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Morgenstern NA, Esposito MS. The Basal Ganglia and Mesencephalic Locomotor Region Connectivity Matrix. Curr Neuropharmacol 2024; 22:1454-1472. [PMID: 37559244 PMCID: PMC11097982 DOI: 10.2174/1570159x21666230809112840] [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: 12/09/2022] [Revised: 02/16/2023] [Accepted: 02/23/2023] [Indexed: 08/11/2023] Open
Abstract
Although classically considered a relay station for basal ganglia (BG) output, the anatomy, connectivity, and function of the mesencephalic locomotor region (MLR) were redefined during the last two decades. In striking opposition to what was initially thought, MLR and BG are actually reciprocally and intimately interconnected. New viral-based, optogenetic, and mapping technologies revealed that cholinergic, glutamatergic, and GABAergic neurons coexist in this structure, which, in addition to extending descending projections, send long-range ascending fibers to the BG. These MLR projections to the BG convey motor and non-motor information to specific synaptic targets throughout different nuclei. Moreover, MLR efferent fibers originate from precise neuronal subpopulations located in particular MLR subregions, defining independent anatomo-functional subcircuits involved in particular aspects of animal behavior such as fast locomotion, explorative locomotion, posture, forelimb- related movements, speed, reinforcement, among others. In this review, we revised the literature produced during the last decade linking MLR and BG. We conclude that the classic framework considering the MLR as a homogeneous output structure passively receiving input from the BG needs to be revisited. We propose instead that the multiple subcircuits embedded in this region should be taken as independent entities that convey relevant and specific ascending information to the BG and, thus, actively participate in the execution and tuning of behavior.
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Affiliation(s)
- Nicolás A. Morgenstern
- Champalimaud Research, Champalimaud Foundation, Lisbon, Portugal
- Faculty of Medicine, University of Lisbon, Instituto De Medicina Molecular João Lobo Antunes, Lisbon, Portugal
| | - Maria S. Esposito
- Department of Medical Physics, Centro Atomico Bariloche, CNEA, CONICET, Av. Bustillo 9500, San Carlos de Bariloche, Rio Negro, Argentina
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Tan X, Zhu R, Xie Y, Chai Y. Suppression of absence seizures by using different stimulations in a reduced corticothalamic-basal ganglion-pedunculopontine nucleus model. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2023; 20:20468-20485. [PMID: 38124561 DOI: 10.3934/mbe.2023905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Coupled neural network models are playing an increasingly important part in the modulation of absence seizures today. However, it is currently unclear how basal ganglia, corticothalamic network and pedunculopontine nucleus can coordinate with each other to develop a whole coupling circuit, theoretically. In addition, it is still difficult to select effective parameters of electrical stimulation on the regulation of absence seizures in clinical trials. Therefore, to develop a coupled model and reduce computation cost, a new model constructed by a simplified basal ganglion, two corticothalamic circuits and a pedunculopontine nucleus was proposed. Further, to seek better inhibition therapy, three electrical stimulations, high frequency stimulation (HFS), 1:0 coordinate reset stimulation (CRS) and 3:2 CRS, were applied to the thalamic reticular nucleus (RE) in the first corticothalamic circuit in the coupled model. The simulation results revealed that increasing the frequency and pulse width of an electrical stimulation within a certain range can also suppress seizures. Under the same parameters of electrical stimulation, the inhibitory effect of HFS on seizures was better than that of 1:0 CRS and 3:2 CRS. The research established a reduced corticothalamic-basal ganglion-pedunculopontine nucleus model, which lays a theoretical foundation for future optimal parameters selection of electrical stimulation. We hope that the findings will provide new insights into the role of theoretical models in absence seizures.
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Affiliation(s)
- Xiaolong Tan
- School of Mathematics and Physics, Shanghai University of Electric Power, Shanghai 201306, China
| | - Rui Zhu
- School of Mathematics and Physics, Shanghai University of Electric Power, Shanghai 201306, China
| | - Yan Xie
- School of Mathematics and Physics, Shanghai University of Electric Power, Shanghai 201306, China
| | - Yuan Chai
- School of Mathematics and Physics, Shanghai University of Electric Power, Shanghai 201306, China
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3
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Emmi A, Campagnolo M, Stocco E, Carecchio M, Macchi V, Antonini A, De Caro R, Porzionato A. Neurotransmitter and receptor systems in the subthalamic nucleus. Brain Struct Funct 2023; 228:1595-1617. [PMID: 37479801 PMCID: PMC10471682 DOI: 10.1007/s00429-023-02678-z] [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: 02/10/2023] [Accepted: 07/02/2023] [Indexed: 07/23/2023]
Abstract
The Subthalamic Nucleus (STh) is a lens-shaped subcortical structure located ventrally to the thalamus, that despite being embryologically derived from the diencephalon, is functionally implicated in the basal ganglia circuits. Because of this strict structural and functional relationship with the circuits of the basal ganglia, the STh is a current target for deep brain stimulation, a neurosurgical procedure employed to alleviate symptoms in movement disorders, such as Parkinson's disease and dystonia. However, despite the great relevance of this structure for both basal ganglia physiology and pathology, the neurochemical and molecular anatomy of the STh remains largely unknown. Few studies have specifically addressed the detection of neurotransmitter systems and their receptors within the structure, and even fewer have investigated their topographical distribution. Here, we have reviewed the scientific literature on neurotransmitters relevant in the STh function of rodents, non-human primates and humans including glutamate, GABA, dopamine, serotonin, noradrenaline with particular focus on their subcellular, cellular and topographical distribution. Inter-species differences were highlighted to provide a framework for further research priorities, particularly in humans.
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Affiliation(s)
- Aron Emmi
- Institute of Human Anatomy, Department of Neuroscience, University of Padova, Padua, Italy
- Parkinson and Movement Disorders Unit, Centre for Rare Neurological Diseases, Department of Neuroscience, University of Padova, Padua, Italy
- Center for Neurodegenerative Disease Research (CESNE), University of Padova, Padua, Italy
| | - Marta Campagnolo
- Parkinson and Movement Disorders Unit, Centre for Rare Neurological Diseases, Department of Neuroscience, University of Padova, Padua, Italy
- Center for Neurodegenerative Disease Research (CESNE), University of Padova, Padua, Italy
| | - Elena Stocco
- Institute of Human Anatomy, Department of Neuroscience, University of Padova, Padua, Italy
| | - Miryam Carecchio
- Parkinson and Movement Disorders Unit, Centre for Rare Neurological Diseases, Department of Neuroscience, University of Padova, Padua, Italy
- Center for Neurodegenerative Disease Research (CESNE), University of Padova, Padua, Italy
| | - Veronica Macchi
- Institute of Human Anatomy, Department of Neuroscience, University of Padova, Padua, Italy
- Center for Neurodegenerative Disease Research (CESNE), University of Padova, Padua, Italy
| | - Angelo Antonini
- Parkinson and Movement Disorders Unit, Centre for Rare Neurological Diseases, Department of Neuroscience, University of Padova, Padua, Italy
- Center for Neurodegenerative Disease Research (CESNE), University of Padova, Padua, Italy
| | - Raffaele De Caro
- Institute of Human Anatomy, Department of Neuroscience, University of Padova, Padua, Italy.
- Center for Neurodegenerative Disease Research (CESNE), University of Padova, Padua, Italy.
| | - Andrea Porzionato
- Institute of Human Anatomy, Department of Neuroscience, University of Padova, Padua, Italy
- Center for Neurodegenerative Disease Research (CESNE), University of Padova, Padua, Italy
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4
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Ma R, Yin Z, Chen Y, Yuan T, An Q, Gan Y, Xu Y, Jiang Y, Du T, Yang A, Meng F, Zhu G, Zhang J. Sleep outcomes and related factors in Parkinson's disease after subthalamic deep brain electrode implantation: a retrospective cohort study. Ther Adv Neurol Disord 2023; 16:17562864231161163. [PMID: 37200769 PMCID: PMC10185976 DOI: 10.1177/17562864231161163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 02/15/2023] [Indexed: 05/20/2023] Open
Abstract
Background Subthalamic nucleus deep brain stimulation (STN-DBS) improves sleep qualities in Parkinson's disease (PD) patients; however, it remains elusive whether STN-DBS improves sleep by directly influencing the sleep circuit or alleviates other cardinal symptoms such as motor functions, other confounding factors including stimulation intensity may also involve. Studying the effect of microlesion effect (MLE) on sleep after STN-DBS electrode implantation may address this issue. Objective To examine the influence of MLE on sleep quality and related factors in PD, as well as the effects of regional and lateral specific correlations with sleep outcomes after STN-DBS electrode implantation. Study Design Case-control study; Level of evidence, 3. Data Sources and Methods In 78 PD patients who underwent bilateral STN-DBS surgery in our center, we compared the sleep qualities, motor performances, anti-Parkinsonian drug dosage, and emotional conditions at preoperative baseline and postoperative 1-month follow-up. We determined the related factors of sleep outcomes and visualized the electrodes position, simulated the MLE-engendered volume of tissue lesioned (VTL), and investigated sleep-related sweet/sour spots and laterality in STN. Results MLE improves sleep quality with Pittsburgh Sleep Quality Index (PSQI) by 13.36% and Parkinson's Disease Sleep Scale-2 (PDSS-2) by 17.95%. Motor (P = 0.014) and emotional (P = 0.001) improvements were both positively correlated with sleep improvements. However, MLE in STN associative subregions, as an independent factor, may cause sleep deterioration (r = 0.348, P = 0.002), and only the left STN showed significance (r = 0.327, P = 0.004). Sweet spot analysis also indicated part of the left STN associative subregion is the sour spot indicative of sleep deterioration. Conclusion The MLE of STN-DBS can overall improve sleep quality in PD patients, with a positive correlation between motor and emotional improvements. However, independent of all other factors, the MLE in the STN associative subregion, particularly the left side, may cause sleep deterioration.
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Affiliation(s)
- Ruoyu Ma
- Department of Neurosurgery, Beijing Tiantan
Hospital, Capital Medical University, Beijing, China
| | - Zixiao Yin
- Department of Neurosurgery, Beijing Tiantan
Hospital, Capital Medical University, Beijing, China
| | - Yingchuan Chen
- Department of Neurosurgery, Beijing Tiantan
Hospital, Capital Medical University, Beijing, China
| | - Tianshuo Yuan
- Department of Neurosurgery, Beijing Tiantan
Hospital, Capital Medical University, Beijing, China
| | - Qi An
- Department of Neurosurgery, Beijing Tiantan
Hospital, Capital Medical University, Beijing, China
| | - Yifei Gan
- Department of Neurosurgery, Beijing Tiantan
Hospital, Capital Medical University, Beijing, China
| | - Yichen Xu
- Department of Neurosurgery, Beijing Tiantan
Hospital, Capital Medical University, Beijing, China
| | - Yin Jiang
- Department of Functional Neurosurgery, Beijing
Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Tingting Du
- Department of Functional Neurosurgery, Beijing
Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Anchao Yang
- Department of Neurosurgery, Beijing Tiantan
Hospital, Capital Medical University, Beijing, China
| | - Fangang Meng
- Department of Functional Neurosurgery, Beijing
Neurosurgical Institute, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Neurostimulation,
Beijing, China
| | - Guanyu Zhu
- Department of Neurosurgery, Beijing Tiantan
Hospital, Capital Medical University, No. 119 South 4th Ring West Road,
Fengtai District, Beijing 100070, China
| | - Jianguo Zhang
- Department of Neurosurgery, Beijing Tiantan
Hospital, Capital Medical University, No. 119 South 4th Ring West Road,
Fengtai District, Beijing 100070, China
- Department of Functional Neurosurgery, Beijing
Neurosurgical Institute, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Neurostimulation,
Beijing, China
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Witzig VS, Alosaimi F, Temel Y, Schulz JB, Jahanshahi A, Tan SKH. Gait improvement by high-frequency stimulation of the subthalamic nucleus in Parkinsonian mice is not associated with changes of the cholinergic system in the pedunculopontine nucleus. Neurosci Lett 2023; 802:137134. [PMID: 36801348 DOI: 10.1016/j.neulet.2023.137134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/30/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023]
Abstract
Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is standard care for severe motor symptoms of Parkinson's disease (PD). However, a challenge of DBS remains improving gait. Gait has been associated with the cholinergic system in the pedunculopontine nucleus (PPN). In this study, we investigated the effects of long-term intermittent bilateral STN-DBS on PPN cholinergic neurons in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) Parkinsonian mouse model. Motor behavior, previously assessed by the automated Catwalk gait analysis, demonstrated a parkinsonian-like motor phenotype with static and dynamic gait impairments, which were reversed by STN-DBS. In this study, a subset of brains was further immunohistochemically processed for choline acetyltransferase (ChAT) and the neuronal activation marker c-Fos. MPTP treatment resulted in a significant reduction of PPN ChAT expressing neurons compared to saline treatment. STN-DBS did not alter the number of ChAT expressing neurons, nor the number of double-labelled PPN neurons for ChAT and c-Fos. Although STN-DBS improved gait in our model this was not associated with an altered expression or activation of PPN acetylcholine neurons. Motor and gait effects of STN-DBS are therefore less likely to be mediated by the STN-PPN connection and PPN cholinergic system.
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Affiliation(s)
- V S Witzig
- Department of Neurology, RWTH Aachen University, Aachen, Germany.
| | - F Alosaimi
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht, Netherlands
| | - Y Temel
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht, Netherlands
| | - J B Schulz
- Department of Neurology, RWTH Aachen University, Aachen, Germany; JARA Institute Molecular Neuroscience and Neuroimaging, Forschungszentrum Jülich and RWTH Aachen University, Aachen, Germany
| | - A Jahanshahi
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht, Netherlands
| | - S K H Tan
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht, Netherlands; Department of Neurosurgery, RWTH Aachen University, Aachen, Germany.
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Water Drinking Behavior Associated with Aversive Arousal in Rats: An Integrative Approach. Brain Sci 2022; 13:brainsci13010060. [PMID: 36672042 PMCID: PMC9857118 DOI: 10.3390/brainsci13010060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 12/26/2022] [Accepted: 12/27/2022] [Indexed: 12/30/2022] Open
Abstract
Cholinergic muscarinic stimulation of vast areas of the limbic brain induced a well-documented polydipsia in laboratory rats. This excessive water-drinking behavior has not received any convincing biological and physiological interpretation for the last 50 years. This review offers such an interpretation and suggests that cholinergically induced drinking response, mostly by carbachol, is associated with activation of the ascending mesolimbic cholinergic system that serves for initiation of emotional aversive arousal of the organism. The ascending cholinergic system originates from the laterodorsal tegmental nucleus, has a diffuse nature, and affects numerous subcortical limbic structures. It is proposed that the carbachol-induced drinking response is related to the state of anxiety and does not serve the regulation of thirst. Instead, the response is anxiety-induced polydipsia that might occur as a soothing procedure that decreases the aversiveness of the negative emotional state induced by carbachol. It is concluded that carbachol-induced water-drinking behavior is a rewarding process that contributes to alleviating the feeling of anxiety by bringing some relief from the cholinergically induced aversive state, and it is a homologue to anxiety-driven polydipsia in humans.
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Masini D, Kiehn O. Targeted activation of midbrain neurons restores locomotor function in mouse models of parkinsonism. Nat Commun 2022; 13:504. [PMID: 35082287 PMCID: PMC8791953 DOI: 10.1038/s41467-022-28075-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 01/07/2022] [Indexed: 12/26/2022] Open
Abstract
The pedunculopontine nucleus (PPN) is a locomotor command area containing glutamatergic neurons that control locomotor initiation and maintenance. These motor actions are deficient in Parkinson’s disease (PD), where dopaminergic neurodegeneration alters basal ganglia activity. Being downstream of the basal ganglia, the PPN may be a suitable target for ameliorating parkinsonian motor symptoms. Here, we use in vivo cell-type specific PPN activation to restore motor function in two mouse models of parkinsonism made by acute pharmacological blockage of dopamine transmission. With a combination of chemo- and opto-genetics, we show that excitation of caudal glutamatergic PPN neurons can normalize the otherwise severe locomotor deficit in PD, whereas targeting the local GABAergic population only leads to recovery of slow locomotion. The motor rescue driven by glutamatergic PPN activation is independent of activity in nearby locomotor promoting glutamatergic Cuneiform neurons. Our observations point to caudal glutamatergic PPN neurons as a potential target for neuromodulatory restoration of locomotor function in PD. Here, the authors use cell-type specific stimulation of brainstem neurons within the caudal pedunculopontine nucleus to show that activation of excitatory neurons can normalize severe locomotor deficit in mouse models of parkinsonism. The study defines a potential target for neuromodulatory restoration of locomotor function in Parkinson’s disease.
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Affiliation(s)
- Débora Masini
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Ole Kiehn
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark. .,Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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8
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Luquin E, Paternain B, Zugasti I, Santomá C, Mengual E. Stereological estimations and neurochemical characterization of neurons expressing GABAA and GABAB receptors in the rat pedunculopontine and laterodorsal tegmental nuclei. Brain Struct Funct 2022; 227:89-110. [PMID: 34510281 PMCID: PMC8741722 DOI: 10.1007/s00429-021-02375-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 08/31/2021] [Indexed: 11/29/2022]
Abstract
To better understand GABAergic transmission at two targets of basal ganglia downstream projections, the pedunculopontine (PPN) and laterodorsal (LDT) tegmental nuclei, the anatomical localization of GABAA and GABAB receptors was investigated in both nuclei. Specifically, the total number of neurons expressing the GABAA receptor γ2 subunit (GABAAR γ2) and the GABAB receptor R2 subunit (GABAB R2) in PPN and LDT was estimated using stereological methods, and the neurochemical phenotype of cells expressing each subunit was also determined. The mean number of non-cholinergic cells expressing GABAAR γ2 was 9850 ± 1856 in the PPN and 8285 ± 962 in the LDT, whereas those expressing GABAB R2 were 7310 ± 1970 and 9170 ± 1900 in the PPN and LDT, respectively. In addition, all cholinergic neurons in both nuclei co-expressed GABAAR γ2 and 95-98% of them co-expressed GABAB R2. Triple labeling using in situ hybridization revealed that 77% of GAD67 mRNA-positive cells in the PPT and 49% in the LDT expressed GABAAR γ2, while 90% (PPN) and 65% (LDT) of Vglut2 mRNA-positive cells also expressed GABAAR γ2. In contrast, a similar proportion (~2/3) of glutamatergic and GABAergic cells co-expressed GABAB R2 in both nuclei. The heterogeneous distribution of GABAAR and GABABR among non-cholinergic cells in PPN and LDT may give rise to physiological differences within each neurochemical subpopulation. In addition, the dissimilar proportion of GABAAR γ2-expressing glutamatergic and GABAergic neurons in the PPN and LDT may contribute to some of the functional differences found between the two nuclei.
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Affiliation(s)
- Esther Luquin
- Department of Pathology, Anatomy, and Physiology, School of Medicine, University of Navarra, Ed. Los Castaños, Irunlarrea 1, 31008 Pamplona, Spain
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
| | - Beatriz Paternain
- Department of Pathology, Anatomy, and Physiology, School of Medicine, University of Navarra, Ed. Los Castaños, Irunlarrea 1, 31008 Pamplona, Spain
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
| | - Inés Zugasti
- Department of Pathology, Anatomy, and Physiology, School of Medicine, University of Navarra, Ed. Los Castaños, Irunlarrea 1, 31008 Pamplona, Spain
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
| | - Carmen Santomá
- Department of Pathology, Anatomy, and Physiology, School of Medicine, University of Navarra, Ed. Los Castaños, Irunlarrea 1, 31008 Pamplona, Spain
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
| | - Elisa Mengual
- Department of Pathology, Anatomy, and Physiology, School of Medicine, University of Navarra, Ed. Los Castaños, Irunlarrea 1, 31008 Pamplona, Spain
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
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King G, Veros KM, MacLaren DAA, Leigh MPK, Spernyak JA, Clark SD. Human wildtype tau expression in cholinergic pedunculopontine tegmental neurons is sufficient to produce PSP-like behavioural deficits and neuropathology. Eur J Neurosci 2021; 54:7688-7709. [PMID: 34668254 DOI: 10.1111/ejn.15496] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/30/2021] [Accepted: 10/12/2021] [Indexed: 11/30/2022]
Abstract
Progressive Supranuclear Palsy (PSP) is the most common atypical parkinsonism and exhibits hallmark symptomology including motor function impairment and dysexecutive dementia. In contrast to Parkinson's disease, the underlying pathology displays aggregation of the protein tau, which is also seen in disorders such as Alzheimer's disease. Currently, there are no pharmacological treatments for PSP, and drug discovery efforts are hindered by the lack of an animal model specific to PSP. Based on previous results and clinical pathology, it was hypothesized that viral deposition of tau in cholinergic neurons within the hindbrain would produce a tauopathy along neural connections to produce PSP-like symptomology and pathology. By using a combination of ChAT-CRE rats and CRE-dependent AAV vectors, wildtype human tau (the PSP-relevant 1N4R isoform; hTau) was expressed in hindbrain cholinergic neurons. Compared to control subjects (GFP), rats with tau expression displayed deficits in a variety of behavioural paradigms: acoustic startle reflex, marble burying, horizontal ladder and hindlimb motor reflex. Postmortem, the hTau rats had significantly reduced number of cholinergic pedunculopontine tegmentum and dopaminergic substantia nigra neurons, as well as abnormal tau deposits. This preclinical model has multiple points of convergence with the clinical features of PSP, some of which distinguish between PSP and Parkinson's disease.
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Affiliation(s)
- Gabriella King
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York, USA
| | - Kaliana M Veros
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York, USA
| | | | | | - Joseph A Spernyak
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA
| | - Stewart D Clark
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York, USA
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10
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Zuzuárregui JRP, Ostrem JL. The Impact of Deep Brain Stimulation on Sleep in Parkinson's Disease: An update. JOURNAL OF PARKINSONS DISEASE 2021; 10:393-404. [PMID: 32250316 PMCID: PMC7242854 DOI: 10.3233/jpd-191862] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Background: Parkinson’s disease (PD) can have a significant impact on sleep. Deep brain stimulation (DBS) is an effective treatment for motor features of PD, but less is understood about the impact DBS may have on sleep architecture and various sleep issues commonly seen in PD. Objective: To review the impact of DBS on various sleep issues in PD. Methods: We reviewed the literature regarding the impact of DBS on sleep patterns, nocturnal motor and non-motor symptoms, and sleep disorders in PD. Results: Objective sleep measures on polysomnography (PSG), including sleep latency and wake after sleep onset improve after subthalamic nucleus (STN) and globus pallidus interna (GPi) DBS. Subjective sleep measures, nocturnal motor symptoms, and some non-motor symptoms (nocturia) also may improve. Current evidence suggests STN DBS has no impact on Rapid Eye Movement Behavior Disorder (RBD), while STN DBS may improve symptoms of Restless Legs Syndrome (RLS). There are no studies that have evaluated the impact of GPi DBS on RBD, while it is unclear if GPi has an effect on RLS in PD. Conclusion: DBS therapy at either site appears to improve objective and subjective sleep parameters in patients with PD. Most likely, the improvement of motor and some non-motor nocturnal symptoms leads to an increase in total sleep time by up to an hour, as well as reduction of sleep fragmentation. DBS most likely has no impact on RBD, while there is evidence that STN DBS appears to help reduce RLS severity. Further studies are needed.
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Affiliation(s)
| | - Jill L Ostrem
- Department of Neurology, University of California, San Francisco, CA, USA
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11
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Grillner S, Robertson B, Kotaleski JH. Basal Ganglia—A Motion Perspective. Compr Physiol 2020; 10:1241-1275. [DOI: 10.1002/cphy.c190045] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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12
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Cortical Control of Subthalamic Neuronal Activity through the Hyperdirect and Indirect Pathways in Monkeys. J Neurosci 2020; 40:7451-7463. [PMID: 32847963 DOI: 10.1523/jneurosci.0772-20.2020] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 08/07/2020] [Accepted: 08/17/2020] [Indexed: 12/22/2022] Open
Abstract
The subthalamic nucleus (STN) plays a key role in the control of voluntary movements and basal ganglia disorders, such as Parkinson's disease and hemiballismus. The STN receives glutamatergic inputs directly from the cerebral cortex via the cortico-STN hyperdirect pathway and GABAergic inputs from the external segment of the globus pallidus (GPe) via the cortico-striato-GPe-STN indirect pathway. The STN then drives the internal segment of the globus pallidus, which is the output nucleus of the basal ganglia. Thus, clarifying how STN neuronal activity is controlled by the two inputs is crucial. Cortical stimulation evokes early excitation and late excitation in STN neurons, intervened by a short gap. Here, to examine the origin of each component of this biphasic response, we recorded neuronal activity in the STN, combined with electrical stimulation of the motor cortices and local drug application in two male monkeys (Macaca fuscata) in the awake state. Local application of glutamate receptor antagonists, a mixture of an AMPA/kainate receptor antagonist and an NMDA receptor antagonist, into the vicinity of recorded STN neurons specifically diminished early excitation. Blockade of the striatum (putamen) or GPe with local injection of a GABAA receptor agonist, muscimol, diminished late excitation in the STN. Blockade of striato-GPe transmission with local injection of a GABAA receptor antagonist, gabazine, into the GPe also abolished late excitation. These results indicate that cortically evoked early and late excitation in the STN is mediated by the cortico-STN glutamatergic hyperdirect and the cortico-striato-GPe-STN indirect pathways, respectively.SIGNIFICANCE STATEMENT Here we show that the subthalamic nucleus (STN), an input station of the basal ganglia, receives cortical inputs through the cortico-STN hyperdirect and cortico-striato-external pallido-STN indirect pathways. This knowledge is important for understanding not only the normal functions of the STN, but also the pathophysiology of STN-related disorders and therapy targeting the STN. Lesions or application of high-frequency stimulation in the STN ameliorates parkinsonian symptoms. These procedures could affect all components in the STN, such as afferent inputs through the hyperdirect and indirect pathways, and STN neuronal activity. If we can understand which component is most affected by such procedures, we may be able to identify more effective manipulation targets or methods to treat Parkinson's disease.
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Gut NK, Mena-Segovia J. Dichotomy between motor and cognitive functions of midbrain cholinergic neurons. Neurobiol Dis 2019; 128:59-66. [PMID: 30213733 PMCID: PMC7176324 DOI: 10.1016/j.nbd.2018.09.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 07/18/2018] [Accepted: 09/09/2018] [Indexed: 12/15/2022] Open
Abstract
Cholinergic neurons of the pedunculopontine nucleus (PPN) are interconnected with all the basal ganglia structures, as well as with motor centers in the brainstem and medulla. Recent theories put into question whether PPN cholinergic neurons form part of a locomotor region that directly regulates the motor output, and rather suggest a modulatory role in adaptive behavior involving both motor and cognitive functions. In support of this, experimental studies in animals suggest that cholinergic neurons reinforce actions by signaling reward prediction and shape adaptations in behavior during changes of environmental contingencies. This is further supported by clinical studies proposing that decreased cholinergic transmission originated in the PPN is associated with impaired sensorimotor integration and perseverant behavior, giving rise to some of the symptoms observed in Parkinson's disease and progressive supranuclear palsy. Altogether, the evidence suggests that cholinergic neurons of the PPN, mainly through their interactions with the basal ganglia, have a leading role in action control.
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Affiliation(s)
- Nadine K Gut
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ, USA
| | - Juan Mena-Segovia
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ, USA.
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MacLaren DAA, Ljungberg TL, Griffin ME, Clark SD. Pedunculopontine tegmentum cholinergic loss leads to a progressive decline in motor abilities and neuropathological changes resembling progressive supranuclear palsy. Eur J Neurosci 2018; 48:3477-3497. [PMID: 30339310 DOI: 10.1111/ejn.14212] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 08/28/2018] [Accepted: 09/27/2018] [Indexed: 11/28/2022]
Abstract
Progressive supranuclear palsy (PSP) is the most common atypical Parkinsonism. Although PSP shares some symptomology with Parkinson's disease (PD), PSP has a different underlying pathology characterized by tau aggregation. Furthermore, PSP sufferers respond poorly to PD medications and there are no effective alternative therapeutics. The development of both palliative and disease altering therapeutics has been hampered by the lack of an animal model that displays relevant PSP-like pathology and behavioral deficits. Previously, our lab found that in rats the selective removal of cholinergic pedunculopontine neurons (whose axonal projections overlap with areas of PSP pathology), mimics the extensive loss of cholinergic pedunculopontine neurons seen in PSP, and produces a unique PSP-like combination of deficits in: startle reflex, attention, and motor function. The present study extends those findings by allowing the lesion to incubate for over a year and compares behavioral and post-mortem pathology of pedunculopontine-cholinergic-lesioned and sham-lesioned rats. There was an early startle reflex deficit which did not improve over time. Progressive declines in motor function developed over the course of the year, including an increase in the number of "slips" while navigating various beams and poorly coordinated transitions from an elevated platform into homecages. Histological analysis discovered that the loss off cholinergic pedunculopontine neurons precipitated a significant loss of substantia nigra tyrosine hydroxylase-positive neurons and a significant enlargement of the lateral ventricles. The latter is a distinguishing feature between PSP and PD. This preclinical animal model of PSP has the potential to further our understanding of PSP and aid in the testing of potential therapeutic agents.
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Affiliation(s)
- Duncan A A MacLaren
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, USA
| | - Trisha L Ljungberg
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, USA
| | - Meghan E Griffin
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, USA
| | - Stewart D Clark
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, USA
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Luquin E, Huerta I, Aymerich MS, Mengual E. Stereological Estimates of Glutamatergic, GABAergic, and Cholinergic Neurons in the Pedunculopontine and Laterodorsal Tegmental Nuclei in the Rat. Front Neuroanat 2018; 12:34. [PMID: 29867374 PMCID: PMC5958217 DOI: 10.3389/fnana.2018.00034] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Accepted: 04/16/2018] [Indexed: 01/29/2023] Open
Abstract
The pedunculopontine tegmental nucleus (PPN) and laterodorsal tegmental nucleus (LDT) are functionally associated brainstem structures implicated in behavioral state control and sensorimotor integration. The PPN is also involved in gait and posture, while the LDT plays a role in reward. Both nuclei comprise characteristic cholinergic neurons intermingled with glutamatergic and GABAergic cells whose absolute numbers in the rat have been only partly established. Here we sought to determine the complete phenotypical profile of each nucleus to investigate potential differences between them. Counts were obtained using stereological methods after the simultaneous visualization of cholinergic and either glutamatergic or GABAergic cells. The two isoforms of glutamic acid decarboxylase (GAD), GAD65 and GAD67, were separately analyzed. Dual in situ hybridization revealed coexpression of GAD65 and GAD67 mRNAs in ∼90% of GAD-positive cells in both nuclei; thus, the estimated mean numbers of (1) cholinergic, (2) glutamatergic, and (3) GABAergic cells in PPN and LDT, respectively, were (1) 3,360 and 3,650; (2) 5,910 and 5,190; and (3) 4,439 and 7,599. These data reveal significant differences between PPN and LDT in their relative phenotypical composition, which may underlie some of the functional differences observed between them. The estimation of glutamatergic cells was significantly higher in the caudal PPN, supporting the reported functional rostrocaudal segregation in this nucleus. Finally, a small subset of cholinergic neurons (8% in PPN and 5% in LDT) also expressed the glutamatergic marker Vglut2, providing anatomical evidence for a potential corelease of transmitters at specific target areas.
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Affiliation(s)
- Esther Luquin
- Division of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | - Ibone Huerta
- Division of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | - María S Aymerich
- Division of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain.,Department of Biochemistry and Genetics, School of Science, University of Navarra, Pamplona, Spain
| | - Elisa Mengual
- Division of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain.,Anatomy Department, School of Medicine, University of Navarra, Pamplona, Spain
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16
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Hikosaka O, Kim HF, Amita H, Yasuda M, Isoda M, Tachibana Y, Yoshida A. Direct and indirect pathways for choosing objects and actions. Eur J Neurosci 2018; 49:637-645. [PMID: 29473660 DOI: 10.1111/ejn.13876] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 02/16/2018] [Accepted: 02/19/2018] [Indexed: 01/23/2023]
Abstract
A prominent target of the basal ganglia is the superior colliculus (SC) which controls gaze orientation (saccadic eye movement in primates) to an important object. This 'object choice' is crucial for choosing an action on the object. SC is innervated by the substantia nigra pars reticulata (SNr) which is controlled mainly by the caudate nucleus (CD). This CD-SNr-SC circuit is sensitive to the values of individual objects and facilitates saccades to good objects. The object values are processed differently in two parallel circuits: flexibly by the caudate head (CDh) and stably by the caudate tail (CDt). To choose good objects, we need to reject bad objects. In fact, these contrasting functions are accomplished by the circuit originating from CDt: The direct pathway focuses on good objects and facilitates saccades to them; the indirect pathway focuses on bad objects and suppresses saccades to them. Inactivation of CDt deteriorated the object choice, because saccades to bad objects were no longer suppressed. This suggests that the indirect pathway is important for object choice. However, the direct and indirect pathways for 'object choice', which aim at the same action (i.e., saccade), may not work for 'action choice'. One possibility is that circuits controlling different actions are connected through the indirect pathway. Additional connections of the indirect pathway with brain areas outside the basal ganglia may also provide a wider range of behavioral choice. In conclusion, basal ganglia circuits are composed of the basic direct/indirect pathways and additional connections and thus have acquired multiple functions.
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Affiliation(s)
- Okihide Hikosaka
- Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, 49 Convent Drive, Bldg. 49, Rm. 2A50, Bethesda, MD, 20892-4435, USA
| | - Hyoung F Kim
- Department of Biomedical Engineering, Sungkyunkwan University (SKKU), Suwon, Korea.,Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, Korea
| | - Hidetoshi Amita
- Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, 49 Convent Drive, Bldg. 49, Rm. 2A50, Bethesda, MD, 20892-4435, USA
| | - Masaharu Yasuda
- Department of Physiology, Kansai Medical University, Hirakata, Japan
| | - Masaki Isoda
- Division of Behavioral Development, Department of System Neuroscience, National Institute for Physiological Sciences, Okazaki, Aichi, Japan
| | - Yoshihisa Tachibana
- Division of System Neuroscience, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Atsushi Yoshida
- Functional Architecture Imaging team, RIKEN Center for Life Science Technologies, Kobe, Hyogo, Japan
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Hamani C, Lozano AM, Mazzone PAM, Moro E, Hutchison W, Silburn PA, Zrinzo L, Alam M, Goetz L, Pereira E, Rughani A, Thevathasan W, Aziz T, Bloem BR, Brown P, Chabardes S, Coyne T, Foote K, Garcia-Rill E, Hirsch EC, Okun MS, Krauss JK. Pedunculopontine Nucleus Region Deep Brain Stimulation in Parkinson Disease: Surgical Techniques, Side Effects, and Postoperative Imaging. Stereotact Funct Neurosurg 2016; 94:307-319. [PMID: 27728909 DOI: 10.1159/000449011] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 08/08/2016] [Indexed: 02/05/2023]
Abstract
The pedunculopontine nucleus (PPN) region has received considerable attention in clinical studies as a target for deep brain stimulation (DBS) in Parkinson disease. These studies have yielded variable results with an overall impression of improvement in falls and freezing in many but not all patients treated. We evaluated the available data on the surgical anatomy and terminology of the PPN region in a companion paper. Here we focus on issues concerning surgical technique, imaging, and early side effects of surgery. The aim of this paper was to gain more insight into the reasoning for choosing specific techniques and to discuss shortcomings of available studies. Our data demonstrate the wide range in almost all fields which were investigated. There are a number of important challenges to be resolved, such as identification of the optimal target, the choice of the surgical approach to optimize electrode placement, the impact on the outcome of specific surgical techniques, the reliability of intraoperative confirmation of the target, and methodological differences in postoperative validation of the electrode position. There is considerable variability both within and across groups, the overall experience with PPN DBS is still limited, and there is a lack of controlled trials. Despite these challenges, the procedure seems to provide benefit to selected patients and appears to be relatively safe. One important limitation in comparing studies from different centers and analyzing outcomes is the great variability in targeting and surgical techniques, as shown in our paper. The challenges we identified will be of relevance when designing future studies to better address several controversial issues. We hope that the data we accumulated may facilitate the development of surgical protocols for PPN DBS.
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Affiliation(s)
- Clement Hamani
- Division of Neurosurgery, Toronto Western Hospital, University of Toronto, Toronto, Ont., Canada
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Kita T, Shigematsu N, Kita H. Intralaminar and tectal projections to the subthalamus in the rat. Eur J Neurosci 2016; 44:2899-2908. [PMID: 27717088 PMCID: PMC5157720 DOI: 10.1111/ejn.13413] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 09/19/2016] [Accepted: 09/21/2016] [Indexed: 12/29/2022]
Abstract
Projections from the posterior intralaminar thalamic nuclei and the superior colliculus (SC) to the subthalamic nucleus (STN) and the zona incerta (ZI) have been described in the primate and rodent. The aims of this study was to investigate several questions on these projections, using modern neurotracing techniques in rats, to advance our understanding of the role of STN and ZI. We examined whether projection patterns to the subthlamus can be used to identify homologues of the primate centromedian (CM) and the parafascicular nucleus (Pf) in the rodent, the topography of the projection including what percent of intralaminar neurons participate in the projections, and electron microscopic examination of intralaminar synaptic boutons in STN. The aim on the SC‐subthalamic projection was to examine whether STN is the main target of the projection. This study revealed: (i) the areas similar to primate CM and Pf could be recognized in the rat; (ii) the Pf‐like area sends a very heavy topographically organized projection to STN but very sparse projection to ZI, which suggested that Pf might control basal ganglia function through STN; (iii) the projection from the CM‐like area to the subthalamus was very sparse; (iv) Pf boutons and randomly sampled asymmetrical synapses had similar distributions on the dendrites of STN neurons; and (v) the lateral part of the deep layers of SC sends a very heavy projection to ZI and moderate to sparse projection to limited parts of STN, suggesting that SC is involved in a limited control of basal ganglia function.
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Affiliation(s)
- Takako Kita
- Department of Anatomy and Neurobiology, College of Medicine, The University of Tennessee Health Science Center, 855 Monroe Avenue, Memphis, TN, 38163, USA
| | - Naoki Shigematsu
- Department of Anatomy and Neurobiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Hitoshi Kita
- Department of Anatomy and Neurobiology, College of Medicine, The University of Tennessee Health Science Center, 855 Monroe Avenue, Memphis, TN, 38163, USA
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Darbin O, Gubler C, Naritoku D, Dees D, Martino A, Adams E. Parkinsonian Balance Deficits Quantified Using a Game Industry Board and a Specific Battery of Four Paradigms. Front Hum Neurosci 2016; 10:431. [PMID: 27625601 PMCID: PMC5003866 DOI: 10.3389/fnhum.2016.00431] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Accepted: 08/11/2016] [Indexed: 11/13/2022] Open
Abstract
This study describes a cost-effective screening protocol for parkinsonism based on combined objective and subjective monitoring of balance function. Objective evaluation of balance function was performed using a game industry balance board and an automated analyses of the dynamic of the center of pressure in time, frequency, and non-linear domains collected during short series of stand up tests with different modalities and severity of sensorial deprivation. The subjective measurement of balance function was performed using the Dizziness Handicap Inventory questionnaire. Principal component analyses on both objective and subjective measurements of balance function allowed to obtained a specificity and selectivity for parkinsonian patients (vs. healthy subjects) of 0.67 and 0.71 respectively. The findings are discussed regarding the relevance of cost-effective balance-based screening system as strategy to meet the needs of broader and earlier screening for parkinsonism in communities with limited access to healthcare.
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Affiliation(s)
- Olivier Darbin
- Department of Neurology, University of South AlabamaMobile, AL, USA
- Division of System Neurophysiology, National Institute for Physiological SciencesOkazaki, Japan
- Animal Resource Program, University of Alabama at BirminghamBirmingham, AL, USA
- Vestibular Research, University of South AlabamaMobile, AL, USA
| | - Coral Gubler
- Vestibular Research, University of South AlabamaMobile, AL, USA
- Department of Physical Therapy, University of South AlabamaMobile, AL, USA
| | - Dean Naritoku
- Department of Neurology, University of South AlabamaMobile, AL, USA
| | - Daniel Dees
- Department of Neurology, University of South AlabamaMobile, AL, USA
| | - Anthony Martino
- Department of Neurosurgery, University of South AlabamaMobile, AL, USA
| | - Elizabeth Adams
- Vestibular Research, University of South AlabamaMobile, AL, USA
- Department of Speech Pathology and Audiology, University of South AlabamaMobile, AL, USA
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20
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Syed A, Baker PM, Ragozzino ME. Pedunculopontine tegmental nucleus lesions impair probabilistic reversal learning by reducing sensitivity to positive reward feedback. Neurobiol Learn Mem 2016; 131:1-8. [PMID: 26976089 PMCID: PMC4862904 DOI: 10.1016/j.nlm.2016.03.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 02/25/2016] [Accepted: 03/03/2016] [Indexed: 01/15/2023]
Abstract
Recent findings indicate that pedunculopontine tegmental nucleus (PPTg) neurons encode reward-related information that is context-dependent. This information is critical for behavioral flexibility when reward outcomes change signaling a shift in response patterns should occur. The present experiment investigated whether NMDA lesions of the PPTg affects the acquisition and/or reversal learning of a spatial discrimination using probabilistic reinforcement. Male Long-Evans rats received a bilateral infusion of NMDA (30nmoles/side) or saline into the PPTg. Subsequently, rats were tested in a spatial discrimination test using a probabilistic learning procedure. One spatial location was rewarded with an 80% probability and the other spatial location rewarded with a 20% probability. After reaching acquisition criterion of 10 consecutive correct trials, the spatial location - reward contingencies were reversed in the following test session. Bilateral and unilateral PPTg-lesioned rats acquired the spatial discrimination test comparable to that as sham controls. In contrast, bilateral PPTg lesions, but not unilateral PPTg lesions, impaired reversal learning. The reversal learning deficit occurred because of increased regressions to the previously 'correct' spatial location after initially selecting the new, 'correct' choice. PPTg lesions also reduced the frequency of win-stay behavior early in the reversal learning session, but did not modify the frequency of lose-shift behavior during reversal learning. The present results suggest that the PPTg contributes to behavioral flexibility under conditions in which outcomes are uncertain, e.g. probabilistic reinforcement, by facilitating sensitivity to positive reward outcomes that allows the reliable execution of a new choice pattern.
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Affiliation(s)
- Anam Syed
- Department of Psychology, University of Illinois at Chicago, 1007 West Harrison Street, Chicago, IL 60607-7137, United States
| | - Phillip M Baker
- Department of Psychology, University of Illinois at Chicago, 1007 West Harrison Street, Chicago, IL 60607-7137, United States; Graduate Program in Neuroscience, University of Illinois at Chicago, Chicago, IL 60607, United States
| | - Michael E Ragozzino
- Department of Psychology, University of Illinois at Chicago, 1007 West Harrison Street, Chicago, IL 60607-7137, United States.
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21
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Gut NK, Winn P. The pedunculopontine tegmental nucleus-A functional hypothesis from the comparative literature. Mov Disord 2016; 31:615-24. [PMID: 26880095 PMCID: PMC4949639 DOI: 10.1002/mds.26556] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 12/22/2015] [Accepted: 12/28/2015] [Indexed: 12/21/2022] Open
Abstract
We present data from animal studies showing that the pedunculopontine tegmental nucleus-conserved through evolution, compartmentalized, and with a complex pattern of inputs and outputs-has functions that involve formation and updates of action-outcome associations, attention, and rapid decision making. This is in contrast to previous hypotheses about pedunculopontine function, which has served as a basis for clinical interest in the pedunculopontine in movement disorders. Current animal literature points to it being neither a specifically motor structure nor a master switch for sleep regulation. The pedunculopontine is connected to basal ganglia circuitry but also has primary sensory input across modalities and descending connections to pontomedullary, cerebellar, and spinal motor and autonomic control systems. Functional and anatomical studies in animals suggest strongly that, in addition to the pedunculopontine being an input and output station for the basal ganglia and key regulator of thalamic (and consequently cortical) activity, an additional major function is participation in the generation of actions on the basis of a first-pass analysis of incoming sensory data. Such a function-rapid decision making-has very high adaptive value for any vertebrate. We argue that in developing clinical strategies for treating basal ganglia disorders, it is necessary to take an account of the normal functions of the pedunculopontine. We believe that it is possible to use our hypothesis to explain why pedunculopontine deep brain stimulation used clinically has had variable outcomes in the treatment of parkinsonism motor symptoms and effects on cognitive processing. © 2016 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Nadine K Gut
- Biozentrum, University of Basel, Basel, Switzerland
| | - Philip Winn
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
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22
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Hahn JD, Swanson LW. Connections of the juxtaventromedial region of the lateral hypothalamic area in the male rat. Front Syst Neurosci 2015; 9:66. [PMID: 26074786 PMCID: PMC4445319 DOI: 10.3389/fnsys.2015.00066] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 04/06/2015] [Indexed: 01/09/2023] Open
Abstract
Evolutionary conservation of the hypothalamus attests to its critical role in the control of fundamental behaviors. However, our knowledge of hypothalamic connections is incomplete, particularly for the lateral hypothalamic area (LHA). Here we present the results of neuronal pathway-tracing experiments to investigate connections of the LHA juxtaventromedial region, which is parceled into dorsal (LHAjvd) and ventral (LHAjvv) zones. Phaseolus vulgaris leucoagglutinin (PHAL, for outputs) and cholera toxin B subunit (CTB, for inputs) coinjections were targeted stereotaxically to the LHAjvd/v. Results: LHAjvd/v connections overlapped highly but not uniformly. Major joint outputs included: Bed nuc. stria terminalis (BST), interfascicular nuc. (BSTif) and BST anteromedial area, rostral lateral septal (LSr)- and ventromedial hypothalamic (VMH) nuc., and periaqueductal gray. Prominent joint LHAjvd/v input sources included: BSTif, BST principal nuc., LSr, VMH, anterior hypothalamic-, ventral premammillary-, and medial amygdalar nuc., and hippocampal formation (HPF) field CA1. However, LHAjvd HPF retrograde labeling was markedly more abundant than from the LHAjvv; in the LSr this was reversed. Furthermore, robust LHAjvv (but not LHAjvd) targets included posterior- and basomedial amygdalar nuc., whereas the midbrain reticular nuc. received a dense input from the LHAjvd alone. Our analyses indicate the existence of about 500 LHAjvd and LHAjvv connections with about 200 distinct regions of the cerebral cortex, cerebral nuclei, and cerebrospinal trunk. Several highly LHAjvd/v-connected regions have a prominent role in reproductive behavior. These findings contrast with those from our previous pathway-tracing studies of other LHA medial and perifornical tier regions, with different connectional behavioral relations. The emerging picture is of a highly differentiated LHA with extensive and far-reaching connections that point to a role as a central coordinator of behavioral control.
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Affiliation(s)
- Joel D Hahn
- Department of Biological Sciences, University of Southern California Los Angeles, CA, USA
| | - Larry W Swanson
- Department of Biological Sciences, University of Southern California Los Angeles, CA, USA
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23
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MacLaren DAA, Wilson DIG, Winn P. Selective lesions of the cholinergic neurons within the posterior pedunculopontine do not alter operant learning or nicotine sensitization. Brain Struct Funct 2015; 221:1481-97. [PMID: 25586659 DOI: 10.1007/s00429-014-0985-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 11/30/2014] [Indexed: 02/02/2023]
Abstract
Cholinergic neurons within the pedunculopontine tegmental nucleus have been implicated in a range of functions, including behavioral state control, attention, and modulation of midbrain and basal ganglia systems. Previous experiments with excitotoxic lesions have found persistent learning impairment and altered response to nicotine following lesion of the posterior component of the PPTg (pPPTg). These effects have been attributed to disrupted input to midbrain dopamine systems, particularly the ventral tegmental area. The pPPTg contains a dense collection of cholinergic neurons and also large numbers of glutamatergic and GABAergic neurons. Because these interdigitated populations of neurons are all susceptible to excitotoxins, the effects of such lesions cannot be attributed to one neuronal population. We wished to assess whether the learning impairments and altered responses to nicotine in excitotoxic PPTg-lesioned rats were due to loss of cholinergic neurons within the pPPTg. Selective depletion of cholinergic pPPTg neurons is achievable with the fusion toxin Dtx-UII, which targets UII receptors expressed only by cholinergic neurons in this region. Rats bearing bilateral lesions of cholinergic pPPTg neurons (>90% ChAT+ neuronal loss) displayed no deficits in the learning or performance of fixed and variable ratio schedules of reinforcement for pellet reward. Separate rats with the same lesions had a normal locomotor response to nicotine and furthermore sensitized to repeated administration of nicotine at the same rate as sham controls. Previously seen changes in these behaviors following excitotoxic pPPTg lesions cannot be attributed solely to loss of cholinergic neurons. These findings indicate that non-cholinergic neurons within the pPPTg are responsible for the learning deficits and altered responses to nicotine seen after excitotoxic lesions. The functions of cholinergic neurons may be related to behavioral state control and attention rather than learning.
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Affiliation(s)
- Duncan A A MacLaren
- Strathclyde Institute of Pharmacy and Biomedical Sciences, 161 Cathedral Street, Glasgow, G4 0RE, UK. .,School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife, KY16 9JP, UK.
| | - David I G Wilson
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife, KY16 9JP, UK
| | - Philip Winn
- Strathclyde Institute of Pharmacy and Biomedical Sciences, 161 Cathedral Street, Glasgow, G4 0RE, UK
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24
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Enhanced consumption of salient solutions following pedunculopontine tegmental lesions. Neuroscience 2014; 284:381-399. [PMID: 25305665 DOI: 10.1016/j.neuroscience.2014.09.075] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 09/26/2014] [Accepted: 09/30/2014] [Indexed: 12/19/2022]
Abstract
Rats with lesions of the pedunculopontine tegmental nucleus (PPTg) reliably overconsume high concentration sucrose solution. This effect is thought to be indicative of response-perseveration or loss of behavioral control in conditions of high excitement. While these theories have anatomical and behavioral support, they have never been explicitly tested. Here, we used a contact lickometer to examine the microstructure of drinking behavior to gain insight into the behavioral changes during overconsumption. Rats received either excitotoxic (ibotenic acid) damage to all PPTg neuronal subpopulations or selective depletion of the cholinergic neuronal sub-population (diphtheria toxin-urotensin II (Dtx-UII) lesions). We offered rats a variety of pleasant, neutral and aversive tastants to assess the generalizability and specificity of the overconsumption effect. Ibotenic-lesioned rats consumed significantly more 20% sucrose than sham controls, and did so through licking significantly more times. However, the behavioral microstructure during overconsumption was unaffected by the lesion and showed no indications of response-perseveration. Furthermore, the overconsumption effect did not generalize to highly consumed saccharin. In contrast, while only consuming small amounts of quinine solution, ibotenic-lesioned rats had significantly more licks and bursts for this tastant. Selective depletion of cholinergic PPTg neurons had no effect on consumption of any tastant. We then assessed whether it is the salience of the solution which determines overconsumption by ibotenic-lesioned rats. While maintained on free-food, ibotenic-lesioned rats had normal consumption of sucrose and hypertonic saline. After mild food deprivation ibotenic PPTg-lesioned rats overconsumed 20% sucrose. Subsequently, after dietary-induced sodium deficiency, lesioned rats consumed significantly more saline than controls. These results establish that it is the salience of the solution which is the determining factor leading to overconsumption following excitotoxic PPTg lesion. They also find no support for response-perseveration contributing to this effect. Results are discussed in terms of altered dopamine (DA) and salience signaling.
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25
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Martinez-Gonzalez C, van Andel J, Bolam JP, Mena-Segovia J. Divergent motor projections from the pedunculopontine nucleus are differentially regulated in Parkinsonism. Brain Struct Funct 2014; 219:1451-62. [PMID: 23708060 PMCID: PMC4072066 DOI: 10.1007/s00429-013-0579-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 05/10/2013] [Indexed: 01/28/2023]
Abstract
The pedunculopontine nucleus (PPN) is composed of neurons with different connectivity patterns that express different neurochemical markers, display distinct firing characteristics and are topographically organized in functional domains across its rostro-caudal axis. Previous reports have shown that the caudal region of the PPN is interconnected with motor regions of both the basal ganglia and brainstem/medulla. The co-distribution of ascending and descending motor outputs raises the question as to whether the PPN provides a coordinated or differential modulation of its targets in the basal ganglia and the medulla. To address this, we retrogradely labeled neurons in the two main PPN pathways involved in motor control and determined whether they project to one or both structures, their neurochemical phenotype, and their activity in normal and dopamine depleted rats, as indicated by Egr-1 expression. We show that ascending and descending motor pathways from the PPN arise largely from separate neurons that intermingle in the same region of the PPN, but have a distinct neurochemical composition and are differentially regulated in the Parkinsonian state. Thus, neurons projecting to the subthalamic nucleus consist of cholinergic, calbindin- and calretinin-expressing neurons, and Egr-1 is upregulated following a 6-hydroxydopamine lesion. In contrast, a larger proportion of neurons projecting to the gigantocellular nucleus are cholinergic, none express calbindin and the expression of Egr-1 is not changed by the dopamine lesion. Our results suggest that ascending and descending motor connections of the PPN are largely mediated by different sets of neurons and there are cell type-specific changes in Parkinsonian rats.
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Affiliation(s)
- Cristina Martinez-Gonzalez
- MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3TH UK
| | - Judith van Andel
- MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3TH UK
| | - J. Paul Bolam
- MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3TH UK
| | - Juan Mena-Segovia
- MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3TH UK
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26
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Dautan D, Huerta-Ocampo I, Witten IB, Deisseroth K, Bolam JP, Gerdjikov T, Mena-Segovia J. A major external source of cholinergic innervation of the striatum and nucleus accumbens originates in the brainstem. J Neurosci 2014; 34:4509-18. [PMID: 24671996 PMCID: PMC3965779 DOI: 10.1523/jneurosci.5071-13.2014] [Citation(s) in RCA: 242] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 01/24/2014] [Accepted: 02/15/2014] [Indexed: 02/01/2023] Open
Abstract
Cholinergic transmission in the striatal complex is critical for the modulation of the activity of local microcircuits and dopamine release. Release of acetylcholine has been considered to originate exclusively from a subtype of striatal interneuron that provides widespread innervation of the striatum. Cholinergic neurons of the pedunculopontine (PPN) and laterodorsal tegmental (LDT) nuclei indirectly influence the activity of the dorsal striatum and nucleus accumbens through their innervation of dopamine and thalamic neurons, which in turn converge at the same striatal levels. Here we show that cholinergic neurons in the brainstem also provide a direct innervation of the striatal complex. By the expression of fluorescent proteins in choline acetyltransferase (ChAT)::Cre(+) transgenic rats, we selectively labeled cholinergic neurons in the rostral PPN, caudal PPN, and LDT. We show that cholinergic neurons topographically innervate wide areas of the striatal complex: rostral PPN preferentially innervates the dorsolateral striatum, and LDT preferentially innervates the medial striatum and nucleus accumbens core in which they principally form asymmetric synapses. Retrograde labeling combined with immunohistochemistry in wild-type rats confirmed the topography and cholinergic nature of the projection. Furthermore, transynaptic gene activation and conventional double retrograde labeling suggest that LDT neurons that innervate the nucleus accumbens also send collaterals to the thalamus and the dopaminergic midbrain, thus providing both direct and indirect projections, to the striatal complex. The differential activity of cholinergic interneurons and cholinergic neurons of the brainstem during reward-related paradigms suggest that the two systems play different but complementary roles in the processing of information in the striatum.
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Affiliation(s)
- Daniel Dautan
- Medical Research Council Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Oxford OX1 3TH, United Kingdom
- School of Psychology, University of Leicester, Leicester LE1 9HN, United Kingdom
| | - Icnelia Huerta-Ocampo
- Medical Research Council Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Oxford OX1 3TH, United Kingdom
| | - Ilana B. Witten
- Princeton Neuroscience Institute, Princeton New Jersey 08540, and
| | - Karl Deisseroth
- Department of Psychiatry, Stanford University, Stanford, California 94305
| | - J. Paul Bolam
- Medical Research Council Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Oxford OX1 3TH, United Kingdom
| | - Todor Gerdjikov
- School of Psychology, University of Leicester, Leicester LE1 9HN, United Kingdom
| | - Juan Mena-Segovia
- Medical Research Council Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Oxford OX1 3TH, United Kingdom
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27
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PET imaging with [18F]fluoroethoxybenzovesamicol ([18F]FEOBV) following selective lesion of cholinergic pedunculopontine tegmental neurons in rat. Nucl Med Biol 2014; 41:96-101. [DOI: 10.1016/j.nucmedbio.2013.10.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 09/25/2013] [Accepted: 10/02/2013] [Indexed: 11/19/2022]
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28
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Schmidt R, Leventhal DK, Mallet N, Chen F, Berke JD. Canceling actions involves a race between basal ganglia pathways. Nat Neurosci 2013; 16:1118-24. [PMID: 23852117 PMCID: PMC3733500 DOI: 10.1038/nn.3456] [Citation(s) in RCA: 268] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 05/31/2013] [Indexed: 11/10/2022]
Abstract
Salient cues can prompt the rapid interruption of planned actions. It has been proposed that fast, reactive behavioral inhibition involves specific basal ganglia pathways, and we tested this by comparing activity in multiple rat basal ganglia structures during performance of a stop-signal task. Subthalamic nucleus (STN) neurons exhibited low-latency responses to 'Stop' cues, irrespective of whether actions were canceled or not. By contrast, neurons downstream in the substantia nigra pars reticulata (SNr) only responded to Stop cues in trials with successful cancellation. Recordings and simulations together indicate that this sensorimotor gating arises from the relative timing of two distinct inputs to neurons in the SNr dorsolateral 'core' subregion: cue-related excitation from STN and movement-related inhibition from striatum. Our results support race models of action cancellation, with stopping requiring Stop-cue information to be transmitted from STN to SNr before increased striatal input creates a point of no return.
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Affiliation(s)
- Robert Schmidt
- Department of Psychology, University of Michigan, Ann Arbor, Michigan, USA
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29
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Hahn JD, Swanson LW. Connections of the lateral hypothalamic area juxtadorsomedial region in the male rat. J Comp Neurol 2012; 520:1831-90. [PMID: 22488503 DOI: 10.1002/cne.23064] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The connections of the lateral hypothalamic area juxtadorsomedial region (LHAjd) were investigated in a series of pathway-tracing experiments involving iontophoretic co-injection of the tracers Phaseolus vulgaris-leucoagglutinin (PHA-L; for outputs) and cholera toxin B subunit (CTB; for inputs). Results revealed that the LHAjd has connections with some 318 distinct gray matter regions encompassing all four subsystems-motor, sensory, cognitive, and behavioral state-included in a basic structure-function network model of the nervous system. Integration of these subsystems is necessary for the coordination and control of emotion and behavior, and in that regard the connections of the LHAjd indicate that it may have a prominent role. Furthermore, the LHAjd connections, together with the connections of other LHA differentiations studied similarly to date, indicate a distinct topographic organization that suggests each LHA differentiation has specifically differing degrees of involvement in the control of multiple behaviors. For the LHAjd, its involvement to a high degree in the control of defensive behavior, and to a lesser degree in the control of other behaviors, including ingestive and reproductive, is suggested. Moreover, the connections of the LHAjd suggest that its possible role in the control of these behaviors may be very broad in scope because they involve the somatic, neuroendocrine, and autonomic divisions of the nervous system. In addition, we suggest that connections between LHA differentiations may provide, at the level of the hypothalamus, a neuronal substrate for the coordinated control of multiple themes in the behavioral repertoire.
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Affiliation(s)
- Joel D Hahn
- Department of Biological Sciences, University of Southern California, Los Angeles, California 90089-2520, USA.
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Martinez-Gonzalez C, Wang HL, Micklem BR, Bolam JP, Mena-Segovia J. Subpopulations of cholinergic, GABAergic and glutamatergic neurons in the pedunculopontine nucleus contain calcium-binding proteins and are heterogeneously distributed. Eur J Neurosci 2012; 35:723-34. [PMID: 22356461 DOI: 10.1111/j.1460-9568.2012.08002.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Neurons in the pedunculopontine nucleus (PPN) are highly heterogeneous in their discharge properties, their neurochemical markers, their pattern of connectivity and the behavioural processes in which they participate. Three main transmitter phenotypes have been described, cholinergic, GABAergic and glutamatergic, and yet electrophysiological evidence suggests heterogeneity within these subtypes. To gain further insight into the molecular composition of these three populations in the rat, we investigated the pattern of expression of calcium binding proteins (CBPs) across distinct regions of the PPN and in relation to the presence of other neurochemical markers. Calbindin- and calretinin-positive neurons are as abundant as cholinergic neurons, and their expression follows a rostro-caudal gradient, whereas parvalbumin is expressed by a low number of neurons. We observed a high degree of expression of CBPs by GABAergic and glutamatergic neurons, with a large majority of calbindin- and calretinin-positive neurons expressing GAD or VGluT2 mRNA. Notably, CBP-positive neurons expressing GAD mRNA were more concentrated in the rostral PPN, whereas the caudal PPN was characterized by a higher density of CBP-positive neurons expressing VGluT2 mRNA. In contrast to these two large populations, in cholinergic neurons expression of calretinin is observed only in low numbers and expression of calbindin is virtually non-existent. These findings thus identify novel subtypes of cholinergic, GABAergic and glutamatergic neurons based on their expression of CBPs, and further contribute to the notion of the PPN as a highly heterogeneous structure, an attribute that is likely to underlie its functional complexity.
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Affiliation(s)
- Cristina Martinez-Gonzalez
- Medical Research Council Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3TH, UK
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31
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Brudzynski SM, Iku A, Harness (neé Savoy) A. Activity of cholinergic neurons in the laterodorsal tegmental nucleus during emission of 22kHz vocalization in rats. Behav Brain Res 2011; 225:276-83. [DOI: 10.1016/j.bbr.2011.07.040] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 07/20/2011] [Accepted: 07/22/2011] [Indexed: 02/02/2023]
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32
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Alam M, Heissler HE, Schwabe K, Krauss JK. Deep brain stimulation of the pedunculopontine tegmental nucleus modulates neuronal hyperactivity and enhanced beta oscillatory activity of the subthalamic nucleus in the rat 6-hydroxydopamine model. Exp Neurol 2011; 233:233-42. [PMID: 22036687 DOI: 10.1016/j.expneurol.2011.10.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 09/28/2011] [Accepted: 10/09/2011] [Indexed: 01/03/2023]
Abstract
Deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) area has been introduced as a novel surgical therapy for dopamine refractory gait problems, freezing and postural instability in the late stage of Parkinson's disease (PD). Lesions of the pedunculopontine tegmental (PPTg) nucleus, the equivalent of the PPN in rodents, were shown to reduce the elevated discharge rate of the subthalamic nucleus (STN) in the 6-hydroxydopamine (6-OHDA) rat model of PD. In order to further elucidate the modulatory effect of the PPTg on the STN we examined the effect of 25 Hz low frequency PPTg stimulation on neuronal single unit activity and oscillatory local field potentials (LFPs) of the STN, and on the electrocorticogram (ECoG) of the primary motor cortex region in rats with unilateral 6-OHDA induced nigrostriatal lesions. Stimulation of the PPTg reduced the enhanced firing rate in the STN, without affecting the firing pattern or approximate entropy (ApEn). It also reduced the activity in the beta band (15-30 Hz) of the STN, which is elevated in 6-OHDA lesioned rats, without affecting beta activity in the motor cortex. We showed a modulatory effect of PPTg stimulation on altered neuronal STN activity in the PD 6-OHDA rat model, indicating that PPTg DBS may alter activity of the basal ganglia circuitry at least partially. It remains unclear, however, how these changes are exactly mediated and whether they are relevant with regard to the descending PPTg projections in the lower brainstem.
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Affiliation(s)
- Mesbah Alam
- Department of Neurosurgery, Hannover Medical School, Hannover, Germany.
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Martinez-Gonzalez C, Bolam JP, Mena-Segovia J. Topographical organization of the pedunculopontine nucleus. Front Neuroanat 2011; 5:22. [PMID: 21503154 PMCID: PMC3074429 DOI: 10.3389/fnana.2011.00022] [Citation(s) in RCA: 169] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Accepted: 03/21/2011] [Indexed: 11/27/2022] Open
Abstract
Neurons in the pedunculopontine nucleus (PPN) exhibit a wide heterogeneity in terms of their neurochemical nature, their discharge properties, and their connectivity. Such characteristics are reflected in their functional properties and the behaviors in which they are involved, ranging from motor to cognitive functions, and the regulation of brain states. A clue to understand this functional versatility arises from the internal organization of the PPN. Thus, two main areas of the PPN have been described, the rostral and the caudal, which display remarkable differences in terms of the distribution of neurons with similar phenotype and the projections that originate from them. Here we review these differences with the premise that in order to understand the function of the PPN it is necessary to understand its intricate connectivity. We support the case that the PPN should not be considered as a homogeneous structure and conclude that the differences between rostral and caudal PPN, along with their intrinsic connectivity, may underlie the basis of its complexity.
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Affiliation(s)
- Cristina Martinez-Gonzalez
- Medical Research Council Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford Oxford, UK
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