (i.e., pharmacology and biochemistry), it is now feasible to address those relevant questions--which gene products are modulated, and when that processes are necessary for the proper storage of memories--with unprecedented resolution and scale. Using one-trial inhibitory (passive) avoidance training of rats, one of the most studied tasks so far, we found two time windows of sensitivity to transcriptional and translational inhibitors infused into the hippocampus: around the time of training and 3-6 h after training. Remarkably, these periods perfectly overlap with the involvement of hippocampal cAMP/PKA (protein kinase A) signaling pathways in memory consolidation. Given the complexity of transcriptional responses in the brain, particularly those related to processing of behavioral information, it was clearly necessary to address this issue with a multi-variable, parallel-oriented approach. We used cDNA arrays to screen for candidate inhibitory avoidance learning-related genes and analyze the dynamic pattern of gene expression that emerges during memory consolidation. These include genes involved in intracellular kinase networks, synaptic function, DNA-binding and chromatin modification, transcriptional activation and repression, translation, membrane receptors, and oncogenes, among others. Our findings suggest that differential and orchestrated hippocampal gene expression is necessary in both early and late periods of long-term memory consolidation. Additionally, this kind of studies may lead to the identification and characterization of genes that are relevant for the pathogenesis of complex psychiatric disorders involving learning and memory impairments, and may allow the development of new methods for the diagnosis and treatment of these diseases.
Collapse
Affiliation(s)
- Lionel Muller Igaz
- Instituto de Biología Celular y Neurociencia Eduardo de Robertis, Facultad de Medicina, Universidad de Buenos Aires, (1113) Buenos Aires, Argentina
| | | | | | | | | |
Collapse
|
290
|
Depino AM, Alonso M, Ferrari C, del Rey A, Anthony D, Besedovsky H, Medina JH, Pitossi F. Learning modulation by endogenous hippocampal IL-1: Blockade of endogenous IL-1 facilitates memory formation. Hippocampus 2004; 14:526-35. [PMID: 15224987 DOI: 10.1002/hipo.10164] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The interleukin-1 (IL-1) cytokine family (IL-1alpha, IL-beta, and the IL-1 receptor antagonist) is involved in immune and inflammatory responses both in the brain and in the periphery. Recently, it has also been shown to influence behavior and memory consolidation. However, within the experimental systems studied, it has remained unclear whether the role of IL-1beta is associated solely with a pathophysiological process or whether it is a neuromodulator in normal adult brain. To evaluate the involvement of the nonpathological endogenous IL-1 system in learning, we studied the expression of IL-1alpha, IL-1beta, and IL-1ra during memory consolidation. We observed a learning-specific hippocampal IL-1alpha mRNA induction, but not that of IL-1beta or IL-1ra mRNAs, after inhibitory avoidance training. Moreover, when IL-1 receptor activity was inhibited using an adenoviral vector that expresses the IL-1 receptor antagonist (IL-1ra) in the hippocampus, both short-term and long-term memory retention scores were facilitated. In contrast, endogenous hippocampal IL-1 played no role in the habituation to a novel environment. These results demonstrate that endogenous hippocampal IL-1 specifically modulates a fear-motivated learning task, and suggest that IL-1alpha activity in the CNS is part of the hippocampal memory processing.
Collapse
Affiliation(s)
- Amaicha M Depino
- Fundación Instituto Leloir, UBA-CONICET, Buenos Aires, Argentina.
| | | | | | | | | | | | | | | |
Collapse
|
291
|
Schneider AM, Wilkins E, Firestone A, Everbach EC, Naylor JC, Simson PE. Enhanced retention in the passive-avoidance task by 5-HT(1A) receptor blockade is not associated with increased activity of the central nucleus of the amygdala. Learn Mem 2003; 10:394-400. [PMID: 14557612 PMCID: PMC218005 DOI: 10.1101/lm.54903] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The effect of blockade of 5-HT1A receptors was investigated on (1). retention in a mildly aversive passive-avoidance task, and (2). spontaneous single-unit activity of central nucleus of the amygdala (CeA) neurons, a brain site implicated in modulation of retention. Systemic administration of the selective 5-HT1A antagonist NAN-190 immediately after training markedly-and dose-dependently-facilitated retention in the passive-avoidance task; enhanced retention was time-dependent and was not attributable to variations in wattages of shock received by animals. Systemic administration of NAN-190 had mixed effects on spontaneous single-unit activity of CeA neurons recorded extracellularly in vivo; microiontophoretic application of 5-HT, in contrast, consistently and potently suppressed CeA activity. The present findings-that 5-HT1A receptor blockade by NAN-190 (1). enhances retention in the passive-avoidance task, and (2). does not consistently increase spontaneous neuronal activity of the CeA-provide evidence that a serotonergic system tonically inhibits modulation of retention in the passive-avoidance task through activation of the 5-HT1A receptor subtype at brain sites located outside the CeA.
Collapse
Affiliation(s)
- Allen M Schneider
- Department of Psychology, Swarthmore College, Swarthmore, Pennsylvania 19081, USA.
| | | | | | | | | | | |
Collapse
|
292
|
Zhang JJ, Okutani F, Inoue S, Kaba H. Activation of the mitogen-activated protein kinase/extracellular signal-regulated kinase signaling pathway leading to cyclic AMP response element-binding protein phosphorylation is required for the long-term facilitation process of aversive olfactory learning in young rats. Neuroscience 2003; 121:9-16. [PMID: 12946695 DOI: 10.1016/s0306-4522(03)00392-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The mitogen-activated protein kinase/extracellular-signal regulated kinase (MAPK/ERK) cascade is an important contributor to synaptic plasticity that underlies learning and memory. ERK activation by the MAPK/ERK kinase (MEK) leading to cyclic-AMP response element binding protein (CREB) phosphorylation is implicated in the formation of long-term memory. We have demonstrated that CREB phosphorylation in the olfactory bulb (OB) is important for aversive olfactory learning in young rats, yet whether MAPK/ERK functions as an upstream regulator are necessary for this olfactory learning remains to be determined. Therefore, we addressed this issue using behavioral and Western blot analyses. The MEK inhibitor PD98059 was continuously infused into the OB of postnatal day 11 rat pups during a 30-min training session regarding the pairing of citral odor and foot shock. On the following day, the time spent in the part of the apparatus where the odor was present was measured as an index of odor aversion. PD98059 impaired olfactory learning in a dose-dependent manner without affecting memory retention 1 h after training. We further tested whether odor-shock training leads to MAPK/ERK activation in the OB and defines the time course of the activation. Phosphorylated ERKs (P-ERKs) 1 and 2 were significantly increased for 60 min after the training without changes in total ERKs 1 and 2. By contrast, intrabulbar infusion of PD98059 during the training significantly reduced P-ERKs 1 and 2 as well as phosphorylated CREB without any effects on the total ERKs or CREB. Taken together with the previous findings, these results indicate that the MAPK/ERK-CREB pathway is required for the long-term, but not the short-term, facilitation process of aversive olfactory learning in young rats.
Collapse
Affiliation(s)
- J-J Zhang
- Department of Neuropsychiatry, Kochi Medical School, Nankoku, Kochi 783-8505, Japan
| | | | | | | |
Collapse
|
293
|
Adamec RE, Blundell J, Burton P. Phosphorylated cyclic AMP response element binding protein expression induced in the periaqueductal gray by predator stress: its relationship to the stress experience, behavior and limbic neural plasticity. Prog Neuropsychopharmacol Biol Psychiatry 2003; 27:1243-67. [PMID: 14659479 DOI: 10.1016/j.pnpbp.2003.09.017] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Electrophysiological studies in cats and recently in rats implicate neuroplasticity in the periaqueductal gray (PAG) and its afferents in stressor-induced increases in fearful behavior and anxiety-like behavior (ALB). Such increases may model aspects of affective changes following traumatic stress in humans. The present study explored the role of neuroplasticity in PAG and its connection with the central nucleus of the amygdala (ACE) in male rodent anxiety-like response to predator stress. In the first of two studies, the effects of predator stress on the induction of phosphorylated cyclic AMP response element binding protein (pCREB) were investigated. pCREB expression in the PAG and ventromedial hypothalamus (VMH) was examined immunohistochemically. Predator stress increased the degree of pCREB expression in PAG cells (measured densitometrically) but did not increase the number of cells expressing pCREB (measured stereologically). Moreover, predator stress-specific increase in pCREB-like immunoreactivity (lir) was restricted to the right lateral column of the PAG. In addition, pCREB lir in the right lateral column likely reflects aspects of the stress experience because the stressor (cat behavior) and the response to the stressor (rat defensive behavior) are highly predictive of degree of pCREB expression. There was no effect of predator stress on pCREB lir in the VMH. Because pCREB expression has been associated with long-lasting potentiation (LLP) of neural transmission, we examined the effects of predator stress on transmission in the ACE-PAG pathway in a second study. Predator stress elevated evoked potential measures of ACE-PAG transmission in the right hemisphere but not in the left hemisphere 11-12 days after predator stress. This finding is consistent with the longer-lived effects of pharmacological stress on amygdalo-PAG transmission in the right hemisphere but not in the left hemisphere in cats. Of interest is the fact that the same aspects of the stressor experience and reaction to it, which are predictive of the degree of pCREB expression, are also highly predictive of the degree of potentiation of measures of ACE-PAG transmission. Behavioral analyses revealed that the most consistent effects of predator stress are on behavior in the plus maze (open arm exploration and risk assessment) and on startle. In addition, covariance analysis suggests that ACE-PAG potentiation mediates some but not all of the changes in ALB produced by predator stress. Because pCREB expression may be a precursor to neuroplastic changes in certain forms of memory and LLP, the present findings complement studies in the cat, showing that neuroplastic changes in the PAG underlie changes in affect following stress. Furthermore, these findings suggest that neuroplastic changes in PAG may be important mediators of predator stress-induced changes in affective behavior in rodents. Finally, consistent with cat and human studies, the right hemisphere appears particularly important in long-term response to stress.
Collapse
Affiliation(s)
- Robert E Adamec
- Department of Psychology, Memorial University, 232 Elizabeth Avenue, A1B 3X9, St. John's, Newfoundland, Canada.
| | | | | |
Collapse
|
294
|
Buhot MC, Wolff M, Benhassine N, Costet P, Hen R, Segu L. Spatial Learning in the 5-HT1B Receptor Knockout Mouse: Selective Facilitation/Impairment Depending on the Cognitive Demand. Learn Mem 2003; 10:466-77. [PMID: 14657258 DOI: 10.1101/lm.60203] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Age-related memory decline is associated with a combined dysfunction of the cholinergic and serotonergic systems in the hippocampus and frontal cortex, in particular. The 5-HT1B receptor occupies strategic cellular and subcellular locations in these structures, where it plays a role in the modulation of ACh release. In an attempt to characterize the contribution of this receptor to memory functions, 5-HT1B receptor knockout (KO) mice were submitted to various behavioral paradigms carried out in the same experimental context (water maze), which were aimed at exposing mice to various levels of memory demand. 5-HT1BKO mice exhibited a facilitation in the acquisition of a hippocampal-dependent spatial reference memory task in the Morris water maze. This facilitation was selective of task difficulty, showing thus that the genetic inactivation of the 5-HT1B receptor is associated with facilitation when the complexity of the task is increased, and reveals a protective effect on age-related hippocampal-dependent memory decline. Young-adult and aged KO and wild-type (WT) mice were equally able to learn a delayed spatial matching-to-sample working memory task in a radial-arm water maze with short (0 or 5 min) delays. However, 5-HT1BKO mice, only, exhibited a selective memory impairment at intermediate and long (15, 30, and 60 min) delays. Treatment by scopolamine induced the same pattern of performance in wild type as did the mutation for short (5 min, no impairment) and long (60 min, impairment) delays. Taken together, these studies revealed a beneficial effect of the mutation on the acquisition of a spatial reference memory task, but a deleterious effect on a working memory task for long delays. This 5-HT1BKO mouse story highlights the problem of the potential existence of "global memory enhancers."
Collapse
Affiliation(s)
- Marie-Christine Buhot
- Centre National de la Recherche Scientifique-Unité Mixte de Recherche 5106, Laboratoire de Neurosciences Cognitives, Université de Bordeaux 1, 33405 Talence, France.
| | | | | | | | | | | |
Collapse
|
295
|
Hale MW, Crowe SF. Facilitation and disruption of memory for the passive avoidance task in the day-old chick using dopamine D1 receptor compounds. Behav Pharmacol 2003; 14:525-32. [PMID: 14557720 DOI: 10.1097/00008877-200311000-00005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
This series of studies provides a behavioural account of dopamine D1-receptor-dependent facilitation and disruption of memory for the single-trial passive avoidance task in the day-old chick. The D1 antagonist, SCH23390, induced memory disruption in a dose-dependent manner from 60 min after training with a strong (100% methyl anthranilate) aversant experience. The D1 agonist, SKF38393, was found to facilitate memory in chicks given a weak (20% vol/vol methyl anthranilate) training experience. The D2 antagonist, sulpiride, and the D2 agonist, quinpirole, showed no memory effects. The research indicates an important role for dopamine D1-dependent mechanisms in memory formation in the chick.
Collapse
MESH Headings
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology
- Age Factors
- Animals
- Appetitive Behavior/drug effects
- Association Learning/drug effects
- Avoidance Learning/drug effects
- Benzazepines/pharmacology
- Brain/drug effects
- Chickens
- Discrimination Learning/drug effects
- Dopamine Agonists/pharmacology
- Dopamine Antagonists/pharmacology
- Dose-Response Relationship, Drug
- Injections, Subcutaneous
- Memory, Short-Term/drug effects
- Mental Recall/drug effects
- Quinpirole/pharmacology
- Receptors, Dopamine D1/drug effects
- Receptors, Dopamine D2/drug effects
- Retention, Psychology/drug effects
- Sulpiride/pharmacology
- Taste/drug effects
Collapse
Affiliation(s)
- M W Hale
- School of Psychological Science, La Trobe University, Bundoora, Australia 3086
| | | |
Collapse
|
296
|
Yang HW, Hu XD, Zhang HM, Xin WJ, Li MT, Zhang T, Zhou LJ, Liu XG. Roles of CaMKII, PKA, and PKC in the induction and maintenance of LTP of C-fiber-evoked field potentials in rat spinal dorsal horn. J Neurophysiol 2003; 91:1122-33. [PMID: 14586032 DOI: 10.1152/jn.00735.2003] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Long-term potentiation (LTP) of C-fiber-evoked field potentials in spinal dorsal horn may be relevant to hyperalgesia, an increased response to noxious stimulation. The mechanism underlying this form of synaptic plasticity is, however, still unclear. Considerable evidence has shown that calcium/calmodulin-dependent protein kinase II (CaMKII), protein kinase A (PKA), and protein kinase C (PKC) are important for LTP in hippocampus. In this study, the roles of these three protein kinases in the induction and maintenance of LTP of C-fiber-evoked field potentials were evaluated by application of specific inhibitors of CaMKII (KN-93 and AIP), PKA (Rp-CPT-cAMPS), and PKC (chelerythrine and Gö 6983) at the recording segments before and after LTP induction in urethane-anesthetized Sprague-Dawley rats. We found both KN-93 and AIP, when applied at 30 min prior to tetanic stimulation, completely blocked LTP induction. At 30 min after LTP induction, KN-93 and AIP reversed LTP completely, and at 60 min after LTP induction, they depressed spinal LTP in most rats tested. Three hours after LTP induction, however, KN-93 or AIP did not affect the spinal LTP. Rp-CPT-cAMPS, chelerythrine, and Gö 6983 blocked the spinal LTP when applied at 30 min before tetanic stimulation and reversed LTP completely at 15 min after LTP induction. In contrast, at 30 min after LTP induction, the drugs never affected the spinal LTP. These results suggest that activation of CaMKII, PKA, and PKC may be crucial for the induction and the early-phase but not for the late-phase maintenance of the spinal LTP.
Collapse
Affiliation(s)
- Hong-Wei Yang
- Department of Physiology, Zhongshan Medical School of Sun Yat-sen University, Guangzhou 510089, Peoples Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
297
|
The similarities and diversities of signal pathways leading to consolidation of conditioning and consolidation of extinction of fear memory. J Neurosci 2003. [PMID: 12967993 DOI: 10.1523/jneurosci.23-23-08310.2003] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
It is generally believed that consolidation of long-term memory requires activation of protein kinases, transcription of genes, and new protein synthesis. However, little is known about the signal cascades involved in the extinction of memory, which occurs when the conditioned stimulus is no longer followed by the unconditioned stimulus. Here, we show for the first time that an intra-amygdala injection of transcription inhibitor actinomycin D at the dose that blocked acquisition failed to affect extinction of a learned response. Conversely, protein synthesis inhibitor anisomycin blocked both acquisition and extinction. Extinction training-induced expression of calcineurin was blocked by anisomycin but not by actinomycin D. NMDA receptor antagonist, phosphatidylinositol 3-kinase (PI-3 kinase), and MAP kinase inhibitors that blocked the acquisition also blocked the extinction of conditioned fear. Likewise, PI-3 kinase inhibitor blocked fear training-induced cAMP response element-binding protein (CREB) phosphorylation as well as extinction training-induced decrease in CREB phosphorylation, the latter of which was associated with calcineurin expression and could be reversed by a specific calcineurin inhibitor. Thus, molecular processes that underlie long-term behavioral changes after acquisition and extinction share some common mechanisms and also display different characteristics.
Collapse
|
298
|
Lin CH, Yeh SH, Lu HY, Gean PW. The similarities and diversities of signal pathways leading to consolidation of conditioning and consolidation of extinction of fear memory. J Neurosci 2003; 23:8310-7. [PMID: 12967993 PMCID: PMC6740702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2003] [Revised: 07/14/2003] [Accepted: 07/17/2003] [Indexed: 03/04/2023] Open
Abstract
It is generally believed that consolidation of long-term memory requires activation of protein kinases, transcription of genes, and new protein synthesis. However, little is known about the signal cascades involved in the extinction of memory, which occurs when the conditioned stimulus is no longer followed by the unconditioned stimulus. Here, we show for the first time that an intra-amygdala injection of transcription inhibitor actinomycin D at the dose that blocked acquisition failed to affect extinction of a learned response. Conversely, protein synthesis inhibitor anisomycin blocked both acquisition and extinction. Extinction training-induced expression of calcineurin was blocked by anisomycin but not by actinomycin D. NMDA receptor antagonist, phosphatidylinositol 3-kinase (PI-3 kinase), and MAP kinase inhibitors that blocked the acquisition also blocked the extinction of conditioned fear. Likewise, PI-3 kinase inhibitor blocked fear training-induced cAMP response element-binding protein (CREB) phosphorylation as well as extinction training-induced decrease in CREB phosphorylation, the latter of which was associated with calcineurin expression and could be reversed by a specific calcineurin inhibitor. Thus, molecular processes that underlie long-term behavioral changes after acquisition and extinction share some common mechanisms and also display different characteristics.
Collapse
Affiliation(s)
- Chih-Hung Lin
- Department of Pharmacology, College of Medicine, National Cheng-Kung University, Tainan City, Taiwan 701
| | | | | | | |
Collapse
|
299
|
Das UN. Can memory be improved? A discussion on the role of ras, GABA, acetylcholine, NO, insulin, TNF-alpha, and long-chain polyunsaturated fatty acids in memory formation and consolidation. Brain Dev 2003; 25:251-61. [PMID: 12767456 DOI: 10.1016/s0387-7604(02)00221-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
It is proposed that long-chain polyunsaturated fatty acids when given from the perinatal period will ensure proper development and growth of the brain and maintain the activity and/or concentrations of ras, nitric oxide, insulin, and various neurotransmitters and cytokines at physiological level and thus, improve memory and prevent learning deficits.
Collapse
Affiliation(s)
- Undurti N Das
- EFA Sciences LLC, 1420 Providence Highway, Suite # 266, Norwood, MA 02062, USA.
| |
Collapse
|
300
|
Cognitive strategy-specific increases in phosphorylated cAMP response element-binding protein and c-Fos in the hippocampus and dorsal striatum. J Neurosci 2003. [PMID: 12716964 DOI: 10.1523/jneurosci.23-08-03547.2003] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Extensive research has shown that the hippocampus and striatum have dissociable roles in memory and are necessary for "place" and "response" learning, respectively. In the present study, rats were trained on a cross maze task that could be solved by either a place or a response strategy, and the strategy used was determined by a probe trial. Phosphorylated cAMP response element-binding protein (pCREB) and c-Fos immunoreactivity (IR) were measured in the hippocampus and striatum either immediately or 1 hr after cross maze training. Immediately after training, pCREB-IR and c-Fos-IR were significantly higher in the hippocampus and striatum of trained rats than in control rats matched for motor activity, but the increase was independent of the strategy revealed at probe. One hour after training, however, pCREB-IR and c-Fos-IR were sustained in the hippocampal pyramidal and granule cell layers of place learners but returned to basal levels among response learners. In addition, pCREB-IR was sustained in the dorsomedial and dorsolateral striatum of response learners but returned to basal levels among place learners. There were no differences between place and response learners in c-Fos-IR in the striatum at either time point. The present results indicate that cross maze training causes an initial activation of transcription factors in both the hippocampus and striatum. Formation of memory for a place strategy, however, is related to sustained phosphorylation of CREB and expression of c-Fos for at least 1 hr in the hippocampus, whereas formation of memory for a response strategy is related to phosphorylation of CREB in the striatum.
Collapse
|