51
|
Milad MR, Rauch SL, Pitman RK, Quirk GJ. Fear extinction in rats: Implications for human brain imaging and anxiety disorders. Biol Psychol 2006; 73:61-71. [PMID: 16476517 DOI: 10.1016/j.biopsycho.2006.01.008] [Citation(s) in RCA: 439] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2005] [Indexed: 11/22/2022]
Abstract
Fear extinction is the decrease in conditioned fear responses that normally occurs when a conditioned stimulus (CS) is repeatedly presented in the absence of the aversive unconditioned stimulus (US). Extinction does not erase the initial CS-US association, but is thought to form a new memory. After extinction training, extinction memory competes with conditioning memory for control of fear expression. Deficits in fear extinction are thought to contribute to post-traumatic stress disorder (PTSD). Herein, we review studies performed in rats showing that the medial prefrontal cortex plays a critical role in the retention and expression of extinction memory. We also review human studies indicating that prefrontal areas homologous to those critical for extinction in rats are structurally and functionally deficient in patients with PTSD. We then discuss how findings from rat studies may allow us to: (1) develop new fear extinction paradigms in humans, (2) make specific predictions as to the location of extinction-related areas in humans, and (3) improve current extinction-based behavioral therapies for anxiety disorders.
Collapse
Affiliation(s)
- Mohammed R Milad
- Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Bldg 149 13th St., Charlestown, 02129, USA
| | | | | | | |
Collapse
|
52
|
Corstens GJH, van Boxtel R, van den Hurk MJJ, Roubos EW, Jenks BG. The effects of disruption of A kinase anchoring protein-protein kinase A association on protein kinase A signalling in neuroendocrine melanotroph cells of Xenopus laevis. J Neuroendocrinol 2006; 18:477-83. [PMID: 16774496 DOI: 10.1111/j.1365-2826.2006.01439.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The secretory activity of melanotroph cells from Xenopus laevis is regulated by multiple neurotransmitters that act through adenylyl cyclase. Cyclic adenosine monophosphate (cAMP), acting on protein kinase A (PKA), stimulates the frequency of intracellular Ca(2+) oscillations and the secretory activity of the melanotroph cell. Anchoring of PKA near target proteins is essential for many PKA-regulated processes, and the family of A kinase anchoring proteins (AKAPs) is involved in the compartmentalisation of PKA type II (PKA II) regulatory subunits. In the present study, we determined to what degree cAMP signalling in Xenopus melanotrophs depends on compartmentalised PKA II. For this purpose, a membrane-permeable stearated form of Ht31 (St-Ht31), which dislodges PKA II from AKAP (thus disrupting PKA II signalling), was used. The effect of St-Ht31 on both secretion of radiolabelled peptides and intracellular Ca(2+) signalling by superfused Xenopus melanotrophs was assessed. St-Ht31 stimulated secretion but had no effect on Ca(2+) signalling. We conclude Xenopus melanotrophs possess a St-Ht31-sensitive PKA II that is associated with the exocytosis machinery and, furthermore, that Ca(2+) signalling is regulated by an AKAP-independent signalling system. Moreover, our results support a recent proposal that AKAP participates in regulating PKA activity independently from cAMP.
Collapse
Affiliation(s)
- G J H Corstens
- Department of Cellular Animal Physiology, Institute for Neuroscience, Radboud University Nijmegen, the Netherlands
| | | | | | | | | |
Collapse
|
53
|
Stoppel C, Albrecht A, Pape HC, Stork O. Genes and neurons: molecular insights to fear and anxiety. GENES BRAIN AND BEHAVIOR 2006; 5 Suppl 2:34-47. [PMID: 16681799 DOI: 10.1111/j.1601-183x.2006.00229.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Experimental animal models provide an important tool for the identification of inheritable components of fear and anxiety. 'Pavlovian' fear conditioning has been tremendously successful to characterize the neuronal circuitry and cellular mechanisms of the formation, consolidation and extinction of fear memories. Here we summarize recent progress that has led to the identification of gene products contributing to such experience-dependent changes in fear and anxiety and may guide the search for genetic factors involved in the development and treatment of human anxiety disorders.
Collapse
Affiliation(s)
- C Stoppel
- Institute of Physiology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | | | | | | |
Collapse
|
54
|
Lin HC, Mao SC, Gean PW. Effects of intra-amygdala infusion of CB1 receptor agonists on the reconsolidation of fear-potentiated startle. Learn Mem 2006; 13:316-21. [PMID: 16705137 PMCID: PMC1475812 DOI: 10.1101/lm.217006] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Accepted: 02/16/2006] [Indexed: 11/25/2022]
Abstract
The cannabinoid CB1 receptor has been shown to be critically involved in the extinction of fear memory. Systemic injection of a CB1 receptor antagonist prior to extinction training blocked extinction. Conversely, administration of the cannabinoid uptake inhibitor AM404 facilitated extinction in a dose-dependent manner. Here we show that bilateral infusion of CB1 receptor agonists into the amygdala after memory reactivation blocked reconsolidation of fear memory measured with fear-potentiated startle. The effect was dose-dependent and could be blocked by AM251, a specific CB1 receptor antagonist. In contrast, the effect of CB1 agonists on reconsolidation was no longer seen if memory reactivation was omitted. Concomitant with block of reconsolidation, CB1 agonist-treated animals did not exhibit shock-induced reinstatement or spontaneous recovery of fear. The absence of recovery was not attributable to permanent damage to the amygdala in WIN-treated rats, nor did the effect result from alteration of baseline startle or shock reactivity. These results suggest that CB1 agonists could impair fear memory via blocking reconsolidation.
Collapse
MESH Headings
- Amygdala/drug effects
- Amygdala/metabolism
- Analysis of Variance
- Animals
- Arachidonic Acids/administration & dosage
- Association Learning/drug effects
- Association Learning/physiology
- Benzoxazines
- Cannabinoids/administration & dosage
- Cannabinoids/agonists
- Cannabinoids/antagonists & inhibitors
- Cannabinoids/metabolism
- Conditioning, Classical/drug effects
- Conditioning, Classical/physiology
- Dose-Response Relationship, Drug
- Dronabinol/administration & dosage
- Dronabinol/analogs & derivatives
- Extinction, Psychological/drug effects
- Extinction, Psychological/physiology
- Fear/drug effects
- Fear/physiology
- Memory/drug effects
- Memory/physiology
- Microinjections
- Morpholines/administration & dosage
- Naphthalenes/administration & dosage
- Piperidines/administration & dosage
- Pyrazoles/administration & dosage
- Rats
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB1/metabolism
- Reflex, Startle/drug effects
- Reflex, Startle/physiology
Collapse
Affiliation(s)
- Hui-Ching Lin
- Institute of Basic Medical Sciences and Department of Pharmacology, National Cheng-Kung University, Tainan, Taiwan.
| | | | | |
Collapse
|
55
|
Hu JY, Wu F, Schacher S. Two signaling pathways regulate the expression and secretion of a neuropeptide required for long-term facilitation in Aplysia. J Neurosci 2006; 26:1026-35. [PMID: 16421322 PMCID: PMC6675361 DOI: 10.1523/jneurosci.4258-05.2006] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Activation of several signaling pathways contributes to long-term synaptic plasticity, but how brief stimuli produce coordinated activation of these pathways is not understood. In Aplysia, the long-term facilitation (LTF) of sensory neuron synapses by 5-hydroxytryptamine (serotonin; 5-HT) requires the activation of several kinases, including mitogen-activated protein kinase (MAPK). The 5-HT-enhanced secretion of the sensory neuron-specific neuropeptide sensorin mediates the activation of MAPK. We find that stimulus-induced activation of two signaling pathways, phosphoinositide 3-kinase (PI3K) and type II protein kinase A (PKA), regulate sensorin secretion and responses. Treatment with 5-HT produces a rapid increase in sensorin synthesis, especially at varicosities, which precedes the secretion of sensorin. PI3K inhibitor and rapamycin block LTF and the rapid synthesis of sensorin at varicosities even in the absence of sensory neuron cell bodies. Secretion of the newly synthesized sensorin from the varicosities and activation of the autocrine responses of sensorin to produce LTF require type II PKA interaction with AKAPs (A-kinase anchoring proteins). Thus, long-term synaptic plasticity is produced when multiple signaling pathways that are important for regulating distinct cellular functions are activated in a specific sequence and recruit the secretion of a neuropeptide to activate additional critical pathways.
Collapse
Affiliation(s)
- Jiang-Yuan Hu
- Center for Neurobiology and Behavior, Columbia University College of Physicians and Surgeons, New York State Psychiatric Institute, New York, New York 10032, USA
| | | | | |
Collapse
|
56
|
Yeh SH, Mao SC, Lin HC, Gean PW. Synaptic Expression of Glutamate Receptor after Encoding of Fear Memory in the Rat Amygdala. Mol Pharmacol 2005; 69:299-308. [PMID: 16219906 DOI: 10.1124/mol.105.017194] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Fear conditioning has been ascribed to presynaptic mechanisms, particularly presynaptic facilitation of transmission at thalamo- and cortico-amygdala synapses. Here, by labeling surface receptors with biotin or using membrane fractionation approaches, we report that fear conditioning resulted in an increase in surface expression of GluR1 subunit of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors in the amygdala, whereas total GluR1 mRNA and protein levels were unchanged. The control group that received conditioned stimulus (CS) and unconditioned stimulus in an unpaired fashion did not present any increase, indicating that GluR1 increase was specific to the learning component of the task. Conditioning-induced increase in surface expression of GluR1 depended on the activation of N-methyl-d-aspartate receptors and protein kinases and required the synthesis of new proteins. CS-alone trials applied 24 h before training attenuated fear-potentiated startle and prevented conditioning-induced increase in surface expression of GluR1. Increase in GluR1 was also observed in the amygdala slices after delivery of tetanic stimulation that elicited long-term potentiation of synaptic transmission. Proteasome inhibitor increased surface expression of GluR1 in a time- and dose-dependent manner. Furthermore, pretraining administration of proteasome inhibitor into the amygdala facilitated the fear-potentiated startle. These results suggest that long-term memory formation is correlated with the change in synaptic expression of GluR1, and trafficking of GluR1 to the synaptic sites contributes at least in part to the expression of fear memory.
Collapse
Affiliation(s)
- Shiu-Hwa Yeh
- Department of Pharmacology, College of Medicine, National Cheng-Kung University, Tainan, Taiwan
| | | | | | | |
Collapse
|
57
|
Bogoyevitch MA, Barr RK, Ketterman AJ. Peptide inhibitors of protein kinases-discovery, characterisation and use. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1754:79-99. [PMID: 16182621 DOI: 10.1016/j.bbapap.2005.07.025] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2005] [Revised: 07/26/2005] [Accepted: 07/28/2005] [Indexed: 12/20/2022]
Abstract
Protein kinases are now the second largest group of drug targets, and most protein kinase inhibitors in clinical development are directed towards the ATP-binding site. However, these inhibitors must compete with high intracellular ATP concentrations and they must discriminate between the ATP-binding sites of all protein kinases as well the other proteins that also utilise ATP. It would therefore be beneficial to target sites on protein kinases other than the ATP-binding site. This review describes the discovery, characterisation and use of peptide inhibitors of protein kinases. In many cases, the development of these peptides has resulted from an understanding of the specific protein-binding partners for a particular protein kinase. In addition, novel peptide sequences have been discovered in library screening approaches and have provided new leads in the discovery and/or design of peptide inhibitors of protein kinases. These approaches are therefore providing exciting new opportunities in the development of ATP non-competitive inhibitors of protein kinases.
Collapse
Affiliation(s)
- Marie A Bogoyevitch
- Cell Signalling Laboratory, Biochemistry and Molecular Biology (M310), School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
| | | | | |
Collapse
|
58
|
Parada CA, Reichling DB, Levine JD. Chronic hyperalgesic priming in the rat involves a novel interaction between cAMP and PKCepsilon second messenger pathways. Pain 2005; 113:185-90. [PMID: 15621379 DOI: 10.1016/j.pain.2004.10.021] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2004] [Revised: 10/13/2004] [Accepted: 10/14/2004] [Indexed: 11/20/2022]
Abstract
Toward the goal of defining new pharmacological targets for the treatment of chronic pain conditions, in previous studies we established a model, termed 'hyperalgesic priming,' in which an acute inflammatory stimulus causes a long-lasting latent susceptibility to hyperalgesia induced by subsequent exposures to the inflammatory mediator, prostaglandin E2 (PGE2). Those investigations suggested the hypothesis that priming induces a novel linkage between the PGE2-activated second messenger cascade and the epsilon isoform of protein kinase C (PKCepsilon). In the present study, comparison of dose-response relations for hyperalgesia produced by PGE2, forskolin, 8-Br-cAMP, or the protein kinase A (PKA) catalytic subunit, in primed versus normal animals, demonstrated that priming-induced enhancement of the PGE2-activated second messenger cascade occurs downstream to adenylate cyclase and upstream to PKA. Therefore, PGE2-induced hyperalgesia in the primed animal is enhanced by the recruitment of a novel cAMP/PKCepsilon signaling pathway in addition to the usual cAMP/PKA pathway. These observations suggest that pharmacological disruption of the novel interaction between cAMP and PKCepsilon might provide a route toward the development of highly specific methods to reverse cellular processes that underlie chronic pain states.
Collapse
Affiliation(s)
- C A Parada
- Department of Oral and Maxillofacial Surgery, and Program in Neuroscience, University of California, San Francisco, CA 94143-0440, USA
| | | | | |
Collapse
|
59
|
Snyder EM, Colledge M, Crozier RA, Chen WS, Scott JD, Bear MF. Role for A kinase-anchoring proteins (AKAPS) in glutamate receptor trafficking and long term synaptic depression. J Biol Chem 2005; 280:16962-16968. [PMID: 15718245 PMCID: PMC3923403 DOI: 10.1074/jbc.m409693200] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Expression of N-methyl d-aspartate (NMDA) receptor-dependent homosynaptic long term depression at synapses in the hippocampus and neocortex requires the persistent dephosphorylation of postsynaptic protein kinase A substrates. An attractive mechanism for expression of long term depression is the loss of surface AMPA (alpha-amino-3-hydroxy-5-methylisoxazale-4-propionate) receptors at synapses. Here we show that a threshold level of NMDA receptor activation must be exceeded to trigger a stable loss of AMPA receptors from the surface of cultured hippocampal neurons. NMDA also causes displacement of protein kinase A from the synapse, and inhibiting protein kinase A (PKA) activity mimics the NMDA-induced loss of surface AMPA receptors. PKA is targeted to the synapse by an interaction with the A kinase-anchoring protein, AKAP79/150. Disruption of the PKA-AKAP interaction is sufficient to cause a long-lasting reduction in synaptic AMPA receptors in cultured neurons. In addition, we demonstrate in hippocampal slices that displacement of PKA from AKADs occludes synaptically induced long term depression. These data indicate that synaptic anchoring of PKA through association with AKAPs plays an important role in the regulation of AMPA receptor surface expression and synaptic plasticity.
Collapse
Affiliation(s)
- Eric M. Snyder
- Howard Hughes Medical Institute, The Picower Center for Learning and Memory and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Marcie Colledge
- Howard Hughes Medical Institute, Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239
| | - Robert A. Crozier
- Howard Hughes Medical Institute, The Picower Center for Learning and Memory and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Wendy S. Chen
- Howard Hughes Medical Institute, The Picower Center for Learning and Memory and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - John D. Scott
- Howard Hughes Medical Institute, Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239
| | - Mark F. Bear
- Howard Hughes Medical Institute, The Picower Center for Learning and Memory and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- To whom correspondence should be addressed: MIT, E19–551, 77 Massachusetts Ave., Cambridge, MA 02139. Tel.: 617-324-7002; Fax: 617-324-7007;
| |
Collapse
|
60
|
Malkani S, Wallace KJ, Donley MP, Rosen JB. An egr-1 (zif268) antisense oligodeoxynucleotide infused into the amygdala disrupts fear conditioning. Learn Mem 2004; 11:617-24. [PMID: 15466317 PMCID: PMC523081 DOI: 10.1101/lm.73104] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2003] [Accepted: 06/29/2004] [Indexed: 11/25/2022]
Abstract
Studies of gene expression following fear conditioning have demonstrated that the inducible transcription factor, egr-1, is increased in the lateral nucleus of the amygdala shortly following fear conditioning. These studies suggest that egr-1 and its protein product Egr-1 in the amygdala are important for learning and memory of fear. To directly test this hypothesis, an egr-1 antisense oligodeoxynucleotide (antisense-ODN) was injected bilaterally into the amygdala prior to contextual fear conditioning. The antisense-ODN reduced Egr-1 protein in the amygdala and interfered with fear conditioning. A 250-pmole dose produced an 11% decrease in Egr-1 protein and reduced long-term memory of fear as measured by freezing in a retention test 24 h after conditioning, but left shock-induced freezing intact. A larger 500-pmole dose produced a 25% reduction in Egr-1 protein and significantly decreased both freezing immediately following conditioning and freezing in the retention test. A nonsense-ODN had no effect on postshock or retention test freezing. In addition, 500 pmole of antisense-ODN infused prior to the retention test in previously trained rats did not reduce freezing, indicating that antisense-ODN did not suppress conditioned fear behavior. Finally, rats infused with 500 pmole of antisense-ODN displayed unconditioned fear to a predator odor, demonstrating that unconditioned freezing was unaffected by the antisense-ODN. The data indicate that the egr-1 antisense-ODN interferes with learning and memory processes of fear without affecting freezing behavior and suggests that the inducible transcription factor Egr-1 within the amygdala plays important functions in long-term learning and memory of fear.
Collapse
Affiliation(s)
- Seema Malkani
- Program in Behavioral Neuroscience, Department of Psychology, University of Delaware, Newark, Delaware 19716, USA
| | | | | | | |
Collapse
|
61
|
Rodrigues SM, Schafe GE, LeDoux JE. Molecular Mechanisms Underlying Emotional Learning and Memory in the Lateral Amygdala. Neuron 2004; 44:75-91. [PMID: 15450161 DOI: 10.1016/j.neuron.2004.09.014] [Citation(s) in RCA: 355] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fear conditioning is a valuable behavioral paradigm for studying the neural basis of emotional learning and memory. The lateral nucleus of the amygdala (LA) is a crucial site of neural changes that occur during fear conditioning. Pharmacological manipulations of the LA, strategically timed with respect to training and testing, have shed light on the molecular events that mediate the acquisition of fear associations and the formation and maintenance of long-term memories of those associations. Similar mechanisms have been found to underlie long-term potentiation (LTP) in LA, an artificial means of inducing synaptic plasticity and a physiological model of learning and memory. Thus, LTP-like changes in synaptic plasticity may underlie fear conditioning. Given that the neural circuit underlying fear conditioning has been implicated in emotional disorders in humans, the molecular mechanisms of fear conditioning are potential targets for psychotherapeutic drug development.
Collapse
|
62
|
Mucignat-Caretta C, Caretta A. Regional variations in the localization of insoluble kinase A regulatory isoforms during rodent brain development. J Chem Neuroanat 2004; 27:201-12. [PMID: 15183205 DOI: 10.1016/j.jchemneu.2004.03.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2003] [Revised: 02/05/2004] [Accepted: 03/05/2004] [Indexed: 10/26/2022]
Abstract
In eukaryothes, the second messenger cAMP regulates many cellular functions by binding to the regulatory subunits of cAMP-dependent protein kinases, and releasing the catalytic subunits. In the mammalian brain all four regulatory isoforms (RIalpha and beta, RIIalpha and beta) are present. Apparently, they are simple inhibitors of the catalytic subunits. It is still unclear why four isoforms are needed, but possibly they can target kinase activity at precise intracellular locations. Therefore, we examined the distribution of the insoluble regulatory isoforms in rat and mouse brains during prenatal (from embryonic day 8) and postnatal development up to senescence (13 months), via immunohistochemistry. RIIalpha labelling is always restricted to the ventricular ependyma. Punctated RIIbeta labelling is observed in the embryo from early stages of development, and is mainly localized in the cortical plate. After birth, punctate RIIbeta labelling is present throughout almost the whole brain, often observed in proximity of neurofilaments. It shows different characteristics and relationships to the other isoforms: for example in the CA1 hippocampal field, RIIbeta is substituted by RIalpha 2 weeks after birth, while in CA2 it persists for life. In other regions, as in the reticular formation, RIIbeta and RIalpha aggregates are found in the same cell, although clearly segregated. The different regulatory isoforms show distinct patterns of distribution that change consistently during development. A careful characterization of second messenger systems may be as useful as the study of neurotransmitters to understand neuronal properties and their modifications during development, so as to relate biochemical to functional properties.
Collapse
Affiliation(s)
- Carla Mucignat-Caretta
- Department of Human Anatomy and Physiology, University of Padua, Via Marzolo 3, 35131 Padua, Italy.
| | | |
Collapse
|
63
|
Mucignat-Caretta C, Bondi' M, Caretta A. Animal models of depression: olfactory lesions affect amygdala, subventricular zone, and aggression. Neurobiol Dis 2004; 16:386-95. [PMID: 15193295 DOI: 10.1016/j.nbd.2004.03.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2003] [Revised: 02/27/2004] [Accepted: 03/05/2004] [Indexed: 10/26/2022] Open
Abstract
Psychiatric or depressed patients show alterations in both olfactory projection areas and mucosa. In rodents, ablation of olfactory bulbs causes a depression-like syndrome, useful to test antidepressant agents. We studied in mice the behavioral symptoms and neuroanatomical correlates after mucosal damage or ablation of the olfactory bulb. Our results are based on a battery of tests exploiting anxious, aggressive, and depressive behavior, on morphological and immunohistochemical analysis. We found similar results in both sensory-damaged and bulbectomized animals, with a behavioral dissociation concerning different forms of aggression. These findings do not support a simple downregulation of social interactions in damaged mice. The most prominent modifications in the brains of sensory damaged and bulbectomized mice are detected in the subventricular zone (SVZ), the source area of neural stem cells, and in the content of cAMP-dependent protein kinase within the amygdala, suggesting a central role of this structure in the functional modulation of behavior.
Collapse
|
64
|
Stork O, Zhdanov A, Kudersky A, Yoshikawa T, Obata K, Pape HC. Neuronal functions of the novel serine/threonine kinase Ndr2. J Biol Chem 2004; 279:45773-81. [PMID: 15308672 DOI: 10.1074/jbc.m403552200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We have identified a novel member of the Ndr subfamily of serine/threonine protein kinases, Ndr2, as a gene product that is induced in the mouse amygdala during fear memory consolidation and examined a possible function of this kinase in neural differentiation. Expression of Ndr2 mRNA was detected in various cortical and subcortical brain regions, as well as non-neuronal tissues. Its expression in the amygdala was increased 6 h after Pavlovian fear conditioning training and returned to control levels within 24 h. To study intracellular localization and functions of Ndr2, EGFP::Ndr2 fusion proteins were expressed in rat pheochromocytoma (PC12) cells and acutely isolated cortical neurons, thereby revealing an association of Ndr2 with the actin cytoskeleton in somata, neurites and filopodia, in spines and at sites of cell contact. Co-precipitation and pull-down experiments support this finding. Evidence for an involvement of Ndr2 in actin-mediated cellular functions further comes from the observation of decreased cell spreading and changes in neurite outgrowth that were associated with protein serine phosphorylation in transfected PC12 cells. Together, our data suggest that Ndr2 is an interesting candidate gene for the regulation of structural processes in differentiating and mature neuronal cells.
Collapse
Affiliation(s)
- Oliver Stork
- Institute of Physiology, Otto-von-Guericke University Magdeburg, D-39120 Magdeburg, Germany.
| | | | | | | | | | | |
Collapse
|
65
|
O'Connor V, Genin A, Davis S, Karishma KK, Doyère V, De Zeeuw CI, Sanger G, Hunt SP, Richter-Levin G, Mallet J, Laroche S, Bliss TVP, French PJ. Differential Amplification of Intron-containing Transcripts Reveals Long Term Potentiation-associated Up-regulation of Specific Pde10A Phosphodiesterase Splice Variants. J Biol Chem 2004; 279:15841-9. [PMID: 14752115 DOI: 10.1074/jbc.m312500200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We employed differential display of expressed mRNAs (Liang, P., and Pardee, A. B. (1992) Science 257, 967-971) to identify genes up-regulated after long term potentiation (LTP) induction in the hippocampus of awake adult rats. In situ hybridization confirmed the differential expression of five independently amplified clones representing two distinct transcripts, cl13/19/90 and cl95/96. Neither cl13/19/90 nor cl95/96 showed significant sequence homology to known transcripts (mRNA or expressed sequence tag) or to the mouse or human genome. However, comparison with the rat genome revealed that they are localized to a predicted intron of the phosphodiesterase Pde10A gene. cl13/19/90 and cl95/96 are likely to be part of the Pde10A primary transcript as, using reverse transcriptase-PCR, we could specifically amplify distinct introns of the Pde10A primary transcript, and in situ hybridization demonstrated that a subset of Pde10A splice variants are also up-regulated after LTP induction. These results indicate that amplification of a primary transcript can faithfully report gene activity and that differential display can be used to identify differential expression of RNA species other than mRNA. In transiently transfected Cos7 cells, Pde10A3 reduces the atrial natriuretic peptide-induced elevation in cGMP levels without affecting basal cGMP levels. This cellular function of LTP-associated Pde10A transcripts argues for a role of the cGMP/cGMP-dependent kinase pathway in long term synaptic plasticity.
Collapse
Affiliation(s)
- Vincent O'Connor
- School of Biological Sciences, University of Southampton, Southampton SO16 7PX, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
66
|
Alto NM, Scott JD. The role of A-kinase anchoring proteins in cAMP-mediated signal transduction pathways. Cell Biochem Biophys 2004. [DOI: 10.1007/bf02739024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
67
|
Affiliation(s)
- Raphael Lamprecht
- Center for Neural Science, New York University, 4 Washington Place, New York, New York 10003, USA
| | | |
Collapse
|
68
|
Affiliation(s)
- Graeme K Carnegie
- Howard Hughes Medical Institute, Vollum Institute, Oregon Health and Sciences University, Portland, Oregon 97201, USA
| | | |
Collapse
|
69
|
Alto NM, Soderling SH, Hoshi N, Langeberg LK, Fayos R, Jennings PA, Scott JD. Bioinformatic design of A-kinase anchoring protein-in silico: a potent and selective peptide antagonist of type II protein kinase A anchoring. Proc Natl Acad Sci U S A 2003; 100:4445-50. [PMID: 12672969 PMCID: PMC153575 DOI: 10.1073/pnas.0330734100] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Compartmentalization of the cAMP-dependent protein kinase (PKA) is coordinated through association with A-kinase anchoring proteins (AKAPs). A defining characteristic of most AKAPs is a 14- to 18-aa sequence that binds to the regulatory subunits (RI or RII) of the kinase. Cellular delivery of peptides to these regions disrupts PKA anchoring and has been used to delineate a physiological role for AKAPs in the facilitation of certain cAMP-responsive events. Here, we describe a bioinformatic approach that yields an RII-selective peptide, called AKAP-in silico (AKAP-IS), that binds RII with a K(d) of 0.4 nM and binds RI with a K(d) of 277 nM. AKAP-IS associates with the type II PKA holoenzyme inside cells and displaces the kinase from natural anchoring sites. Electrophysiological recordings indicate that perfusion of AKAP-IS evokes a more rapid and complete attenuation of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor currents than previously described anchoring inhibitor peptides. Thus, computer-based and peptide array screening approaches have generated a reagent that binds PKA with higher affinity than previously described AKAPs.
Collapse
Affiliation(s)
- Neal M Alto
- Howard Hughes Medical Institute, Vollum Institute, Oregon Health and Science University, Portland OR 97239, USA
| | | | | | | | | | | | | |
Collapse
|
70
|
Esteban JA, Shi SH, Wilson C, Nuriya M, Huganir RL, Malinow R. PKA phosphorylation of AMPA receptor subunits controls synaptic trafficking underlying plasticity. Nat Neurosci 2003; 6:136-43. [PMID: 12536214 DOI: 10.1038/nn997] [Citation(s) in RCA: 667] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2002] [Accepted: 12/12/2002] [Indexed: 11/09/2022]
Abstract
The regulated incorporation of AMPA receptors into synapses is important for synaptic plasticity. Here we examine the role of protein kinase A (PKA) in this process. We found that PKA phosphorylation of the AMPA receptor subunits GluR4 and GluR1 directly controlled the synaptic incorporation of AMPA receptors in organotypic slices from rat hippocampus. Activity-driven PKA phosphorylation of GluR4 was necessary and sufficient to relieve a retention interaction and drive receptors into synapses. In contrast, PKA phosphorylation of GluR1 and the activity of calcium/calmodulin-dependent kinase II (CaMKII) were both necessary for receptor incorporation. Thus, PKA phosphorylation of AMPA receptor subunits contributes to diverse mechanisms underlying synaptic plasticity.
Collapse
Affiliation(s)
- José A Esteban
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA.
| | | | | | | | | | | |
Collapse
|
71
|
Moita MA, Lamprecht R, Nader K, LeDoux JE. Erratum: A-kinase anchoring proteins in amygdala are involved in auditory fear memory. Nat Neurosci 2002. [DOI: 10.1038/nn1002-1017d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|