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Spaeth L, Khodakhah K. The cerebellum tells the amygdala, "Nothing diminishes anxiety faster than action". Neuron 2024; 112:1037-1039. [PMID: 38574726 DOI: 10.1016/j.neuron.2024.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 03/11/2024] [Accepted: 03/11/2024] [Indexed: 04/06/2024]
Abstract
In this issue of Neuron, Zhang et al. question the neural substrates of exercise-based alleviation of anxiety in rodents. In brief, they propose a model where physical activity provides an anxiolytic effect by recruiting specific cerebello-limbic circuits.
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Affiliation(s)
- Ludovic Spaeth
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA; Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, USA.
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2
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Bhuvanasundaram R, Washburn S, Krzyspiak J, Khodakhah K. Zona incerta modulation of the inferior olive and the pontine nuclei. Netw Neurosci 2024; 8:260-274. [PMID: 38562296 PMCID: PMC10927296 DOI: 10.1162/netn_a_00350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 11/07/2023] [Indexed: 04/04/2024] Open
Abstract
The zona incerta (ZI) is a subthalamic structure that has been implicated in locomotion, fear, and anxiety. Recently interest has grown in its therapeutic efficacy in deep brain stimulation in movement disorders. This efficacy might be due to the ZI's functional projections to the other brain regions. Notwithstanding some evidence of anatomical connections between the ZI and the inferior olive (IO) and the pontine nuclei (PN), how the ZI modulates the neuronal activity in these regions remains to be determined. We first tested this by monitoring responses of single neurons in the PN and IO to optogenetic activation of channelrhodopsin-expressing ZI axons in wild-type mice, using an in vivo awake preparation. Stimulation of short, single pulses and trains of stimuli at 20 Hz elicited rapid responses in the majority of recorded cells in the PN and IO. Furthermore, the excitatory response of PN neurons scaled with the strength of ZI activation. Next, we used in vitro electrophysiology to study synaptic transmission at ZI-IO synapses. Optogenetic activation of ZI axons evoked a strong excitatory postsynaptic response in IO neurons, which remained robust with repeated stimulation at 20 Hz. Overall, our results demonstrate a functional connection within ZI-PN and ZI-IO pathways.
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Affiliation(s)
| | - Samantha Washburn
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, USA
| | - Joanna Krzyspiak
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, USA
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, USA
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3
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Washburn S, Oñate M, Yoshida J, Vera J, Bhuvanasundaram R, Khatami L, Nadim F, Khodakhah K. The cerebellum directly modulates the substantia nigra dopaminergic activity. Nat Neurosci 2024; 27:497-513. [PMID: 38272967 DOI: 10.1038/s41593-023-01560-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 12/13/2023] [Indexed: 01/27/2024]
Abstract
Evidence of direct reciprocal connections between the cerebellum and basal ganglia has challenged the long-held notion that these structures function independently. While anatomical studies have suggested the presence of cerebellar projections to the substantia nigra pars compacta (SNc), the nature and function of these connections (Cb-SNc) is unknown. Here we show, in mice, that Cb-SNc projections form monosynaptic glutamatergic synapses with dopaminergic and non-dopaminergic neurons in the SNc. Optogenetic activation of Cb-SNc axons in the SNc is associated with increased SNc activity, elevated striatal dopamine levels and increased locomotion. During behavior, Cb-SNc projections are bilaterally activated before ambulation and unilateral lever manipulation. Cb-SNc projections show prominent activation for water reward and higher activation for sweet water, suggesting that the pathway also encodes reward value. Thus, the cerebellum directly, rapidly and effectively modulates basal ganglia dopamine levels and conveys information related to movement initiation, vigor and reward processing.
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Affiliation(s)
- Samantha Washburn
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Maritza Oñate
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Junichi Yoshida
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Jorge Vera
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | | | - Leila Khatami
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Farzan Nadim
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Biological Sciences, New Jersey Institute of Technology, Newark, NJ, USA
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA.
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA.
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, USA.
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4
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Biundo F, Chitu V, Tindi J, Burghardt NS, Shlager GGL, Ketchum HC, DeTure MA, Dickson DW, Wszolek ZK, Khodakhah K, Stanley ER. Elevated granulocyte colony stimulating factor (CSF) causes cerebellar deficits and anxiety in a model of CSF-1 receptor related leukodystrophy. Glia 2023; 71:775-794. [PMID: 36433736 PMCID: PMC9868112 DOI: 10.1002/glia.24310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/14/2022] [Accepted: 11/15/2022] [Indexed: 11/28/2022]
Abstract
Colony stimulating factor (CSF) receptor-1 (CSF-1R)-related leukoencephalopathy (CRL) is an adult-onset, demyelinating and neurodegenerative disease caused by autosomal dominant mutations in CSF1R, modeled by the Csf1r+/- mouse. The expression of Csf2, encoding granulocyte-macrophage CSF (GM-CSF) and of Csf3, encoding granulocyte CSF (G-CSF), are elevated in both mouse and human CRL brains. While monoallelic targeting of Csf2 has been shown to attenuate many behavioral and histological deficits of Csf1r+/- mice, including cognitive dysfunction and demyelination, the contribution of Csf3 has not been explored. In the present study, we investigate the behavioral, electrophysiological and histopathological phenotypes of Csf1r+/- mice following monoallelic targeting of Csf3. We show that Csf3 heterozygosity normalized the Csf3 levels in Csf1r+/- mouse brains and ameliorated anxiety-like behavior, motor coordination and social interaction deficits, but not the cognitive impairment of Csf1r+/- mice. Csf3 heterozygosity failed to prevent callosal demyelination. However, consistent with its effects on behavior, Csf3 heterozygosity normalized microglial morphology in the cerebellum and in the ventral, but not in the dorsal hippocampus. Csf1r+/- mice exhibited altered firing activity in the deep cerebellar nuclei (DCN) associated with increased engulfment of glutamatergic synapses by DCN microglia and increased deposition of the complement factor C1q on glutamatergic synapses. These phenotypes were significantly ameliorated by monoallelic deletion of Csf3. Our current and earlier findings indicate that G-CSF and GM-CSF play largely non-overlapping roles in CRL-like disease development in Csf1r+/- mice.
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Affiliation(s)
- Fabrizio Biundo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Violeta Chitu
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Jaafar Tindi
- The Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Nesha S. Burghardt
- Department of Psychology, Hunter College, The City University of New York, New York, NY, USA
| | - Gabriel G. L. Shlager
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Harmony C. Ketchum
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | | | | | | | - Kamran Khodakhah
- The Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - E. Richard Stanley
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA
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Yoshida J, Oñate M, Khatami L, Vera J, Nadim F, Khodakhah K. Cerebellar Contributions to the Basal Ganglia Influence Motor Coordination, Reward Processing, and Movement Vigor. J Neurosci 2022; 42:8406-8415. [PMID: 36351826 PMCID: PMC9665921 DOI: 10.1523/jneurosci.1535-22.2022] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 08/30/2022] [Accepted: 08/30/2022] [Indexed: 11/17/2022] Open
Abstract
Both the cerebellum and the basal ganglia are known for their roles in motor control and motivated behavior. These two systems have been classically considered as independent structures that coordinate their contributions to behavior via separate cortico-thalamic loops. However, recent evidence demonstrates the presence of a rich set of direct connections between these two regions. Although there is strong evidence for connections in both directions, for brevity we limit our discussion to the better-characterized connections from the cerebellum to the basal ganglia. We review two sets of such connections: disynaptic projections through the thalamus and direct monosynaptic projections to the midbrain dopaminergic nuclei, the VTA and the SNc. In each case, we review the evidence for these pathways from anatomic tracing and physiological recordings, and discuss their potential functional roles. We present evidence that the disynaptic pathway through the thalamus is involved in motor coordination, and that its dysfunction contributes to motor deficits, such as dystonia. We then discuss how cerebellar projections to the VTA and SNc influence dopamine release in the respective targets of these nuclei: the NAc and the dorsal striatum. We argue that the cerebellar projections to the VTA may play a role in reward-based learning and therefore contribute to addictive behavior, whereas the projection to the SNc may contribute to movement vigor. Finally, we speculate how these projections may explain many of the observations that indicate a role for the cerebellum in mental disorders, such as schizophrenia.
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Affiliation(s)
- Junichi Yoshida
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Maritza Oñate
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Leila Khatami
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Jorge Vera
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Farzan Nadim
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
- Department of Biological Sciences, New Jersey Institute of Technology, Newark, New Jersey, 07102
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
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6
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Bhuvanasundaram R, Krzyspiak J, Khodakhah K. Subthalamic Nucleus Modulation of the Pontine Nuclei and Its Targeting of the Cerebellar Cortex. J Neurosci 2022; 42:5538-5551. [PMID: 35641185 PMCID: PMC9295842 DOI: 10.1523/jneurosci.2388-19.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 03/25/2022] [Accepted: 04/29/2022] [Indexed: 01/16/2023] Open
Abstract
The subthalamic nucleus (STN) has been implicated in motor and nonmotor tasks, and is an effective target of deep brain stimulation for the treatment of Parkinson's disease, likely in part because of the STN's projections outside of the basal ganglia to other brain regions. While there is some evidence of a disynaptic connection between the STN and the cerebellum via the pontine nuclei (PN), how the STN modulates the activity of the neurons in the PN remains unknown. Here we addressed this question using a combination of anatomical tracings, optogenetics, and in vivo electrophysiology in both wild-type (WT) and transgenic mice of both sexes. Approximately half of recorded neurons in the PN, which were located primarily in the medial area, responded with short latency to both single pulses and trains of optogenetic stimulation of channelrhodopsin (ChR2)-expressing STN axons in awake, head-restrained mice. Furthermore, the increase in the activity of PN neurons correlated with the strength of activation of STN axons, suggesting that the STN projections to the PN could, in principle, encode information in a graded manner. In addition, transsynaptic retrograde tracing confirmed that the STN sends disynaptic projections to the cerebellar cortex. These results suggest that the STN sends robust functional projections to the PN, which then propagate to the cerebellum, and have important implications for understanding motor control of normal conditions, and Parkinsonian symptoms, where this pathway may have a role in the therapeutic efficacy of STN deep brain stimulation.SIGNIFICANCE STATEMENT The primary excitatory nucleus in the basal ganglia, the subthalamic nucleus, is known to play a role in pathways modulating movement. The pontine nuclei are the main precerebellar nuclei, which transmit signals through their axonal projections to the cerebellum as mossy fibers. The pathway we have functionally characterized in this paper represents an additional cortex-independent pathway capable of relaying information between the basal ganglia and cerebellum. The effectiveness of subthalamic nucleus deep brain stimulation in Parkinson's disease suggests that this pathway could be explored as an avenue of investigation for therapeutic purposes.
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Affiliation(s)
| | - Joanna Krzyspiak
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, 10461
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, 10461
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7
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Matlashov ME, Vera J, Kasatkina LA, Khodakhah K, Verkhusha VV. Design and Initial Characterization of a Small Near-Infrared Fluorescent Calcium Indicator. Front Cell Dev Biol 2022; 10:880107. [PMID: 35846350 PMCID: PMC9277108 DOI: 10.3389/fcell.2022.880107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 05/27/2022] [Indexed: 11/13/2022] Open
Abstract
Near-infrared (NIR) genetically encoded calcium indicators (GECIs) are becoming powerful tools for neuroscience. Because of their spectral characteristics, the use of NIR GECIs helps to avoid signal loss from the absorption by body pigments, light-scattering, and autofluorescence in mammalian tissues. In addition, NIR GECIs do not suffer from cross-excitation artifacts when used with common fluorescent indicators and optogenetics actuators. Although several NIR GECIs have been developed, there is no NIR GECI currently available that would combine the high brightness in cells and photostability with small size and fast response kinetics. Here, we report a small FRET-based NIR fluorescent calcium indicator iGECInano. We characterize iGECInano in vitro, in non-neuronal mammalian cells, and primary mouse neurons. iGECInano demonstrates the improvement in the signal-to-noise ratio and response kinetics compared to other NIR GECIs.
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Affiliation(s)
- Mikhail E. Matlashov
- Department of Genetics and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Jorge Vera
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Ludmila A. Kasatkina
- Department of Genetics and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Kamran Khodakhah
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Vladislav V. Verkhusha
- Department of Genetics and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, United States
- Medicum, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- *Correspondence: Vladislav V. Verkhusha,
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8
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Mayoral-Palarz K, Neves-Carvalho A, Duarte-Silva S, Monteiro-Fernandes D, Maciel P, Khodakhah K. Cerebellar neuronal dysfunction accompanies early motor symptoms in spinocerebellar ataxia type 3. Dis Model Mech 2022; 15:275597. [PMID: 35660856 PMCID: PMC9367011 DOI: 10.1242/dmm.049514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/25/2022] [Indexed: 11/30/2022] Open
Abstract
Spinocerebellar ataxia type 3 (SCA3) is an adult-onset, progressive ataxia. SCA3 presents with ataxia before any gross neuropathology. A feature of many cerebellar ataxias is aberrant cerebellar output that contributes to motor dysfunction. We examined whether abnormal cerebellar output was present in the CMVMJD135 SCA3 mouse model and, if so, whether it correlated with the disease onset and progression. In vivo recordings showed that the activity of deep cerebellar nuclei neurons, the main output of the cerebellum, was altered. The aberrant activity correlated with the onset of ataxia. However, although the severity of ataxia increased with age, the severity of the aberrant cerebellar output was not progressive. The abnormal cerebellar output, however, was accompanied by non-progressive abnormal activity of their upstream synaptic inputs, the Purkinje cells. In vitro recordings indicated that alterations in intrinsic Purkinje cell pacemaking and in their synaptic inputs contributed to abnormal Purkinje cell activity. These findings implicate abnormal cerebellar physiology as an early, consistent contributor to pathophysiology in SCA3, and suggest that the aberrant cerebellar output could be an appropriate therapeutic target in SCA3. Summary: In a mouse model of spinocerebellar ataxia type 3 (SCA3), aberrant cerebellar physiology is apparent early in disease, prior to cerebellar neuronal pathology. Aberrant cerebellar output could be a therapeutic target in SCA3.
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Affiliation(s)
- Kristin Mayoral-Palarz
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Andreia Neves-Carvalho
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA.,Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Sara Duarte-Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Daniela Monteiro-Fernandes
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Patrícia Maciel
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Krzyspiak J, Khodakhah K, Hébert JM. Potential Variables for Improved Reproducibility of Neuronal Cell Grafts at Stroke Sites. Cells 2022; 11:1656. [PMID: 35626693 PMCID: PMC9139220 DOI: 10.3390/cells11101656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/14/2022] [Accepted: 05/16/2022] [Indexed: 01/27/2023] Open
Abstract
Interest is growing in using cell replacements to repair the damage caused by an ischemic stroke. Yet, the usefulness of cell transplants can be limited by the variability observed in their successful engraftment. For example, we recently showed that, although the inclusion of donor-derived vascular cells was necessary for the formation of large grafts (up to 15 mm3) at stroke sites in mice, the size of the grafts overall remained highly variable. Such variability can be due to differences in the cells used for transplantation or the host environment. Here, as possible factors affecting engraftment, we test host sex, host age, the extent of ischemic damage, time of transplant after ischemia, minor differences in donor cell maturity, and cell viability at the time of transplantation. We find that graft size at stroke sites correlates with the size of ischemic damage, host sex (females having graft sizes that correlate with damage), donor cell maturity, and host age, but not with the time of transplant after stroke. A general linear model revealed that graft size is best predicted by stroke severity combined with donor cell maturity. These findings can serve as a guide to improving the reproducibility of cell-based repair therapies.
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Affiliation(s)
- Joanna Krzyspiak
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA; (J.K.); (K.K.)
- Stem Cell Institute, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
| | - Kamran Khodakhah
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA; (J.K.); (K.K.)
| | - Jean M. Hébert
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA; (J.K.); (K.K.)
- Stem Cell Institute, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
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10
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Snell HD, Vitenzon A, Tara E, Chen C, Tindi J, Jordan BA, Khodakhah K. Mechanism of stress-induced attacks in an episodic neurologic disorder. Sci Adv 2022; 8:eabh2675. [PMID: 35442745 PMCID: PMC9020779 DOI: 10.1126/sciadv.abh2675] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 03/02/2022] [Indexed: 05/21/2023]
Abstract
Stress is the most common trigger among episodic neurologic disorders. In episodic ataxia type 2 (EA2), physical or emotional stress causes episodes of severe motor dysfunction that manifest as ataxia and dystonia. We used the tottering (tg/tg) mouse, a faithful animal model of EA2, to dissect the mechanisms underlying stress-induced motor attacks. We find that in response to acute stress, activation of α1-adrenergic receptors (α1-Rs) on Purkinje cells by norepinephrine leads to their erratic firing and consequently motor attacks. We show that norepinephrine induces erratic firing of Purkinje cells by disrupting their spontaneous intrinsic pacemaking via a casein kinase 2 (CK2)-dependent signaling pathway, which likely reduces the activity of calcium-dependent potassium channels. Moreover, we report that disruption of this signaling cascade at a number of nodes prevents stress-induced attacks in the tottering mouse. Together, our results suggest that norepinephrine and CK2 are required for the initiation of stress-induced attacks in EA2 and provide previously unidentified targets for therapeutic intervention.
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Affiliation(s)
- Heather D. Snell
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ariel Vitenzon
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Esra Tara
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Chris Chen
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jaafar Tindi
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Bryen A. Jordan
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Psychiatry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Psychiatry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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11
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Krzyspiak J, Yan J, Ghosh HS, Galinski B, Lituma PJ, Alvina K, Quezada A, Kee S, Grońska-Pęski M, Tai YD, McDermott K, Gonçalves JT, Zukin RS, Weiser DA, Castillo PE, Khodakhah K, Hébert JM. Corrigendum to "Donor-derived vasculature is required to support neocortical cell grafts after stroke" [59 (2022) 102642]. Stem Cell Res 2022; 60:102700. [PMID: 35134695 DOI: 10.1016/j.scr.2022.102700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Joanna Krzyspiak
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA; Stem Cell Institute, Albert Einstein College of Medicine, Bronx, USA
| | - Jingqi Yan
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA
| | - Hiyaa S Ghosh
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, USA
| | - Basia Galinski
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, USA; Department of Pediatrics, Albert Einstein College of Medicine, Bronx, USA
| | - Pablo J Lituma
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA
| | - Karina Alvina
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA
| | - Alexandra Quezada
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA; Stem Cell Institute, Albert Einstein College of Medicine, Bronx, USA
| | - Samantha Kee
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA
| | - Marta Grońska-Pęski
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA; Stem Cell Institute, Albert Einstein College of Medicine, Bronx, USA
| | - Yi De Tai
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA; University of Rochester, Rochester, USA
| | - Kelsey McDermott
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA
| | - J Tiago Gonçalves
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA; Stem Cell Institute, Albert Einstein College of Medicine, Bronx, USA
| | - R Suzanne Zukin
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA
| | - Daniel A Weiser
- Department of Genetics, Albert Einstein College of Medicine, Bronx, USA; Department of Pediatrics, Albert Einstein College of Medicine, Bronx, USA
| | - Pablo E Castillo
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA; Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, USA
| | - Kamran Khodakhah
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA
| | - Jean M Hébert
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, USA; Stem Cell Institute, Albert Einstein College of Medicine, Bronx, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, USA.
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12
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Krzyspiak J, Yan J, Ghosh HS, Galinski B, Lituma PJ, Alvina K, Quezada A, Kee S, Grońska-Pęski M, Tai YD, McDermott K, Gonçalves JT, Zukin RS, Weiser DA, Castillo PE, Khodakhah K, Hébert JM. Donor-derived vasculature is required to support neocortical cell grafts after stroke. Stem Cell Res 2022; 59:102642. [PMID: 34971934 DOI: 10.1016/j.scr.2021.102642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 12/14/2021] [Accepted: 12/23/2021] [Indexed: 11/27/2022] Open
Abstract
Neural precursor cells (NPCs) transplanted into the adult neocortex generate neurons that synaptically integrate with host neurons, supporting the possibility of achieving functional tissue repair. However, poor survival and functional neuronal recovery of transplanted NPCs greatly limits engraftment. Here, we test the hypothesis that combining blood vessel-forming vascular cells with neuronal precursors improves engraftment. By transplanting mixed embryonic neocortical cells into adult mice with neocortical strokes, we show that transplant-derived neurons synapse with appropriate targets while donor vascular cells form vessels that fuse with the host vasculature to perfuse blood within the graft. Although all grafts became vascularized, larger grafts had greater contributions of donor-derived vessels that increased as a function of their distance from the host-graft border. Moreover, excluding vascular cells from the donor cell population strictly limited graft size. Thus, inclusion of vessel-forming vascular cells with NPCs is required for more efficient engraftment and ultimately for tissue repair.
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Affiliation(s)
- Joanna Krzyspiak
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA; Stem Cell Institute, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Jingqi Yan
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Hiyaa S Ghosh
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Basia Galinski
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Pablo J Lituma
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Karina Alvina
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Alexandra Quezada
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA; Stem Cell Institute, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Samantha Kee
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Marta Grońska-Pęski
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA; Stem Cell Institute, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Yi De Tai
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA; University of Rochester, Rochester, NY, USA
| | - Kelsey McDermott
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - J Tiago Gonçalves
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA; Stem Cell Institute, Albert Einstein College of Medicine, Bronx, NY, USA
| | - R Suzanne Zukin
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Daniel A Weiser
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Pablo E Castillo
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Kamran Khodakhah
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Jean M Hébert
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA; Stem Cell Institute, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA.
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13
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Kwak YD, Shaw TI, Downing SM, Tewari A, Jin H, Li Y, Dumitrache LC, Katyal S, Khodakhah K, Russell HR, McKinnon PJ. Chromatin architecture at susceptible gene loci in cerebellar Purkinje cells characterizes DNA damage-induced neurodegeneration. Sci Adv 2021; 7:eabg6363. [PMID: 34910524 DOI: 10.1126/sciadv.abg6363] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The pathogenesis of inherited genome instability neurodegenerative syndromes remains largely unknown. Here, we report new disease-relevant murine models of genome instability–driven neurodegeneration involving disabled ATM and APTX that develop debilitating ataxia. We show that neurodegeneration and ataxia result from transcriptional interference in the cerebellum via aberrant messenger RNA splicing. Unexpectedly, these splicing defects were restricted to only Purkinje cells, disrupting the expression of critical homeostatic regulators including ITPR1, GRID2, and CA8. Abundant genotoxic R loops were also found at these Purkinje cell gene loci, further exacerbating DNA damage and transcriptional disruption. Using ATAC-seq to profile global chromatin accessibility in the cerebellum, we found a notably unique chromatin conformation specifically in Purkinje chromatin at the affected gene loci, thereby promoting susceptibility to DNA damage. These data reveal the pathogenic basis of DNA damage in the nervous system and suggest chromatin conformation as a feature in directing genome instability–associated neuropathology.
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Affiliation(s)
- Young Don Kwak
- Departments of Genetics and Cell Molecular Biology, Center for Pediatric Neurological Disease Research, St. Jude Pediatric Translational Neuroscience Initiative, Memphis, TN 38105, USA
| | | | - Susanna M Downing
- Departments of Genetics and Cell Molecular Biology, Center for Pediatric Neurological Disease Research, St. Jude Pediatric Translational Neuroscience Initiative, Memphis, TN 38105, USA
| | - Ambika Tewari
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Hongjian Jin
- Center for Applied Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Yang Li
- Departments of Genetics and Cell Molecular Biology, Center for Pediatric Neurological Disease Research, St. Jude Pediatric Translational Neuroscience Initiative, Memphis, TN 38105, USA
| | - Lavinia C Dumitrache
- Departments of Genetics and Cell Molecular Biology, Center for Pediatric Neurological Disease Research, St. Jude Pediatric Translational Neuroscience Initiative, Memphis, TN 38105, USA
| | - Sachin Katyal
- CancerCare Manitoba Research Institute, CancerCare Manitoba and Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB R3E OV9, Canada
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Helen R Russell
- Departments of Genetics and Cell Molecular Biology, Center for Pediatric Neurological Disease Research, St. Jude Pediatric Translational Neuroscience Initiative, Memphis, TN 38105, USA
| | - Peter J McKinnon
- Departments of Genetics and Cell Molecular Biology, Center for Pediatric Neurological Disease Research, St. Jude Pediatric Translational Neuroscience Initiative, Memphis, TN 38105, USA
- St. Jude Graduate School of Biomedical Sciences, Memphis, TN 38105, USA
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14
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Washburn S, Fremont R, Moreno-Escobar MC, Angueyra C, Khodakhah K. Acute cerebellar knockdown of Sgce reproduces salient features of myoclonus-dystonia (DYT11) in mice. eLife 2019; 8:52101. [PMID: 31868164 PMCID: PMC6959989 DOI: 10.7554/elife.52101] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 12/20/2019] [Indexed: 12/15/2022] Open
Abstract
Myoclonus dystonia (DYT11) is a movement disorder caused by loss-of-function mutations in SGCE and characterized by involuntary jerking and dystonia that frequently improve after drinking alcohol. Existing transgenic mouse models of DYT11 exhibit only mild motor symptoms, possibly due to rodent-specific developmental compensation mechanisms, which have limited the study of neural mechanisms underlying DYT11. To circumvent potential compensation, we used short hairpin RNA (shRNA) to acutely knock down Sgce in the adult mouse and found that this approach produced dystonia and repetitive, myoclonic-like, jerking movements in mice that improved after administration of ethanol. Acute knockdown of Sgce in the cerebellum, but not the basal ganglia, produced motor symptoms, likely due to aberrant cerebellar activity. The acute knockdown model described here reproduces the salient features of DYT11 and provides a platform to study the mechanisms underlying symptoms of the disorder, and to explore potential therapeutic options.
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Affiliation(s)
- Samantha Washburn
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, United States
| | - Rachel Fremont
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, United States
| | - Maria Camila Moreno-Escobar
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, United States
| | - Chantal Angueyra
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, United States
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, United States
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15
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Khodakhah K. Cerebellar modulation of the basal ganglia. IBRO Rep 2019. [DOI: 10.1016/j.ibror.2019.07.094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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16
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Carta I, Chen CH, Schott AL, Dorizan S, Khodakhah K. Cerebellar modulation of the reward circuitry and social behavior. Science 2019; 363:363/6424/eaav0581. [PMID: 30655412 DOI: 10.1126/science.aav0581] [Citation(s) in RCA: 305] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 11/21/2018] [Indexed: 12/13/2022]
Abstract
The cerebellum has been implicated in a number of nonmotor mental disorders such as autism spectrum disorder, schizophrenia, and addiction. However, its contribution to these disorders is not well understood. In mice, we found that the cerebellum sends direct excitatory projections to the ventral tegmental area (VTA), one of the brain regions that processes and encodes reward. Optogenetic activation of the cerebello-VTA projections was rewarding and, in a three-chamber social task, these projections were more active when the animal explored the social chamber. Intriguingly, activity in the cerebello-VTA pathway was required for the mice to show social preference in this task. Our data delineate a major, previously unappreciated role for the cerebellum in controlling the reward circuitry and social behavior.
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Affiliation(s)
- Ilaria Carta
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Christopher H Chen
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Amanda L Schott
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Schnaude Dorizan
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA. .,Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, New York, NY 10461, USA.,Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, New York, NY 10461, USA
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17
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Kros L, Lykke-Hartmann K, Khodakhah K. Increased susceptibility to cortical spreading depression and epileptiform activity in a mouse model for FHM2. Sci Rep 2018; 8:16959. [PMID: 30446731 PMCID: PMC6240030 DOI: 10.1038/s41598-018-35285-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 11/02/2018] [Indexed: 01/03/2023] Open
Abstract
Migraine is a highly prevalent, debilitating, episodic headache disorder affecting roughly 15% of the population. Familial hemiplegic migraine type 2 (FHM2) is a rare subtype of migraine caused by mutations in the ATP1A2 gene, encoding the α2 isoform of the Na+/K+-ATPase, predominantly expressed in astrocytes. Differential comorbidities such as epilepsy and psychiatric disorders manifest in patients. Using a mouse model harboring the G301R disease-mutation in the α2 isoform, we set to unravel whether α2+/G301R mice show an increased susceptibility for epilepsy and cortical spreading depression (CSD). We performed in vivo experiments involving cortical application of KCl in awake head-restrained male and female mice of different age groups (adult and aged). Interestingly, α2+/G301R mice indeed showed an increased susceptibility to both CSD and epileptiform activity, closely replicating symptoms in FHM2 patients harboring the G301R and other FHM2-causing mutations. Additionally, this epileptiform activity was superimposed on CSDs. The age-related alteration towards CSD indicates the influence of female sex hormones on migraine pathophysiology. Therefore, the FHM2, α2+/G301R mouse model can be utilized to broaden our understanding of generalized epilepsy and comorbidity hereof in migraine, and may be utilized toward future selection of possible treatment options for migraine.
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Affiliation(s)
- Lieke Kros
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1410 Pelham Parkway South, Bronx, NY, 10461, USA.
- Department of Neuroscience, Erasmus Medical Center, Wytemaweg 80, 3015, CN Rotterdam, The Netherlands.
| | - Karin Lykke-Hartmann
- Aarhus University, Department of Biomedicine, Department of Clinical Medicine, Wilhelm Meyers Allé 4, DK-8000, Aarhus C, Denmark
- Department of Clinical Genetics, Aarhus University Hospital, Brendstrupgårdsvej 21, DK-8200, Aarhus N, Denmark
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1410 Pelham Parkway South, Bronx, NY, 10461, USA.
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18
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Tara E, Vitenzon A, Hess E, Khodakhah K. Aberrant cerebellar Purkinje cell activity as the cause of motor attacks in a mouse model of episodic ataxia type 2. Dis Model Mech 2018; 11:11/9/dmm034181. [PMID: 30279196 PMCID: PMC6177005 DOI: 10.1242/dmm.034181] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 07/30/2018] [Indexed: 11/20/2022] Open
Abstract
Many cerebellar-induced neurological disorders, such as ataxias and cerebellar-induced dystonias, are associated with abnormal Purkinje cell activity. In tottering mice, a well-established mouse model of episodic ataxia type 2 (EA2), cerebellar Purkinje cells are required for the initiation of motor attacks. How Purkinje cells contribute to the initiation of attacks is not known, and to date there are no reports on the activity of Purkinje cells during motor attacks in the tottering mice. Here, we show that tottering Purkinje cells exhibit high-frequency burst firing during attacks, reminiscent of other mouse models of cerebellar-induced motor dysfunction. We recorded the activity of Purkinje cells in awake head-restrained tottering mice at baseline, or during caffeine-induced attacks. During motor attacks, firing of Purkinje cells transformed to high-frequency burst firing. Interestingly, the extent to which the activity of Purkinje cells was erratic was correlated with the severity of the motor dysfunction. In support of a causal role for erratic activity in generating motor dysfunction, we found that direct infusion of the small conductance calcium-activated potassium (SK) channel activator NS309 into the cerebellum of tottering mice in the midst of an attack normalized the firing of Purkinje cells and aborted attacks. Conversely, we found that inducing high-frequency burst firing of Purkinje cells in wild-type animals is sufficient to produce severe motor signs. We report that erratic activity of wild-type Purkinje cells results in ataxia and dystonic postures. Moreover, this aberrant activity is the cause of motor attacks in the tottering mice. Summary: Here, we report that in the well-established mouse model of episodic ataxia type 2, tottering, the severe episodic motor signs are caused by highly erratic activity of Purkinje cells.
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Affiliation(s)
- Esra Tara
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ariel Vitenzon
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ellen Hess
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322-3090, USA
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Abstract
Background Although there is a great wealth of knowledge about the neurobiological processes underlying migraine and its accompanying symptoms, the mechanisms by which an attack starts remain elusive, and the disease remains undertreated. Although the vast majority of literature focuses on the involvement of the trigeminovascular systems and higher systems it innervates, such as thalamic and hypothalamic nuclei, several lines of evidence implicate the cerebellum in the pathophysiology of migraine. Aim In this review, we aim to summarize potential cerebellar involvement seen from different perspectives including the results from imaging studies, cerebellar connectivity to migraine-related brain structures, comorbidity with disorders implying cerebellar dysfunction, similarities in triggers precipitating both such disorders, and migraine and cerebellar expression of migraine-related genes and neuropeptides. We aim to inspire an increase in interest for future research on the subject. Conclusion It is hoped that future studies can provide an answer as to how the cerebellum may be involved and whether treatment options specifically targeting the cerebellum could provide alleviation of this disorder.
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Affiliation(s)
- Lieke Kros
- 1 Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, USA.,2 Department of Neuroscience, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | - Kamran Khodakhah
- 1 Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, USA
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20
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Shakkottai VG, Batla A, Bhatia K, Dauer WT, Dresel C, Niethammer M, Eidelberg D, Raike RS, Smith Y, Jinnah HA, Hess EJ, Meunier S, Hallett M, Fremont R, Khodakhah K, LeDoux MS, Popa T, Gallea C, Lehericy S, Bostan AC, Strick PL. Current Opinions and Areas of Consensus on the Role of the Cerebellum in Dystonia. Cerebellum 2017; 16:577-594. [PMID: 27734238 DOI: 10.1007/s12311-016-0825-6] [Citation(s) in RCA: 156] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A role for the cerebellum in causing ataxia, a disorder characterized by uncoordinated movement, is widely accepted. Recent work has suggested that alterations in activity, connectivity, and structure of the cerebellum are also associated with dystonia, a neurological disorder characterized by abnormal and sustained muscle contractions often leading to abnormal maintained postures. In this manuscript, the authors discuss their views on how the cerebellum may play a role in dystonia. The following topics are discussed: The relationships between neuronal/network dysfunctions and motor abnormalities in rodent models of dystonia. Data about brain structure, cerebellar metabolism, cerebellar connections, and noninvasive cerebellar stimulation that support (or not) a role for the cerebellum in human dystonia. Connections between the cerebellum and motor cortical and sub-cortical structures that could support a role for the cerebellum in dystonia. Overall points of consensus include: Neuronal dysfunction originating in the cerebellum can drive dystonic movements in rodent model systems. Imaging and neurophysiological studies in humans suggest that the cerebellum plays a role in the pathophysiology of dystonia, but do not provide conclusive evidence that the cerebellum is the primary or sole neuroanatomical site of origin.
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Affiliation(s)
- Vikram G Shakkottai
- Department of Neurology, University of Michigan, Room 4009, BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA. .,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109-2200, USA.
| | - Amit Batla
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London, London, UK
| | - Kailash Bhatia
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London, London, UK
| | - William T Dauer
- Department of Neurology, University of Michigan, Room 4009, BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA.,Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Christian Dresel
- Center for Neurosciences, The Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - Martin Niethammer
- Center for Neurosciences, The Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - David Eidelberg
- Center for Neurosciences, The Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - Robert S Raike
- Global Research Organization, Medtronic Inc. Neuromodulation, Minneapolis, MN, USA
| | - Yoland Smith
- Yerkes National Primate Center and Department of Neurology, Emory University, Atlanta, GA, USA
| | - H A Jinnah
- Department of Neurology, Human Genetics and Pediatrics, Emory University, Atlanta, GA, USA
| | - Ellen J Hess
- Departments of Pharmacology and Neurology, Emory University, Atlanta, GA, USA
| | - Sabine Meunier
- Institut du Cerveau et de la Moelle épinière (ICM), Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR, S 1127, Paris, France.,Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Mark Hallett
- Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Rachel Fremont
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, USA
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Department of Psychiatry and Behavioral Sciences, and The Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, New York, NY, USA
| | - Mark S LeDoux
- Departments of Neurology, and Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Traian Popa
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Cécile Gallea
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France.,Centre de NeuroImagerie de Recherche - CENIR, ICM, F-75013, Paris, France
| | - Stéphane Lehericy
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Andreea C Bostan
- Systems Neuroscience Institute and Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Peter L Strick
- Systems Neuroscience Institute and Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Neurobiology, University of Pittsburgh Brain Institute, University of Pittsburgh, Pittsburgh, PA, USA
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21
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Tewari A, Fremont R, Khodakhah K. It's not just the basal ganglia: Cerebellum as a target for dystonia therapeutics. Mov Disord 2017; 32:1537-1545. [PMID: 28843013 DOI: 10.1002/mds.27123] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 06/26/2017] [Accepted: 06/27/2017] [Indexed: 01/01/2023] Open
Abstract
Dystonia is a common movement disorder that devastates the lives of many patients, but the etiology of this disorder remains poorly understood. Dystonia has traditionally been considered a disorder of the basal ganglia. However, growing evidence suggests that the cerebellum may be involved in certain types of dystonia, raising several questions. Can different types of dystonia be classified as either a basal ganglia disorder or a cerebellar disorder? Is dystonia a network disorder that involves the cerebellum and basal ganglia? If dystonia is a network disorder, how can we target treatments to alleviate symptoms in patients? A recent study by Chen et al, using the pharmacological mouse model of rapid-onset dystonia parkinsonism, has provided some insight into these important questions. They showed that the cerebellum can directly modulate basal ganglia activity through a short latency cerebello-thalamo-basal ganglia pathway. Further, this article and others have provided evidence that in some cases, aberrant cerebello-basal ganglia communication can be involved in dystonia. In this review we examine the evidence for the involvement of the cerebellum and cerebello-basal ganglia interactions in dystonia. We conclude that there is ample evidence to suggest that the cerebellum plays a role in some dystonias, including the early-onset primary torsion dystonia DYT1 and that further studies examining the role of this brain region and its interaction with the basal ganglia in dystonia are warranted. © 2017 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Ambika Tewari
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Rachel Fremont
- Columbia University Medical Center, Department of Psychiatry, New York, New York, USA
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
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22
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Isaksen TJ, Kros L, Vedovato N, Holm TH, Vitenzon A, Gadsby DC, Khodakhah K, Lykke-Hartmann K. Hypothermia-induced dystonia and abnormal cerebellar activity in a mouse model with a single disease-mutation in the sodium-potassium pump. PLoS Genet 2017; 13:e1006763. [PMID: 28472154 PMCID: PMC5436892 DOI: 10.1371/journal.pgen.1006763] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 05/18/2017] [Accepted: 04/17/2017] [Indexed: 11/18/2022] Open
Abstract
Mutations in the neuron-specific α3 isoform of the Na+/K+-ATPase are found in patients suffering from Rapid onset Dystonia Parkinsonism and Alternating Hemiplegia of Childhood, two closely related movement disorders. We show that mice harboring a heterozygous hot spot disease mutation, D801Y (α3+/D801Y), suffer abrupt hypothermia-induced dystonia identified by electromyographic recordings. Single-neuron in vivo recordings in awake α3+/D801Y mice revealed irregular firing of Purkinje cells and their synaptic targets, the deep cerebellar nuclei neurons, which was further exacerbated during dystonia and evolved into abnormal high-frequency burst-like firing. Biophysically, we show that the D-to-Y mutation abolished pump-mediated Na+/K+ exchange, but allowed the pumps to bind Na+ and become phosphorylated. These findings implicate aberrant cerebellar activity in α3 isoform-related dystonia and add to the functional understanding of the scarce and severe mutations in the α3 isoform Na+/K+-ATPase. The neurological spectrum associated with mutations in the ATP1A3 gene, encoding the α3 isoform of the Na+/K+-ATPase, is complex and still poorly understood. To elucidate the disease-specific pathophysiology, we examined a mouse model harboring the mutation D801Y, which was originally found in a patient with Rapid onset Dystonia Parkinsonism, but recently, also in a patient with Alternating Hemiplegia of Childhood. We found that this model exhibited motor deficits and developed dystonia when exposed to a drop in body temperature. Cerebellar in vivo recordings in awake mice revealed irregular firing of Purkinje cells and their synaptic targets, the deep cerebellar nuclei neurons, which was further exacerbated and evolved into abnormal high-frequency burst firing during dystonia. The development of specific neurological features within the ATP1A3 mutation spectrum, such as dystonia, are thought to reflect the functional consequences of each mutation, thus to investigate the consequence of the D801Y mutations we characterized mutated D-to-Y Na+/K+-ATPases expressed in Xenopus oocytes. These in vitro studies showed that the D-to-Y mutation abolishes pump-mediated Na+/K+ exchange, but still allows the pumps to bind Na+ and become phosphorylated, trapping them in conformations that instead support proton influx.
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Affiliation(s)
- Toke Jost Isaksen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Lieke Kros
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Natascia Vedovato
- The Laboratory of Cardiac/Membrane Physiology, The Rockefeller University, New York, New York, United States of America
| | - Thomas Hellesøe Holm
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Ariel Vitenzon
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - David C. Gadsby
- The Laboratory of Cardiac/Membrane Physiology, The Rockefeller University, New York, New York, United States of America
| | - Kamran Khodakhah
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Karin Lykke-Hartmann
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
- Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Aarhus C, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- * E-mail:
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Abstract
DYT1 is a debilitating movement disorder caused by loss-of-function mutations in torsinA. How these mutations cause dystonia remains unknown. Mouse models which have embryonically targeted torsinA have failed to recapitulate the dystonia seen in patients, possibly due to differential developmental compensation between rodents and humans. To address this issue, torsinA was acutely knocked down in select brain regions of adult mice using shRNAs. TorsinA knockdown in the cerebellum, but not in the basal ganglia, was sufficient to induce dystonia. In agreement with a potential developmental compensation for loss of torsinA in rodents, torsinA knockdown in the immature cerebellum failed to produce dystonia. Abnormal motor symptoms in knockdown animals were associated with irregular cerebellar output caused by changes in the intrinsic activity of both Purkinje cells and neurons of the deep cerebellar nuclei. These data identify the cerebellum as the main site of dysfunction in DYT1, and offer new therapeutic targets. DOI:http://dx.doi.org/10.7554/eLife.22775.001 Dystonia is the third most common type of movement disorder after Parkinson’s disease and tremor. Patients with dystonia experience prolonged involuntary contractions of their muscles, often causing uncontrollable postures or repetitive movements. Almost thirty years ago, genetic studies revealed that a mutation in the gene that encodes a protein called torsinA causes the most common type of dystonia, called DYT1. Exactly how mutations that affect the torsinA protein give rise to DYT1 remains unclear, and there are still no effective treatments for the disorder. Part of the problem is that we do not fully understand how torsinA works, or which of its many proposed functions is relevant to dystonia. Moreover, attempts to study DYT1 using genetically modified mice have proved largely unsuccessful. This is because mice that simply express the same genetic mutations that cause dystonia in humans do not show the overt symptoms of dystonia. Fremont, Tewari et al. have now generated a mouse ‘model’ that does show symptoms of dystonia, and used these model mice to investigate the role of torsinA in the disorder. Acutely reducing the amount of torsinA protein in a region of the brain called the cerebellum induced the symptoms of dystonia in the mice. Conversely, reducing the amount of torsinA in a different brain area known as the basal ganglia had no such effect, even though both the cerebellum and the basal ganglia contribute to movement. Furthermore, neither manipulation had any effect in juvenile mice, which suggests that, in contrast to humans, young mice can compensate for the loss of torsinA. Fremont, Tewari et al. also found that the loss of torsinA causes the cerebellum to generate incorrect output signals, which in turn trigger the abnormal movements seen in dystonia. In the future, further studies of the model mice could identify the exact changes that occur in neurons following the loss of torsinA from the cerebellum. Understanding these changes could potentially pave the way for developing effective treatments for DYT1 and other dystonias. DOI:http://dx.doi.org/10.7554/eLife.22775.002
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Affiliation(s)
- Rachel Fremont
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, United States
| | - Ambika Tewari
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, United States
| | - Chantal Angueyra
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, United States
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, United States
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24
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Abstract
PURPOSE OF REVIEW To identify the different indications for the treatment of neurologic disorders with the potassium channel blockers 4-aminopyridine (4-AP) and 3,4-diaminopyridine (3,4-DAP). RECENT FINDINGS 4-AP is an effective symptomatic treatment for downbeat nystagmus (DBN), episodic ataxia type 2 (EA2) (5-10 mg TID), and impaired gait in multiple sclerosis (MS) (10 mg BID). 3,4-DAP (5 mg/d-20 mg TID) improves symptoms in Lambert-Eaton myasthenic syndrome (LEMS) (randomized placebo-controlled trials for all 4 entities). 4-AP may also be effective in cerebellar gait ataxia of different etiologies (2 case series), upbeat nystagmus, and limb ataxia in MS (single cases). In the recommended dosages, they are well tolerated. The assumed mode of action is a blockade of mainly Kv1.5: in DBN, this increases the excitability of Purkinje cells (PC), and in EA2, restores the precision of resting discharge of PC. In MS, 4-AP improves the conduction of action potentials in demyelinated axons, and in LEMS, 3,4-DAP facilitates the transmission at the neuromuscular endplate by prolonging the action potential duration. SUMMARY There is sufficient evidence that APs are indicated for the symptomatic treatment of DBN, EA2, gait ataxia due to MS and cerebellar disorders, and LEMS with a reasonable risk-benefit profile.
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Affiliation(s)
- Michael Strupp
- University Hospital (MS, JT, AZ, RS, KF), Munich, Germany; and Albert Einstein College of Medicine (KK), New York, NY
| | - Julian Teufel
- University Hospital (MS, JT, AZ, RS, KF), Munich, Germany; and Albert Einstein College of Medicine (KK), New York, NY
| | - Andreas Zwergal
- University Hospital (MS, JT, AZ, RS, KF), Munich, Germany; and Albert Einstein College of Medicine (KK), New York, NY
| | - Roman Schniepp
- University Hospital (MS, JT, AZ, RS, KF), Munich, Germany; and Albert Einstein College of Medicine (KK), New York, NY
| | - Kamran Khodakhah
- University Hospital (MS, JT, AZ, RS, KF), Munich, Germany; and Albert Einstein College of Medicine (KK), New York, NY
| | - Katharina Feil
- University Hospital (MS, JT, AZ, RS, KF), Munich, Germany; and Albert Einstein College of Medicine (KK), New York, NY
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25
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Abstract
In this issue of Neuron, Gao et al. (2016) report on a little-studied feedback pathway from the cerebellar nuclei back to the cerebellar cortex. They find that it contributes to associative conditioning and execution of learned movements, highlighting a role for local feedback loops in the brain.
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Affiliation(s)
- Abigail L Person
- Department of Physiology & Biophysics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA; Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, New York, NY 10461, USA; Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, New York, NY 10461, USA.
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26
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Affiliation(s)
- Kamran Khodakhah
- Dominik P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, New York 10461, USA
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27
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Keller CJ, Chen C, Lado FA, Khodakhah K. The Limited Utility of Multiunit Data in Differentiating Neuronal Population Activity. PLoS One 2016; 11:e0153154. [PMID: 27111446 PMCID: PMC4844128 DOI: 10.1371/journal.pone.0153154] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 03/06/2016] [Indexed: 11/19/2022] Open
Abstract
To date, single neuron recordings remain the gold standard for monitoring the activity of neuronal populations. Since obtaining single neuron recordings is not always possible, high frequency or ‘multiunit activity’ (MUA) is often used as a surrogate. Although MUA recordings allow one to monitor the activity of a large number of neurons, they do not allow identification of specific neuronal subtypes, the knowledge of which is often critical for understanding electrophysiological processes. Here, we explored whether prior knowledge of the single unit waveform of specific neuron types is sufficient to permit the use of MUA to monitor and distinguish differential activity of individual neuron types. We used an experimental and modeling approach to determine if components of the MUA can monitor medium spiny neurons (MSNs) and fast-spiking interneurons (FSIs) in the mouse dorsal striatum. We demonstrate that when well-isolated spikes are recorded, the MUA at frequencies greater than 100Hz is correlated with single unit spiking, highly dependent on the waveform of each neuron type, and accurately reflects the timing and spectral signature of each neuron. However, in the absence of well-isolated spikes (the norm in most MUA recordings), the MUA did not typically contain sufficient information to permit accurate prediction of the respective population activity of MSNs and FSIs. Thus, even under ideal conditions for the MUA to reliably predict the moment-to-moment activity of specific local neuronal ensembles, knowledge of the spike waveform of the underlying neuronal populations is necessary, but not sufficient.
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Affiliation(s)
- Corey J. Keller
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States of America
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States of America
- Stanford Neurosciences Institute, Stanford University, Stanford, CA, United States of America
- * E-mail:
| | - Christopher Chen
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Fred A. Lado
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States of America
- Department of Neurology, Montefiore Medical Center, Bronx, NY, United States of America
| | - Kamran Khodakhah
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States of America
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Alviña K, Tara E, Khodakhah K. Developmental change in the contribution of voltage-gated Ca(2+) channels to the pacemaking of deep cerebellar nuclei neurons. Neuroscience 2016; 322:171-7. [PMID: 26902515 DOI: 10.1016/j.neuroscience.2016.02.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 01/29/2016] [Accepted: 02/15/2016] [Indexed: 10/22/2022]
Abstract
The activity of the deep cerebellar nuclei (DCN) neurons conveys the bulk of the output of the cerebellum. To generate these motor signals, DCN neurons integrate synaptic inputs with their own spontaneous activity. We have previously reported that N-type voltage-gated Ca(2+) channels modulate the spontaneous activity of the majority of juvenile DCN neurons in vitro. Specifically, pharmacologically blocking N-type Ca(2+) channels increases their firing rate causing DCN cells to burst. Adult DCN neurons however, behaved differently. To further investigate this change, we have studied here the effect of cadmium on the firing rate of DCN neurons in acute cerebellar slices obtained from adult (>2 months old) or juvenile (12-21 days old) rats and mice. Strikingly, and in contrast to juvenile DCN cells, cadmium did not affect the pacemaking of adult DCN cells. The activity of Purkinje cells (PCs) however was transformed into high-frequency bursting, regardless the age. Further, we questioned whether these findings could be due to an artifact associated with the added difficulty of preparing adult DCN slices. Hence we proceeded to examine the spontaneous activity of DCN neurons in anesthetized juvenile and adult rats and mice in vivo. When cadmium was injected into the DCN in vivo no significant change in firing rate was observed, conversely to most juvenile DCN neurons which showed high-frequency bursts after cadmium injection. In these same animals, PCs pacemaking showed no developmental difference. Thus our results demonstrate a remarkable age-dependent functional modification in the regulation of DCN neurons pacemaking.
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Affiliation(s)
- K Alviña
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States.
| | - E Tara
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States; Present address: Neurodegeneration Research Laboratory, Molecular Biology and Genetics Department, Bogazici University, Istanbul 34342, Turkey
| | - K Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States; Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, United States; Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, United States
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29
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Liu YB, Tewari A, Salameh J, Arystarkhova E, Hampton TG, Brashear A, Ozelius LJ, Khodakhah K, Sweadner KJ. A dystonia-like movement disorder with brain and spinal neuronal defects is caused by mutation of the mouse laminin β1 subunit, Lamb1. eLife 2015; 4. [PMID: 26705335 PMCID: PMC4749547 DOI: 10.7554/elife.11102] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 12/15/2015] [Indexed: 12/30/2022] Open
Abstract
A new mutant mouse (lamb1t) exhibits intermittent dystonic hindlimb movements and postures when awake, and hyperextension when asleep. Experiments showed co-contraction of opposing muscle groups, and indicated that symptoms depended on the interaction of brain and spinal cord. SNP mapping and exome sequencing identified the dominant causative mutation in the Lamb1 gene. Laminins are extracellular matrix proteins, widely expressed but also known to be important in synapse structure and plasticity. In accordance, awake recording in the cerebellum detected abnormal output from a circuit of two Lamb1-expressing neurons, Purkinje cells and their deep cerebellar nucleus targets, during abnormal postures. We propose that dystonia-like symptoms result from lapses in descending inhibition, exposing excess activity in intrinsic spinal circuits that coordinate muscles. The mouse is a new model for testing how dysfunction in the CNS causes specific abnormal movements and postures.
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Affiliation(s)
- Yi Bessie Liu
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, United States
| | - Ambika Tewari
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, United States
| | - Johnny Salameh
- Department of Neurology, University of Massachusetts Medical School, Worcester, United States
| | - Elena Arystarkhova
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, United States
| | - Thomas G Hampton
- Neuroscience Discovery Core, Mouse Specifics Inc., Framingham, United States
| | - Allison Brashear
- Department of Neurology, Wake Forest University School of Medicine, Winston-Salem, United States
| | - Laurie J Ozelius
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, United States
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, United States
| | - Kathleen J Sweadner
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, United States
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30
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Fremont R, Tewari A, Khodakhah K. Aberrant Purkinje cell activity is the cause of dystonia in a shRNA-based mouse model of Rapid Onset Dystonia-Parkinsonism. Neurobiol Dis 2015; 82:200-212. [PMID: 26093171 DOI: 10.1016/j.nbd.2015.06.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 06/08/2015] [Accepted: 06/09/2015] [Indexed: 11/19/2022] Open
Abstract
Loss-of-function mutations in the α3 isoform of the sodium pump are responsible for Rapid Onset Dystonia-Parkinsonism (RDP). A pharmacologic model of RDP replicates the most salient features of RDP, and implicates both the cerebellum and basal ganglia in the disorder; dystonia is associated with aberrant cerebellar output, and the parkinsonism-like features are attributable to the basal ganglia. The pharmacologic agent used to generate the model, ouabain, is selective for sodium pumps. However, close to the infusion sites in vivo it likely affects all sodium pump isoforms. Therefore, it remains to be established whether selective loss of α3-containing sodium pumps replicates the pharmacologic model. Moreover, while the pharmacologic model suggested that aberrant firing of Purkinje cells was the main cause of abnormal cerebellar output, it did not allow the scrutiny of this hypothesis. To address these questions RNA interference using small hairpin RNAs (shRNAs) delivered via adeno-associated viruses (AAV) was used to specifically knockdown α3-containing sodium pumps in different regions of the adult mouse brain. Knockdown of the α3-containing sodium pumps mimicked both the behavioral and electrophysiological changes seen in the pharmacologic model of RDP, recapitulating key aspects of the human disorder. Further, we found that knockdown of the α3 isoform altered the intrinsic pacemaking of Purkinje cells, but not the neurons of the deep cerebellar nuclei. Therefore, acute knockdown of proteins associated with inherited dystonias may be a good strategy for developing phenotypic genetic mouse models where traditional transgenic models have failed to produce symptomatic mice.
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Affiliation(s)
- Rachel Fremont
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ambika Tewari
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Kamran Khodakhah
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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31
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Wen J, Chen C, Stock A, Doerner J, Burkly L, Gulinello M, Khodakhah K, Putterman C. Intracerebroventricular TWEAK (TNF-like weak inducer of apoptosis) induces depressive-like behavior and cognitive dysfunction in non-autoimmune mice (CCR5P.200). The Journal of Immunology 2015. [DOI: 10.4049/jimmunol.194.supp.186.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Fn14, the sole receptor for the TNF family member TWEAK, is inducibly expressed in the brain in endothelial cells, astrocytes, microglia, and neurons. Previously, we had found that Fn14 knockout lupus MRL/lpr mice display significantly attenuated neuropsychiatric manifestations. To establish whether this improvement in disease is secondary to ablation of TWEAK-Fn14 signaling within the CNS or the periphery and determine whether TWEAK-mediated neuropsychiatric effects are strain dependent, we performed intracerebraventricular injection (ICV) of Fc-TWEAK or a control protein to B6 mice. Interestingly, we found that the Fc-TWEAK injected mice developed significant depressive-like behavior and abnormal cognitive dysfunction. Inflammatory mediators including MCP-1, C3, and iNOS were significantly elevated in the brains of Fc-TWEAK treated mice. Furthermore, Fc-TWEAK directly increased BBB disruption, as demonstrated by increased fibronectin deposition in the brain and reduced aquaporin-4 expression. Finally, Fc-TWEAK increased apoptotic cell death in the cortex, hippocampus, and brain stem. In conclusion, TWEAK can contribute to lupus-associated neurobehavioral deficits by acting within the CNS to enhance production of inflammatory mediators, promote permeability of the BBB, and induce apoptosis in resident brain cells. Our study provides further support that the TWEAK/Fn14 signaling pathway may be a potential therapeutic target for inflammatory diseases involving the CNS.
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Affiliation(s)
- Jing Wen
- 1Albert Einstein College of Medicine, Bronx, NY
| | - Chris Chen
- 1Albert Einstein College of Medicine, Bronx, NY
| | - Ariel Stock
- 1Albert Einstein College of Medicine, Bronx, NY
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32
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Calderon DP, Khodakhah K. Modeling Dystonia-Parkinsonism. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00029-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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33
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Heck DH, De Zeeuw CI, Jaeger D, Khodakhah K, Person AL. The neuronal code(s) of the cerebellum. J Neurosci 2013; 33:17603-9. [PMID: 24198351 PMCID: PMC3818542 DOI: 10.1523/jneurosci.2759-13.2013] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 08/28/2013] [Accepted: 08/29/2013] [Indexed: 01/30/2023] Open
Abstract
Understanding how neurons encode information in sequences of action potentials is of fundamental importance to neuroscience. The cerebellum is widely recognized for its involvement in the coordination of movements, which requires muscle activation patterns to be controlled with millisecond precision. Understanding how cerebellar neurons accomplish such high temporal precision is critical to understanding cerebellar function. Inhibitory Purkinje cells, the only output neurons of the cerebellar cortex, and their postsynaptic target neurons in the cerebellar nuclei, fire action potentials at high, sustained frequencies, suggesting spike rate modulation as a possible code. Yet, millisecond precise spatiotemporal spike activity patterns in Purkinje cells and inferior olivary neurons have also been observed. These results and ongoing studies suggest that the neuronal code used by cerebellar neurons may span a wide time scale from millisecond precision to slow rate modulations, likely depending on the behavioral context.
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Affiliation(s)
- Detlef H. Heck
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - Chris I. De Zeeuw
- Department of Neuroscience, Erasmus MC, 3000 DR Rotterdam, The Netherlands
- Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, 1105 BA Amsterdam, The Netherlands
| | - Dieter Jaeger
- Department of Biology, Emory University, Atlanta, Georgia 30322
| | - Kamran Khodakhah
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, and
| | - Abigail L. Person
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, Colorado 80045
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34
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Abstract
Dystonia is a movement disorder characterized by involuntary muscle contractions resulting in abnormal postures. Although common in the clinic, the etiology of dystonia remains unclear. Most dystonias are idiopathic and are not associated with clear pathological brain abnormalities. Attempts to genetically model these dystonias in rodents have failed to replicate dystonic symptoms. This is at odds with the fact that rodents can exhibit dystonia. Because of this discrepancy, it is necessary to consider alternative approaches to generate phenotypically and genotypically faithful models of dystonia. Conditional knockout of dystonia-related genes is 1 technique that may prove useful for modeling genetic dystonias. Lentiviral-mediated small or short hairpin RNA (shRNA) knockdown of particular genes is another approach. Finally, in cases in which the function of a dystonia-related gene is well-known, pharmacological blockade of the protein product can be used. Such an approach was successfully implemented in the case of rapid-onset dystonia parkinsonism, DYT12. This (DYT12) is a hereditary dystonia caused by mutations in the α₃ isoform of the sodium potassium adenosine triphosphatase (ATPase) pump (sodium pump), which partially hampers its physiological function. It was found that partial selective pharmacological block of the sodium pumps in the cerebellum and basal ganglia of mice recapitulates all of the salient features of DYT12, including dystonia and parkinsonism induced by stress. This DYT12 model is unique in that it faithfully replicates human symptoms of DYT12, while targeting the genetic cause of this disorder. Acute disruption of proteins implicated in dystonia may prove a generally fruitful method to model dystonia in rodents.
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Affiliation(s)
- Rachel Fremont
- Dominic P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461 USA
| | - Kamran Khodakhah
- Dominic P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461 USA
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35
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Abstract
Reciprocal activity between populations of neurons has been widely observed in the brain and is essential for neuronal computation. The different mechanisms by which reciprocal neuronal activity is generated remain to be established. A common motif in neuronal circuits is the presence of afferents that provide excitation to one set of principal neurons and, via interneurons, inhibition to a second set of principal neurons. This circuitry can be the substrate for generation of reciprocal signals. Here we demonstrate that this equivalent circuit in the cerebellar cortex enables the reciprocal firing rates of Purkinje cells to be efficiently generated from a common set of mossy fiber inputs. The activity of a mossy fiber is relayed to Purkinje cells positioned immediately above it by excitatory granule cells. The firing rates of these Purkinje cells increase as a linear function of mossy fiber, and thus granule cell, activity. In addition to exciting Purkinje cells positioned immediately above it, the activity of a mossy fiber is relayed to laterally positioned Purkinje cells by a disynaptic granule cell → molecular layer interneuron pathway. Here we show in acutely prepared cerebellar slices that the input-output relationship of these laterally positioned Purkinje cells is linear and reciprocal to the first set. A similar linear input-output relationship between decreases in Purkinje cell firing and strength of stimulation of laterally positioned granule cells was also observed in vivo. Use of interneurons to generate reciprocal firing rates may be a common mechanism by which the brain generates reciprocal signals.
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Affiliation(s)
- Sung-min Park
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1410 Pelham Parkway South, Kennedy Center, Bronx, NY 10461, USA
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Womack MD, Hoang C, Khodakhah K. Large conductance calcium-activated potassium channels affect both spontaneous firing and intracellular calcium concentration in cerebellar Purkinje neurons. Neuroscience 2009; 162:989-1000. [PMID: 19446607 DOI: 10.1016/j.neuroscience.2009.05.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Revised: 04/17/2009] [Accepted: 05/08/2009] [Indexed: 10/20/2022]
Abstract
We investigated the contribution of large conductance calcium-activated potassium (BK) channels to spontaneous activity of cerebellar Purkinje neurons in mice and rats. In Purkinje neurons which fire tonically, block of BK channels increased the firing rate and caused the neurons to fire irregularly. In Purkinje neurons which exhibited a trimodal pattern of activity, present primarily in mature animals, block of BK channels had little effect on firing rate or regularity but shortened the single cycle duration of the trimodal pattern. The contribution of BK channels to the action potential waveform was also examined. BK channels contributed a brief afterhyperpolarization (AHP) of approximately 3 mV which followed each action potential, but made little contribution to action potential repolarization. The amplitude of the BK-dependent AHP did not change with age although there was an increase in the total AHP. The difference in the contribution of BK channels to the firing rate among the two populations of Purkinje neurons was the consequence of the decrease in the fractional contribution of BK channels to the AHP. We also found that block of BK channels increases intracellular calcium concentration during spontaneous firing. Thus, although BK channels do not affect action potential repolarization, they nevertheless control calcium entry with each action potential by contributing to the AHP.
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Affiliation(s)
- M D Womack
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, 506 Kennedy Center, 1410 Pelham Parkway South, Bronx, NY 10461, USA
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Alviña K, Walter J, Kohn A, Ellis-Davies G, Khodakhah K. Questioning the role of rebound firing in the cerebellum. Nat Neurosci 2008; 11:1256-8. [PMID: 18820695 PMCID: PMC2691662 DOI: 10.1038/nn.2195] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Accepted: 08/06/2008] [Indexed: 11/08/2022]
Abstract
A key component of recent theories on cerebellar function is rebound firing in neurons of the deep cerebellar nuclei (DCN). Despite the robustness of this phenomenon in vitro, in vivo studies have provided little evidence for its prevalence. We found that intact mouse or rat DCN neurons rarely showed rebound firing under physiological conditions in vitro or in vivo. These observations necessitate a critical re-evaluation of recent cerebellar models.
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Affiliation(s)
- Karina Alviña
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
- Departmento de Ciencias Fisiologicas, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Joy Walter
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Adam Kohn
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Graham Ellis-Davies
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
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Alviña K, Ellis-Davies G, Khodakhah K. T-type calcium channels mediate rebound firing in intact deep cerebellar neurons. Neuroscience 2008; 158:635-41. [PMID: 18983899 DOI: 10.1016/j.neuroscience.2008.09.052] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Revised: 09/22/2008] [Accepted: 09/26/2008] [Indexed: 10/21/2022]
Abstract
Neurons of the deep cerebellar nuclei (DCN) form the main output of the cerebellar circuitry and thus play an important role in cerebellar motor coordination. A prominent biophysical property observed in rat DCN neurons is rebound firing; a brief but strong hyperpolarizing input transiently increases their firing rate to much higher levels compared with that prior to the inhibitory input. Low-threshold T-type voltage-gated calcium channels have been suspected for a long time to be responsible for this phenomenon, but direct pharmacological evidence in support of this proposition is lacking. Even though a multitude of functional roles has been assigned to rebound firing in DCN neurons, their prevalence under physiological conditions is in question. Studies aimed at delineating the physiological role of rebound firing are hampered by the lack of a good pharmacological blocker. Here we show that mibefradil, a compound that blocks T-type calcium channels, potently blocks rebound firing in DCN neurons. In whole-cell experiments both mibefradil and NNC 55-0396 [(1S,2S)-2-(2-(N-[(3-benzimidazol-2-yl)propyl]-N-methylamino)ethyl)-6-fluoro-1,2,3,4-tetrahydro-1-isopropyl-2-naphtyl cyclopropanecarboxylate dihydrochloride]. a more selective T-type calcium channel blocker, effectively blocked rebound firing produced by direct current injection. Thus, mibefradil and other T-type channel modulators may prove to be invaluable tools for elucidating the functional importance of DCN rebound firing in cerebellar computation.
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Affiliation(s)
- K Alviña
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1410 Pelham Parkway South, Kennedy Center Room 506, Bronx, NY 10461, USA
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Alviña K, Khodakhah K. Selective regulation of spontaneous activity of neurons of the deep cerebellar nuclei by N-type calcium channels in juvenile rats. J Physiol 2008; 586:2523-38. [PMID: 18372310 DOI: 10.1113/jphysiol.2007.148197] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The cerebellum coordinates movement and maintains body posture. The main output of the cerebellum is formed by three deep nuclei, which receive direct inhibitory inputs from cerebellar Purkinje cells, and excitatory collaterals from mossy and climbing fibres. Neurons of deep cerebellar nuclei (DCN) are spontaneously active, and disrupting their activity results in severe cerebellar ataxia. It is suggested that voltage-gated calcium channels make a significant contribution to the spontaneous activity of DCN neurons, although the exact identity of these channels is not known. We sought to delineate the functional role and identity of calcium channels that contribute to pacemaking in DCN neurons of juvenile rats. We found that in the majority of cells blockade of calcium currents results in avid high-frequency bursting, consistent with the notion that the net calcium-dependent current in DCN neurons is outward. We showed that the bursting seen in these neurons after block of calcium channels is the consequence of reduced activation of small-conductance calcium-activated (SK) potassium channels. With the use of selective pharmacological blockers we showed that L-, P/Q-, R- and T-type calcium channels do not contribute to the spontaneous activity of DCN neurons. In contrast, blockade of high-threshold N-type calcium channels increased the firing rate and caused the cells to burst. Our results thus suggest a selective coupling of N-type voltage-gated calcium channels with calcium-activated potassium channels in DCN neurons. In addition, we demonstrate the presence of a cadmium-sensitive calcium conductance coupled with SK channels, that is pharmacologically distinct from L-, N-, P/Q-, R- and T-type calcium channels.
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Affiliation(s)
- Karina Alviña
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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40
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Abstract
The orchestration of simple motor tasks by the cerebellum results in coordinated movement and the maintenance of balance. The cerebellum integrates sensory and cortical information to generate the signals required for the coordinated execution of simple motor tasks. These signals originate in the firing rate of Purkinje cells, each of which integrates sensory and cortical information conveyed by granule cell synaptic inputs. Given the importance of the granule cell input-Purkinje cell output function for cerebellar computation, this algorithm was determined. Using several stimulation paradigms, including those that mimicked patterns of granule cell activity similar to those observed in vivo, we quantified the poststimulus maximum firing rate and number of extra spikes in response to granule cell synaptic input. Both of these parameters linearly encoded the strength of synaptic input when inhibitory synaptic transmission was blocked. This linear algorithm was independent of the location or temporal pattern of synaptic input. With inhibitory synaptic transmission intact, the maximum firing rate, but not the number of extra spikes, encoded the strength of granule cell synaptic input. Furthermore, the maximum firing rate of Purkinje cells linearly encoded the strength of synaptic input whether or not the activation of granule cells resulted in a pause in Purkinje cell firing. On the basis of the data presented, we propose that Purkinje cells encode the strength of granule cell synaptic input in their maximum firing rate with a linear algorithm.
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Affiliation(s)
- Joy T. Walter
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
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Walter JT, Alviña K, Womack MD, Chevez C, Khodakhah K. Decreases in the precision of Purkinje cell pacemaking cause cerebellar dysfunction and ataxia. Nat Neurosci 2006; 9:389-97. [PMID: 16474392 DOI: 10.1038/nn1648] [Citation(s) in RCA: 308] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Accepted: 01/20/2006] [Indexed: 11/08/2022]
Abstract
Episodic ataxia type-2 (EA2) is caused by mutations in P/Q-type voltage-gated calcium channels that are expressed at high densities in cerebellar Purkinje cells. Because P/Q channels support neurotransmitter release at many synapses, it is believed that ataxia is caused by impaired synaptic transmission. Here we show that in ataxic P/Q channel mutant mice, the precision of Purkinje cell pacemaking is lost such that there is a significant degradation of the synaptic information encoded in their activity. The irregular pacemaking is caused by reduced activation of calcium-activated potassium (K(Ca)) channels and was reversed by pharmacologically increasing their activity with 1-ethyl-2-benzimidazolinone (EBIO). Moreover, chronic in vivo perfusion of EBIO into the cerebellum of ataxic mice significantly improved motor performance. Our data support the hypothesis that the precision of intrinsic pacemaking in Purkinje cells is essential for motor coordination and suggest that K(Ca) channels may constitute a potential therapeutic target in EA2.
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Affiliation(s)
- Joy T Walter
- Department of Neuroscience, Albert Einstein College of Medicine, 506 Kennedy Center, 1410 Pelham Parkway South, Bronx, New York 10461, USA
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Abstract
Purkinje cells, the sole output of the cerebellar cortex, encode the timing signals required for motor coordination in their firing rate and activity pattern. Dendrites of Purkinje cells express a high density of P/Q-type voltage-gated calcium channels and fire dendritic calcium spikes. Here we show that dendritic subthreshold Kv1.2 subunit-containing Kv1 potassium channels prevent generation of random spontaneous calcium spikes. With Kv1 channels blocked, dendritic calcium spikes drive bursts of somatic sodium spikes and prevent the cell from faithfully encoding motor timing signals. The selective dendritic function of Kv1 channels in Purkinje cells allows them to effectively suppress dendritic hyperexcitability without hindering the generation of somatic action potentials. Further, we show that Kv1 channels also contribute to dendritic integration of parallel fibre synaptic input. Kv1 channels are often targeted to soma and axon and the data presented support a major dendritic function for these channels.
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Affiliation(s)
- Simin Khavandgar
- Department of Neuroscience, Albert Einstein College of Medicine, 506 Kennedy Center, 1410 Pelham Parkway South, Bronx, NY 10461, USA
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Womack MD, Chevez C, Khodakhah K. Calcium-activated potassium channels are selectively coupled to P/Q-type calcium channels in cerebellar Purkinje neurons. J Neurosci 2005; 24:8818-22. [PMID: 15470147 PMCID: PMC6729958 DOI: 10.1523/jneurosci.2915-04.2004] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cerebellar Purkinje neurons fire spontaneously in the absence of synaptic transmission. P/Q-type voltage-gated calcium channels and calcium-activated potassium channels are required for normal spontaneous activity. Blocking P/Q-type calcium channels paradoxically mimics the effects of blocking calcium-activated potassium channels. Thus, an important function of the P/Q-type calcium channels is to provide calcium for activation of calcium-activated potassium channels. Purkinje neurons express several classes of voltage-gated calcium channels, and the P/Q- and T-type channels make comparable contributions to total calcium entry after an action potential. Here we demonstrate that calcium-activated potassium channels are activated exclusively by calcium entering through P/Q-type voltage-gated calcium channels. This selective coupling is maintained even when calcium flux through voltage-gated channels is increased by increasing the extracellular calcium concentration. Small decreases in P/Q current density are likely to alter spontaneous activity of Purkinje neurons via decreased recruitment of calcium-activated potassium channels. In both human and murine animal models, mutations that decrease P/Q current density in Purkinje neurons also cause cerebellar ataxia. Alterations in the spontaneous activity of Purkinje neurons may be an important contributing factor to the ataxia in these subjects.
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Affiliation(s)
- Mary D Womack
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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45
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Abstract
We investigated the mechanisms that contribute to spontaneous regular bursting in adult Purkinje neurons in acutely prepared cerebellar slices. Bursts consisted of 3-20 spikes and showed a stereotypic waveform. Each burst developed with an increase in firing rate and was terminated by a more rapid increase in firing rate and a decrease in spike height. Whole-cell current-clamp recordings showed that each burst ended with a rapid depolarization followed by a hyperpolarization. Dual dendritic and somatic extracellular recordings revealed that each burst was terminated by a dendritic calcium spike. The contributions of T- and P/Q-type calcium current, large (BK) and small (SK) conductance calcium-activated potassium currents, and hyperpolarization-activated (I(H)) current to bursting were investigated with specific channel blockers. None of the currents, except for P/Q, were required to sustain spontaneous bursting or the stereotypic burst waveform. T-type calcium, BK, and SK channels contributed to interspike and interburst intervals. The effect of T-type calcium channel block was more pronounced after BK channel block and vice versa, indicating that these two currents interact to regulate burst firing. Block of I(H) current had no effect on bursting. Partial block of P/Q-type calcium channels concurrently eliminated dendritic calcium spikes and caused a switch from regular bursting to tonic firing or irregular bursting. Dendritic calcium spikes persisted in the presence of tetrodotoxin, indicating that their initiation did not require somatic sodium spikes. Our results demonstrate an important role for dendritic conductances in burst firing in intact Purkinje neurons.
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Affiliation(s)
- Mary D Womack
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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46
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Womack MD, Khodakhah K. Somatic and dendritic small-conductance calcium-activated potassium channels regulate the output of cerebellar Purkinje neurons. J Neurosci 2003; 23:2600-7. [PMID: 12684445 PMCID: PMC6742089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Abstract
Cerebellar Purkinje neurons provide the sole output of the cerebellar cortex and play a crucial role in motor coordination and maintenance of balance. They are spontaneously active, and it is thought that they encode timing signals in the rate and pattern of their activity. An understanding of factors that control their excitability is important for delineating their computational role in the cerebellum. We evaluated the role of small-conductance calcium-activated potassium (SK) channels in the regulation of activity of mouse and rat Purkinje neurons. We find that somatic SK channels effectively limit the maximum firing rate of Purkinje neurons; when SK channels are blocked by the specific antagonists apamin or scyllatoxin, cells fire spontaneously at rates as high as 500 spikes per second. Dendritic SK channels, however, control primarily the extent to which dendrites contribute to the firing rate of Purkinje cells. Given their presence in the dendrites, it is likely that SK channels in the proximal dendrites govern the efficacy of dendrosomatic electrical coupling. When studied under physiological conditions, it is found that SK channels play the same role in controlling the excitability of adult Purkinje neurons as they do in young cells.
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Affiliation(s)
- Mary D Womack
- Department of Physiology and Biophysics, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA
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47
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Morikawa H, Khodakhah K, Williams JT. Two intracellular pathways mediate metabotropic glutamate receptor-induced Ca2+ mobilization in dopamine neurons. J Neurosci 2003; 23:149-57. [PMID: 12514211 PMCID: PMC1408315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
Activation of metabotropic glutamate receptors (mGluRs) causes membrane hyperpolarization in midbrain dopamine neurons. This hyperpolarization results from the opening of Ca(2+)-sensitive K(+) channels, which is mediated by the release of Ca(2+) from intracellular stores. Neurotransmitter-induced mobilization of Ca(2+) is generally ascribed to the action of inositol 1,4,5-triphosphate (IP(3)) in neurons. Here we show that the mGluR-mediated Ca(2+) mobilization in dopamine neurons is caused by two intracellular second messengers: IP(3) and cyclic ADP-ribose (cADPR). Focal activation of mGluRs, attained by synaptic release of glutamate or iontophoretic application of aspartate, induced a wave of Ca(2+) that spread over a distance of approximately 50 microm through dendrites and the soma. Simultaneous inhibition of both IP(3)- and cADPR-dependent pathways with heparin and 8-NH(2)-cADPR was required to block the mGluR-induced Ca(2+) release, indicating a redundancy in the signaling mechanism. Activation of ryanodine receptors was suggested to mediate the cADPR-dependent pathway, because ruthenium red, an antagonist of ryanodine receptors, inhibited the mGluR response only when the cADPR-dependent pathway was isolated by blocking the IP(3)-dependent pathway with heparin. Finally, the mGluR-mediated hyperpolarization was shown to induce a transient pause in the spontaneous firing of dopamine neurons. These results demonstrate that an excitatory neurotransmitter glutamate uses multiple intracellular pathways to exert an inhibitory control on the excitability of dopamine neurons.
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Affiliation(s)
- Hitoshi Morikawa
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97201, USA
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Womack M, Khodakhah K. Active contribution of dendrites to the tonic and trimodal patterns of activity in cerebellar Purkinje neurons. J Neurosci 2002; 22:10603-12. [PMID: 12486152 PMCID: PMC6758439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
The cerebellum is responsible for coordination of movement and maintenance of balance. Cerebellar architecture is based on repeats of an anatomically well defined circuit. At the center of these functional circuits are Purkinje neurons, which form the sole output of the cerebellar cortex. It is proposed that coordination of movement is achieved by encoding timing signals in the rate of firing and pattern of activity of Purkinje cells. An understanding of cerebellar timing requires an appreciation of the intrinsic firing behavior of Purkinje cells and the extent to which their activity is regulated within the functional circuits. We have examined the spontaneous firing of Purkinje neurons in isolation from the rest of the cerebellar circuitry by blocking fast synaptic transmission in acutely prepared cerebellar slices. We find that, intrinsically, mature Purkinje cells show a complex pattern of activity in which they continuously cycle among tonically firing, bursting, and silent modes. This trimodal pattern of activity emerges as the cerebellum matures anatomically and functionally. Concurrent with the transformation of the immature tonically firing cells to those with the trimodal pattern of activity, the dendrites assume a prominent role in regulating the excitability of Purkinje cells. Thus, alterations in the rate and pattern of activity of Purkinje neurons are not solely the result of synaptic input but also arise as a consequence of the intrinsic properties of the cells.
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Affiliation(s)
- Mary Womack
- Department of Physiology and Biophysics, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA
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49
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Abstract
We investigated the role of large conductance, calcium-activated potassium channels (BK channels) in regulation of the excitability of cerebellar Purkinje neurons. Block of BK channels by iberiotoxin reduced the afterhyperpolarization of spontaneous action potentials in Purkinje neurons in acutely prepared cerebellar slices. To establish the conditions required for activation of BK channels in Purkinje neurons, the dependence of BK channel open probability on calcium concentration and membrane voltage were investigated in excised patches from soma of acutely prepared Purkinje cells. Single channel currents were studied under conditions designed to select for potassium currents and in which voltage-activated currents were largely inactivated. Micromolar calcium concentrations activated channels with a mean single channel conductance of 266 pS. BK channels were activated by both calcium and membrane depolarization, and showed no sign of inactivation. At a given calcium concentration, depolarization over a 60-mV range increased the mean open probability (P(O)) from < 0.1 to > 0.8. Increasing the calcium concentration shifted the voltage required for half maximal activation to more hyperpolarized potentials. The apparent affinity of the channels for calcium increased with depolarization. At -60 mV the apparent affinity was approximately 35 micro m decreasing to approximately 3 micro M at +40 mV. These results suggest that BK channels are unlikely to be activated at resting membrane potentials and calcium concentrations. We tested the hypothesis that Purkinje cell BK channels may be activated by calcium entry during individual action potentials. Significant BK channel activation could be detected when brief action potential-like depolarizations were applied to patches under conditions in which the sole source of calcium was flux across the plasma membrane via the endogenous voltage-gated calcium channels. It is proposed that BK channels regulate the excitability of Purkinje cells by contributing to afterhyperpolarizations and perhaps by shaping individual action potentials.
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Affiliation(s)
- Mary D Womack
- Department of Physiology and Biophysics, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, Denver, CO 80262, USA
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50
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Morikawa H, Imani F, Khodakhah K, Williams JT. Inositol 1,4,5-triphosphate-evoked responses in midbrain dopamine neurons. J Neurosci 2000; 20:RC103. [PMID: 11027254 PMCID: PMC6772861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Synaptically released glutamate evokes slow IPSPs mediated by metabotropic glutamate receptors (mGluRs) in midbrain dopamine neurons. These mGluR IPSPs are caused by release of Ca(2+) from intracellular stores and subsequent activation of small-conductance Ca(2+)-activated K(+) channels (SK channels). To further investigate the intracellular mechanisms involved, the effect of photolyzing intracellular caged inositol 1,4,5-triphosphate (InsP(3)) on membrane conductance and intracellular Ca(2+) concentration ([Ca(2+)](i)) was examined in rat midbrain slices. Photolytic release of InsP(3) elicited a transient outward current and a sharp rise in [Ca(2+)](i) that lasted for approximately 5 sec. Apamin, a blocker of SK channels, abolished the InsP(3)-induced outward current without affecting the rise in [Ca(2+)](i). Depleting intracellular Ca(2+) stores with cyclopiazonic acid completely blocked both the outward current and the Ca(2+) transient elicited by InsP(3). InsP(3)-evoked Ca(2+) mobilization was not affected by blockade of ryanodine receptors with ruthenium red, whereas depleting ryanodine-sensitive Ca(2+) stores with ryanodine almost eliminated InsP(3)-induced Ca(2+) release. Increasing the size of intracellular Ca(2+) stores by means of prolonged depolarization added a late component to the outward current and a slow component to the rising phase of [Ca(2+)](i). These effects of depolarization were blocked by ruthenium red. These results show that InsP(3) activates SK channels by releasing Ca(2+) from InsP(3)-sensitive stores that also contain ryanodine receptors. Increasing intracellular Ca(2+) stores boosts InsP(3)-evoked responses by invoking Ca(2+)-induced Ca(2+) release through ryanodine receptors. This intracellular signaling pathway may play a significant role in regulating the excitability of midbrain dopamine neurons.
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Affiliation(s)
- H Morikawa
- Vollum Institute, Oregon Health Sciences University, Portland, Oregon 97201, USA
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