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Tsui KC, Roy J, Chau SC, Wong KH, Shi L, Poon CH, Wang Y, Strekalova T, Aquili L, Chang RCC, Fung ML, Song YQ, Lim LW. Distribution and inter-regional relationship of amyloid-beta plaque deposition in a 5xFAD mouse model of Alzheimer’s disease. Front Aging Neurosci 2022; 14:964336. [PMID: 35966777 PMCID: PMC9371463 DOI: 10.3389/fnagi.2022.964336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 06/28/2022] [Indexed: 11/13/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common form of dementia. Although previous studies have selectively investigated the localization of amyloid-beta (Aβ) deposition in certain brain regions, a comprehensive characterization of the rostro-caudal distribution of Aβ plaques in the brain and their inter-regional correlation remain unexplored. Our results demonstrated remarkable working and spatial memory deficits in 9-month-old 5xFAD mice compared to wildtype mice. High Aβ plaque load was detected in the somatosensory cortex, piriform cortex, thalamus, and dorsal/ventral hippocampus; moderate levels of Aβ plaques were observed in the motor cortex, orbital cortex, visual cortex, and retrosplenial dysgranular cortex; and low levels of Aβ plaques were located in the amygdala, and the cerebellum; but no Aβ plaques were found in the hypothalamus, raphe nuclei, vestibular nucleus, and cuneate nucleus. Interestingly, the deposition of Aβ plaques was positively associated with brain inter-regions including the prefrontal cortex, somatosensory cortex, medial amygdala, thalamus, and the hippocampus. In conclusion, this study provides a comprehensive morphological profile of Aβ deposition in the brain and its inter-regional correlation. This suggests an association between Aβ plaque deposition and specific brain regions in AD pathogenesis.
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Affiliation(s)
- Ka Chun Tsui
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Jaydeep Roy
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Sze Chun Chau
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Kah Hui Wong
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Lei Shi
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Chi Him Poon
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Yingyi Wang
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Tatyana Strekalova
- Department of Neuroscience, Maastricht University, Maastricht, Netherlands
- Department of Normal Physiology and Laboratory of Psychiatric Neurobiology, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Luca Aquili
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Discipline of Psychology, College of Science, Health, Engineering, and Education, Murdoch University, Perth, WA, Australia
| | - Raymond Chuen-Chung Chang
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Man-Lung Fung
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- *Correspondence: Man-Lung Fung,
| | - You-qiang Song
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- You-qiang Song,
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Lee Wei Lim,
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Devos JVP, Temel Y, Ackermans L, Visser-Vandewalle V, Onur OA, Schruers K, Smit J, Janssen MLF. Methodological Considerations for Setting Up Deep Brain Stimulation Studies for New Indications. J Clin Med 2022; 11:jcm11030696. [PMID: 35160153 PMCID: PMC8836606 DOI: 10.3390/jcm11030696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 01/25/2022] [Accepted: 01/27/2022] [Indexed: 11/29/2022] Open
Abstract
Deep brain stimulation (DBS) is a neurosurgical treatment with a growing range of indications. The number of clinical studies is expanding because of DBS for new indications and efforts to improve DBS for existing indications. To date, various methods have been used to perform DBS studies. Designing a clinical intervention study with active implantable medical devices has specific challenges while expanding patient treatment. This paper provides an overview of the key aspects that are essential for setting up a DBS study.
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Affiliation(s)
- Jana V. P. Devos
- School for Mental Health and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands; (L.A.); (J.S.); (M.L.F.J.)
- Department of Ear, Nose, Throat, Head and Neck Surgery, Maastricht University Medical Center, Maastricht University, 6229 HX Maastricht, The Netherlands
- Correspondence: (J.V.P.D.); (Y.T.)
| | - Yasin Temel
- School for Mental Health and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands; (L.A.); (J.S.); (M.L.F.J.)
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht University, 6229 HX Maastricht, The Netherlands
- Correspondence: (J.V.P.D.); (Y.T.)
| | - Linda Ackermans
- School for Mental Health and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands; (L.A.); (J.S.); (M.L.F.J.)
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht University, 6229 HX Maastricht, The Netherlands
| | - Veerle Visser-Vandewalle
- Department of Stereotactic and Functional Neurosurgery, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50923 Cologne, Germany;
| | - Oezguer A. Onur
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50923 Cologne, Germany;
| | - Koen Schruers
- Department of Psychiatry and Neuropsychology, Maastricht University Medical Center, Maastricht University, 6229 HX Maastricht, The Netherlands;
| | - Jasper Smit
- School for Mental Health and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands; (L.A.); (J.S.); (M.L.F.J.)
- Department of Ear, Nose, Throat, Head and Neck Surgery, Zuyderland Medical Center, 6419 PC Heerlen, The Netherlands
| | - Marcus L. F. Janssen
- School for Mental Health and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands; (L.A.); (J.S.); (M.L.F.J.)
- Department of Clinical Neurophysiology, Maastricht University Medical Center, Maastricht University, 6229 HX Maastricht, The Netherlands
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Tan SZK, Temel Y, Chan AY, Mok ATC, Perucho JAU, Blokland A, Aquili L, Lim WL, Lim LW. Serotonergic treatment normalizes midbrain dopaminergic neuron increase after periaqueductal gray stimulation. Brain Struct Funct 2020; 225:1957-66. [PMID: 32594260 DOI: 10.1007/s00429-020-02102-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 06/15/2020] [Indexed: 12/23/2022]
Abstract
Electrical stimulation of the dorsolateral periaqueductal gray (dlPAG) in rats has been shown to elicit panic-like behaviour and can be a useful as an unconditioned stimulus for modelling anticipatory fear and agoraphobia in a contextual fear conditioning paradigm. In this study, we further analysed our previous data on the effects of escitalopram (a selective serotonin reuptake inhibitor, SSRI) and buspirone (a 5-HT1A receptor partial agonist) on dlPAG-induced anticipatory fear behaviour in a rat model using freezing as a measure. We then attempted to unravel some of the interactions with dopamine signalling using tyrosine hydroxylase (TH) immunohistochemistry to probe the effects on dopaminergic neurons. We showed that acute treatment of escitalopram, but not buspirone, was effective in reducing anticipatory freezing behaviour, while chronic administrations of both drugs were effective. We found that the dlPAG stimulation induced increase number of dopaminergic neurons in the ventral tegmental area (VTA) which was reversed in both chronic buspirone and escitalopram groups. We further found a strong positive correlation between the number of dopaminergic neurons and freezing in the VTA and showed positive correlations between dopaminergic neurons in the VTA and substantia nigra pars compacta (SNpc) in escitalopram and buspirone groups, respectively. Overall, we showed that chronic treatment with an SSRI and a 5-HT1A agonist reduced anticipatory freezing behaviour which seems to be associated, through correlative studies, with a reversal of dlPAG stimulation induced increase in number of dopaminergic neurons in the VTA and/or SNpc.
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Roet M, Pol S, Schaper FLWVJ, Hoogland G, Jahanshahi A, Temel Y. Severe seizures as a side effect of deep brain stimulation in the dorsal peduncular cortex in a rat model of depression. Epilepsy Behav 2019; 92:269-275. [PMID: 30731292 DOI: 10.1016/j.yebeh.2019.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/29/2018] [Accepted: 01/04/2019] [Indexed: 12/14/2022]
Abstract
Deep brain stimulation (DBS) has shown to have antidepressant effects in both human trials and animal studies. However, the optimal target and the underlying therapeutic mechanisms remain to be determined. In this study, we investigated if high frequency (HF) DBS in the dorsal peduncular cortex (DPC) alleviates depressive-like behavior in an experimental model of depression. Surprisingly, HF DBS in the DPC caused acute induction of seizures in ~40% of animals stimulated with clinically relevant stimulation parameters. Reducing the stimulation's amplitude by 50% did not alter seizure occurrence. Electroencephalographic (EEG) recordings showed seizures up to Racine stage IV lasting up to 4 min after cessation of stimulation. We conclude that HF DBS in the DPC is not suitable for mood-related experiments in rats but could be a potential model for seizure induction.
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Affiliation(s)
- Milaine Roet
- School for Mental Health and Neuroscience, Department of Neurosurgery, The Netherlands; School for Mental Health and Neuroscience, European Graduate School of Neuroscience (EURON), The Netherlands.
| | - Sylvana Pol
- School for Mental Health and Neuroscience, Department of Neurosurgery, The Netherlands; School for Mental Health and Neuroscience, European Graduate School of Neuroscience (EURON), The Netherlands
| | - Frédéric L W V J Schaper
- School for Mental Health and Neuroscience, Department of Neurosurgery, The Netherlands; School for Mental Health and Neuroscience, European Graduate School of Neuroscience (EURON), The Netherlands
| | - Govert Hoogland
- School for Mental Health and Neuroscience, Department of Neurosurgery, The Netherlands; School for Mental Health and Neuroscience, European Graduate School of Neuroscience (EURON), The Netherlands
| | - Ali Jahanshahi
- School for Mental Health and Neuroscience, Department of Neurosurgery, The Netherlands; School for Mental Health and Neuroscience, European Graduate School of Neuroscience (EURON), The Netherlands
| | - Yasin Temel
- School for Mental Health and Neuroscience, Department of Neurosurgery, The Netherlands; School for Mental Health and Neuroscience, European Graduate School of Neuroscience (EURON), The Netherlands.
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Wscieklica T, Silva MS, Lemes JA, Melo-Thomas L, Céspedes IC, Viana MB. Deep brain stimulation of the dorsal raphe inhibits avoidance and escape reactions and activates forebrain regions related to the modulation of anxiety/panic. Behav Brain Res 2017; 321:193-200. [DOI: 10.1016/j.bbr.2016.11.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 11/11/2016] [Accepted: 11/17/2016] [Indexed: 12/24/2022]
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Abstract
The technology of optogenetics provides a new method to modulate neural activity with spatial specificity and millisecond-temporal scale. This nonelectrical modulation method also gives chance for simultaneous electrophysiological recording during stimulations. Here, we describe our locomotor activity modulation on free-behaving rats using optogenetic techniques. The target sites of the rat brain were dorsal periaqueductal gray (dPAG) and ventral tegmental area (VTA) for the modulation of defensive and reward behaviors, respectively.
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Affiliation(s)
- Kedi Xu
- Qiushi Academy for Advanced Studies (QAAS), Zhejiang University, Hangzhou, 310027, China
- Department of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Education Ministry, Zhejiang University, Hangzhou, 310027, China
- Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Hangzhou, 310027, China
| | - Jiacheng Zhang
- Qiushi Academy for Advanced Studies (QAAS), Zhejiang University, Hangzhou, 310027, China
- Department of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Education Ministry, Zhejiang University, Hangzhou, 310027, China
- Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Hangzhou, 310027, China
| | - Songchao Guo
- Qiushi Academy for Advanced Studies (QAAS), Zhejiang University, Hangzhou, 310027, China
- Department of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Education Ministry, Zhejiang University, Hangzhou, 310027, China
- Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Hangzhou, 310027, China
| | - Xiaoxiang Zheng
- Qiushi Academy for Advanced Studies (QAAS), Zhejiang University, Hangzhou, 310027, China.
- Department of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Education Ministry, Zhejiang University, Hangzhou, 310027, China.
- Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Hangzhou, 310027, China.
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Lim LW, Prickaerts J, Huguet G, Kadar E, Hartung H, Sharp T, Temel Y. Electrical stimulation alleviates depressive-like behaviors of rats: investigation of brain targets and potential mechanisms. Transl Psychiatry 2015; 5:e535. [PMID: 25826110 DOI: 10.1038/tp.2015.24] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 01/16/2015] [Accepted: 01/20/2015] [Indexed: 02/06/2023] Open
Abstract
Deep brain stimulation (DBS) is a promising therapy for patients with refractory depression. However, key questions remain with regard to which brain target(s) should be used for stimulation, and which mechanisms underlie the therapeutic effects. Here, we investigated the effect of DBS, with low- and high-frequency stimulation (LFS, HFS), in different brain regions (ventromedial prefrontal cortex, vmPFC; cingulate cortex, Cg; nucleus accumbens (NAc) core or shell; lateral habenula, LHb; and ventral tegmental area) on a variety of depressive-like behaviors using rat models. In the naive animal study, we found that HFS of the Cg, vmPFC, NAc core and LHb reduced anxiety levels and increased motivation for food. In the chronic unpredictable stress model, there was a robust depressive-like behavioral phenotype. Moreover, vmPFC HFS, in a comparison of all stimulated targets, produced the most profound antidepressant effects with enhanced hedonia, reduced anxiety and decreased forced-swim immobility. In the following set of electrophysiological and histochemical experiments designed to unravel some of the underlying mechanisms, we found that vmPFC HFS evoked a specific modulation of the serotonergic neurons in the dorsal raphe nucleus (DRN), which have long been linked to mood. Finally, using a neuronal mapping approach by means of c-Fos expression, we found that vmPFC HFS modulated a brain circuit linked to the DRN and known to be involved in affect. In conclusion, HFS of the vmPFC produced the most potent antidepressant effects in naive rats and rats subjected to stress by mechanisms also including the DRN.
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Chen S, Zhou H, Guo S, Zhang J, Qu Y, Feng Z, Xu K, Zheng X. Optogenetics Based Rat-Robot Control: Optical Stimulation Encodes "Stop" and "Escape" Commands. Ann Biomed Eng 2015; 43:1851-64. [PMID: 25567506 DOI: 10.1007/s10439-014-1235-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Accepted: 12/19/2014] [Indexed: 12/15/2022]
Abstract
Electric brain stimulation is frequently used in bio-robot control. However, one possible limitation of electric stimulation is the resultant wide range of influences that may lead to unexpected side-effects. Although there has been prior research done towards optogenetics based brain activation, there has not been much development regarding the comparisons between electric and optical methods of brain activation. In this study, we first encode "Stop" and "Escape" commands by optical stimulation in the dorsal periaqueductal grey (dPAG). The rats behavioral comparisons are then noted down under these two methods. The dPAG neural activity recorded during optical stimulation suggests rate and temporal coding mechanisms in behavioral control. The behavioral comparisons show that rats exhibit anxiety under the "Stop" command conveyed through both optical and electric methods. However, rats are able to recover more quickly from freezing only under optical "Stop" command. Under "Escape" commands, also conveyed through optical means, the rat would move with lessened urgency but the results are more stable. Moreover, c-Fos study shows the optical stimulation activates restricted range in midbrain: the optical stimulation affected only dPAG and its downstreams but electric stimulation activates both the upstream and downstream circuits, in which the glutamatergic neurons are largely occupied and play important role in "Stop" and "Escape" behavior controls. We conclude that optical stimulation is more suited for encoding "Stop" and "Escape" commands for rat-robot control.
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Affiliation(s)
- SiCong Chen
- Department of Biomedical Engineering, Key Laboratory of Ministry of Education, Zhejiang University, Hangzhou, 310027, People's Republic of China
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Hestermann D, Temel Y, Blokland A, Lim LW. Acute serotonergic treatment changes the relation between anxiety and HPA-axis functioning and periaqueductal gray activation. Behav Brain Res 2014; 273:155-65. [DOI: 10.1016/j.bbr.2014.07.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 06/28/2014] [Accepted: 07/01/2014] [Indexed: 10/25/2022]
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Mickley GA, Ketchesin KD, Ramos L, Luchsinger JR, Rogers MM, Wiles NR, Hoxha N. Stimulation of the dorsal periaqueductal gray enhances spontaneous recovery of a conditioned taste aversion. Brain Res 2013. [PMID: 23183042 DOI: 10.1016/j.brainres.2012.11.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Due to its relevance to clinical practice, extinction of learned fears has been a major focus of recent research. However, less is known about the means by which conditioned fears re-emerge (i.e., spontaneously recover) as time passes or contexts change following extinction. The periaqueductal gray represents the final common pathway mediating defensive reactions to fear and we have reported previously that the dorsolateral PAG (dlPAG) exhibits a small but reliable increase in neural activity (as measured by c-fos protein immunoreactivity) when spontaneous recovery (SR) of a conditioned taste aversion (CTA) is reduced. Here we extend these correlational studies to determine if inducing dlPAG c-fos expression through electrical brain stimulation could cause a reduction in SR of a CTA. Male Sprague-Dawley rats acquired a strong aversion to saccharin (conditioned stimulus; CS) and then underwent CTA extinction through multiple non-reinforced exposures to the CS. Following a 30-day latency period after asymptotic extinction was achieved; rats either received stimulation of the dorsal PAG (dPAG) or stimulation of closely adjacent structures. Sixty minutes following the stimulation, rats were again presented with the saccharin solution as we tested for SR of the CTA. The brain stimulation evoked c-fos expression around the tip of the electrodes. However, stimulation of the dPAG failed to reduce SR of the previously extinguished CTA. In fact, dPAG stimulation caused rats to significantly suppress their saccharin drinking (relative to controls) - indicating an enhanced SR. These data refute a cause-and-effect relationship between enhanced dPAG c-fos expression and a reduction in SR. However, they highlight a role for the dPAG in modulating SR of extinguished CTAs.
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Affiliation(s)
- G Andrew Mickley
- The Neuroscience Program, Baldwin Wallace University, 275 Eastland Rd., Berea, OH 44017, USA.
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Temel Y, Blokland A, Lim LW. Deactivation of the parvalbumin-positive interneurons in the hippocampus after fear-like behaviour following electrical stimulation of the dorsolateral periaqueductal gray of rats. Behav Brain Res 2012; 233:322-5. [DOI: 10.1016/j.bbr.2012.05.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 05/11/2012] [Accepted: 05/16/2012] [Indexed: 11/28/2022]
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Ettrup K, Sørensen J, Rodell A, Alstrup A, Bjarkam C. Hypothalamic Deep Brain Stimulation Influences Autonomic and Limbic Circuitry Involved in the Regulation of Aggression and Cardiocerebrovascular Control in the Göttingen Minipig. Stereotact Funct Neurosurg 2012; 90:281-91. [DOI: 10.1159/000338087] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 02/29/2012] [Indexed: 11/19/2022]
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de Andrade JS, Abrão RO, Céspedes IC, Garcia MC, Nascimento JOG, Spadari-Bratfisch RC, Melo LL, da Silva RCB, Viana MB. Acute restraint differently alters defensive responses and fos immunoreactivity in the rat brain. Behav Brain Res 2012; 232:20-9. [PMID: 22487246 DOI: 10.1016/j.bbr.2012.03.034] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 03/21/2012] [Accepted: 03/23/2012] [Indexed: 11/30/2022]
Abstract
Results from a previous study show that rats exposed to acute restraint display anxiogenic-like behavior, evidenced by facilitation of avoidance responses in the elevated T-maze (ETM) model of anxiety. In contrast, escape responses were unaltered by stress exposure. Since ETM avoidance and escape tasks seem to activate distinct sets of brain structures, it is possible that the differences observed with acute restraint are due to particularities in the neurobiological mechanisms which modulate these responses. In the present study, analysis of fos protein immunoreactivity (fos-ir) was used to map areas activated by exposure of male Wistar rats to restraint stress (30 min) previously (30 min) to the ETM. Corticosterone levels were also measured in stressed and non-stressed animals. Confirming previous observations restraint facilitated avoidance performance, an anxiogenic result, while leaving escape unaltered. Performance of the avoidance task increased fos-ir in the frontal cortex, intermediate lateral septum, basolateral amygdala, basomedial amygdala, lateral amygdala, anterior hypothalamus and dorsal raphe nucleus. In contrast, performance of escape increased fos-ir in the ventromedial hypothalamus, dorsolateral periaqueductal gray and locus ceruleus. Both behavioral tasks also increased fos-ir in the dorsomedial hypothalamus. Restraint significantly raised corticosterone levels. Additionally after restraint, fos-ir was predominantly seen in the basolateral amygdala and dorsal raphe of animals submitted to the avoidance task. This data confirms that different sets of brain structures are activated by ETM avoidance and escape tasks and suggests that acute restraint differently alters ETM behavior and the pattern of fos activation in the brain.
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Affiliation(s)
- J S de Andrade
- Department of Biosciences, Federal University of São Paulo (UNIFESP), Santos, SP, Brazil
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Blokland A, ten Oever S, van Gorp D, van Draanen M, Schmidt T, Nguyen E, Krugliak A, Napoletano A, Keuter S, Klinkenberg I. The use of a test battery assessing affective behavior in rats: Order effects. Behav Brain Res 2012; 228:16-21. [DOI: 10.1016/j.bbr.2011.11.042] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 11/25/2011] [Accepted: 11/28/2011] [Indexed: 01/09/2023]
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16
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Broiz AC, Bassi GS, De Souza Silva MA, Brandão ML. Effects of neurokinin-1 and 3-receptor antagonists on the defensive behavior induced by electrical stimulation of the dorsal periaqueductal gray. Neuroscience 2011; 201:134-45. [PMID: 22123168 DOI: 10.1016/j.neuroscience.2011.11.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 11/09/2011] [Accepted: 11/11/2011] [Indexed: 12/17/2022]
Abstract
The dorsal periaqueductal gray (dPAG) is the main output structure for the defensive response to proximal aversive stimulation. Panic-like responses, such as freezing and escape behaviors, often result when this structure is electrically stimulated. Freezing also ensues after termination of the dPAG stimulation (post-stimulation freezing (PSF)). GABA and 5-HT have been proposed as the main neuromediators of these defense reactions. Neurokinins (NKs) also play a role in the defense reaction; however, it is unclear how the distinct types of NK receptors are involved in the expression of these fear responses. This study investigated the role of NK-1 and NK-3 receptors in the unconditioned defensive behaviors induced by electrical stimulation of the dPAG of rats, with and without previous experience with contextual fear conditioning (CFC). Spantide (100 ρmol/0.2 μl) and SB 222200 (50 and 100 ρmol/0.2 μl), selective antagonists of NK-1 and NK-3 receptors, respectively, were injected into the dPAG. Injection of spantide had antiaversive effects as determined by stimulation of the dPAG in naive animals and in animals subjected previously to CFC. SB 222200 also increased these aversive thresholds but only at doses that caused a motor deficit. Moreover, neither spantide nor SB 222200 influenced the PSF. The results suggest that NK-1 receptors are mainly involved in the mediation of the defensive behaviors organized in the dPAG. Because dPAG-evoked PSF was not affected by intra-dPAG injections of either spantide or SB 222200, it is suggested that neurokinin-mediated mechanisms are not involved in the processing of ascending aversive information from the dPAG.
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Affiliation(s)
- A C Broiz
- Instituto de Neurociências e Comportamento-INeC, Campus USP, 14040-901 Ribeirão Preto, SP, Brasil
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Easton AC, Lucchesi W, Schumann G, Giese KP, Müller CP, Fernandes C. αCaMKII autophosphorylation controls exploratory activity to threatening novel stimuli. Neuropharmacology 2011; 61:1424-31. [PMID: 21903107 DOI: 10.1016/j.neuropharm.2011.08.036] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2011] [Revised: 08/17/2011] [Accepted: 08/20/2011] [Indexed: 02/07/2023]
Abstract
Autophosphorylation of αCaMKII is regarded as a 'molecular memory' for Ca(2+) transients and a crucial mechanism in aversely, but less so in appetitively, motivated learning and memory. While there is a growing body of research implicating αCaMKII in general in behavioral responses to threat or fearful stimuli, little is known about the contribution of the autophosphorylation. The present study asked how αCaMKII autophosphorylation controls anxiety-like behavioral responses toward novel, potentially threatening stimuli. We tested homozygous and heterozygous T286A αCaMKII autophosphorylation deficient mice and wild types in a systematic series of behavioral tests. Homozygous mutants were more active in the open field test and showed reduced anxiety-related behavior in the light/dark test, but these findings were confounded by a hyperlocomotor phenotype. The analysis of elevated plus maze showed significantly reduced anxiety-related behavior in the αCaMKII autophosphorylation-deficient mice which appeared to mediate a hyperlocomotor response. An analysis of home cage behavior, where neither novel nor threatening stimuli were present, showed no differences in locomotor activity between genotypes. Increased locomotion was not observed in the novel object exploration test in the αCaMKII autophosphorylation-deficient mice, implying that hyperactivity does not occur in response to discrete novel stimuli. The present data suggest that the behavior of αCaMKII autophosphorylation-deficient mice cannot simply be described as a low anxiety phenotype. Instead it is suggested that αCaMKII autophosphorylation influences locomotor reactivity to novel environments that are potentially, but not necessarily threatening.
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Affiliation(s)
- Alanna C Easton
- MRC Social, Genetic and Developmental Psychiatry Research Centre, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK
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Moers-Hornikx VMP, Vles JSH, Lim LW, Ayyildiz M, Kaplan S, Gavilanes AWD, Hoogland G, Steinbusch HWM, Temel Y. Periaqueductal grey stimulation induced panic-like behaviour is accompanied by deactivation of the deep cerebellar nuclei. Cerebellum 2011; 10:61-9. [PMID: 21076996 PMCID: PMC3038216 DOI: 10.1007/s12311-010-0228-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Until recently, the cerebellum was primarily considered to be a structure involved in motor behaviour. New anatomical and clinical evidence has shown that the cerebellum is also involved in higher cognitive functions and non-motor behavioural changes. Functional imaging in patients with anxiety disorders and in cholecystokinin tetrapeptide-induced panic-attacks shows activation changes in the cerebellum. Deep brain stimulation of the dorsolateral periaqueductal grey (dlPAG) and the ventromedial hypothalamus (VMH) in rats has been shown to induce escape behaviour, which mimics a panic attack in humans. We used this animal model to study the neuronal activation in the deep cerebellar nuclei (DCbN) using c-Fos immunohistochemistry. c-Fos expression in the DCbN decreased significantly after inducing escape behaviour by stimulation of the dlPAG and the VMH, indicating that the DCbN were deactivated. This study demonstrates that the DCbN are directly or indirectly involved in panic attacks. We suggest that the cerebellum plays a role in the selection of relevant information, and that deactivation of the cerebellar nuclei is required to allow inappropriate behaviour to occur, such as panic attacks.
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Kádár E, Lim LW, Carreras G, Genís D, Temel Y, Huguet G. High-frequency stimulation of the ventrolateral thalamus regulates gene expression in hippocampus, motor cortex and caudate–putamen. Brain Res 2011; 1391:1-13. [DOI: 10.1016/j.brainres.2011.03.059] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 03/22/2011] [Accepted: 03/23/2011] [Indexed: 02/05/2023]
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Lemaire JJ, Frew AJ, McArthur D, Gorgulho AA, Alger JR, Salomon N, Chen C, Behnke EJ, De Salles AAF. White matter connectivity of human hypothalamus. Brain Res 2011; 1371:43-64. [PMID: 21122799 DOI: 10.1016/j.brainres.2010.11.072] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2010] [Revised: 11/02/2010] [Accepted: 11/19/2010] [Indexed: 11/28/2022]
Affiliation(s)
- Jean-Jacques Lemaire
- Univ Clermont 1, UFR Médecine, EA3295, Equipe de Recherche en signal et Imagerie Médicale, Clermont-Ferrand, F-63001, France.
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Lim LW, Blokland A, van Duinen M, Visser-Vandewalle V, Tan S, Vlamings R, Janssen M, Jahanshahi A, Aziz-Mohammadi M, Steinbusch HW, Schruers K, Temel Y. Increased plasma corticosterone levels after periaqueductal gray stimulation-induced escape reaction or panic attacks in rats. Behav Brain Res 2011; 218:301-7. [PMID: 21185871 DOI: 10.1016/j.bbr.2010.12.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 12/12/2010] [Accepted: 12/16/2010] [Indexed: 11/21/2022]
Abstract
The hypothalamo-pituitary-adrenal (HPA) axis is involved in stress, depression and anxiety. Controversy exists on HPA axis activation during panic attacks (PAs). We examined whether the HPA axis is involved in the escape or panic-like response in an animal model of PAs induced by electrical stimulation of the dorsolateral periaqueductal gray (dlPAG) in rats. Additionally, rats were also treated with chronic administration of buspirone (BUSP) and escitalopram (ESCIT), respectively; and they were stimulated in the open-field arena for panic-like reaction. Levels of stress hormone corticosterone were measured following 30 min after escape or panic condition. Our results demonstrated that the levels of plasma corticosterone were significantly increased after the induction of escape or panic-like response in comparison with the sham animals. The levels of corticosterone were significantly decreased in the dlPAG stimulated groups after rats were treated chronically with the ESCIT but not the BUSP as compared to the saline treated animals. Importantly, the increase of corticosterone level after escape or panic-like response was paralleled by an increase of neuronal activation of c-Fos in both the parvocellular and magnocellular paraventricular nucleus of the hypothalamus. Moreover, the c-Fos data also showed a decrease in the number of positive cells particularly for the ESCIT as well as the BUSP in comparison with the saline stimulated animals. In conclusion, the present study clearly demonstrated that PA or escape response activates the HPA axis and it remains difficult to anticipate the mechanism underlying HPA axis during PAs and its relationship with 5-HT drugs.
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Lim LW, Blokland A, Tan S, Vlamings R, Sesia T, Aziz-Mohammadi M, Visser-Vandewalle V, Steinbusch HW, Schruers K, Temel Y. Attenuation of fear-like response by escitalopram treatment after electrical stimulation of the midbrain dorsolateral periaqueductal gray. Exp Neurol 2010; 226:293-300. [DOI: 10.1016/j.expneurol.2010.08.035] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 08/26/2010] [Accepted: 08/30/2010] [Indexed: 11/26/2022]
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Tan SKH, Vlamings R, Lim L, Sesia T, Janssen MLF, Steinbusch HWM, Visser-Vandewalle V, Temel Y. Experimental Deep Brain Stimulation in Animal Models. Neurosurgery 2010; 67:1073-9; discussion1080. [DOI: 10.1227/neu.0b013e3181ee3580] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Sonny KH Tan
- Department of Neuroscience, Maastricht University, Department of Neurosurgery, Maastricht University Medical Center, European Graduate School of Neuroscience (EURON), Maastricht Institute of Neuromodulative Development (MIND), Maastricht, the Netherlands
| | - Rinske Vlamings
- Department of Neuroscience, Maastricht University, Department of Neurosurgery, Maastricht University Medical Center, European Graduate School of Neuroscience (EURON), Maastricht Institute of Neuromodulative Development (MIND), Maastricht, the Netherlands
| | - LeeWei Lim
- Department of Neuroscience, Maastricht University, Department of Neurosurgery, Maastricht University Medical Center, European Graduate School of Neuroscience (EURON), Maastricht Institute of Neuromodulative Development (MIND), Maastricht, the Netherlands
| | - Thibault Sesia
- Department of Neuroscience, Maastricht University, Department of Neurosurgery, Maastricht University Medical Center, European Graduate School of Neuroscience (EURON), Maastricht Institute of Neuromodulative Development (MIND), Maastricht, the Netherlands
| | - Marcus LF Janssen
- Department of Neuroscience, Maastricht University, Department of Neurosurgery, Maastricht University Medical Center, European Graduate School of Neuroscience (EURON), Maastricht Institute of Neuromodulative Development (MIND), Maastricht, the Netherlands
| | - Harry WM Steinbusch
- Department of Neuroscience, Maastricht University, European Graduate School of Neuroscience (EURON), Maastricht, the Netherlands
| | | | - Yasin Temel
- Department of Neuroscience, Maastricht University, Department of Neurosurgery, Maastricht University Medical Center, European Graduate School of Neuroscience (EURON), Maastricht Institute of Neuromodulative Development (MIND), Maastricht, the Netherlands
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Wilent WB, Oh MY, Buetefisch CM, Bailes JE, Cantella D, Angle C, Whiting DM. Induction of panic attack by stimulation of the ventromedial hypothalamus. J Neurosurg 2010; 112:1295-8. [PMID: 19852539 DOI: 10.3171/2009.9.jns09577] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Panic attacks are sudden debilitating attacks of intense distress often accompanied by physical symptoms such as shortness of breath and heart palpitations. Numerous brain regions, hormones, and neurotransmitter systems are putatively involved, but the etiology and neurocircuitry of panic attacks is far from established. One particular brain region of interest is the ventromedial hypothalamus (VMH). In cats and rats, electrical stimulation delivered to the VMH has been shown to evoke an emotional “panic attack–like” escape behavior, and in humans, stimulation targeting nuclei just posterior or anterior to the VMH has reportedly induced panic attacks. The authors report findings obtained in an awake patient undergoing bilateral implantation of deep brain stimulation electrodes into the hypothalamus that strongly implicates the VMH as being critically involved in the genesis of panic attacks. First, as the stimulating electrode progressed deeper into the VMH, the intensity of stimulation required to evoke an attack systematically decreased; second, while stimulation of the VMH in either hemisphere evoked panic, stimulation that appeared to be in the center of the VMH was more potent. Thus, this evidence supports the role of the VMH in the induction of panic attacks purported by animal studies.
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Affiliation(s)
| | - Michael Y. Oh
- 2Department of Neurosurgery, Allegheny General Hospital, Pittsburgh, Pennsylvania; and
- 3Department of Neurosurgery, West Virginia University, Morgantown, West Virginia
| | | | - Julian E. Bailes
- 3Department of Neurosurgery, West Virginia University, Morgantown, West Virginia
| | - Diane Cantella
- 2Department of Neurosurgery, Allegheny General Hospital, Pittsburgh, Pennsylvania; and
| | - Cindy Angle
- 2Department of Neurosurgery, Allegheny General Hospital, Pittsburgh, Pennsylvania; and
| | - Donald M. Whiting
- 2Department of Neurosurgery, Allegheny General Hospital, Pittsburgh, Pennsylvania; and
- 3Department of Neurosurgery, West Virginia University, Morgantown, West Virginia
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Moers-Hornikx VM, Sesia T, Basar K, Lim LW, Hoogland G, Steinbusch HW, Gavilanes DA, Temel Y, Vles JS. Cerebellar nuclei are involved in impulsive behaviour. Behav Brain Res 2009; 203:256-63. [DOI: 10.1016/j.bbr.2009.05.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 04/16/2009] [Accepted: 05/09/2009] [Indexed: 10/20/2022]
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Lim LW, Temel Y, Visser-Vandewalle V, Blokland A, Steinbusch H. Fos immunoreactivity in the rat forebrain induced by electrical stimulation of the dorsolateral periaqueductal gray matter. J Chem Neuroanat 2009; 38:83-96. [DOI: 10.1016/j.jchemneu.2009.06.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Revised: 06/29/2009] [Accepted: 06/29/2009] [Indexed: 10/20/2022]
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Freitas RL, Uribe-Mariño A, Castiblanco-Urbina MA, Elias-Filho DH, Coimbra NC. GABA(A) receptor blockade in dorsomedial and ventromedial nuclei of the hypothalamus evokes panic-like elaborated defensive behaviour followed by innate fear-induced antinociception. Brain Res 2009; 1305:118-31. [PMID: 19799880 DOI: 10.1016/j.brainres.2009.09.096] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 09/23/2009] [Accepted: 09/24/2009] [Indexed: 01/02/2023]
Abstract
Dysfunction in the hypothalamic GABAergic system has been implicated in panic syndrome in humans. Furthermore, several studies have implicated the hypothalamus in the elaboration of pain modulation. Panic-prone states are able to be experimentally induced in laboratory animals to study this phenomenon. The aim of the present work was to investigate the involvement of medial hypothalamic nuclei in the organization of panic-like behaviour and the innate fear-induced oscillations of nociceptive thresholds. The blockade of GABA(A) receptors in the neuronal substrates of the ventromedial or dorsomedial hypothalamus was followed by elaborated defensive panic-like reactions. Moreover, innate fear-induced antinociception was consistently elicited after the escape behaviour. The escape responses organized by the dorsomedial and ventromedial hypothalamic nuclei were characteristically more elaborated, and a remarkable exploratory behaviour was recorded during GABA(A) receptor blockade in the medial hypothalamus. The motor characteristic of the elaborated defensive escape behaviour and the patterns of defensive alertness and defensive immobility induced by microinjection of the bicuculline either into the dorsomedial or into the ventromedial hypothalamus were very similar. This was followed by the same pattern of innate fear-induced antinociceptive response that lasted approximately 40 min after the elaborated defensive escape reaction in both cases. These findings suggest that dysfunction of the GABA-mediated neuronal system in the medial hypothalamus causes panic-like responses in laboratory animals, and that the elaborated escape behaviour organized in both dorsomedial and ventromedial hypothalamic nuclei are followed by significant innate-fear-induced antinociception. Our findings indicate that the GABA(A) receptor of dorsomedial and ventromedial hypothalamic nuclei are critically involved in the modulation of panic-like behaviour.
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Affiliation(s)
- Renato Leonardo Freitas
- Laboratório de Neuroanatomia & Neuropsicobiologia, Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (USP), Av. dos Bandeirantes, 3900, Ribeirão Preto (SP), 14049-900, Brasil.
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Lim LW, Temel Y, Sesia T, Vlamings R, Visser-Vandewalle V, Steinbusch HW, Blokland A. Buspirone induced acute and chronic changes of neural activation in the periaqueductal gray of rats. Neuroscience 2008; 155:164-73. [PMID: 18588948 DOI: 10.1016/j.neuroscience.2008.05.038] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Revised: 05/27/2008] [Accepted: 05/30/2008] [Indexed: 11/28/2022]
Abstract
5-HT(1A) modulation within the midbrain periaqueductal gray (PAG) is closely associated with anxiety- or panic-like behavior. Several findings have demonstrated that the properties of buspirone (a 5-HT(1A) partial agonist) would function as either anxiolytic or panicolytic in both clinical and laboratory animal research. In this study, we have investigated the neuronal activity occurring within the different regions of the PAG induced by buspirone treatment. Twenty-eight albino Wistar rats (350-400 g) were injected with either acute or chronic saline/buspirone (each, n=7), respectively. Our results show that buspirone treatment reduced locomotor activity, body weight and fecal boli, particularly in the chronic buspirone group. Two-way ANOVA revealed a significant decrease of c-Fos-immunoreactive (ir) cells expression in all regions of the rostral PAG after both acute and chronic buspirone (acute buspirone (AB) and chronic buspirone (CB), respectively) treatment. However, no effects on c-Fos-ir were detected in the caudal lateral periaqueductal gray (lPAG) and ventrolateral periaqueductal gray (vlPAG) in both the AB and CB groups, and in the dorsolateral periaqueductal gray (dlPAG) of the CB group. Interestingly, c-Fos-ir cells in the dorsomedial periaqueductal gray (dmPAG) column were reduced consistently in both the rostral and caudal PAG in both AB and CB groups. Besides, in all regions the number of c-Fos-ir cells was higher in the AB than in the CB group with exception of the rostral lPAG. In conclusion, the main anxiolytic effect of buspirone was specifically localized in all regions of the rostral PAG and in the caudal dmPAG. However, the caudal dlPAG, lPAG and vlPAG were found to be ineffective to buspirone treatment, probably due to their distinctive function in mediating higher level of anxiety in defensive behavior. This indicates that the longitudinal anatomical structure of the PAG possesses a different level of receptor sensitivity of 5-HT(1A) in the pathophysiology of anxiety and panic disorder.
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