1
|
Rosa I, Di Censo D, Ranieri B, Di Giovanni G, Scarnati E, Alecci M, Galante A, Florio TM. Comparison between Tail Suspension Swing Test and Standard Rotation Test in Revealing Early Motor Behavioral Changes and Neurodegeneration in 6-OHDA Hemiparkinsonian Rats. Int J Mol Sci 2020; 21:ijms21082874. [PMID: 32326015 PMCID: PMC7216013 DOI: 10.3390/ijms21082874] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 04/07/2020] [Accepted: 04/16/2020] [Indexed: 12/25/2022] Open
Abstract
The unilateral 6-hydroxydopamine (6-OHDA) model of Parkinson’s disease (PD) is one of the most commonly used in rodents. The anatomical, metabolic, and behavioral changes that occur after severe and stable 6-OHDA lesions have been extensively studied. Here, we investigated whether early motor behavioral deficits can be observed in the first week after the injection of 6-OHDA into the right substantia nigra pars compacta (SNc), and if they were indicative of the severity of the dopaminergic (DAergic) lesion in the SNc and the striatum at different time-points (day 1, 3, 5, 7, 14, 21). With this aim, we used our newly modified tail suspension swing test (TSST), the standard rotation test (RT), and immunohistochemical staining for tyrosine hydroxylase (TH). The TSST, but not the standard RT, revealed a spontaneous motor bias for the 6-OHDA-lesioned rats from the day 1 post-surgery. Both tests detected the motor asymmetry induced by (single and repeated) apomorphine (APO) challenges that correlated, in the first week, with the DAergic neuronal degeneration. The described TSST is fast and easy to perform, and in the drug-free condition is useful for the functional assessment of early motor asymmetry appearing after the 6-OHDA-lesion in the SNc, without the confounding effect of APO challenges.
Collapse
Affiliation(s)
- Ilaria Rosa
- Department of Life, Health and Environmental Sciences (MESVA), University of L’Aquila, 67100 L’Aquila, Italy; (D.D.C.); (B.R.); (M.A.); (A.G.); (T.M.F.)
- Correspondence: (I.R.); (G.D.G.)
| | - Davide Di Censo
- Department of Life, Health and Environmental Sciences (MESVA), University of L’Aquila, 67100 L’Aquila, Italy; (D.D.C.); (B.R.); (M.A.); (A.G.); (T.M.F.)
| | - Brigida Ranieri
- Department of Life, Health and Environmental Sciences (MESVA), University of L’Aquila, 67100 L’Aquila, Italy; (D.D.C.); (B.R.); (M.A.); (A.G.); (T.M.F.)
| | - Giuseppe Di Giovanni
- Department of Life, Health and Environmental Sciences (MESVA), University of L’Aquila, 67100 L’Aquila, Italy; (D.D.C.); (B.R.); (M.A.); (A.G.); (T.M.F.)
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida MSD 2080, Malta
- Correspondence: (I.R.); (G.D.G.)
| | - Eugenio Scarnati
- Department of Biotechnological and Applied Clinical Sciences (DISCAB), University of L’Aquila, 67100 L’Aquila, Italy;
| | - Marcello Alecci
- Department of Life, Health and Environmental Sciences (MESVA), University of L’Aquila, 67100 L’Aquila, Italy; (D.D.C.); (B.R.); (M.A.); (A.G.); (T.M.F.)
- National Institute of Nuclear Physics, Gran Sasso National Laboratories, Assergi, 67100 L’Aquila, Italy
- SPIN-CNR Institute, Department of Physical and Chemical Sciences, 67100 L’Aquila, Italy
| | - Angelo Galante
- Department of Life, Health and Environmental Sciences (MESVA), University of L’Aquila, 67100 L’Aquila, Italy; (D.D.C.); (B.R.); (M.A.); (A.G.); (T.M.F.)
- National Institute of Nuclear Physics, Gran Sasso National Laboratories, Assergi, 67100 L’Aquila, Italy
- SPIN-CNR Institute, Department of Physical and Chemical Sciences, 67100 L’Aquila, Italy
| | - Tiziana Marilena Florio
- Department of Life, Health and Environmental Sciences (MESVA), University of L’Aquila, 67100 L’Aquila, Italy; (D.D.C.); (B.R.); (M.A.); (A.G.); (T.M.F.)
| |
Collapse
|
2
|
Faynveitz A, Lavian H, Jacob A, Korngreen A. Proliferation of Inhibitory Input to the Substantia Nigra in Experimental Parkinsonism. Front Cell Neurosci 2019; 13:417. [PMID: 31572130 PMCID: PMC6753199 DOI: 10.3389/fncel.2019.00417] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 08/30/2019] [Indexed: 12/17/2022] Open
Abstract
The substantia nigra pars reticulata (SNr) is one of the output nuclei of the basal ganglia (BG) and plays a vital role in movement execution. Death of dopaminergic neurons in the neighboring nucleus, the substantia nigra pars compacta (SNc), leads to Parkinson's disease. The ensuing dopamine depletion affects all BG nuclei. However, the long-term effects of dopamine depletion on BG output are less characterized. In this in vitro study, we applied electrophysiological and immunohistochemical techniques to investigate the long-term effects of dopamine depletion on GABAergic transmission to the SNr. The findings showed a reduction in firing rate and regularity in SNr neurons after unilateral dopamine depletion with 6-OHDA, which we associate with homeostatic mechanisms. The strength of the GABAergic synapses between the globus pallidus (GP) and the SNr increased but not their short-term dynamics. Consistent with this observation, there was an increase in the frequency and amplitude of spontaneous inhibitory synaptic events to SNr neurons. Immunohistochemistry revealed an increase in the density of vGAT-labeled puncta in dopamine depleted animals. Overall, these results may suggest that synaptic proliferation can explain how dopamine depletion augments GABAergic transmission in the SNr.
Collapse
Affiliation(s)
- Anna Faynveitz
- The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel
| | - Hagar Lavian
- The Leslie and Susan Gonda Interdisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, Israel
| | - Avi Jacob
- The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel
| | - Alon Korngreen
- The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel.,The Leslie and Susan Gonda Interdisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, Israel
| |
Collapse
|
3
|
Neuronal firing activity in the basal ganglia after striatal transplantation of dopamine neurons in hemiparkinsonian rats. Neuroscience 2017; 360:197-209. [DOI: 10.1016/j.neuroscience.2017.07.069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 07/28/2017] [Indexed: 01/27/2023]
|
4
|
Galvan A, Devergnas A, Wichmann T. Alterations in neuronal activity in basal ganglia-thalamocortical circuits in the parkinsonian state. Front Neuroanat 2015; 9:5. [PMID: 25698937 PMCID: PMC4318426 DOI: 10.3389/fnana.2015.00005] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 01/10/2015] [Indexed: 12/15/2022] Open
Abstract
In patients with Parkinson’s disease and in animal models of this disorder, neurons in the basal ganglia and related regions in thalamus and cortex show changes that can be recorded by using electrophysiologic single-cell recording techniques, including altered firing rates and patterns, pathologic oscillatory activity and increased inter-neuronal synchronization. In addition, changes in synaptic potentials or in the joint spiking activities of populations of neurons can be monitored as alterations in local field potentials (LFPs), electroencephalograms (EEGs) or electrocorticograms (ECoGs). Most of the mentioned electrophysiologic changes are probably related to the degeneration of diencephalic dopaminergic neurons, leading to dopamine loss in the striatum and other basal ganglia nuclei, although degeneration of non-dopaminergic cell groups may also have a role. The altered electrical activity of the basal ganglia and associated nuclei may contribute to some of the motor signs of the disease. We here review the current knowledge of the electrophysiologic changes at the single cell level, the level of local populations of neural elements, and the level of the entire basal ganglia-thalamocortical network in parkinsonism, and discuss the possible use of this information to optimize treatment approaches to Parkinson’s disease, such as deep brain stimulation (DBS) therapy.
Collapse
Affiliation(s)
- Adriana Galvan
- Yerkes National Primate Research Center, Emory University Atlanta, GA, USA ; Department of Neurology, School of Medicine, Emory University Atlanta, GA, USA ; Udall Center of Excellence for Parkinson's Disease Research, Emory University Atlanta, GA, USA
| | - Annaelle Devergnas
- Yerkes National Primate Research Center, Emory University Atlanta, GA, USA ; Udall Center of Excellence for Parkinson's Disease Research, Emory University Atlanta, GA, USA
| | - Thomas Wichmann
- Yerkes National Primate Research Center, Emory University Atlanta, GA, USA ; Department of Neurology, School of Medicine, Emory University Atlanta, GA, USA ; Udall Center of Excellence for Parkinson's Disease Research, Emory University Atlanta, GA, USA
| |
Collapse
|
5
|
Rubin JE, McIntyre CC, Turner RS, Wichmann T. Basal ganglia activity patterns in parkinsonism and computational modeling of their downstream effects. Eur J Neurosci 2012; 36:2213-28. [PMID: 22805066 DOI: 10.1111/j.1460-9568.2012.08108.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The availability of suitable animal models and the opportunity to record electrophysiologic data in movement disorder patients undergoing neurosurgical procedures has allowed researchers to investigate parkinsonism-related changes in neuronal firing patterns in the basal ganglia and associated areas of the thalamus and cortex. These studies have shown that parkinsonism is associated with increased activity in the basal ganglia output nuclei, along with increases in burst discharges, oscillatory firing and synchronous firing patterns throughout the basal ganglia. Computational approaches have the potential to play an important role in the interpretation of these data. Such efforts can provide a formalized view of neuronal interactions in the network of connections between the basal ganglia, thalamus, and cortex, allow for the exploration of possible contributions of particular network components to parkinsonism, and potentially result in new conceptual frameworks and hypotheses that can be subjected to biological testing. It has proven very difficult, however, to integrate the wealth of the experimental findings into coherent models of the disease. In this review, we provide an overview of the abnormalities in neuronal activity that have been associated with parkinsonism. Subsequently, we discuss some particular efforts to model the pathophysiologic mechanisms that may link abnormal basal ganglia activity to the cardinal parkinsonian motor signs and may help to explain the mechanisms underlying the therapeutic efficacy of deep brain stimulation for Parkinson's disease. We emphasize the logical structure of these computational studies, making clear the assumptions from which they proceed and the consequences and predictions that follow from these assumptions.
Collapse
Affiliation(s)
- Jonathan E Rubin
- Department of Mathematics and Center for the Neural Basis of Cognition, University of Pittsburgh, 301 Thackeray Hall, Pittsburgh, PA 15260, USA
| | | | | | | |
Collapse
|
6
|
Short- and long-term unilateral 6-hydroxydopamine lesions in rats show different changes in characteristics of spontaneous firing of substantia nigra pars reticulata neurons. Exp Brain Res 2012; 224:15-24. [PMID: 23283416 DOI: 10.1007/s00221-012-3285-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 09/20/2012] [Indexed: 10/27/2022]
Abstract
The unilateral 6-hydroxydopamine (6-OHDA) lesion of the medial forebrain bundle induces hemiparkinsonism in rats and is a well established animal model of Parkinson's disease. In this study, we assessed the spontaneous activity of substantia nigra pars reticulata (SNr) neurons in unilateral 6-OHDA- or sham-treated rats. Extracellular single cell recordings revealed a bilaterally decreased firing rate in short-term 6-OHDA-lesioned rats (8-10 weeks post lesion) while no rate differences were evident in long-term lesioned animals (5-8 months post lesion) in vivo under chloral hydrate anaesthesia. However, firing pattern of the SNr neurons (indicated by interspike interval (ISI) histogram parameters: coefficient of variation, skewness and kurtosis) was significantly altered only after long-term lesion: 53.8 % of the recorded cells in the ipsilateral 6-OHDA-lesioned SNr fired in a bursting pattern (compared to 5.9-16.7 % in contralateral SNr or sham controls). Additionally, behavioural effects of the lesion were assessed 4 weeks post lesion by the forelimb adjusting stepping test. A decreased number of adjusting steps with the contralateral forepaw, as well as an increased performance with the ipsilateral paw was found for the 6-OHDA-lesioned rats as compared to sham controls. Furthermore, stepping values were negatively correlated with the ISI parameters after long-term lesion, while there were no correlations with the short-term groups. Firing rate was not correlated regardless of the time frame. In conclusion, long-term changes in firing pattern may represent a neuronal correlate of the 6-OHDA-induced hemiparkinsonism and may be useful for the interpretation of 6-OHDA-induced motor deficits and compensatory mechanisms as well.
Collapse
|
7
|
The Antiparkinsonian and Antidyskinetic Mechanisms of Mucuna pruriens in the MPTP-Treated Nonhuman Primate. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 2012:840247. [PMID: 22997535 PMCID: PMC3445014 DOI: 10.1155/2012/840247] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Accepted: 07/27/2012] [Indexed: 12/01/2022]
Abstract
Chronic treatment with levodopa (LD) in Parkinson's disease (PD) can cause drug induced dyskinesias. Mucuna pruriens endocarp powder (MPEP) contains several compounds including natural LD and has been reported to not cause drug-induced dyskinesias. We evaluated the effects of Mucuna pruriens to determine if its underlying mechanistic actions are exclusively due to LD. We first compared MPEP with and without carbidopa (CD), and LD+CD in hemiparkinsonian (HP) monkeys. Each treatment ameliorated parkinsonism. We then compared the neuronal firing properties of the substantia nigra reticulata (SNR) and subthalamic nucleus (STN) in HP monkeys with MPEP+CD and LD+CD to evaluate basal ganglia circuitry alterations. Both treatments decreased SNR firing rate compared to HP state. However, LD+CD treatments significantly increased SNR bursting firing patterns that were not seen with MPEP+CD treatments. No significant changes were seen in STN firing properties. We then evaluated the effects of a water extract of MPEP. Oral MPWE ameliorated parkinsonism without causing drug-induced dyskinesias. The distinctive neurophysiological findings in the basal ganglia and the ability to ameliorate parkinsonism without causing dyskinesias strongly suggest that Mucuna pruriens acts through a novel mechanism that is different from that of LD.
Collapse
|
8
|
Gamma-aminobutyric acid(B) receptor activation suppresses stimulus-evoked burst firing in rat substantia nigra reticulata neurons. Neuroreport 2012; 23:40-4. [PMID: 22127013 DOI: 10.1097/wnr.0b013e32834e4899] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Previous whole-cell patch-pipette studies showed that focal electrical stimulation of the subthalamic nucleus (STN) evokes a long-lasting complex excitatory postsynaptic currents (EPSC) and synaptically evoked bursts of action potentials in substantia nigra pars reticulata (SNR) neurons. Although synaptically evoked bursting may play a role in normal physiology, excessive burst firing correlates with symptoms of Parkinson's disease. We used patch-pipette recordings in rat brain slices to study the effects of baclofen on complex EPSCs and STN-induced burst firing in SNR neurons. Baclofen (1 µM) caused a reversible, 73% reduction in complex EPSCs, and this effect was blocked by the γ-aminobutyric acid(B) antagonist CGP35348 (100 µM). Using the loose-patch method to record extracellular potentials, a lower concentration of baclofen (100 nM) inhibited STN-evoked bursts, while leaving spontaneous firing of action potentials less affected. We suggest that strategies that selectively inhibit burst firing in the SNR might have therapeutic potential in the treatment of Parkinson's disease.
Collapse
|
9
|
Wichmann T, Dostrovsky JO. Pathological basal ganglia activity in movement disorders. Neuroscience 2011; 198:232-44. [PMID: 21723919 DOI: 10.1016/j.neuroscience.2011.06.048] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 06/13/2011] [Accepted: 06/14/2011] [Indexed: 11/16/2022]
Abstract
Our understanding of the pathophysiology of movement disorders and associated changes in basal ganglia activities has significantly changed during the last few decades. This process began with the development of detailed anatomical models of the basal ganglia, followed by studies of basal ganglia activity patterns in animal models of common movement disorders and electrophysiological recordings in movement disorder patients undergoing functional neurosurgical procedures. These investigations first resulted in an appreciation of global activity changes in the basal ganglia in parkinsonism and other disorders, and later in the detailed description of pathological basal ganglia activity patterns, specifically burst patterns and oscillatory synchronous discharge of basal ganglia neurons. In this review, we critically summarize our current knowledge of the pathological discharge patterns of basal ganglia neurons in Parkinson's disease, dystonia, and dyskinesias.
Collapse
Affiliation(s)
- T Wichmann
- Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA.
| | | |
Collapse
|
10
|
Wang Y, Zhang QJ, Liu J, Ali U, Gui ZH, Hui YP, Chen L, Wu ZH, Li Q. Noradrenergic lesion of the locus coeruleus increases apomorphine-induced circling behavior and the firing activity of substantia nigra pars reticulata neurons in a rat model of Parkinson's disease. Brain Res 2010; 1310:189-99. [DOI: 10.1016/j.brainres.2009.10.070] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 10/27/2009] [Accepted: 10/29/2009] [Indexed: 11/25/2022]
|
11
|
Avila I, Parr-Brownlie LC, Brazhnik E, Castañeda E, Bergstrom DA, Walters JR. Beta frequency synchronization in basal ganglia output during rest and walk in a hemiparkinsonian rat. Exp Neurol 2009; 221:307-19. [PMID: 19948166 DOI: 10.1016/j.expneurol.2009.11.016] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Revised: 11/12/2009] [Accepted: 11/18/2009] [Indexed: 12/01/2022]
Abstract
Synchronized oscillatory neuronal activity in the beta frequency range has been observed in the basal ganglia of Parkinson's disease patients and hypothesized to be antikinetic. The unilaterally lesioned rat model of Parkinson's disease allows examination of this hypothesis by direct comparison of beta activity in basal ganglia output in non-lesioned and dopamine cell lesioned hemispheres during motor activity. Bilateral substantia nigra pars reticulata (SNpr) recordings of units and local field potentials (LFP) were obtained with EMG activity from the scapularis muscle in control and unilaterally nigrostriatal lesioned rats trained to walk on a rotary treadmill. After left hemispheric lesion, rats had difficulty walking contraversive on the treadmill but could walk in the ipsiversive direction. During inattentive rest, SNpr LFP power in the 12-25 Hz range (low beta) was significantly greater in the dopamine-depleted hemisphere than in non-lesioned and control hemispheres. During walking, low beta power was reduced in all hemispheres, while 25-40 Hz (high beta) activity was selectively increased in the lesioned hemisphere. High beta power increases were reduced by l-DOPA administration. SNpr spiking was significantly more synchronized with SNpr low beta LFP oscillations during rest and high beta LFP oscillations during walking in the dopamine-depleted hemispheres compared with non-lesioned hemispheres. Data show that dopamine loss is associated with opposing changes in low and high beta range SNpr activity during rest and walk and suggest that increased synchronization of high beta activity in SNpr output from the lesioned hemisphere during walking may contribute to gait impairment in the hemiparkinsonian rat.
Collapse
Affiliation(s)
- Irene Avila
- Neurophysiological Pharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Building 35 Room 1C 905, Bethesda, MD 20892-3702, USA
| | | | | | | | | | | |
Collapse
|
12
|
Mean-field modeling of the basal ganglia-thalamocortical system. II Dynamics of parkinsonian oscillations. J Theor Biol 2008; 257:664-88. [PMID: 19154745 DOI: 10.1016/j.jtbi.2008.12.013] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 12/08/2008] [Accepted: 12/08/2008] [Indexed: 11/21/2022]
Abstract
Neuronal correlates of Parkinson's disease (PD) include a shift to lower frequencies in the electroencephalogram (EEG) and enhanced synchronized oscillations at 3-7 and 7-30 Hz in the basal ganglia, thalamus, and cortex. This study describes the dynamics of a recent physiologically based mean-field model of the basal ganglia-thalamocortical system, and shows how it accounts for many key electrophysiological correlates of PD. Its detailed functional connectivity comprises partially segregated direct and indirect pathways through two populations of striatal neurons, a hyperdirect pathway involving a corticosubthalamic projection, thalamostriatal feedback, and local inhibition in striatum and external pallidum (GPe). In a companion paper, realistic steady-state firing rates were obtained for the healthy state, and after dopamine loss modeled by weaker direct and stronger indirect pathways, reduced intrapallidal inhibition, lower firing thresholds of the GPe and subthalamic nucleus (STN), a stronger projection from striatum to GPe, and weaker cortical interactions. Here it is shown that oscillations around 5 and 20 Hz can arise with a strong indirect pathway, which also causes increased synchronization throughout the basal ganglia. Furthermore, increased theta power with progressive nigrostriatal degeneration is correlated with reduced alpha power and peak frequency, in agreement with empirical results. Unlike the hyperdirect pathway, the indirect pathway sustains oscillations with phase relationships that coincide with those found experimentally. Alterations in the responses of basal ganglia to transient stimuli accord with experimental observations. Reduced cortical gains due to both nigrostriatal and mesocortical dopamine loss lead to slower changes in cortical activity and may be related to bradykinesia. Finally, increased EEG power found in some studies may be partly explained by a lower effective GPe firing threshold, reduced GPe-GPe inhibition, and/or weaker intracortical connections in parkinsonian patients. Strict separation of the direct and indirect pathways is not necessary to obtain these results.
Collapse
|
13
|
Galvan A, Wichmann T. Pathophysiology of parkinsonism. Clin Neurophysiol 2008; 119:1459-74. [PMID: 18467168 DOI: 10.1016/j.clinph.2008.03.017] [Citation(s) in RCA: 327] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Revised: 03/10/2008] [Accepted: 03/20/2008] [Indexed: 01/05/2023]
Abstract
The motor signs of Parkinson's disease are thought to result in large part from a reduction of the level of dopamine in the basal ganglia. Over the last few years, many of the functional and anatomical consequences of dopamine loss in these structures have been identified, both in the basal ganglia and in related areas in thalamus and cortex. This knowledge has contributed significantly to our understanding of the link between the degeneration of dopamine neurons in the midbrain and the development of parkinsonism. This review discusses the evidence that implicates electrophysiologic changes (including altered discharge rates, increased incidence of burst firing, interneuronal synchrony, oscillatory activity, and altered sensorimotor processing) in basal ganglia, thalamus, and cortex, in parkinsonism. From these studies, parkinsonism emerges as a complex network disorder, in which abnormal activity in groups of neurons in the basal ganglia strongly affects the excitability, oscillatory activity, synchrony and sensory responses of areas of the cerebral cortex that are involved in the planning and execution of movement, as well as in executive, limbic or sensory functions. Detailed knowledge of these changes will help us to develop more effective and specific symptomatic treatments for patients with Parkinson's disease.
Collapse
Affiliation(s)
- Adriana Galvan
- Department of Neurology, School of Medicine and Division of Sensorimotor Systems, Yerkes National Primate Center, Emory University, Atlanta, GA 30329, United States
| | | |
Collapse
|
14
|
Breit S, Martin A, Lessmann L, Cerkez D, Gasser T, Schulz J. Bilateral changes in neuronal activity of the basal ganglia in the unilateral 6-hydroxydopamine rat model. J Neurosci Res 2008; 86:1388-96. [DOI: 10.1002/jnr.21588] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
15
|
Wichmann T, Soares J. Neuronal firing before and after burst discharges in the monkey basal ganglia is predictably patterned in the normal state and altered in parkinsonism. J Neurophysiol 2005; 95:2120-33. [PMID: 16371459 DOI: 10.1152/jn.01013.2005] [Citation(s) in RCA: 173] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It is known that burst discharges in basal ganglia neurons are more common in parkinsonism than under normal conditions, but changes in the structure of burst or peri-burst epochs have not been reported. In this study, the temporal structure of bursts and the timing of neuronal discharges that precede or follow them were examined in neuronal spike trains recorded in the subthalamic nucleus (STN) and the external and internal pallidal segment (GPe, GPi) in two awake Rhesus monkeys before and after they were rendered hemiparkinsonian by unilateral intracarotid infusion of the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Bursts were detected by the "surprise" method. In the normal state, interspike intervals (ISIs) preceding or following bursts were frequently significantly longer than the average baseline ISI, and their duration was correlated with the burst length (i.e., the number of spikes/burst). Significant correlations were also found in all three structures between the burst length and the duration of interburst intervals. The incidence of burst discharges and the proportion of time spent in bursts increased in GPe, STN, and GPi after MPTP treatment. Burst lengths became more tightly related to preburst ISIs in the STN after MPTP treatment and to postburst ISI duration in all three structures. These results show that bursts in spontaneous GPe, STN, and GPi discharge are often preceded or followed by long ISIs, and that burst length, the length of pre- and postburst ISIs, and the length of interburst intervals are related to one another. Complex changes in these interactions may contribute to abnormal information processing in parkinsonism.
Collapse
Affiliation(s)
- Thomas Wichmann
- Department of Neurology, Emory University, Atlanta, GA 30322, USA.
| | | |
Collapse
|
16
|
Abstract
This review covers beta-phenylethylamines and isoquinoline alkaloids derived from them, including further products of oxidation. condensation with formaldehyde and rearrangement, some of which do not contain an isoquinoline system, together with naphthylisoquinoline alkaloids, which have a different biogenetic origin. The occurrence of the alkaloids, with the structures of new bases, together with their reactions, syntheses and biological activities are reported. The literature from July 2002 to June 2003 is reviewed, with 568 references cited.
Collapse
|