51
|
Activation of hippocampal nitric oxide and calcium/calmodulin-dependent protein kinase II in response to Morris water maze learning in rats. Pharmacol Biochem Behav 2008; 92:260-6. [PMID: 19135080 DOI: 10.1016/j.pbb.2008.12.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 12/01/2008] [Accepted: 12/08/2008] [Indexed: 11/23/2022]
Abstract
This study investigates the interactive roles of nitric oxide (NO) and CaM-kinase II (calcium/calmodulin-dependent protein kinase II) in Morris water maze learning. In Experiment I, experimental rats received 5 days of training on a Morris water maze, where the controls were trained in the water maze with no spatial cue condition or were trained via a visually guided landmark condition. The experimental rats showed improvement in their rate of spatial learning in the water maze. The escape latencies were significantly correlated with the Ca2+-independent activity of the hippocampal CaM-kinase II. Moreover, there was a significant increase in the endogenous phosphorylation of neuronal NOS and CaM-kinase II in the experimental group when compared to the controls. The intra-hippocampal infusion of 7-NI, KN-93, or AP5 did disrupt water maze learning. SDS-PAGE analysis showed that these drugs significantly depressed phosphorylation of hippocampal NOS. The Ca2+-independent activity of hippocampal CaM-kinase II was significantly lower in the KN-93 or the AP5 infused group when compared to the controls. Although these depressed activities were not reversed by the infusion of NO donor (sodium nitroprusside, SNP), the rats' water maze learning behavior were ameliorated significantly. These results, taken together, indicate that the NOS activation is essential for water maze learning, which may be triggered via the CaM-kinase II activation in hippocampus.
Collapse
|
52
|
Ota KT, Pierre VJ, Ploski JE, Queen K, Schafe GE. The NO-cGMP-PKG signaling pathway regulates synaptic plasticity and fear memory consolidation in the lateral amygdala via activation of ERK/MAP kinase. Learn Mem 2008; 15:792-805. [PMID: 18832566 DOI: 10.1101/lm.1114808] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Recent studies have shown that nitric oxide (NO) signaling plays a crucial role in memory consolidation of Pavlovian fear conditioning and in synaptic plasticity in the lateral amygdala (LA). In the present experiments, we examined the role of the cGMP-dependent protein kinase (PKG), a downstream effector of NO, in fear memory consolidation and long-term potentiation (LTP) at thalamic and cortical input pathways to the LA. In behavioral experiments, rats given intra-LA infusions of either the PKG inhibitor Rp-8-Br-PET-cGMPS or the PKG activator 8-Br-cGMP exhibited dose-dependent impairments or enhancements of fear memory consolidation, respectively. In slice electrophysiology experiments, bath application of Rp-8-Br-PET-cGMPS or the guanylyl cyclase inhibitor LY83583 impaired LTP at thalamic, but not cortical inputs to the LA, while bath application of 8-Br-cGMP or the guanylyl cyclase activator YC-1 resulted in enhanced LTP at thalamic inputs to the LA. Interestingly, YC-1-induced enhancement of LTP in the LA was reversed by concurrent application of the MEK inhibitor U0126, suggesting that the NO-cGMP-PKG signaling pathway may promote synaptic plasticity and fear memory formation in the LA, in part by activating the ERK/MAPK signaling cascade. As a test of this hypothesis, we next showed that rats given intra-LA infusion of the PKG inhibitor Rp-8-Br-PET-cGMPS or the PKG activator 8-Br-cGMP exhibit impaired or enhanced activation, respectively, of ERK/MAPK in the LA after fear conditioning. Collectively, our findings suggest that an NO-cGMP-PKG-dependent form of synaptic plasticity at thalamic input synapses to the LA may underlie memory consolidation of Pavlovian fear conditioning, in part, via activation of the ERK/MAPK signaling cascade.
Collapse
Affiliation(s)
- Kristie T Ota
- Department of Psychology, Yale University, New Haven, Connecticut 06520, USA
| | | | | | | | | |
Collapse
|
53
|
Abu-Ghanem Y, Cohen H, Buskila Y, Grauer E, Amitai Y. Enhanced stress reactivity in nitric oxide synthase type 2 mutant mice: Findings in support of astrocytic nitrosative modulation of behavior. Neuroscience 2008; 156:257-65. [DOI: 10.1016/j.neuroscience.2008.07.043] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 07/15/2008] [Accepted: 07/23/2008] [Indexed: 11/28/2022]
|
54
|
Chien WL, Liang KC, Fu WM. Enhancement of active shuttle avoidance response by the NO-cGMP-PKG activator YC-1. Eur J Pharmacol 2008; 590:233-40. [PMID: 18590724 DOI: 10.1016/j.ejphar.2008.06.040] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 05/23/2008] [Accepted: 06/08/2008] [Indexed: 10/21/2022]
Abstract
Although much has been learned about the role of the amygdala in Pavlovian fear conditioning, relatively little is known about the signaling pathway involved in the acquisition of an active avoidance reaction. The aim of this study is to investigate the potentiating effects of the NO-guanylate cyclase activator YC-1 on learning and memory of shuttle avoidance test in rats. YC-1 enhanced the induction of long-term potentiation (LTP) in amygdala through NO-cGMP-PKG-ERK pathway and the increase of BDNF expression. The Western blot and PCR methods were used to examine the signaling pathways involved in fear memory. It was found that YC-1 increased the avoidance responses during learning period and the memory retention lasted longer than one week. The enhancement of learning behavior by YC-1 was antagonized by intracerebroventricular injection of NOS inhibitor l-NAME, PKG inhibitor Rp-8-Br-PET-cGMPS and MEK inhibitor PD98059, indicating that NO-cGMP-PKG and ERK pathways are involved in the learning potentiating action of YC-1. In addition, YC-1 increased the activation of ERK and Akt 30 min after Day-1 training in amygdala. YC-1 also potentiated the expression of BDNF and CREB in response to fear memory test. Taken together, these findings suggest that NO-cGMP-PKG-ERK signaling pathway is involved in the action of YC-1 in enhancing the fear memory.
Collapse
Affiliation(s)
- Wei-Lin Chien
- Pharmacological Institute, College of Medicine, National Taiwan University, Taipei, Taiwan
| | | | | |
Collapse
|
55
|
Baratti CM, Boccia MM, Blake MG, Acosta GB. Reactivated memory of an inhibitory avoidance response in mice is sensitive to a nitric oxide synthase inhibitor. Neurobiol Learn Mem 2008; 89:426-40. [DOI: 10.1016/j.nlm.2007.11.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2007] [Revised: 11/08/2007] [Accepted: 11/09/2007] [Indexed: 10/22/2022]
|
56
|
Individual differences predict susceptibility to conditioned fear arising from psychosocial trauma. J Psychiatr Res 2008; 42:371-83. [PMID: 17449061 DOI: 10.1016/j.jpsychires.2007.01.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Revised: 01/30/2007] [Accepted: 01/31/2007] [Indexed: 11/16/2022]
Abstract
BACKGROUND Classical Pavlovian fear conditioning has been widely used in preclinical studies to gain insights into anxiety-related disorders. In this study we examined whether pre-existing behavioral differences, and/or behavioral differences displayed during fear induction, predict the severity of the conditioned fear response that can develop after an episode of psychosocial conflict. METHODS Prior to conditioning, male rats (intruders) were behaviorally assessed using the novel environment exploration and defensive burying tests. These animals were subsequently placed in the territory of an older male (resident) that invariably attacked the intruder. RESULTS Upon return to this territory 24 h later, intruders moved less than controls and produced more distress vocalizations, indicating conditioned fear to context. Additionally, analyses revealed that both pre-existing behavioral differences, and the animal's response during social conflict, predicted the magnitude of the subsequent conditioned fear response. Specifically, animals that engaged in higher levels of novel environment exploration, that exhibited a greater number of defensive burying behaviors, and that demonstrated higher levels of fighting and guarding during social conflict, displayed less evidence of conditioned fear. CONCLUSION These findings show that the behavioral variability existent within a normal outbred population can predict the magnitude of the conditioned fear response.
Collapse
|
57
|
Schafe GE, Swank MW, Rodrigues SM, Debiec J, Doyère V. Phosphorylation of ERK/MAP kinase is required for long-term potentiation in anatomically restricted regions of the lateral amygdala in vivo. Learn Mem 2008; 15:55-62. [PMID: 18230673 DOI: 10.1101/lm.746808] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We have previously shown that the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/ MAPK) is transiently activated in anatomically restricted regions of the lateral amygdala (LA) following Pavlovian fear conditioning and that blockade of ERK/MAPK activation in the LA impairs both fear memory consolidation and long-term potentiation (LTP) in the amygdala, in vitro. The present experiments evaluated the role of the ERK/MAPK signaling cascade in LTP at thalamo-LA input synapses, in vivo. We first show that ERK/MAPK is transiently activated/phosphorylated in the LA at 5 min, but not 15 or 60 min, after high-frequency, but not low-frequency, stimulation of the auditory thalamus. ERK activation induced by LTP-inducing stimulation was anatomically restricted to the same regions of the LA previously shown to exhibit ERK regulation following fear conditioning. We next show that intra-LA infusion of U0126, an inhibitor of ERK/MAPK activation, impairs LTP at thalamo-LA input synapses. Collectively, results demonstrate that ERK/MAPK activation is necessary for synaptic plasticity in anatomically defined regions of the LA, in vivo.
Collapse
Affiliation(s)
- Glenn E Schafe
- Department of Psychology and Interdepartmental Neuroscience Program, Yale University, New Haven, Connecticut 06520, USA.
| | | | | | | | | |
Collapse
|
58
|
Buskila Y, Abu-Ghanem Y, Levi Y, Moran A, Grauer E, Amitai Y. Enhanced astrocytic nitric oxide production and neuronal modifications in the neocortex of a NOS2 mutant mouse. PLoS One 2007; 2:e843. [PMID: 17786214 PMCID: PMC1952109 DOI: 10.1371/journal.pone.0000843] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Accepted: 08/13/2007] [Indexed: 11/19/2022] Open
Abstract
Background It has been well accepted that glial cells in the central nervous system (CNS) produce nitric oxide (NO) through the induction of a nitric oxide synthase isoform (NOS2) only in response to various insults. Recently we described rapid astroglial, NOS2-dependent, NO production in the neocortex of healthy mice on a time scale relevant to neuronal activity. To explore a possible role for astroglial NOS2 in normal brain function we investigated a NOS2 knockout mouse (B6;129P2-Nos2tm1Lau/J, Jackson Laboratory). Previous studies of this mouse strain revealed mainly altered immune responses, but no compensatory pathways and no CNS abnormalities have been reported. Methodology/Principal Findings To our surprise, using NO imaging in brain slices in combination with biochemical methods we uncovered robust NO production by neocortical astrocytes of the NOS2 mutant. These findings indicate the existence of an alternative pathway that increases basal NOS activity. In addition, the astroglial mutation instigated modifications of neuronal attributes, shown by changes in the membrane properties of pyramidal neurons, and revealed in distinct behavioral abnormalities characterized by an increase in stress-related parameters. Conclusions/Significance The results strongly indicate the involvement of astrocytic-derived NO in modifying the activity of neuronal networks. In addition, the findings corroborate data linking NO signaling with stress-related behavior, and highlight the potential use of this genetic model for studies of stress-susceptibility. Lastly, our results beg re-examination of previous studies that used this mouse strain to examine the pathophysiology of brain insults, assuming lack of astrocytic nitrosative reaction.
Collapse
Affiliation(s)
- Yossi Buskila
- Department of Physiology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
| | - Yasmin Abu-Ghanem
- Department of Physiology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
| | - Yifat Levi
- Department of Physiology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
| | - Arie Moran
- Department of Physiology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
| | - Ettie Grauer
- Department of Pharmacology, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Yael Amitai
- Department of Physiology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
- * To whom correspondence should be addressed. E-mail:
| |
Collapse
|
59
|
Barklamb K, Cassaday HJ. Rated salience of internal and external cues in cases of self-reported hunger and illness. Appetite 2007; 49:511-5. [PMID: 17482315 DOI: 10.1016/j.appet.2007.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2006] [Revised: 01/05/2007] [Accepted: 02/16/2007] [Indexed: 10/23/2022]
Abstract
An event contingent diary method compared the rated salience of ambient external and internal cues reported in association with instances of feeling hungry and ill, to test whether environmental and psychological factors might be differentially identified in conjunction with these states. In cases of hunger but not illness, external and internal events were equally salient cues. However, within the general category of external cues, for those feeling hungry, smells were rated more salient than sounds. Within the category of internal cues, in both cases of hunger and illness, cognitions were rated as more salient than moods. We consider Pavlovian conditioning as a mechanism for these effects.
Collapse
Affiliation(s)
- Kelly Barklamb
- School of Psychology, University of Nottingham, University Park, Nottingham, UK
| | | |
Collapse
|
60
|
Tan SE. Roles of hippocampal nitric oxide and calcium/calmodulin-dependent protein kinase II in inhibitory avoidance learning in rats. Behav Pharmacol 2007; 18:29-38. [PMID: 17218795 DOI: 10.1097/fbp.0b013e3280142636] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
This study investigated the interactive roles of nitric oxide and calcium/calmodulin-dependent protein kinase II in inhibitory avoidance learning. In Experiment I, rats were trained on a one-trial step-through inhibitory avoidance learning task, whereas the controls were trained in a noncontingent stimulus-pairing condition. The experimental rats showed significantly higher retention scores than the control rats. Correspondingly, the rats in the experimental group showed significantly higher Ca2+-independent activity of the hippocampal calcium/calmodulin-dependent protein kinase II and a significant increase in the endogenous phosphorylation of neuronal nitric oxide synthase. The intrahippocampal infusion of 7-nitro-indazole, 2-[N-(2-hidroxyethyl)-N-(4-methoxy-benzenesulfonyl)]-amino-N-(4-chlorocinnamyl)-N-methylbenzylamine, or 2-amino-5-phosphonopentanoic acid disrupted inhibitory avoidance learning. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed that these drugs significantly depressed phosphorylation of hippocampal nitric oxide synthase. The Ca2+-independent activity of hippocampal calcium/calmodulin-dependent protein kinase II was significantly lower in the 2-[N-(2-hidroxyethyl)-N-(4-methoxy-benzenesulfonyl)]-amino-N-(4-chlorocinnamyl)-N-methylbenzylamine or the 2-amino-5-phosphonopentanoic acid-infused group compared with the controls. Although these depressed activities were not reversed by the infusion of a nitric oxide donor (sodium nitroprusside), this did significantly improve the rats' inhibitory avoidance deficit. These results, taken together, indicate that the nitric oxide synthase activation is essential for inhibitory avoidance learning, which may be triggered via the calcium/calmodulin-dependent protein kinase II activation in the hippocampus.
Collapse
Affiliation(s)
- Soon-Eng Tan
- Department of Psychology, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China.
| |
Collapse
|
61
|
Rameau GA, Tukey DS, Garcin-Hosfield ED, Titcombe RF, Misra C, Khatri L, Getzoff ED, Ziff EB. Biphasic coupling of neuronal nitric oxide synthase phosphorylation to the NMDA receptor regulates AMPA receptor trafficking and neuronal cell death. J Neurosci 2007; 27:3445-55. [PMID: 17392461 PMCID: PMC6672118 DOI: 10.1523/jneurosci.4799-06.2007] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Postsynaptic nitric oxide (NO) production affects synaptic plasticity and neuronal cell death. Ca2+ fluxes through the NMDA receptor (NMDAR) stimulate the production of NO by neuronal nitric oxide synthase (nNOS). However, the mechanisms by which nNOS activity is regulated are poorly understood. We evaluated the effect of neuronal stimulation with glutamate on the phosphorylation of nNOS. We show that, in cortical neurons, a low glutamate concentration (30 microM) induces rapid and transient NMDAR-dependent phosphorylation of S1412 by Akt, followed by sustained phosphorylation of S847 by CaMKII (calcium-calmodulin-dependent kinase II). We demonstrate that phosphorylation of S1412 by Akt is necessary for activation of nNOS by the NMDAR. nNOS mutagenesis confirms that these phosphorylations respectively activate and inhibit nNOS and, thus, transiently activate NO production. A constitutively active (S1412D), but not a constitutively repressed (S847D) nNOS mutant elevated surface glutamate receptor 2 levels, demonstrating that these phosphorylations can control AMPA receptor trafficking via NO. Notably, an excitotoxic stimulus (150 microM glutamate) induced S1412, but not S847 phosphorylation, leading to deregulated nNOS activation. S1412D did not kill neurons; however, it enhanced the excitotoxicity of a concomitant glutamate stimulus. We propose a swinging domain model for the regulation of nNOS: S1412 phosphorylation facilitates electron flow within the reductase module of nNOS, increasing nNOS sensitivity to Ca2+-calmodulin. These findings suggest a critical role for a kinetically complex and novel series of regulatory nNOS phosphorylations induced by the NMDA receptor for the in vivo control of nNOS.
Collapse
Affiliation(s)
- Gerald A Rameau
- Department of Urology, Johns Hopkins School of Medicine, Baltimore, Maryland 21287, USA.
| | | | | | | | | | | | | | | |
Collapse
|
62
|
Albrecht D. Angiotensin-(1-7)-induced plasticity changes in the lateral amygdala are mediated by COX-2 and NO. Learn Mem 2007; 14:177-84. [PMID: 17351141 PMCID: PMC1838559 DOI: 10.1101/lm.425907] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
It is known from studies outside the brain that upon binding to its receptor, angiotensin-(1-7) elicits the release of prostanoids and nitric oxide (NO). Cyclooxygenase (COX) is a key enzyme that converts arachidonic acid to prostaglandins. Since there are no data available so far on the role of COX-2 in the amygdala, in a first step we demonstrated that the selective COX-2 inhibitor NS-398 significantly reduced the probability of long-term potentiation (LTP) induction in the lateral nucleus of the amygdala. Similarly, in COX-2(-/-) mice, LTP induced by external capsule (EC) stimulation was impaired. Second, we evaluated the action of angiotensin-(1-7) in the amygdala. In wild-type mice, angiotensin-(1-7) increased LTP. This LTP-enhancing effect of Ang-(1-7) was not observed in COX-2(+/-) mice. However, in COX-2(-/-) mice, Ang-(1-7) caused an enhancement of LTP similar to that in wild-type mice. The NO synthetase inhibitor L-NAME blocked this angiotensin-(1-7)-induced increase in LTP in COX-2(-/-) mice. Low-frequency stimulation of external capsule fibers did not cause long-term depression (LTD) in drug-free and angiotensin-(1-7)-treated brain slices in wild-type mice. In contrast, in COX-2(-/-) mice, angiotensin-(1-7) caused stable LTD. Increasing NO concentration by the NO-donor SNAP also caused LTD in wild-type mice. Our study shows for the first time that LTP in the amygdala is dependent on COX-2 activity. Moreover, COX-2 is involved in the mediation of angiotensin-(1-7) effects on LTP. Finally, it is recognized that there is a molecular cross-talk between COX-2 and NO that may regulate synaptic plasticity.
Collapse
Affiliation(s)
- Doris Albrecht
- Institute of Neurophysiology, Charité-Universitätsklinikum Berlin, Berlin, Germany.
| |
Collapse
|
63
|
Wultsch T, Chourbaji S, Fritzen S, Kittel S, Grünblatt E, Gerlach M, Gutknecht L, Chizat F, Golfier G, Schmitt A, Gass P, Lesch KP, Reif A. Behavioural and expressional phenotyping of nitric oxide synthase-I knockdown animals. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 2007:69-85. [PMID: 17982880 DOI: 10.1007/978-3-211-73574-9_10] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The gaseous messenger nitric oxide (NO) has been implicated in a wide range of behaviors, including aggression, anxiety, depression, and cognitive functioning. To further elucidate the physiological role of NO and its down-stream mechanisms, we conducted behavioral and expressional phenotyping of mice lacking the neuronal isoform of nitric oxide synthase (NOS-I), the major source of NO in the central nervous system. No differences were observed in activity-related parameters; in contrast to the a priori hypothesis, derived from pharmacological treatments, depression-related tests (Forced Swim Test, Learned Helplessness) also yielded no significantly different results. A subtle anxiolytic phenotype however was present, with knockdown mice displaying a higher open arm time as compared to their respective wildtypes, yet all other investigated anxiety-related parameters were unchanged. The most prominent feature however was gender-independent cognitive impairment in spatial learning and memory, as assessed by the Water Maze test and an automatized holeboard paradigm. No significant dysregulation of monoamine transporters was evidenced by qRT PCR. To further examine the underlying molecular mechanisms, the transcriptome of knockdown animals was thus examined in the hippocampus, striatum and cerebellum by microarray analysis. A set of >120 differentially expressed genes was identified, whereat the hippocampus and the striatum showed similar expressional profiles as compared to the cerebellum in hierarchical clustering. Among the most significantly up-regulated genes were Peroxiredoxon 3, Atonal homologue 1, Kcnj1, Kcnj8, CCAAT/enhancer binding protein (C/EBP), alpha, 3 genes involved in GABA(B) signalling and, intriguingly, the glucocorticoid receptor GR. While GABAergic genes might underlie reduced anxiety, dysregulation of the glucocorticoid receptor can well contribute to a blunted stress response as found in NOS1 knockdown mice. Furthermore, by CREB inhibition, glucocorticoid receptor upregulation could at least partially explain cognitive deficits in these animals. Taken together, NOS1 knockdown mice display a characteristic behavioural profile consisting of reduced anxiety and impaired learning and memory, paralleled by differential expression of the glucocorticoid receptor and GABAergic genes. Further research has to assess the value of these mice as animal models e.g. for Alzheimer's disease or attention deficit disorder, in order to clarify a possible pathophysiological role of NO therein.
Collapse
Affiliation(s)
- T Wultsch
- Molecular and Clinical Psychobiology, Department of Psychiatry and Psychotherapy, University of Würzburg, Würzburg, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
64
|
Bombardi C, Grandis A, Chiocchetti R, Lucchi ML. Distribution of calbindin-D28k, neuronal nitric oxide synthase, and nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) in the lateral nucleus of the sheep amygdaloid complex. ACTA ACUST UNITED AC 2006; 211:707-20. [PMID: 17047987 DOI: 10.1007/s00429-006-0133-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2006] [Indexed: 10/24/2022]
Abstract
This study describes calbindin-D28k (CB), neuronal nitric oxide synthase (nNOS), and nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) expression in the lateral nucleus of the sheep amygdaloid complex. Double immunofluorescence protocol was used in order to determine whether there is colocalization of CB and nNOS. The CB-immunoreactive (IR) neuronal population was composed especially of non-pyramidal neurons, but a few pyramidal cells were also present. The non-pyramidal neurons showed a multipolar and, occasionally, a fusiform morphology. The comparison between single-labeled CB-IR non-pyramidal neurons and cells belonging to CB-IR neuronal population showed they were identical for morphology, mean size, and distribution. The single-labeled CB-IR non-pyramidal neurons were only the 17.8% of the total non-pyramidal neurons counted. The nNOS-IR neuronal population was represented by non-pyramidal multipolar and fusiform neurons. Single-labeled nNOS-IR non-pyramidal neurons had the same morphology, mean area, and distribution as cells belonging to nNOS-IR neuronal population. Single-labeled nNOS-IR non-pyramidal neurons were more numerous than single-labeled CB-IR, and represented the 73.7% of total non-pyramidal neurons counted. NADPH-d-positive cells had the same morphology and distribution as the nNOS-IR neurons. Double immunolabeling (CB/nNOS) was found mostly in non-pyramidal multipolar neurons and only in a few non-pyramidal fusiform cells. These neurons had a mean perikaryal area significantly higher and significantly smaller than that of single-labeled nNOS and single-labeled CB-IR non-pyramidal neurons, respectively. CB and nNOS coexist only in a minority of non-pyramidal neurons (8.5%). The 32.4% of all CB-IR non-pyramidal neurons were nNOS-positive; only 10.4% of nNOS-IR non-pyramidal neurons were CB-positive. These results indicate that CB and nNOS are expressed by selective neurons and that the majority of nNOS-IR non-pyramidal neurons are lacking in CB.
Collapse
Affiliation(s)
- Cristiano Bombardi
- Department of Veterinary Morphophysiology and Animal Productions, Faculty of Veterinary Medicine, University of Bologna, Via Tolara di Sopra, 50, 40064, Ozzano dell'Emilia (BO), Italy.
| | | | | | | |
Collapse
|
65
|
Sato T, Suzuki E, Yokoyama M, Watanabe S, Miyaoka H. Auditory fear conditioning and conditioned stress raise NO(3) level in the Amygdala. Neuropsychobiology 2006; 53:142-7. [PMID: 16679778 DOI: 10.1159/000093100] [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] [Received: 10/25/2005] [Accepted: 03/02/2006] [Indexed: 11/19/2022]
Abstract
BACKGROUND The conditioned fear response is considered to be acquired by experimental animals when tone information is combined with that of an electrical foot shock (unconditioned stimulus) in the amygdala. Nitric oxide biosynthesized in the brain is reportedly involved in several kinds of learning. METHODS In this study, we continuously monitored the NO(3)(-) level, as a marker of nitric oxide production, in the amygdala starting before the application of tone and electrical foot shock stimuli together (conditioned group) or the tone stimulus alone (control group) on day 1, until after the tone information was given (both groups) on day 2, using the in vivo microdialysis method. RESULTS The NO(3)(-) level of the conditioned group was increased on both day 1 and day 2, while that of the control group was not elevated on either day. Freezing behavior was observed in the conditioned but not the control rats. CONCLUSIONS Although the sources of NO(3)(-) remain uncertain, these results suggest that nitric oxide is associated with auditory fear conditioning and the response to a conditioned stimulus.
Collapse
Affiliation(s)
- Taku Sato
- Department of Psychiatry, Kitasato University School of Medicine, Sagamihara, Japan
| | | | | | | | | |
Collapse
|
66
|
Kopec CD, Kessels HWHG, Bush DEA, Cain CK, LeDoux JE, Malinow R. A robust automated method to analyze rodent motion during fear conditioning. Neuropharmacology 2006; 52:228-33. [PMID: 16926033 DOI: 10.1016/j.neuropharm.2006.07.028] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Revised: 07/07/2006] [Accepted: 07/17/2006] [Indexed: 10/24/2022]
Abstract
A central question in the study of LTP has been to determine what role it plays in memory formation and storage. One valuable form of learning for addressing this issue is associative fear conditioning. In this paradigm an animal learns to associate a tone and shock, such that subsequent presentation of a tone evokes a fear response (freezing behavior). Recent studies indicate that overlapping cellular processes underlie fear conditioning and LTP. The fear response has generally been scored manually which is both labor-intensive and subject to potential artifacts such as inconsistent or biased results. Here we describe a simple automated method that provides unbiased and rapid analysis of animal motion. We show that measured motion, in units termed significant motion pixels (SMPs), is both linear and robust over a wide range of animal speeds and detection thresholds and scores freezing in a quantitatively similar manner to trained human observers. By comparing the frequency distribution of motion during baseline periods and to the response to fox urine (which causes unconditioned fear), we suggest that freezing and non-freezing are distinct behaviors. Finally, we show how this algorithm can be applied to a fear conditioning paradigm yielding information on long and short-term associative memory as well as habituation. This automated analysis of fear conditioning will permit a more rapid and accurate assessment of the role of LTP in memory.
Collapse
Affiliation(s)
- Charles D Kopec
- Cold Spring Harbor Laboratory, Jones Building, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA
| | | | | | | | | | | |
Collapse
|
67
|
Apergis-Schoute AM, Debiec J, Doyère V, LeDoux JE, Schafe GE. Auditory fear conditioning and long-term potentiation in the lateral amygdala require ERK/MAP kinase signaling in the auditory thalamus: a role for presynaptic plasticity in the fear system. J Neurosci 2006; 25:5730-9. [PMID: 15958739 PMCID: PMC6724884 DOI: 10.1523/jneurosci.0096-05.2005] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In the present study, we examined the role of the auditory thalamus [medial division of the medial geniculate nucleus and the adjacent posterior intralaminar nucleus (MGm/PIN)] in auditory pavlovian fear conditioning using pharmacological manipulation of intracellular signaling pathways. In the first experiment, rats were given intrathalamic infusions of the MEK (mitogen-activated protein kinase-kinase) inhibitor 1,4-diamino-2,3-dicyano-1,4-bis(o-aminophenylmercapto) butadiene (U0126) before fear conditioning. Findings revealed that long-term memory (assessed at 24 h) was impaired, whereas short-term memory (assessed at 1-3 h) of fear conditioning was intact. In the second experiment, rats received immediate posttraining intrathalamic infusion of U0126, the mRNA synthesis inhibitor 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB), or infusion of the protein synthesis inhibitor anisomycin. Posttraining infusion of either U0126 or DRB significantly impaired long-term retention of fear conditioning, whereas infusion of anisomycin had no effect. In the final experiment, rats received intrathalamic infusion of U0126 before long-term potentiation (LTP)-inducing stimulation of thalamic inputs to the lateral nucleus of the amygdala (LA). Findings revealed that thalamic infusion of U0126 impaired LTP in the LA. Together, these results suggest the possibility that MGm/PIN cells that project to the LA contribute to memory formation via ERK (extracellular signal-regulated kinase)-mediated transcription, but that they do so by promoting protein synthesis-dependent plasticity locally in the LA.
Collapse
Affiliation(s)
- Annemieke M Apergis-Schoute
- W. M. Keck Foundation Laboratory of Neurobiology, Center for Neural Science, New York University, New York, New York 10003, USA
| | | | | | | | | |
Collapse
|