1
|
Polarity- and Intensity-Independent Modulation of Timing During Delay Eyeblink Conditioning Using Cerebellar Transcranial Direct Current Stimulation. THE CEREBELLUM 2021; 19:383-391. [PMID: 32036562 DOI: 10.1007/s12311-020-01114-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Delay eyeblink conditioning (dEBC) is widely used to assess cerebellar-dependent associative motor learning, including precise timing processes. Transcranial direct current stimulation (tDCS), noninvasive brain stimulation used to indirectly excite and inhibit select brain regions, may be a promising tool for understanding how functional integrity of the cerebellum influences dEBC behavior. The aim of this study was to assess whether tDCS-induced inhibition (cathodal) and excitation (anodal) of the cerebellum differentially impact timing of dEBC. A standard 10-block dEBC paradigm was administered to 102 healthy participants. Participants were randomized to stimulation conditions in a double-blind, between-subjects sham-controlled design. Participants received 20-min active (anodal or cathodal) stimulation at 1.5 mA (n = 20 anodal, n = 22 cathodal) or 2 mA (n = 19 anodal, n = 21 cathodal) or sham stimulation (n = 20) concurrently with dEBC training. Stimulation intensity and polarity effects on percent conditioned responses (CRs) and CR peak and onset latency were examined using repeated-measures analyses of variance. Acquisition of CRs increased over time at a similar rate across sham and all active stimulation groups. CR peak and onset latencies were later, i.e., closer to air puff onset, in all active stimulation groups compared to the sham group. Thus, tDCS facilitated cerebellar-dependent timing of dEBC, irrespective of stimulation intensity and polarity. These findings highlight the feasibility of using tDCS to modify cerebellar-dependent functions and provide further support for cerebellar contributions to human eyeblink conditioning and for exploring therapeutic tDCS interventions for cerebellar dysfunction.
Collapse
|
2
|
Moussa-Tooks AB, Hetrick WP, Green JT. Differential effects of two early life stress paradigms on cerebellar-dependent delay eyeblink conditioning. Neurobiol Stress 2020; 13:100242. [PMID: 33344698 PMCID: PMC7739029 DOI: 10.1016/j.ynstr.2020.100242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/23/2020] [Accepted: 07/14/2020] [Indexed: 11/11/2022] Open
Abstract
Early life stress paradigms have become prominent in the animal literature to model atypical development. Currently, two models have prevailed within the literature: (1) limited bedding or nesting and (2) maternal separation or deprivation. Both models have produced aberrations spanning behavior and neural circuitry. Surprisingly, these two models have yet to be directly compared. The current study utilized delay eyeblink conditioning, an associative learning task with a well-defined cerebellar circuit, to compare the behavioral effects of standard limited bedding (postnatal day 2–9, n = 15) and maternal separation (60 min per day during postnatal day 2–14, n = 13) early life stress paradigms. Animals in all groups exhibited robust learning curves. Surprisingly, facilitated conditioning was observed in the maternal separation group. Rats that underwent limited bedding did not differ from the control or maternal separation groups on any conditioning measures. This study contributes to a clearer understanding of early life stress paradigms and the claims made about their mechanisms, which if better clarified can be properly leveraged to increase translational value.
Collapse
Affiliation(s)
- Alexandra B Moussa-Tooks
- Psychological & Brain Sciences, Indiana University, Bloomington, IN, United States.,Program in Neuroscience, Indiana University, Bloomington, IN, United States
| | - William P Hetrick
- Psychological & Brain Sciences, Indiana University, Bloomington, IN, United States.,Program in Neuroscience, Indiana University, Bloomington, IN, United States.,Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, United States
| | - John T Green
- Department of Psychological Science, University of Vermont, Burlington, VT, United States
| |
Collapse
|
3
|
Steinmetz AB, Freeman JH. Intracerebellar cannabinoid administration impairs delay but not trace eyeblink conditioning. Behav Brain Res 2019; 378:112258. [PMID: 31560921 DOI: 10.1016/j.bbr.2019.112258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/22/2019] [Accepted: 09/22/2019] [Indexed: 10/26/2022]
Abstract
Intracerebellar administration of cannabinoid agonists impairs cerebellum-dependent delay eyeblink conditioning (EBC) in rats. It is not known whether the cannabinoid-induced impairment in EBC is found with shorter interstimulus intervals (ISI), longer ISIs, or with trace EBC. Moreover, systemic administration of cannabinoid agonists does not impair trace EBC, suggesting that cannabinoid receptors within the cerebellum are not involved in trace EBC. To more precisely assess the effects of cannabinoids on cerebellar learning mechanisms the current study examined the effects of the cannabinoid agonist WIN55,212-2 (WIN) infusion into the area of the cerebellar cortex necessary for EBC (the eyeblink microzone) in rats during short delay (250 ms CS), long delay (750 ms CS), and trace (250 ms CS, 500 ms trace interval) EBC. WIN was infused into the eyeblink microzone 30 min before pretraining sessions and five EBC training sessions, followed by five EBC training sessions without infusions to assess recovery from drug effects and savings. WIN had no effect on spontaneous blinks or non-associative responses to the CS or US during the pretraining sessions. Short and long delay EBC were impaired by WIN but trace EBC was unaffected. The results indicate that trace EBC is mediated by mechanisms that are resistant to cannabinoid agonists.
Collapse
Affiliation(s)
- Adam B Steinmetz
- Department of Psychological and Brain Sciences, Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242 USA
| | - John H Freeman
- Department of Psychological and Brain Sciences, Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242 USA.
| |
Collapse
|
4
|
Lesniak A, Chmielewska D, Poznanski P, Bujalska-Zadrozny M, Strzemecka J, Sacharczuk M. Divergent Response to Cannabinoid Receptor Stimulation in High and Low Stress-Induced Analgesia Mouse Lines Is Associated with Differential G-Protein Activation. Neuroscience 2019; 404:246-258. [DOI: 10.1016/j.neuroscience.2019.02.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 02/07/2019] [Accepted: 02/11/2019] [Indexed: 12/21/2022]
|
5
|
Steinmetz AB, Freeman JH. Cannabinoid modulation of memory consolidation within the cerebellum. Neurobiol Learn Mem 2016; 136:228-235. [PMID: 27818269 DOI: 10.1016/j.nlm.2016.11.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 11/01/2016] [Accepted: 11/02/2016] [Indexed: 10/20/2022]
Abstract
Cannabinoid receptors contribute to learning and synaptic plasticity mechanisms. The cerebellum contains a high density of cannabinoid receptors and manipulations of cannabinoid receptors affect synaptic plasticity within the cerebellar cortex. In vivo studies have found that cannabinoid agonists impair learning of cerebellum-dependent eyeblink conditioning in rodents and humans. However, the role of cannabinoid receptors or endocannabinoids in memory consolidation within the cerebellum has not been examined. In the current study, we examined the role of cannabinoid receptors and endocannabinoids during learning and consolidation of eyeblink conditioning in rats. Administration of the cannabinoid receptor agonist WIN55,212-2 or drugs that increase/decrease endocannabinoid levels directly into the cerebellar cortex before each training session resulted in marked learning impairments. When administered 1 h after each training session, during memory consolidation, the cannabinoid inverse agonist SR141716A or the endocannabinoid suppressor THL impaired memory. In contrast, increasing endocannabinoid levels with JZL-184 or infusion of WIN55,212-2 within the cerebellar cortex facilitated memory consolidation 1h post-training. Intracerebellar manipulations of cannabinoid receptors or endocannabinoid levels had no effect on memory consolidation when administered 3 or 6h after each training session. The results demonstrate that cannabinoids impair cerebellar learning, but facilitate memory consolidation mechanisms within the cerebellar cortex 1-3h after training.
Collapse
Affiliation(s)
- Adam B Steinmetz
- Center for Neural Science, New York University, New York, NY, USA
| | - John H Freeman
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, USA.
| |
Collapse
|
6
|
Kishimoto Y, Cagniard B, Yamazaki M, Nakayama J, Sakimura K, Kirino Y, Kano M. Task-specific enhancement of hippocampus-dependent learning in mice deficient in monoacylglycerol lipase, the major hydrolyzing enzyme of the endocannabinoid 2-arachidonoylglycerol. Front Behav Neurosci 2015; 9:134. [PMID: 26082696 PMCID: PMC4451424 DOI: 10.3389/fnbeh.2015.00134] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/11/2015] [Indexed: 12/03/2022] Open
Abstract
Growing evidence indicates that the endocannabinoid system is important for the acquisition and/or extinction of learning and memory. However, it is unclear which endocannabinoid(s) play(s) a crucial role in these cognitive functions, especially memory extinction. To elucidate the physiological role of 2-arachidonoylglycerol (2-AG), a major endocannabinoid, in behavioral and cognitive functions, we conducted a comprehensive behavioral test battery in knockout (KO) mice deficient in monoacylglycerol lipase (MGL), the major hydrolyzing enzyme of 2-AG. We found age-dependent increases in spontaneous physical activity (SPA) in MGL KO mice. Next, we tested the MGL KO mice using 5 hippocampus-dependent learning paradigms (i.e., Morris water maze (MWM), contextual fear conditioning, novel object recognition test, trace eyeblink conditioning, and water-finding test). In the MWM, MGL KO mice showed normal acquisition of reference memory, but exhibited significantly faster extinction of the learned behavior. Moreover, they showed faster memory acquisition on the reversal-learning task of the MWM. In contrast, in the contextual fear conditioning, MGL KO mice tended to show slower memory extinction. In the novel object recognition and water-finding tests, MGL KO mice exhibited enhanced memory acquisition. Trace eyeblink conditioning was not altered in MGL KO mice throughout the acquisition and extinction phases. These results indicate that 2-AG signaling is important for hippocampus-dependent learning and memory, but its contribution is highly task-dependent.
Collapse
Affiliation(s)
- Yasushi Kishimoto
- Laboratory of Neurobiophysics, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University Sanuki, Kagawa, Japan
| | - Barbara Cagniard
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo Bunkyo-ku, Tokyo, Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University Niigata, Japan
| | - Junko Nakayama
- Laboratory of Neurobiophysics, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University Sanuki, Kagawa, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University Niigata, Japan
| | - Yutaka Kirino
- Laboratory of Neurobiophysics, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University Sanuki, Kagawa, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo Bunkyo-ku, Tokyo, Japan
| |
Collapse
|
7
|
Steinmetz AB, Freeman JH. Differential effects of the cannabinoid agonist WIN55,212-2 on delay and trace eyeblink conditioning. Behav Neurosci 2014; 127:694-702. [PMID: 24128358 DOI: 10.1037/a0034210] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Central cannabinoid-1 receptors (CB1R) play a role in the acquisition of delay eyeblink conditioning (EBC) but not trace EBC in humans and animals. However, it is not clear why trace conditioning is immune to the effects of cannabinoid receptor compounds. The current study examined the effects of variants of delay and trace conditioning procedures to elucidate the factors that determine the effects of CB1R agonists on EBC. In Experiment 1, rats were administered the cannabinoid agonist WIN55,212-2 during delay, long-delay, or trace conditioning. Rats were impaired during delay and long-delay, but not trace conditioning; the impairment was greater for long-delay than delay conditioning. Trace conditioning was further examined in Experiment 2 by manipulating the trace interval and keeping constant the conditioned stimulus (conditional stimulus [CS]) duration. It was found that when the trace interval was 300 ms or less, WIN55,212-2 administration impaired the rate of learning. Experiment 3 tested whether the trace interval duration or the relative durations of the CS and trace interval were critical parameters influencing the effects of WIN55,212-2 on EBC. Rats were not impaired with a 100-ms CS, 200-ms trace paradigm but were impaired with a 1,000-ms CS, 500-ms trace paradigm, indicating that the duration of the trace interval does not matter, but the proportion of the interstimulus interval occupied by the CS relative to the trace period is critical. Taken together, the results indicate that cannabinoid agonists affect cerebellar learning when the CS is longer than the trace interval.
Collapse
|