1
|
Kang S, Jeon S, Lee YG, Ye BS. Alteration of medial temporal lobe metabolism related to Alzheimer's disease and dementia with lewy bodies. Alzheimers Res Ther 2024; 16:89. [PMID: 38654300 PMCID: PMC11036684 DOI: 10.1186/s13195-024-01429-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 03/11/2024] [Indexed: 04/25/2024]
Abstract
BACKGROUND Association of medial temporal lobe (MTL) metabolism with Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) has not been evaluated considering their mixed disease (MD). METHODS 131 patients with AD, 133 with DLB, 122 with MD, and 28 normal controls (NCs) underwent neuropsychological tests, assessments for parkinsonism, cognitive fluctuation (CF), and visual hallucinations (VH), and 18F-fluorodeoxyglucose PET to quantify MTL metabolism in the amygdala, hippocampus, and entorhinal cortex. The effects of AD and DLB on MTL metabolism were evaluated using general linear models (GLMs). Associations between MTL metabolism, cognition, and clinical features were evaluated using GLMs or logistic regression models separately performed for the AD spectrum (NC + AD + MD), DLB spectrum (NC + DLB + MD), and disease groups (AD + DLB + MD). Covariates included age, sex, and education. RESULTS AD was associated with hippocampal/entorhinal hypometabolism, whereas DLB was associated with relative amygdalar/hippocampal hypermetabolism. Relative MTL hypermetabolism was associated with lower attention/visuospatial/executive scores and severe parkinsonism in both the AD and DLB spectra and disease groups. Left hippocampal/entorhinal hypometabolism was associated with lower verbal memory scores, whereas right hippocampal hypometabolism was associated with lower visual memory scores in both the AD spectrum and disease groups. Relative MTL hypermetabolism was associated with an increased risk of CF and VH in the disease group, and relative amygdalar hypermetabolism was associated with an increased risk of VH in the DLB spectrum. CONCLUSIONS Entorhinal-hippocampal hypometabolism and relative amygdala-hippocampal hypermetabolism could be characteristics of AD- and DLB-related neurodegeneration, respectively.
Collapse
Affiliation(s)
- Sungwoo Kang
- Department of Neurology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Seun Jeon
- Metabolism-Dementia Research Institute , Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Young-Gun Lee
- Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Republic of Korea
| | - Byoung Seok Ye
- Department of Neurology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
| |
Collapse
|
2
|
Shine JM. Neuromodulatory control of complex adaptive dynamics in the brain. Interface Focus 2023; 13:20220079. [PMID: 37065268 PMCID: PMC10102735 DOI: 10.1098/rsfs.2022.0079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 01/23/2023] [Indexed: 04/18/2023] Open
Abstract
How is the massive dimensionality and complexity of the microscopic constituents of the nervous system brought under sufficiently tight control so as to coordinate adaptive behaviour? A powerful means for striking this balance is to poise neurons close to the critical point of a phase transition, at which a small change in neuronal excitability can manifest a nonlinear augmentation in neuronal activity. How the brain could mediate this critical transition is a key open question in neuroscience. Here, I propose that the different arms of the ascending arousal system provide the brain with a diverse set of heterogeneous control parameters that can be used to modulate the excitability and receptivity of target neurons-in other words, to act as control parameters for mediating critical neuronal order. Through a series of worked examples, I demonstrate how the neuromodulatory arousal system can interact with the inherent topological complexity of neuronal subsystems in the brain to mediate complex adaptive behaviour.
Collapse
Affiliation(s)
- James M. Shine
- Brain and Mind Center, The University of Sydney, Sydney, Australia
| |
Collapse
|
3
|
Xu Z, Feng Z, Zhao M, Sun Q, Deng L, Jia X, Jiang T, Luo P, Chen W, Tudi A, Yuan J, Li X, Gong H, Luo Q, Li A. Whole-brain connectivity atlas of glutamatergic and GABAergic neurons in the mouse dorsal and median raphe nuclei. eLife 2021; 10:65502. [PMID: 34792021 PMCID: PMC8626088 DOI: 10.7554/elife.65502] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 11/17/2021] [Indexed: 11/25/2022] Open
Abstract
The dorsal raphe nucleus (DR) and median raphe nucleus (MR) contain populations of glutamatergic and GABAergic neurons that regulate diverse behavioral functions. However, their whole-brain input-output circuits remain incompletely elucidated. We used viral tracing combined with fluorescence micro-optical sectioning tomography to generate a comprehensive whole-brain atlas of inputs and outputs of glutamatergic and GABAergic neurons in the DR and MR. We found that these neurons received inputs from similar upstream brain regions. The glutamatergic and GABAergic neurons in the same raphe nucleus had divergent projection patterns with differences in critical brain regions. Specifically, MR glutamatergic neurons projected to the lateral habenula through multiple pathways. Correlation and cluster analysis revealed that glutamatergic and GABAergic neurons in the same raphe nucleus received heterogeneous inputs and sent different collateral projections. This connectivity atlas further elucidates the anatomical architecture of the raphe nuclei, which could facilitate better understanding of their behavioral functions.
Collapse
Affiliation(s)
- Zhengchao Xu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Zhao Feng
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China.,HUST-Suzhou Institute for Brainsmatics, JITRI, Suzhou, China
| | - Mengting Zhao
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Qingtao Sun
- HUST-Suzhou Institute for Brainsmatics, JITRI, Suzhou, China
| | - Lei Deng
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Xueyan Jia
- HUST-Suzhou Institute for Brainsmatics, JITRI, Suzhou, China
| | - Tao Jiang
- HUST-Suzhou Institute for Brainsmatics, JITRI, Suzhou, China
| | - Pan Luo
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Wu Chen
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Ayizuohere Tudi
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Jing Yuan
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China.,HUST-Suzhou Institute for Brainsmatics, JITRI, Suzhou, China
| | - Xiangning Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China.,HUST-Suzhou Institute for Brainsmatics, JITRI, Suzhou, China
| | - Hui Gong
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China.,HUST-Suzhou Institute for Brainsmatics, JITRI, Suzhou, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Science, Shanghai, China
| | - Qingming Luo
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China.,HUST-Suzhou Institute for Brainsmatics, JITRI, Suzhou, China.,School of Biomedical Engineering, Hainan University, Haikou, China
| | - Anan Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China.,HUST-Suzhou Institute for Brainsmatics, JITRI, Suzhou, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Science, Shanghai, China
| |
Collapse
|
4
|
Salazar AM, Leisgang AM, Ortiz AA, Murtishaw AS, Kinney JW. Alterations of GABA B receptors in the APP/PS1 mouse model of Alzheimer's disease. Neurobiol Aging 2020; 97:129-143. [PMID: 33232936 DOI: 10.1016/j.neurobiolaging.2020.10.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 09/08/2020] [Accepted: 10/16/2020] [Indexed: 01/20/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the progressive decline of memory and cognitive function. The disease is characterized by the presence of amyloid plaques, tau tangles, altered inflammatory signaling, and alterations in numerous neurotransmitter signaling systems, including γ-aminobutyric acid (GABA). Given the extensive role of GABA in regulating neuronal activity, a careful investigation of GABA-related changes is needed. Further, given persistent inflammation has been demonstrated to drive AD pathology, the presence of GABA B receptor expressed on glia that serve a role regulation of the immune response adds to potential implications of altered GABA in AD. There has not previously been a systematic evaluation of GABA-related changes in an amyloid model of AD that specifically focuses on examining changes in GABA B receptors. In the present study, we examined alterations in several GABA-specific targets in the APP/PS1 mouse model at different ages. In the 4-month-old cohort, no significant deficits in spatial learning and memory or alterations in any of the GABAergic targets were observed compared with wild-type controls. However, we identified significant alterations in several GABA-related targets in the 6-month-old cohort that exhibited spatial learning deficits that include changes in glutamic acid decarboxylase 65, GABA transporter type 3, and GABA B receptors protein and mRNA levels. This was the same cohort at which learning and memory deficits and significant amyloid pathology was observed. Overall, our study provides evidence of altered GABAergic signaling in an amyloid model of AD at a time point consistent with AD-related deficits.
Collapse
Affiliation(s)
- Arnold M Salazar
- Department of Brain Health, School of Integrated Health Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Amanda M Leisgang
- Department of Brain Health, School of Integrated Health Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Andrew A Ortiz
- Department of Brain Health, School of Integrated Health Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Andrew S Murtishaw
- Department of Brain Health, School of Integrated Health Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Jefferson W Kinney
- Department of Brain Health, School of Integrated Health Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA.
| |
Collapse
|
5
|
Andrade TGCSD, Silva JVDS, Batistela MF, Frei F, Sant'Ana AB. Interaction between estradiol and 5-HT 1A receptors in the median raphe nucleus on acquisition of aversive information and association to the context in ovariectomized rats. Neurobiol Stress 2017. [PMID: 28626786 PMCID: PMC5470534 DOI: 10.1016/j.ynstr.2017.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The median raphe nucleus (MRN) is related to stress resistance and defensive responses, a crucial source of serotonergic neurons that project to prosencephalic structures related to stress and anxiety. Estrogen receptors were identified in this mesencephalic structure. It is possible that the estrogen action is related to serotonin effect on somatodendritic 5-HT1A receptors, inhibiting the function of serotonergic neurons and thus preventing of the stress effect and inducing anxiolysis. So, in order to evaluate these aspects, female Wistar rats were ovariectomized and 21 days later were given a direct microinjection of estradiol benzoate (EB) (1200 ng) into the MRN, preceded by microinjections of saline or WAY100.635 (100 ng), a 5-HT1A receptor antagonist. Immediately after the two microinjections, the ovariectomized rats were conditioned with an aversive event (foot shock) session in a Skinner box. Twenty-four hours later, they were exposed to the same context in a test session for 5 min for behavioral assessment: freezing, rearing, locomotion, grooming, and autonomic responses (fecal boluses and micturition). EB microinjection in the MRN prior to the exposure of animals to the foot shocks in the conditioning session did not alter their behavior in this session, but neutralized the association of the aversive experience to the context: there was a decrease in the expression of freezing and an increased rearing activity in the test session. This effect was reversed by prior microinjection of WAY100.635. In conclusion, EB acted on serotonergic neurons in the MRN of the ovariectomized rats, impairing the association of the aversive experience to the context, by co-modulating the functionality of somatodendritic 5-HT1A.
Collapse
Affiliation(s)
| | | | | | - Fernando Frei
- UNESP - Univ Estadual Paulista, FCL, Department of Biological Science, Avenida Dom Antonio, 2100, 19.806-900 Assis, São Paulo, Brazil
| | | |
Collapse
|
6
|
Abstract
Sleep is a complex physiological process that is regulated globally, regionally, and locally by both cellular and molecular mechanisms. It occurs to some extent in all animals, although sleep expression in lower animals may be co-extensive with rest. Sleep regulation plays an intrinsic part in many behavioral and physiological functions. Currently, all researchers agree there is no single physiological role sleep serves. Nevertheless, it is quite evident that sleep is essential for many vital functions including development, energy conservation, brain waste clearance, modulation of immune responses, cognition, performance, vigilance, disease, and psychological state. This review details the physiological processes involved in sleep regulation and the possible functions that sleep may serve. This description of the brain circuitry, cell types, and molecules involved in sleep regulation is intended to further the reader's understanding of the functions of sleep.
Collapse
Affiliation(s)
- Mark R. Zielinski
- Veterans Affairs Boston Healthcare System, West Roxbury, MA 02132, USA and Harvard Medical School, Department of Psychiatry
| | - James T. McKenna
- Veterans Affairs Boston Healthcare System, West Roxbury, MA 02132, USA and Harvard Medical School, Department of Psychiatry
| | - Robert W. McCarley
- Veterans Affairs Boston Healthcare System, Brockton, MA 02301, USA and Harvard Medical School, Department of Psychiatry
| |
Collapse
|
7
|
Role of GABA(B) receptors in learning and memory and neurological disorders. Neurosci Biobehav Rev 2016; 63:1-28. [PMID: 26814961 DOI: 10.1016/j.neubiorev.2016.01.007] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 12/31/2015] [Accepted: 01/21/2016] [Indexed: 01/13/2023]
Abstract
Although it is evident from the literature that altered GABAB receptor function does affect behavior, these results often do not correspond well. These differences could be due to the task protocol, animal strain, ligand concentration, or timing of administration utilized. Because several clinical populations exhibit learning and memory deficits in addition to altered markers of GABA and the GABAB receptor, it is important to determine whether altered GABAB receptor function is capable of contributing to the deficits. The aim of this review is to examine the effect of altered GABAB receptor function on synaptic plasticity as demonstrated by in vitro data, as well as the effects on performance in learning and memory tasks. Finally, data regarding altered GABA and GABAB receptor markers within clinical populations will be reviewed. Together, the data agree that proper functioning of GABAB receptors is crucial for numerous learning and memory tasks and that targeting this system via pharmaceuticals may benefit several clinical populations.
Collapse
|
8
|
Bland BH, Bland CE, MacIver MB. Median raphe stimulation-induced motor inhibition concurrent with suppression of type 1 and type 2 hippocampal theta. Hippocampus 2015; 26:289-300. [PMID: 26314691 DOI: 10.1002/hipo.22521] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 08/24/2015] [Accepted: 08/24/2015] [Indexed: 11/10/2022]
Abstract
This study investigated behavioral, anatomical and electrophysiological effects produced by electrical stimulation of posterior hypothalamic (PH) or median raphe (MR) nuclei, independently and during combined stimulation of both PH and MR. These three stimulation conditions were applied during spontaneous behavior in an open field and during PH stimulation-induced wheel running, while simultaneously recording hippocampal (HPC) field activity. An additional objective was to determine the effects of MR stimulation on Type 1 movement related theta and Type 2 sensory processing related theta. To achieve the latter, when behavioral studies were completed we studied the same rats under urethane anesthesia and then during urethane anesthesia with the addition of atropine sulfate (ATSO4). Here we demonstrated that electrical stimulation of a localized region of the MR nucleus resulted in a profound inhibition of both spontaneously occurring theta related motor behaviors and the theta related motor behaviors induced by electrical stimulation of the PH nucleus. Furthermore, this motor inhibition occurred concurrently with strong suppression of hippocampal theta field oscillations in the freely moving rat, a condition where the theta recorded is Type 2 sensory processing theta occurring coincidently with Type 1 movement related theta (Bland, 1986). Our results indicate that motor inhibition resulted from stimulation of neurons located in the mid central region of the MR, while stimulation in adjacent regions produced variable responses, including movements and theta activity. The present study provided evidence that the pharmacological basis of the suppression of Type 2 sensory processing HPC theta was cholinergic. However, MR inhibition of PH-induced wheel running was not affected by cholinergic blockade, which blocks Type 2 theta, indicating that MR stimulation-induced motor inhibition also requires the suppression of Type 1 theta.
Collapse
Affiliation(s)
- Brian H Bland
- Department of Psychology, Behavioral Neuroscience Research Group, the University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, Faculty of Medicine, the University of Calgary, Calgary, Alberta, Canada
| | - Cheryl E Bland
- Department of Psychology, Behavioral Neuroscience Research Group, the University of Calgary, Calgary, Alberta, Canada
| | - M Bruce MacIver
- Neuropharmacology Laboratory, Stanford School of Medicine, Stanford, California
| |
Collapse
|
9
|
Hodor A, Palchykova S, Gao B, Bassetti CL. Baclofen and gamma-hydroxybutyrate differentially altered behavior, EEG activity and sleep in rats. Neuroscience 2014; 284:18-28. [PMID: 25301745 DOI: 10.1016/j.neuroscience.2014.08.061] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 08/17/2014] [Accepted: 08/27/2014] [Indexed: 12/29/2022]
Abstract
OBJECTIVES Animal and human studies have shown that sleep may have an impact on functional recovery after brain damage. Baclofen (Bac) and gamma-hydroxybutyrate (GHB) have been shown to induce physiological sleep in humans, however, their effects in rodents are unclear. The aim of this study is to characterize sleep and electroencelphalogram (EEG) after Bac and GHB administration in rats. We hypothesized that both drugs would induce physiological sleep. METHODS Adult male Sprague-Dawley rats were implanted with EEG/electromyogram (EMG) electrodes for sleep recordings. Bac (10 or 20 mg/kg), GHB (150 or 300 mg/kg) or saline were injected 1 h after light and dark onset to evaluate time of day effect of the drugs. Vigilance states and EEG spectra were quantified. RESULTS Bac and GHB induced a non-physiological state characterized by atypical behavior and an abnormal EEG pattern. After termination of this state, Bac was found to increase the duration of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep (∼90 and 10 min, respectively), reduce sleep fragmentation and affect NREM sleep episode frequency and duration (p<0.05). GHB had no major effect on vigilance states. Bac drastically increased EEG power density in NREM sleep in the frequencies 1.5-6.5 and 9.5-21.5 Hz compared to saline (p<0.05), while GHB enhanced power in the 1-5-Hz frequency band and reduced it in the 7-9-Hz band. Slow-wave activity in NREM sleep was enhanced 1.5-3-fold during the first 1-2 h following termination of the non-physiological state. The magnitude of drug effects was stronger during the dark phase. CONCLUSION While both Bac and GHB induced a non-physiological resting state, only Bac facilitated and consolidated sleep, and promoted EEG delta oscillations thereafter. Hence, Bac can be considered a sleep-promoting drug and its effects on functional recovery after stroke can be evaluated both in humans and rats.
Collapse
Affiliation(s)
- A Hodor
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital, Switzerland.
| | - S Palchykova
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital, Switzerland
| | - B Gao
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital, Switzerland
| | - C L Bassetti
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital, Switzerland
| |
Collapse
|
10
|
Crooks R, Jackson J, Bland BH. Dissociable pathways facilitate theta and non-theta states in the median raphe-Septohippocampal circuit. Hippocampus 2011; 22:1567-76. [DOI: 10.1002/hipo.20999] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2011] [Indexed: 11/05/2022]
|
11
|
GABA(B) receptor modulation of serotonin neurons in the dorsal raphé nucleus and escalation of aggression in mice. J Neurosci 2010; 30:11771-80. [PMID: 20810897 DOI: 10.1523/jneurosci.1814-10.2010] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The serotonin (5-HT) system in the brain has been studied more than any other neurotransmitter for its role in the neurobiological basis of aggression. However, which mechanisms modulate the 5-HT system to promote escalated aggression is not clear. We here explore the role of GABAergic modulation in the raphé nuclei, from which most 5-HT in the forebrain originates, on escalated aggression in male mice. Pharmacological activation of GABA(B), but not GABA(A), receptors in the dorsal raphé nucleus (DRN) escalated aggressive behaviors. In contrast, GABA agonists did not escalate aggressive behaviors after microinjection into the median raphé nucleus. The aggression-heightening effect of the GABA(B) agonist baclofen depended on the activation of 5-HT neurons in the DRN because it was blocked by coadministration of the 5-HT(1A) agonist 8-OH-DPAT [((+/-)-8-hydroxy-2-(di-n-propylamino)tetralin) hydrobromide] (DPAT), which acts on autoreceptors and inhibits 5-HT neural activity. In vivo microdialysis showed that GABA(B) activation in the DRN increased extracellular 5-HT level in the medial prefrontal cortex. This may be attributable to an indirect action via presynaptic GABA(B) receptors. The presynaptic GABA(B) receptors suppress Ca(2+) channel activity and inhibit neurotransmission, and the coadministration of N-type Ca(2+) channel blocker facilitated the effect of baclofen. These findings suggest that the indirect disinhibition of 5-HT neuron activity by presynaptic GABA(B) receptors on non-5-HT neurons in the DRN is one of the neurobiological mechanisms of escalated aggression.
Collapse
|
12
|
High-dose glycine treatment of refractory obsessive-compulsive disorder and body dysmorphic disorder in a 5-year period. Neural Plast 2010; 2009:768398. [PMID: 20182547 PMCID: PMC2825652 DOI: 10.1155/2009/768398] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 08/12/2009] [Accepted: 12/04/2009] [Indexed: 12/17/2022] Open
Abstract
This paper describes an individual who was diagnosed with obsessive-compulsive disorder (OCD) and body dysmorphic disorder (BDD) at age 17 when education was discontinued. By age 19, he was housebound without social contacts except for parents. Adequate trials of three selective serotonin reuptake inhibitors, two with atypical neuroleptics, were ineffective. Major exacerbations following ear infections involving Group A β-hemolytic streptococcus at ages 19 and 20 led to intravenous immune globulin therapy, which was also ineffective. At age 22, another severe exacerbation followed antibiotic treatment for H. pylori. This led to a hypothesis that postulates deficient signal transduction by the N-methyl-D-aspartate receptor (NMDAR). Treatment with glycine, an NMDAR coagonist, over 5 years led to robust reduction of OCD/BDD signs and symptoms except for partial relapses during treatment cessation. Education and social life were resumed and evidence suggests improved cognition. Our findings motivate further study of glycine treatment of OCD and BDD.
Collapse
|
13
|
Vertes RP. Serotonergic Regulation of Rhythmical Activity of the Brain, Concentrating on the Hippocampus. HANDBOOK OF BEHAVIORAL NEUROSCIENCE 2010. [DOI: 10.1016/s1569-7339(10)70084-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
14
|
Jackson J, Bland BH, Antle MC. Nonserotonergic projection neurons in the midbrain raphe nuclei contain the vesicular glutamate transporter VGLUT3. Synapse 2009; 63:31-41. [PMID: 18925658 DOI: 10.1002/syn.20581] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The brainstem raphe nuclei are typically assigned a role in serotonergic brain function. However, numerous studies have reported that a large proportion of raphe projection cells are nonserotonergic. The identity of these projection cells is unknown. Recent studies have reported that the vesicular glutamate transporter VGLUT3 is found in both serotonergic and nonserotonergic neurons in both the median raphe (MR) and dorsal raphe (DR) nuclei. We injected the retrograde tracer cholera toxin subunit B into either the dorsal hippocampus or the medial septum (MS) and used triple labeled immunofluorescence to determine if nonserotonergic raphe cells projecting to these structures contained VGLUT3. Consistent with previous studies, only about half of retrogradely labeled MR neurons projecting to the hippocampus contained serotonin, whereas a majority of the retrogradely labeled nonserotonergic cells contained VGLUT3. Similar patterns were observed for MR cells projecting to the MS. About half of retrogradely labeled nonserotonergic neurons in the DR contained VGLUT3. Additionally, a large number of retrogradely labeled cells in the caudal linear and interpeduncular nuclei projecting to the MS were found to contain VGLUT3. These data suggest the enigmatic nonserotonergic projection from the MR to forebrain regions may be glutamatergic. In addition, these results demonstrate a dissociation between glutamatergic and serotonergic MR afferent inputs to the MS and hippocampus suggesting divergent and/or complementary roles of these pathways in modulating cellular activity within the septohippocampal network.
Collapse
Affiliation(s)
- Jesse Jackson
- Behavioral Neuroscience Research Group, Department of Psychology, University of Calgary, Calgary, Alberta, Canada
| | | | | |
Collapse
|
15
|
Jackson J, Dickson CT, Bland BH. Median Raphe Stimulation Disrupts Hippocampal Theta Via Rapid Inhibition and State-Dependent Phase Reset of Theta-Related Neural Circuitry. J Neurophysiol 2008; 99:3009-26. [DOI: 10.1152/jn.00065.2008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Evidence has accumulated suggesting that the median raphe (MR) mediates hippocampal theta desynchronization. However, few studies have evaluated theta-related neural circuitry during MR manipulation. In urethane-anesthetized rats, we investigated the effects of MR stimulation on hippocampal field and cell activity using high-frequency (100 Hz), theta burst (TBS), and slow-frequency electrical stimulation (0.5 Hz). We demonstrated that high-frequency stimulation of the MR did not elicit deactivated patterns in the forebrain, but rather elicited low-voltage activity in the neocortex and small-amplitude irregular activity (SIA) in the hippocampus. Both hippocampal phasic theta-on and -off cells were inhibited by high-frequency MR stimulation, although MR stimulation failed to affect cells that had neither state or phase relationships with theta field activity. TBS of the MR-induced theta field activity phase locked to the stimulation. Slow-frequency stimulation elicited a state-dependent reset of theta phase through a short-latency inhibition (5 ms) in phasic theta-on cells. Subpopulations of phasic theta-on cells responded in either oscillatory or nonoscillatory patterns to MR pulses, depending on their intraburst interval. off cells exhibited a state-dependent modulation of cell firing occurring preferentially during nontheta. The magnitude of MR-induced reset varied as a function of the phase of the theta oscillation when the pulse was administered. Therefore high-frequency stimulation of the MR appears to disrupt hippocampal theta through a state-dependent, short-latency inhibition of rhythmic cell populations in the hippocampus functioning to switch theta oscillations to an activated SIA field state.
Collapse
|
16
|
Fiske E, Portas CM, Grønli J, Sørensen E, Bjorvatn B, Bjørkum AA, Ursin R. Increased extracellular 5-HT but no change in sleep after perfusion of a 5-HT1A antagonist into the dorsal raphe nucleus of rats. Acta Physiol (Oxf) 2008; 193:89-97. [PMID: 18081887 DOI: 10.1111/j.1748-1716.2007.01792.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM The 5-HT(1A) receptor antagonist 4-Iodo-N-[2-[4-(methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinyl-benzamide hydrochloride (p-MPPI) (10 microM) was perfused into the dorsal raphe nucleus (DRN) to study simultaneously the effects of the drug on the DRN and frontal cortex extracellular serotonin (5-hydroxytryptamine, 5-HT) levels and concurring behavioural states. METHODS Waking, slow wave sleep and rapid eye movement sleep were determined by polygraphic recordings during microdialysis perfusion and extracellular sample collection. The samples were analysed by microbore high-performance liquid chromatography coupled with electrochemical detection for analysis of 5-HT. RESULTS p-MPPI perfusion into the DRN (n = 6) produced a sixfold 5-HT increase in the DRN during all behavioural states. The increased 5-HT level was most likely related to the blockage of 5-HT(1A) receptors in the DRN by p-MPPI. No significant effect was seen on sleep. CONCLUSION Despite the dramatic increase in DRN extracellular 5-HT produced by p-MPPI, only a transient and nonsignificant effect on sleep was recorded. It is suggested that the usual coupling between 5-HT level and behavioural state may be lost when an excessive serotonergic output is pharmacologically achieved.
Collapse
Affiliation(s)
- E Fiske
- Department of Biomedicine, University of Bergen, Bergen, Norway.
| | | | | | | | | | | | | |
Collapse
|
17
|
Datta S, Maclean RR. Neurobiological mechanisms for the regulation of mammalian sleep-wake behavior: reinterpretation of historical evidence and inclusion of contemporary cellular and molecular evidence. Neurosci Biobehav Rev 2007; 31:775-824. [PMID: 17445891 PMCID: PMC1955686 DOI: 10.1016/j.neubiorev.2007.02.004] [Citation(s) in RCA: 234] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Revised: 01/17/2007] [Accepted: 02/26/2007] [Indexed: 11/17/2022]
Abstract
At its most basic level, the function of mammalian sleep can be described as a restorative process of the brain and body; recently, however, progressive research has revealed a host of vital functions to which sleep is essential. Although many excellent reviews on sleep behavior have been published, none have incorporated contemporary studies examining the molecular mechanisms that govern the various stages of sleep. Utilizing a holistic approach, this review is focused on the basic mechanisms involved in the transition from wakefulness, initiation of sleep and the subsequent generation of slow-wave sleep and rapid eye movement (REM) sleep. Additionally, using recent molecular studies and experimental evidence that provides a direct link to sleep as a behavior, we have developed a new model, the cellular-molecular-network model, explaining the mechanisms responsible for regulating REM sleep. By analyzing the fundamental neurobiological mechanisms responsible for the generation and maintenance of sleep-wake behavior in mammals, we intend to provide a broader understanding of our present knowledge in the field of sleep research.
Collapse
Affiliation(s)
- Subimal Datta
- Sleep and Cognitive Neuroscience Laboratory, Department of Psychiatry and Behavioral Neuroscience, Boston University School of Medicine, Boston, MA 02118, USA.
| | | |
Collapse
|
18
|
Judge SJ, Young RL, Gartside SE. GABA(A) receptor modulation of 5-HT neuronal firing in the median raphe nucleus: implications for the action of anxiolytics. Eur Neuropsychopharmacol 2006; 16:612-9. [PMID: 16531019 DOI: 10.1016/j.euroneuro.2006.01.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Revised: 01/13/2006] [Accepted: 01/24/2006] [Indexed: 10/24/2022]
Abstract
5-HT neurones in the median raphe nucleus (MRN) are involved in anxiety and the sleep/wake cycle. Here, using in vitro electrophysiology, we examined if the firing of MRN 5-HT neurones is regulated by GABA(A) receptors. The GABA(A) receptor agonists THIP and muscimol caused concentration dependent inhibition of MRN 5-HT neurones. The GABA(A) receptor antagonist bicuculline blocked the responses to THIP and muscimol. Bicuculline alone increased the basal firing activity. Responses to THIP were enhanced by the Z hypnotic zolpidem at concentrations selective for the alpha(2)/alpha(3) subunits of the GABA(A) receptor (0.2 and 1microM) but not at a concentration selective for the alpha(1) subunit (0.02microM). Consistent with these functional data, 5-HT neurones have been shown to express the alpha(3) (but not alpha(2)) subunit. The anxiolytic effects of GABA(A) receptor modulators are reportedly mediated by alpha(3)-containing receptors. Hence the MRN 5-HT system may be a target for anxiolytic drugs.
Collapse
Affiliation(s)
- Sarah J Judge
- Psychobiology Research Group, School of Neurology, Neurobiology and Psychiatry, The Medical School, University of Newcastle upon Tyne, NE2 4HH, UK.
| | | | | |
Collapse
|
19
|
Urbain N, Creamer K, Debonnel G. Electrophysiological diversity of the dorsal raphe cells across the sleep-wake cycle of the rat. J Physiol 2006; 573:679-95. [PMID: 16613874 PMCID: PMC1779756 DOI: 10.1113/jphysiol.2006.108514] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Through their widespread projections to the entire brain, dorsal raphe cells participate in many physiological functions and are associated with neuropsychiatric disorders. In previous studies, the width of action potentials was used as a criterion to identify putative serotonergic neurons, and to demonstrate that cells with broad spikes were more active in wakefulness, slowed down their activity in slow wave sleep and became virtually silent during paradoxical sleep. However, recent studies reported that about half of these presumed serotonergic cells were not immunoreactive for tyrosine hydroxylase. Here, we re-examine the electrophysiological properties of dorsal raphe cells across the sleep-wake cycle in rats by the extracellular recording of a large sample of single units (n = 770). We identified two major types of cells, which differ in spike waveform: a first population characterized by broad, mostly positive spikes, and a second one displaying symmetrical positive-negative spikes with a large distribution of spike durations (0.6-3.2 ms). Although we found classical broad-spike cells that were more active in wakefulness, we also found that about one-third of these cells increased or did not change their firing rate during sleep compared with wakefulness. Moreover, 62% of the latter cells were active in paradoxical sleep when most of raphe cells were silent. Such a diversity in the neuronal firing behaviour is important in the light of the recent controversy regarding the neurochemical identity of dorsal raphe cells exhibiting broad spikes. Our results also suggest that the dorsal raphe contains subpopulations of neurons with reciprocal activity across the sleep-wake cycle.
Collapse
Affiliation(s)
- Nadia Urbain
- Department of Psychiatry, McGill University, Montréal, Québec, Canada.
| | | | | |
Collapse
|
20
|
Kocsis B, Varga V, Dahan L, Sik A. Serotonergic neuron diversity: identification of raphe neurons with discharges time-locked to the hippocampal theta rhythm. Proc Natl Acad Sci U S A 2006; 103:1059-64. [PMID: 16418294 PMCID: PMC1347988 DOI: 10.1073/pnas.0508360103] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The serotonergic system plays a key role in the regulation of brain states, and many of the known features of serotonergic neurons appear to match this function. Midbrain raphe nuclei provide a diffuse projection to all regions of the forebrain, and raphe neurons exhibit a slow metronome-like activity that sets the ambient levels of serotonin across the sleep-wake cycle. Serotonergic cells have also been implicated, however, in a variety of more specific functions that can hardly be related to their low-rate monotonous patterns of discharges. The amazing variety of serotonergic receptors and their type-specific distribution on cortical neurons also raise the possibility of a more intimate coordination between the activity of serotonergic neurons and their target cortical circuits. Here we report an unexpected diversity in the behavior of immunohistochemically identified serotonergic neurons. Two outstanding subpopulations were identified by using the in vivo juxtacellular recording and labeling technique. The first subpopulation of serotonergic cells exhibited the classic clock-like activity with no apparent short timescale interaction with the hippocampal electroencephalogram. The other subpopulation discharged action potentials that were phase-locked to the hippocampal theta rhythm, the oscillatory pattern associated with acquisition of information and memory formation. These results indicate that the ascending serotonergic system comprises cells involved in complex information processing beyond the regulation of state transitions. The heterogeneity of serotonergic neuron behavior can also help to explain the complexity of symptoms associated with serotonergic dysfunction.
Collapse
Affiliation(s)
- Bernat Kocsis
- Laboratory of Neurophysiology, Harvard Medical School, Boston, MA 02215, USA
| | | | | | | |
Collapse
|