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Kofler M, Hallett M, Iannetti GD, Versace V, Ellrich J, Téllez MJ, Valls-Solé J. The blink reflex and its modulation - Part 1: Physiological mechanisms. Clin Neurophysiol 2024; 160:130-152. [PMID: 38102022 PMCID: PMC10978309 DOI: 10.1016/j.clinph.2023.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 11/11/2023] [Accepted: 11/22/2023] [Indexed: 12/17/2023]
Abstract
The blink reflex (BR) is a protective eye-closure reflex mediated by brainstem circuits. The BR is usually evoked by electrical supraorbital nerve stimulation but can be elicited by a variety of sensory modalities. It has a long history in clinical neurophysiology practice. Less is known, however, about the many ways to modulate the BR. Various neurophysiological techniques can be applied to examine different aspects of afferent and efferent BR modulation. In this line, classical conditioning, prepulse and paired-pulse stimulation, and BR elicitation by self-stimulation may serve to investigate various aspects of brainstem connectivity. The BR may be used as a tool to quantify top-down modulation based on implicit assessment of the value of blinking in a given situation, e.g., depending on changes in stimulus location and probability of occurrence. Understanding the role of non-nociceptive and nociceptive fibers in eliciting a BR is important to get insight into the underlying neural circuitry. Finally, the use of BRs and other brainstem reflexes under general anesthesia may help to advance our knowledge of the brainstem in areas not amenable in awake intact humans. This review summarizes talks held by the Brainstem Special Interest Group of the International Federation of Clinical Neurophysiology at the International Congress of Clinical Neurophysiology 2022 in Geneva, Switzerland, and provides a state-of-the-art overview of the physiology of BR modulation. Understanding the principles of BR modulation is fundamental for a valid and thoughtful clinical application (reviewed in part 2) (Gunduz et al., submitted).
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Affiliation(s)
- Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria.
| | - Mark Hallett
- National Institute of Neurological Disorders and Stroke, NIH, USA.
| | - Gian Domenico Iannetti
- University College London, United Kingdom; Italian Institute of Technology (IIT), Rome, Italy.
| | - Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Teaching Hospital of the Paracelsus Medical Private University (PMU), Vipiteno-Sterzing, Italy.
| | - Jens Ellrich
- Friedrich-Alexander-University Erlangen-Nuremberg, Germany.
| | | | - Josep Valls-Solé
- IDIBAPS (Institut d'Investigació August Pi i Sunyer), University of Barcelona, Spain.
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2
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Walia P, Ghosh A, Singh S, Dutta A. Portable Neuroimaging-Guided Noninvasive Brain Stimulation of the Cortico-Cerebello-Thalamo-Cortical Loop—Hypothesis and Theory in Cannabis Use Disorder. Brain Sci 2022; 12:brainsci12040445. [PMID: 35447977 PMCID: PMC9027826 DOI: 10.3390/brainsci12040445] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 03/06/2022] [Accepted: 03/22/2022] [Indexed: 12/22/2022] Open
Abstract
Background: Maladaptive neuroplasticity-related learned response in substance use disorder (SUD) can be ameliorated using noninvasive brain stimulation (NIBS); however, inter-individual variability needs to be addressed for clinical translation. Objective: Our first objective was to develop a hypothesis for NIBS for learned response in SUD based on a competing neurobehavioral decision systems model. The next objective was to develop the theory by conducting a computational simulation of NIBS of the cortico-cerebello-thalamo-cortical (CCTC) loop in cannabis use disorder (CUD)-related dysfunctional “cue-reactivity”—a construct closely related to “craving”—that is a core symptom. Our third objective was to test the feasibility of a neuroimaging-guided rational NIBS approach in healthy humans. Methods: “Cue-reactivity” can be measured using behavioral paradigms and portable neuroimaging, including functional near-infrared spectroscopy (fNIRS) and electroencephalogram (EEG) metrics of sensorimotor gating. Therefore, we conducted a computational simulation of NIBS, including transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS) of the cerebellar cortex and deep cerebellar nuclei (DCN) of the CCTC loop for its postulated effects on fNIRS and EEG metrics. We also developed a rational neuroimaging-guided NIBS approach for the cerebellar lobule (VII) and prefrontal cortex based on a healthy human study. Results: Simulation of cerebellar tDCS induced gamma oscillations in the cerebral cortex, while transcranial temporal interference stimulation induced a gamma-to-beta frequency shift. A preliminary healthy human study (N = 10) found that 2 mA cerebellar tDCS evoked similar oxyhemoglobin (HbO) response in the range of 5 × 10−6 M across the cerebellum and PFC brain regions (α = 0.01); however, infra-slow (0.01–0.10 Hz) prefrontal cortex HbO-driven phase–amplitude-coupled (PAC; 4 Hz, ±2 mA (max)) cerebellar tACS evoked HbO levels in the range of 10−7 M that were statistically different (α = 0.01) across these brain regions. Conclusion: Our healthy human study showed the feasibility of fNIRS of cerebellum and PFC and closed-loop fNIRS-driven ctACS at 4 Hz, which may facilitate cerebellar cognitive function via the frontoparietal network. Future work needs to combine fNIRS with EEG for multi-modal imaging for closed-loop NIBS during operant conditioning.
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Affiliation(s)
- Pushpinder Walia
- Neuroengineering and Informatics for Rehabilitation Laboratory, University at Buffalo, Buffalo, NY 14228, USA;
| | - Abhishek Ghosh
- Postgraduate Institute of Medical Education & Research, Chandigarh 700020, India; (A.G.); (S.S.)
| | - Shubhmohan Singh
- Postgraduate Institute of Medical Education & Research, Chandigarh 700020, India; (A.G.); (S.S.)
| | - Anirban Dutta
- Neuroengineering and Informatics for Rehabilitation Laboratory, University at Buffalo, Buffalo, NY 14228, USA;
- Correspondence:
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Batsikadze G, Diekmann N, Ernst TM, Klein M, Maderwald S, Deuschl C, Merz CJ, Cheng S, Quick HH, Timmann D. The cerebellum contributes to context-effects during fear extinction learning: a 7T fMRI study. Neuroimage 2022; 253:119080. [PMID: 35276369 DOI: 10.1016/j.neuroimage.2022.119080] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 02/14/2022] [Accepted: 03/07/2022] [Indexed: 12/13/2022] Open
Abstract
The cerebellum is involved in the acquisition and consolidation of learned fear responses. Knowledge about its contribution to extinction learning, however, is sparse. Extinction processes likely involve erasure of memories, but there is ample evidence that at least part of the original memory remains. We asked the question whether memory persists within the cerebellum following extinction training. The renewal effect, that is the reoccurrence of the extinguished fear memory during recall in a context different from the extinction context, constitutes one of the phenomena indicating that memory of extinguished learned fear responses is not fully erased during extinction training. We performed a differential AB-A/B fear conditioning paradigm in a 7-Tesla (7T) MRI system in 31 young and healthy men. On day 1, fear acquisition training was performed in context A and extinction training in context B. On day 2, recall was tested in contexts A and B. As expected, participants learned to predict that the CS+ was followed by an aversive electric shock during fear acquisition training. Skin conductance responses (SCRs) were significantly higher to the CS+ compared to the CS- at the end of acquisition. Differences in SCRs vanished in extinction and reoccurred in the acquisition context during recall indicating renewal. Fitting SCR data, a deep neural network model was trained to predict the correct shock value for a given stimulus and context. Event-related fMRI analysis with model-derived prediction values as parametric modulations showed significant effects on activation of the posterolateral cerebellum (lobules VI and Crus I) during recall. Since the prediction values differ based on stimulus (CS+ and CS-) and context during recall, data provide support that the cerebellum is involved in context-related recall of learned fear associations. Likewise, mean β values were highest in lobules VI and Crus I bilaterally related to the CS+ in the acquisition context during early recall. A similar pattern was seen in the vermis, but only on a trend level. Thus, part of the original memory likely remains within the cerebellum following extinction training. We found cerebellar activations related to the CS+ and CS- during fear acquisition training which likely reflect associative and non-associative aspects of the task. Cerebellar activations, however, were not significantly different for CS+ and CS-. Since the CS- was never followed by an electric shock, the cerebellum may contribute to associative learning related to the CS, for example as a safety cue.
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Affiliation(s)
- Giorgi Batsikadze
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), Essen University Hospital, University of Duisburg-Essen, Hufelandstraße 55, Essen 45147, Germany.
| | - Nicolas Diekmann
- Institute for Neural Computation, Ruhr University Bochum, Bochum, Germany
| | - Thomas Michael Ernst
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), Essen University Hospital, University of Duisburg-Essen, Hufelandstraße 55, Essen 45147, Germany; Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany
| | - Michael Klein
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), Essen University Hospital, University of Duisburg-Essen, Hufelandstraße 55, Essen 45147, Germany
| | - Stefan Maderwald
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany
| | - Cornelius Deuschl
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, Essen University Hospital, Essen, Germany
| | - Christian Josef Merz
- Department of Cognitive Psychology, Institute of Cognitive Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Sen Cheng
- Institute for Neural Computation, Ruhr University Bochum, Bochum, Germany
| | - Harald H Quick
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany; High-Field and Hybrid MR Imaging, Essen University Hospital, Essen, Germany
| | - Dagmar Timmann
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), Essen University Hospital, University of Duisburg-Essen, Hufelandstraße 55, Essen 45147, Germany; Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany
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4
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Cerebellum and Emotion Memory. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1378:53-73. [DOI: 10.1007/978-3-030-99550-8_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Loi N, Ginatempo F, Doppiu C, Deriu F. Emotional Face Expressions Influence the Delay Eye-blink Classical Conditioning. Neuroscience 2021; 471:72-79. [PMID: 34332014 DOI: 10.1016/j.neuroscience.2021.07.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 11/26/2022]
Abstract
Recent evidence raised the importance of the cerebellum in emotional processes, with specific regard to negative emotions. However, its role in the processing of face emotional expressions is still unknown. This study was aimed at assessing whether face emotional expressions influence the cerebellar learning processes, using the delay eyeblink classical conditioning (EBCC) as a model. Visual stimuli composed of faces expressing happy, sad and neutral emotions were used as conditioning stimulus in forty healthy subjects to modulate the cerebellum-brainstem pathway underlying the EBCC. The same stimuli were used to explore their effects on the blink reflex (BR) and its recovery cycle (BRRC) and on the cerebellar-brain inhibition (CBI). Data analysis revealed that the learning component of the EBCC was significantly reduced following the passive view of sad faces, while the extinction phase was modulated by both sad and happy faces. By contrast, BR, BRRC and CBI were not significantly affected by the view of emotional face expressions. The present study provides first evidence that the passive viewing of faces displaying emotional expressions, are processed by the cerebellum, with no apparent involvement of the brainstem and the cerebello-cortical connection. In particular, the view of sad faces, reduces the excitability of the cerebellar circuit underlying the learning phase of the EBCC. Differently, the extinction phase was shortened by both happy and sad faces, suggesting that different neural bases underlie learning and extinction of emotions expressed by faces.
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Affiliation(s)
- Nicola Loi
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | | | - Cristina Doppiu
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Franca Deriu
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
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6
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Long-term effects of cerebellar anodal transcranial direct current stimulation (tDCS) on the acquisition and extinction of conditioned eyeblink responses. Sci Rep 2020; 10:22434. [PMID: 33384434 PMCID: PMC7775427 DOI: 10.1038/s41598-020-80023-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 12/14/2020] [Indexed: 11/10/2022] Open
Abstract
Cerebellar transcranial direct current stimulation (tDCS) has been reported to enhance the acquisition of conditioned eyeblink responses (CR), a form of associative motor learning. The aim of the present study was to determine possible long-term effects of cerebellar tDCS on the acquisition and extinction of CRs. Delay eyeblink conditioning was performed in 40 young and healthy human participants. On day 1, 100 paired CS (conditioned stimulus)–US (unconditioned stimulus) trials were applied. During the first 50 paired CS–US trials, 20 participants received anodal cerebellar tDCS, and 20 participants received sham stimulation. On days 2, 8 and 29, 50 paired CS–US trials were applied, followed by 30 CS-only extinction trials on day 29. CR acquisition was not significantly different between anodal and sham groups. During extinction, CR incidences were significantly reduced in the anodal group compared to sham, indicating reduced retention. In the anodal group, learning related increase of CR magnitude tended to be reduced, and timing of CRs tended to be delayed. The present data do not confirm previous findings of enhanced acquisition of CRs induced by anodal cerebellar tDCS. Rather, the present findings suggest a detrimental effect of anodal cerebellar tDCS on CR retention and possibly CR performance.
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Steiner KM, Jansen S, Adeishvili N, Hulst T, Ernst TM, Müller O, Wondzinski E, Göricke SL, Siebler M, Uengoer M, Timmann D. Extinction of cognitive associations is preserved in patients with cerebellar disease. Neurobiol Learn Mem 2020; 169:107185. [PMID: 32061996 DOI: 10.1016/j.nlm.2020.107185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 01/29/2020] [Accepted: 02/10/2020] [Indexed: 10/25/2022]
Abstract
In the present study extinction and renewal of cognitive associations were assessed in two experiments in participants with focal and degenerative cerebellar disease. Using a predictive learning task, participants had to learn by trial and error the relationships between food items and the occurrence of stomach trouble in a hypothetical patient. In the first experiment, focus was on renewal effects. Participants with chronic cerebellar stroke (n = 14; mean age 50.9 ± 12 years), participants with degenerative cerebellar disease (n = 16; mean age 58 ± 12 years), age-, sex-, and education matched controls (n = 20; mean age 53.7 ± 10.8 years) and young controls (n = 19; mean age 23.2 ± 2.7 years) were tested. Acquisition and extinction of food-stomach trouble associations took part in two different contexts (represented by restaurants). In a subsequent test phase, food stimuli were presented in both contexts and no feedback was given. This allowed testing for renewal of the initially acquired associations in the acquisition context. Acquisition and extinction learning were not significantly different between groups. Significant renewal effects were present in young controls only. In the second experiment, focus was on extinction. To control for age effects, 19 young participants with chronic surgical lesions of the cerebellum (mean age 25.6 ± 6.1 years), and 24 age-, sex- and education-matched healthy controls were tested. Acquisition and extinction of food-stomach trouble associations took part in the same context. In the extinction phase, the relationship with stomach trouble was reversed in some of the food items. Acquisition and extinction learning were not significantly different between groups. The main finding of the present study was preserved extinction of learned cognitive associations in participants with chronic cerebellar disease. Findings agree with previous observations in the literature that cognitive abnormalities are frequently absent or weak in adults with cerebellar disease. This does not exclude a contribution of the cerebellum to extinction of learned associations. For example, findings may be different in more challenging cognitive tasks, and in participants with acute cerebellar disease with no time for compensation.
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Affiliation(s)
- Katharina M Steiner
- Department of Neurology, Essen University Hospital, University of Duisburg-Essen, Essen, Germany.
| | - Sarah Jansen
- Department of Neurology, Essen University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Nino Adeishvili
- Department of Neurology, Essen University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Thomas Hulst
- Department of Neurology, Essen University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Thomas M Ernst
- Department of Neurology, Essen University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Oliver Müller
- Department of Neurosurgery, Essen University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Elke Wondzinski
- Department of Neurology, MediClin Fachklinik Rhein/Ruhr, Essen, Germany
| | - Sophia L Göricke
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, Essen University Hospital, University of Duisburg-Essen, Germany
| | - Mario Siebler
- Department of Neurology, MediClin Fachklinik Rhein/Ruhr, Essen, Germany
| | - Metin Uengoer
- Department of Psychology, Philipps-Universität Marburg, Germany
| | - Dagmar Timmann
- Department of Neurology, Essen University Hospital, University of Duisburg-Essen, Essen, Germany
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Prefrontal but not cerebellar tDCS attenuates renewal of extinguished conditioned eyeblink responses. Neurobiol Learn Mem 2019; 170:107137. [PMID: 31838223 DOI: 10.1016/j.nlm.2019.107137] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 12/02/2019] [Accepted: 12/11/2019] [Indexed: 01/28/2023]
Abstract
An extended neural network is known to underlie extinction learning. As yet, comparatively little is known about the possible contribution of the cerebellum and the dorsolateral prefrontal cortex (dlPFC). In the present study, transcranial direct current stimulation (tDCS) was used to provide further evidence that the dlPFC and the cerebellum are involved in extinction-related processes. A total of 100 young and healthy human participants were randomly assigned to one of five stimulation groups: (1) anodal tDCS of the cerebellum, (2) cathodal tDCS of the cerebellum, (3) anodal tDCS of the dlPFC, (4) cathodal tDCS of the dlPFC, and (5) sham stimulation. Participants underwent delay eyeblink conditioning using an A-B-A/B renewal paradigm. Two different colors of background light (orange and blue) were used as contexts. On day 1, acquisition of conditioned eyeblink responses was performed in context A, followed by extinction in context B. tDCS was applied during extinction. On day 2, extinction recall was tested in contexts A and B with higher incidence of conditioned responses in acquisition context A compared to extinction context B indicating renewal effects. All groups showed significant effects of acquisition of conditioned eyeblink responses and significant effects of extinction. There was no significant difference in extinction between stimulation groups. During extinction recall, renewal effects were present in all groups, except the group which had received anodal tDCS of the dlPFC during extinction. In the present study, no direct effects of dlPFC or cerebellar tDCS were demonstrated on extinction. Anodal tDCS of the dlPFC, but not the cerebellum, resulted in delayed effects on context-related processes of extinction, possibly explained by shifting attention away from the context and towards the conditioned stimulus during extinction learning. Anodal tDCS of the dlPFC attenuated context-related recall of learned aversive responses. Effects of tDCS, however, were weak and need to be confirmed in future studies. Lack of cerebellar tDCS effects do not exclude a possible role of the cerebellum in extinction-related processes, and are likely explained by methodological limitations of cerebellar tDCS.
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Extinction and Renewal of Conditioned Eyeblink Responses in Focal Cerebellar Disease. THE CEREBELLUM 2019; 18:166-177. [PMID: 30155831 DOI: 10.1007/s12311-018-0973-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Extinction of conditioned aversive responses (CR) has been shown to be context-dependent. The hippocampus and prefrontal cortex are of particular importance. The cerebellum may contribute to context-related processes because of its known connections with the hippocampus and prefrontal cortex. Context dependency of extinction can be demonstrated by the renewal effect. When CR acquisition takes place in context A and is extinguished in context B, renewal refers to the recovery of the CR in context A (A-B-A paradigm). In the present study acquisition, extinction and renewal of classically conditioned eyeblink responses were tested in 18 patients with subacute focal cerebellar lesions and 18 age- and sex-matched healthy controls. Standard delay eyeblink conditioning was performed using an A-B-A paradigm. All cerebellar patients underwent a high-resolution T1-weighted brain MRI scan to perform lesion-symptom mapping. CR acquisition was not significantly different between cerebellar and control participants allowing to draw conclusions on extinction. CR extinction was significantly less in cerebellar patients. Reduction of CR extinction tended to be more likely in patients with lesions in the lateral parts of lobule VI and Crus I. A significant renewal effect was present in controls only. The present data provide further evidence that the cerebellum contributes to extinction of conditioned eyeblink responses. Because acquisition was preserved and extinction took place in another context than acquisition, more lateral parts of the cerebellar hemisphere may contribute to context-related processes. Furthermore, lack of renewal in cerebellar patients suggest a contribution of the cerebellum to context-related processes.
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A method for combining multiple-units readout of optogenetic control with natural stimulation-evoked eyeblink conditioning in freely-moving mice. Sci Rep 2019; 9:1857. [PMID: 30755637 PMCID: PMC6372581 DOI: 10.1038/s41598-018-37885-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 12/12/2018] [Indexed: 01/20/2023] Open
Abstract
A growing pool of transgenic mice expressing Cre-recombinases, together with Cre-dependent opsin viruses, provide good tools to manipulate specific neural circuits related to eyeblink conditioning (EBC). However, currently available methods do not enable to get fast and precise readout of optogenetic control when the freely-moving mice are receiving EBC training. In the current study, we describe a laser diode (LD)-optical fiber (OF)-Tetrode assembly that allows for simultaneous multiple units recording and optical stimulation. Since the numbers of various cables that require to be connected are minimized, the LD-OF-Tetrode assembly can be combined with CS-US delivery apparatus for revealing the effects of optical stimulation on EBC in freely- moving mice. Moreover, this combination of techniques can be utilized to optogenetically intervene in hippocampal neuronal activities during the post-conditioning sleep in a closed-loop manner. This novel device thus enhances our ability to explore how specific neuronal assembly contributes to associative motor memory in vivo.
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11
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Spontaneous recovery of conditioned eyeblink responses is associated with transiently decreased cerebellar theta activity in guinea pigs. Behav Brain Res 2018; 359:457-466. [PMID: 30468789 DOI: 10.1016/j.bbr.2018.11.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 11/19/2018] [Accepted: 11/19/2018] [Indexed: 12/28/2022]
Abstract
Behavioral studies have demonstrated that extinguished conditioned eyeblink responses (CR) can spontaneously recover after extinction. However, the neural mechanisms underlying this process are still unclear. We have shown that spontaneous cerebellar theta activity was predictive of subsequent CR extinction. Here, we sought to further evaluate the association between spontaneous recovery and cerebellar theta activity in behaving guinea pigs. It was found that trace conditioning training significantly diminished the degree of spontaneous recovery during extinction sessions as compared to delay training. Moreover, by recording local field potential in the cerebellum of guinea pigs undergoing an eyeblink conditioning extinction task, we found that spontaneous recovery of delay-paradigm CRs was associated with transiently decreased CS-evoked theta activity in the cerebellum. These findings suggest that decreased CS-evoked cerebellar theta activity may contribute to the neural process that is important for the spontaneous recovery of extinguished motor memory. Future studies are needed to clarify the neural mechanism underlying changed cerebellar theta activity during altered behavioral contingencies.
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12
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Cerebellar-dependent associative learning is impaired in very preterm born children and young adults. Sci Rep 2017; 7:18028. [PMID: 29269751 PMCID: PMC5740078 DOI: 10.1038/s41598-017-18316-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 12/08/2017] [Indexed: 11/21/2022] Open
Abstract
Preterm birth incorporates an increased risk for cerebellar developmental disorders likely contributing to motor and cognitive abnormalities. Experimental evidence of cerebellar dysfunction in preterm subjects, however, is sparse. In this study, classical eyeblink conditioning was used as a marker of cerebellar dysfunction. Standard delay conditioning was investigated in 20 adults and 32 preschool children born very preterm. Focal lesions were excluded based on structural magnetic resonance imaging. For comparison, an equal number of matched term born healthy peers were tested. Subgroups of children (12 preterm, 12 controls) were retested. Preterm subjects acquired significantly less conditioned responses (CR) compared to controls with slower learning rates. A likely explanation for these findings is that preterm birth impedes function of the cerebellum even in the absence of focal cerebellar lesions. The present findings are consistent with the assumption that prematurity results in long-term detrimental effects on the integrity of the cerebellum. It cannot be excluded, however, that extra-cerebellar pathology contributed to the present findings.
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13
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Ernst TM, Thürling M, Müller S, Kahl F, Maderwald S, Schlamann M, Boele HJ, Koekkoek SKE, Diedrichsen J, De Zeeuw CI, Ladd ME, Timmann D. Modulation of 7 T fMRI Signal in the Cerebellar Cortex and Nuclei During Acquisition, Extinction, and Reacquisition of Conditioned Eyeblink Responses. Hum Brain Mapp 2017; 38:3957-3974. [PMID: 28474470 DOI: 10.1002/hbm.23641] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 04/25/2017] [Accepted: 04/26/2017] [Indexed: 11/07/2022] Open
Abstract
Classical delay eyeblink conditioning is likely the most commonly used paradigm to study cerebellar learning. As yet, few studies have focused on extinction and savings of conditioned eyeblink responses (CRs). Saving effects, which are reflected in a reacquisition after extinction that is faster than the initial acquisition, suggest that learned associations are at least partly preserved during extinction. In this study, we tested the hypothesis that acquisition-related plasticity is nihilated during extinction in the cerebellar cortex, but retained in the cerebellar nuclei, allowing for faster reacquisition. Changes of 7 T functional magnetic resonance imaging (fMRI) signals were investigated in the cerebellar cortex and nuclei of young and healthy human subjects. Main effects of acquisition, extinction, and reacquisition against rest were calculated in conditioned stimulus-only trials. First-level β values were determined for a spherical region of interest (ROI) around the acquisition peak voxel in lobule VI, and dentate and interposed nuclei ipsilateral to the unconditioned stimulus. In the cerebellar cortex and nuclei, fMRI signals were significantly lower in extinction compared to acquisition and reacquisition, but not significantly different between acquisition and reacquisition. These findings are consistent with the theory of bidirectional learning in both the cerebellar cortex and nuclei. It cannot explain, however, why conditioned responses reappear almost immediately in reacquisition following extinction. Although the present data do not exclude that part of the initial memory remains in the cerebellum in extinction, future studies should also explore changes in extracerebellar regions as a potential substrate of saving effects. Hum Brain Mapp 38:3957-3974, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Thomas M Ernst
- Department of Neurology, Essen University Hospital, Essen, Germany.,Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany
| | - Markus Thürling
- Department of Neurology, Essen University Hospital, Essen, Germany.,Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany
| | - Sarah Müller
- Department of Neurology, Essen University Hospital, Essen, Germany
| | - Fabian Kahl
- Department of Neurology, Essen University Hospital, Essen, Germany
| | - Stefan Maderwald
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany
| | - Marc Schlamann
- Department for Diagnostic and Interventional Radiology and Neuroradiology, Essen University Hospital, University of Duisburg-Essen, Essen, Germany.,Department of Neuroradiology, University Hospital of Giessen, Justus-Liebig-University of Giessen, Giessen, Germany
| | - Henk-Jan Boele
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands
| | | | - Jörn Diedrichsen
- Department for Computer Science, University of Western Ontario, London, Ontario, Canada
| | - Chris I De Zeeuw
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands.,The Netherlands Institute for Neuroscience, Royal Academy of Arts & Sciences, Amsterdam, The Netherlands
| | - Mark E Ladd
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany.,Division of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany
| | - Dagmar Timmann
- Department of Neurology, Essen University Hospital, Essen, Germany
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14
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Beyer L, Batsikadze G, Timmann D, Gerwig M. Cerebellar tDCS Effects on Conditioned Eyeblinks using Different Electrode Placements and Stimulation Protocols. Front Hum Neurosci 2017; 11:23. [PMID: 28203151 PMCID: PMC5285376 DOI: 10.3389/fnhum.2017.00023] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 01/11/2017] [Indexed: 11/13/2022] Open
Abstract
There is good evidence that the human cerebellum is involved in the acquisition and timing of classically conditioned eyeblink responses (CRs). Animal studies suggest that the cerebellum is also important in CR extinction and savings. Cerebellar transcranial direct current stimulation (tDCS) was reported to modulate CR acquisition and timing in a polarity dependent manner. To extent previous findings three experiments were conducted using standard delay eyeblink conditioning. In a between-group design, effects of tDCS were assessed with stimulation over the right cerebellar hemisphere ipsilaterally to the unconditioned stimulus (US). An extracephalic reference electrode was used in Experiment 1 and a cephalic reference in Experiment 2. In both parts the influence on unconditioned eyeblink responses (UR) was investigated by starting stimulation in the second half of the pseudoconditioning phase lasting throughout the first half of paired trials. In a third experiment, effects of cerebellar tDCS during 40 extinction trials were assessed on extinction and reacquisition on the next day. In each experiment, 30 subjects received anodal, cathodal or sham stimulation in a double-blinded fashion. Using the extracephalic reference electrode, no significant effects on CR incidences comparing stimulation groups were observed. Using the cephalic reference anodal as well as cathodal cerebellar tDCS increased CR acquisition compared to sham only on a trend level. Analysis of timing parameters did not reveal significant effects on CR onset and peaktime latencies nor on UR timing. In the third experiment, cerebellar tDCS during extinction trials had no significant effect on extinction and savings on the next day. The present study did not reveal clear polarity dependent effects of cerebellar tDCS on CR acquisition and timing as previously described. Weaker effects may be explained by start of tDCS before the learning phase i.e., offline, individual thresholds and current flow based on individual anatomy may also play role. Likewise cerebellar tDCS during extinction did not modulate extinction or reacquisition. Further studies are needed in larger subject populations to determine parameters of stimulation and learning paradigms yielding robust cerebellar tDCS effects.
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Affiliation(s)
- Linda Beyer
- Department of Neurology, University of Duisburg-EssenEssen, Germany
| | | | - Dagmar Timmann
- Department of Neurology, University of Duisburg-EssenEssen, Germany
| | - Marcus Gerwig
- Department of Neurology, University of Duisburg-EssenEssen, Germany
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15
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Ernst T, Beyer L, Mueller O, Göricke S, Ladd M, Gerwig M, Timmann D. Pronounced reduction of acquisition of conditioned eyeblink responses in young adults with focal cerebellar lesions impedes conclusions on the role of the cerebellum in extinction and savings. Neuropsychologia 2016; 85:287-300. [DOI: 10.1016/j.neuropsychologia.2016.03.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 03/09/2016] [Accepted: 03/23/2016] [Indexed: 11/30/2022]
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