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Murugaiyan SM, Bhargavan R. Bacopa monnieri alleviates aluminium chloride-induced anxiety by regulating plasma corticosterone level in Wistar rats. J Basic Clin Physiol Pharmacol 2020; 32:/j/jbcpp.ahead-of-print/jbcpp-2019-0379/jbcpp-2019-0379.xml. [PMID: 32651984 DOI: 10.1515/jbcpp-2019-0379] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 05/15/2020] [Indexed: 01/21/2023]
Abstract
Objectives Aluminium is present in food preparations, antacids and many medications. It causes neurodegeneration thereby resulting in a spectrum of neurological disorders such as dementia, Alzheimer's disease and anxiety. Bacopa monnieri (BM) is widely used in ayurvedic medicine to improve memory functions. Its anxiolytic property was investigated in this study by using elevated plus maze (EPM) and plasma corticosterone level. Methods Thirty rats were assigned into five groups. Control group received distilled water, and 0.5% tween 80, AlCl3 group received Aluminium Chloride (AlCl3), Protective groups (BM100 + AlCl3 group and BM200 + AlCl3 group) received AlCl3 and BM at two different doses, and the BM200 group received BM. The EPM experiment was performed at the end of the 4th week of oral administration of BM and AlCl3 followed by the measurement of plasma corticosterone. Results Oral administration of AlCl3 to rats increases the levels of anxiety as seen in a decrease in the percentage of entries into the open arms of EPM, an increase in grooming frequency and defecation index. However, the rats in the protective groups shown an increase in the percentage of open arm entries and rearing frequency, and decreased grooming frequency and defecation index. AlCl3 alone treated group showed a significant increase in the plasma corticosterone levels compared to the control group. Whereas the protective groups have shown a significant decrease in the plasma corticosterone levels than the AlCl3 alone treated group. Conclusions Hence the BM has potential role in reverting the anxiogenic effect of AlCl3 in the amygdala as it is evident from the plasma corticosterone levels and the EPM parameters of different groups under study.
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Affiliation(s)
- Senthil Murugan Murugaiyan
- Department of Anatomy, Bharath Institute of Higher Education and Research (BIHER), Deemed to be University, Chennai, India
- Department of Anatomy, All India Institute of Medical Sciences, Mangalagiri, Andhra Pradesh, India
| | - Rajesh Bhargavan
- Department of Anatomy, Sri Lakshmi Narayana Institute of Medical Sciences, Pondicherry, Affiliated to Bharath Institute of Higher Education and Research (BIHER), Deemed to be University, Chennai, India
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Chronic stress exacerbates neuropathic pain via the integration of stress-affect-related information with nociceptive information in the central nucleus of the amygdala. Pain 2017; 158:717-739. [PMID: 28225710 DOI: 10.1097/j.pain.0000000000000827] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Exacerbation of pain by chronic stress and comorbidity of pain with stress-related psychiatric disorders, including anxiety and depression, represent significant clinical challenges. However, the underlying mechanisms still remain unclear. Here, we investigated whether chronic forced swim stress (CFSS)-induced exacerbation of neuropathic pain is mediated by the integration of stress-affect-related information with nociceptive information in the central nucleus of the amygdala (CeA). We first demonstrated that CFSS indeed produces both depressive-like behaviors and exacerbation of spared nerve injury (SNI)-induced mechanical allodynia in rats. Moreover, we revealed that CFSS induces both sensitization of basolateral amygdala (BLA) neurons and augmentation of long-term potentiation (LTP) at the BLA-CeA synapse and meanwhile, exaggerates both SNI-induced sensitization of CeA neurons and LTP at the parabrachial (PB)-CeA synapse. In addition, we discovered that CFSS elevates SNI-induced functional up-regulation of GluN2B-containing NMDA (GluN2B-NMDA) receptors in the CeA, which is proved to be necessary for CFSS-induced augmentation of LTP at the PB-CeA synapse and exacerbation of pain hypersensitivity in SNI rats. Suppression of CFSS-elicited depressive-like behaviors by antidepressants imipramine or ifenprodil inhibits the CFSS-induced exacerbation of neuropathic pain. Collectively, our findings suggest that CFSS potentiates synaptic efficiency of the BLA-CeA pathway, leading to the activation of GluN2B-NMDA receptors and sensitization of CeA neurons, which subsequently facilitate pain-related synaptic plasticity of the PB-CeA pathway, thereby exacerbating SNI-induced neuropathic pain. We conclude that chronic stress exacerbates neuropathic pain via the integration of stress-affect-related information with nociceptive information in the CeA.
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Stress-Induced Reinstatement of Nicotine Preference Requires Dynorphin/Kappa Opioid Activity in the Basolateral Amygdala. J Neurosci 2017; 36:9937-48. [PMID: 27656031 DOI: 10.1523/jneurosci.0953-16.2016] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 08/05/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED The dynorphin (DYN)/kappa-opioid receptor (KOR) system plays a conserved role in stress-induced reinstatement of drug seeking for prototypical substances of abuse. Due to nicotine's high propensity for stress-induced relapse, we hypothesized that stress would induce reinstatement of nicotine seeking-like behavior in a KOR-dependent manner. Using a conditioned place preference (CPP) reinstatement procedure in mice, we show that both foot-shock stress and the pharmacological stressor yohimbine (2 mg/kg, i.p.) induce reinstatement of nicotine CPP in a norbinaltorphimine (norBNI, a KOR antagonist)-sensitive manner, indicating that KOR activity is necessary for stress-induced nicotine CPP reinstatement. After reinstatement testing, we visualized robust c-fos expression in the basolateral amygdala (BLA), which was reduced in mice pretreated with norBNI. We then used several distinct but complementary approaches of locally disrupting BLA KOR activity to assess the role of KORs and KOR-coupled intracellular signaling cascades on reinstatement of nicotine CPP. norBNI injected locally into the BLA prevented yohimbine-induced nicotine CPP reinstatement without affecting CPP acquisition. Similarly, selective deletion of BLA KORs in KOR conditional knock-out mice prevented foot-shock-induced CPP reinstatement. Together, these findings strongly implicate BLA KORs in stress-induced nicotine seeking-like behavior. In addition, we found that chemogenetic activation of Gαi signaling within CaMKIIα BLA neurons was sufficient to induce nicotine CPP reinstatement, identifying an anatomically specific intracellular mechanism by which stress leads to reinstatement. Considered together, our findings suggest that activation of the DYN/KOR system and Gαi signaling within the BLA is both necessary and sufficient to produce reinstatement of nicotine preference. SIGNIFICANCE STATEMENT Considering the major impact of nicotine use on human health, understanding the mechanisms by which stress triggers reinstatement of drug-seeking behaviors is particularly pertinent to nicotine. The dynorphin (DYN)/kappa-opioid receptor (KOR) system has been implicated in stress-induced reinstatement of drug seeking for other commonly abused drugs. However, the specific role, brain region, and mechanisms that this system plays in reinstatement of nicotine seeking has not been characterized. Here, we report region-specific engagement of the DYN/KOR system and subsequent activation of inhibitory (Gi-linked) intracellular signaling pathways within the basolateral amygdala during stress-induced reinstatement of nicotine preference. We show that the DYN/KOR system is necessary to produce this behavioral state. This work may provide novel insight for the development of therapeutic approaches to prevent stress-related nicotine relapse.
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McCall JG, Siuda ER, Bhatti DL, Lawson LA, McElligott ZA, Stuber GD, Bruchas MR. Locus coeruleus to basolateral amygdala noradrenergic projections promote anxiety-like behavior. eLife 2017; 6. [PMID: 28708061 PMCID: PMC5550275 DOI: 10.7554/elife.18247] [Citation(s) in RCA: 177] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 07/13/2017] [Indexed: 01/01/2023] Open
Abstract
Increased tonic activity of locus coeruleus noradrenergic (LC-NE) neurons induces anxiety-like and aversive behavior. While some information is known about the afferent circuitry that endogenously drives this neural activity and behavior, the downstream receptors and anatomical projections that mediate these acute risk aversive behavioral states via the LC-NE system remain unresolved. Here we use a combination of retrograde tracing, fast-scan cyclic voltammetry, electrophysiology, and in vivo optogenetics with localized pharmacology to identify neural substrates downstream of increased tonic LC-NE activity in mice. We demonstrate that photostimulation of LC-NE fibers in the BLA evokes norepinephrine release in the basolateral amygdala (BLA), alters BLA neuronal activity, conditions aversion, and increases anxiety-like behavior. Additionally, we report that β-adrenergic receptors mediate the anxiety-like phenotype of increased NE release in the BLA. These studies begin to illustrate how the complex efferent system of the LC-NE system selectively mediates behavior through distinct receptor and projection-selective mechanisms. DOI:http://dx.doi.org/10.7554/eLife.18247.001
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Affiliation(s)
- Jordan G McCall
- Department of Anesthesiology, Division of Basic Research, Washington University School of Medicine, St. Louis, United States.,Washington University Pain Center, Washington University School of Medicine, St. Louis, United States.,Department of Neuroscience, Washington University School of Medicine, St. Louis, United States.,Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, United States
| | - Edward R Siuda
- Department of Anesthesiology, Division of Basic Research, Washington University School of Medicine, St. Louis, United States.,Washington University Pain Center, Washington University School of Medicine, St. Louis, United States.,Department of Neuroscience, Washington University School of Medicine, St. Louis, United States.,Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, United States
| | - Dionnet L Bhatti
- Department of Anesthesiology, Division of Basic Research, Washington University School of Medicine, St. Louis, United States.,Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, United States
| | - Lamley A Lawson
- Department of Anesthesiology, Division of Basic Research, Washington University School of Medicine, St. Louis, United States
| | - Zoe A McElligott
- Department of Psychiatry, University of North Carolina, Chapel Hill, United States.,Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, United States
| | - Garret D Stuber
- Department of Psychiatry, University of North Carolina, Chapel Hill, United States.,Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, United States.,Neuroscience Center, University of North Carolina, Chapel Hill, United States
| | - Michael R Bruchas
- Department of Anesthesiology, Division of Basic Research, Washington University School of Medicine, St. Louis, United States.,Washington University Pain Center, Washington University School of Medicine, St. Louis, United States.,Department of Neuroscience, Washington University School of Medicine, St. Louis, United States.,Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, United States.,Department of Biomedical Engineering, Washington University, St. Louis, United States
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Effect of diazepam and yohimbine on neuronal activity in sham and hemiparkinsonian rats. Neuroscience 2017; 351:71-83. [DOI: 10.1016/j.neuroscience.2017.03.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 03/20/2017] [Accepted: 03/25/2017] [Indexed: 11/21/2022]
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Song Y, Liu J, Ma F, Mao L. Diazepam reduces excitability of amygdala and further influences auditory cortex following sodium salicylate treatment in rats. Acta Otolaryngol 2016; 136:1220-1224. [PMID: 27388640 DOI: 10.1080/00016489.2016.1204664] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
CONCLUSION Diazepam can reduce the excitability of lateral amygdala and eventually suppress the excitability of the auditory cortex in rats following salicylate treatment, indicating the regulating effect of lateral amygdala to the auditory cortex in the tinnitus procedure. OBJECTIVE To study the spontaneous firing rates (SFR) of the auditory cortex and lateral amygdala regulated by diazepam in the tinnitus rat model induced by sodium salicylate. MATERIALS AND METHODS This study first created a tinnitus rat modal induced by sodium salicylate, and recorded SFR of both auditory cortex and lateral amygdala. Then diazepam was intraperitoneally injected and the SFR changes of lateral amygdala recorded. Finally, diazepam was microinjected on lateral amygdala and the SFR changes of the auditory cortex recorded. RESULTS Both SFRs of the auditory cortex and lateral amygdala increased after salicylate treatment. SFR of lateral amygdala decreased after intraperitoneal injection of diazepam. Microinjecting diazepam to lateral amygdala decreased SFR of the auditory cortex ipsilaterally and contralaterally.
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Bashiri H, Rezayof A, Sahebgharani M, Tavangar SM, Zarrindast MR. Modulatory effects of the basolateral amygdala α2-adrenoceptors on nicotine-induced anxiogenic-like behaviours of rats in the elevated plus maze. Neuropharmacology 2016; 105:478-486. [PMID: 26878830 DOI: 10.1016/j.neuropharm.2016.02.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 02/04/2016] [Accepted: 02/09/2016] [Indexed: 11/25/2022]
Abstract
The present study was designed to clarify whether α2-adrenoceptors of the basolateral amygdala (BLA) are involved in nicotine-induced anxiogenic-like behaviours. Adult male Wistar rats were bilaterally cannulated in the BLA and anxiety-like behaviours were assessed in an elevated plus maze (EPM) task. Systemic intraperitoneal (i.p.) administration of nicotine (0.3, 0.5 and 0.7 mg/kg) dose-dependently decreased open arm time (%OAT) and open arm entry (%OAE), indicating the anxiogenic-like effect of nicotine. The activation of the BLA α2-adrenoceptors by the injection of α2-receptor agonist, clonidine (0.1, 0.3 and 0.5 μg/rat) into the BLA (intra-BLA) reversed nicotine-induced anxiogenic-like behaviours. It is important to note that intra-BLA injection of a higher dose of clonidine (0.5 μg/rat) by itself increased %OAT, but not %OAE which showed an anxiolytic effect of the agonist. On the other hand, intra-BLA injection of different doses of α2-adrenoceptor antagonist, yohimbine (1, 3 and 5 μg/rat) in combination with an ineffective dose of nicotine (0.3 mg/kg) decreased %OAT and %OAE, suggesting a potentiative effect of the antagonist on nicotine response. In addition, intra-BLA injection of the same doses of yohimbine did not alter %OAT and %OAE. Interestingly, intra-BLA injection of yohimbine (0.5 and 1 μg/rat) significantly reversed the inhibitory effect of clonidine on nicotine-induced anxiogenic-like behaviours. It should be considered that the drug treatments had no effect on locomotor activity in all experiments. Taken together, it can be concluded that nicotine produces anxiogenic-like behaviours which may be mediated through the BLA α2-adrenoceptor mechanism.
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Affiliation(s)
- Hamideh Bashiri
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ameneh Rezayof
- Department of Animal Biology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran
| | - Mousa Sahebgharani
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed Mohammad Tavangar
- Department of Pathology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad-Reza Zarrindast
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran; School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran; Institute of Cognitive Science Studies (ICSS), Tehran, Iran.
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Belujon P, Grace AA. Regulation of dopamine system responsivity and its adaptive and pathological response to stress. Proc Biol Sci 2015; 282:rspb.2014.2516. [PMID: 25788601 DOI: 10.1098/rspb.2014.2516] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Although, historically, the norepinephrine system has attracted the majority of attention in the study of the stress response, the dopamine system has also been consistently implicated. It has long been established that stress plays a crucial role in the pathogenesis of psychiatric disorders. However, the neurobiological mechanisms that mediate the stress response and its effect in psychiatric diseases are not well understood. The dopamine system can play distinct roles in stress and psychiatric disorders. It is hypothesized that, even though the dopamine (DA) system forms the basis for a number of psychiatric disorders, the pathology is likely to originate in the afferent structures that are inducing dysregulation of the DA system. This review explores the current knowledge of afferent modulation of the stress/DA circuitry, and presents recent data focusing on the effect of stress on the DA system and its relevance to psychiatric disorders.
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Affiliation(s)
- Pauline Belujon
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
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Sandusky LA, Flint RW, McNay EC. Elevated glucose metabolism in the amygdala during an inhibitory avoidance task. Behav Brain Res 2013; 245:83-7. [PMID: 23416236 DOI: 10.1016/j.bbr.2013.02.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 01/31/2013] [Accepted: 02/05/2013] [Indexed: 12/14/2022]
Abstract
There is a long-standing debate as to whether the memory process of consolidation is neurochemically similar to or the same as the set of processes involved in retrieval and reconsolidation of that memory. In addition, although we have previously shown that initial memory processing in the hippocampus causes a drainage of hippocampal glucose because of increased local metabolic demand, it is unknown what metabolic changes occur elsewhere in the brain or during subsequent processing of a previously consolidated memory. Male Sprague Dawley rats (3 months old) were implanted with unilateral microdialysis cannulae and in vivo microdialysis of amygdala extracellular fluid (ECF) was performed during both (i) initial learning and (ii) retrieval 24 h later of an aversively motivated avoidance memory task. ECF samples were analyzed for glucose, lactate, pyruvate and glutamate. Results showed close similarity between increases in local glycolysis seen during both consolidation and retrieval, but also suggested that there may perhaps be a difference in amygdalar oxidative phosphorylation stimulated by the two processes. Hence, our data suggest that memory formation places similar metabolic demands across neural systems, and that consolidation may be metabolically different from retrieval.
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Affiliation(s)
- Leslie A Sandusky
- State University of New York at Albany, Behavioral Neuroscience and Center for Neuroscience Research, Albany, NY, USA.
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Hu P, Fan J, Xu P, Zhou S, Zhang L, Tian Y, Wang K. Attention network impairments in patients with focal frontal or parietal lesions. Neurosci Lett 2013; 534:177-81. [PMID: 23295902 DOI: 10.1016/j.neulet.2012.12.038] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 12/19/2012] [Accepted: 12/20/2012] [Indexed: 11/18/2022]
Abstract
Recently, research on attention has focused on 3 networks that are linked to separate brain regions, i.e. orienting, alerting, and executive control. The attention network test (ANT) is one of the methods to measure the three attention functions. However, neuropsychological investigations have not examined the anatomical disassociation of different attention networks with the same task. We compared the efficiencies of the 3 networks between brain-damaged patients (27 frontal lesions, 20 temporal lesions, and 21 parietal lesions) and healthy controls (N=58) with ANT. Comparing the brain damaged group with the normal controls, a reduced efficiency of the executive network was found in patients with frontal lobe and parietal lobe injuries, and there was also a deficit in the orienting network in patients with parietal lobe injuries. Analysis of lateralization indicated the right hemisphere superiority to the alerting system. The present study found that the three attentional networks were selectively impaired following brain damage which affected different areas in the brain.
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Affiliation(s)
- Panpan Hu
- Laboratory of Neuropsychology, Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, PR China
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Zhang J, Muller JF, McDonald AJ. Noradrenergic innervation of pyramidal cells in the rat basolateral amygdala. Neuroscience 2013; 228:395-408. [PMID: 23103792 PMCID: PMC4586037 DOI: 10.1016/j.neuroscience.2012.10.035] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 10/16/2012] [Accepted: 10/16/2012] [Indexed: 11/26/2022]
Abstract
The basolateral nuclear complex of the amygdala (BLC) receives dense noradrenergic/norepinephrine (NE) inputs from the locus coeruleus that play a key role in modulating emotional memory consolidation. Knowledge of the extent of synapse formation by NE inputs to the BLC, as well as the cell types innervated, would contribute to an understanding of how NE modulates the activity of the BLC. To gain a better understanding of NE circuits in the BLC, dual-label immunohistochemistry was used at the light and electron microscopic levels in the present study to analyze NE axons and their innervation of pyramidal cells in the anterior subdivision of the basolateral amygdalar nucleus (BLa). NE axons and BLa pyramidal cells were labeled using antibodies to the norepinephrine transporter (NET) and Ca(2+)/calmodulin-dependent protein kinase (CaMK), respectively. Dual localization studies using antibodies to NET and dopamine-beta-hydroxylase (DBH) revealed that virtually all NE axons and varicosities expressed both proteins. The BLa exhibited a medium density of NET+ fibers. Ultrastructural analysis of serial section reconstructions of NET+ axons revealed that only about half of NET+ terminals formed synapses. The main postsynaptic targets were small-caliber CAMK+ dendritic shafts and spines of pyramidal cells. A smaller number of NET+ terminals formed synapses with unlabeled cell bodies and dendrites. These findings indicate that the distal dendritic domain of BLa pyramidal cells is the major target of NE terminals in the BLa, and the relatively low synaptic incidence suggests that diffusion from non-synaptic terminals may be important for noradrenergic modulation of the BLa.
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Affiliation(s)
- Jingyi Zhang
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC 29208
| | - Jay F. Muller
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC 29208
| | - Alexander J. McDonald
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC 29208
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Li Z, Richter-Levin G. Stimulus intensity-dependent modulations of hippocampal long-term potentiation by basolateral amygdala priming. Front Cell Neurosci 2012; 6:21. [PMID: 22586371 PMCID: PMC3343647 DOI: 10.3389/fncel.2012.00021] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 04/17/2012] [Indexed: 01/12/2023] Open
Abstract
There is growing realization that the relationship between memory and stress/emotionality is complicated, and may include both memory enhancing and memory impairing aspects. It has been suggested that the underlying mechanisms involve amygdala modulation of hippocampal synaptic plasticity, such as long-term potentiation (LTP). We recently reported that while in CA1 basolateral amygdala (BLA) priming impaired theta stimulation induced LTP, it enhanced LTP in the dentate gyrus (DG). However, emotional and stressfull experiences were found to activate synaptic plasticity within the BLA, raising the possibility that BLA modulation of other brain regions may be altered as well, as it may depend on the way the BLA is activated or is responding. In previous studies BLA priming stimulation was relatively weak (1 V, 50 μs pulse duration). In the present study we assessed the effects of two stronger levels of BLA priming stimulation (1 V or 2 V, 100 μs pulse duration) on LTP induction in hippocampal DG and CA1, in anesthetized rats. Results show that 1V-BLA priming stimulation enhanced but 2V-BLA priming stimulation impaired DG LTP; however, both levels of BLA priming stimulation impaired CA1 LTP, suggesting that modulation of hippocampal synaptic plasticity by amygdala is dependent on the degree of amygdala activation. These findings suggest that plasticity-induced within the amygdala, by stressful experiences induces a form of metaplasticity that would alter the way the amygdala may modulate memory-related processes in other brain areas, such as the hippocampus.
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Affiliation(s)
- Zexuan Li
- Institute for the Study of Affective Neuroscience, University of Haifa Haifa, Israel
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Buffalari DM, See RE. Inactivation of the bed nucleus of the stria terminalis in an animal model of relapse: effects on conditioned cue-induced reinstatement and its enhancement by yohimbine. Psychopharmacology (Berl) 2011; 213:19-27. [PMID: 20827461 PMCID: PMC3132192 DOI: 10.1007/s00213-010-2008-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Accepted: 08/21/2010] [Indexed: 02/03/2023]
Abstract
RATIONALE Drug-associated cues and stress increase craving and lead to greater risk of relapse in abstinent drug users. Animal models of reinstatement of drug seeking have been utilized to study the neural circuitry by which either drug-associated cues or stress exposure elicit drug seeking. Recent evidence has shown a strong enhancing effect of yohimbine stress on subsequent cue-elicited reinstatement; however, there has been no examination of the neural substrates of this interactive effect. OBJECTIVES The current study examined whether inactivation of the bed nucleus of the stria terminalis (BNST), an area previously implicated in stress activation of drug seeking, would affect reinstatement of cocaine seeking caused by conditioned cues, yohimbine stress, or the combination of these factors. METHODS Male rats experienced daily IV cocaine self-administration, followed by extinction of lever responding in the absence of cocaine-paired cues. Reinstatement of responding was measured during presentation of cocaine-paired cues, following pretreatment with the pharmacological stressor, yohimbine (2.5 mg/kg, IP), or the combination of cues and yohimbine. RESULTS All three conditions led to reinstatement of cocaine seeking, with the highest responding seen after the combination of cues and yohimbine. Reversible inactivation of the BNST using the gamma-aminobutyric acid receptor agonists, baclofen + muscimol, significantly reduced all three forms of reinstatement. CONCLUSION These results demonstrate a role for the BNST in cocaine seeking elicited by cocaine-paired cues, and suggest the BNST as a key mediator for the interaction of stress and cues for the reinstatement of cocaine seeking.
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Affiliation(s)
- Deanne M. Buffalari
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Ronald E. See
- Department of Neurosciences, Medical University of South Carolina, BSB416B, 173 Ashley Avenue, Charleston, SC 29425, USA
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