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Bernard Le Foll - One of the best experts on this subject based on the ideXlab platform.
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differential involvement of the aGranular vs Granular Insular Cortex in the acquisition and performance of choice behavior in a rodent gambling task
Neuropsychopharmacology, 2015Co-Authors: Abhiram Pushparaj, Aaron Kim, Martin Musiol, Abraham Zangen, Zafiris J Daskalakis, Martin Zack, Catharine A Winstanley, Bernard Le FollAbstract:Differential Involvement of the AGranular vs Granular Insular Cortex in the Acquisition and Performance of Choice Behavior in a Rodent Gambling Task
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Granular Insular Cortex inactivation as a novel therapeutic strategy for nicotine addiction
Biological Psychiatry, 2010Co-Authors: Benoit Forget, Abhiram Pushparaj, Bernard Le FollAbstract:Background Nicotine is the principal component of tobacco smoke, resulting in addiction, and recent evidence suggests that damage to the Insular Cortex (insula) disrupts tobacco addiction in human smokers. However, the effect of an inactivation of this structure in an animal model of nicotine addiction has yet to be evaluated. Methods To study this question, we investigated the effects of reversible inactivation of the Granular insula by local injection of a γ-aminobutyric acid agonists mixture (baclofen/muscimol) on nicotine self-administration (SA) under fixed and progressive ratio and on reinstatement of nicotine seeking induced by nicotine priming or nicotine-associated cues in rats. We also evaluated the effects of Granular insula inactivation on food SA and relapse as a control. Results The inactivation of the Granular insula decreased nicotine SA under both fixed and progressive ratios without affecting the SA of food under the same schedules of reinforcement. This inactivation also prevented the reinstatement, after extinction, of nicotine seeking induced by nicotine-associated cues or nicotine priming without modifying the reinstatement of food seeking. Conclusions Our study indicates that the integrity of the Granular insula is necessary for exhibiting motivation to take nicotine and to relapse to nicotine seeking but not for consuming food pellets or to relapse for food seeking. Indeed, it might be interesting to study the effect of methods that are able to modulate the activity of the insula—such as repetitive transcranial magnetic stimulation or deep brain stimulation—on tobacco addiction and relapse in humans.
Abhiram Pushparaj - One of the best experts on this subject based on the ideXlab platform.
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Differential Involvement of the AGranular vs Granular Insular Cortex in the Acquisition and Performance of Choice Behavior in a Rodent Gambling Task
Neuropsychopharmacology, 2015Co-Authors: Abhiram Pushparaj, Martin Musiol, Abraham Zangen, Zafiris J Daskalakis, Martin Zack, Catharine A Winstanley, Aaron S Kim, Bernard Le FollAbstract:Substance-related and addictive disorders, in particular gambling disorder, are known to be associated with risky decision-making behavior. Several neuroimaging studies have identified the involvement of the Insular Cortex in decision-making under risk. However, the extent of this involvement remains unclear and the specific contributions of two distinct Insular subregions, the rostral aGranular (RAIC) and the caudal Granular (CGIC), have yet to be examined. Animals were trained to perform a rat gambling task (rGT), in which subjects chose between four options that differed in the magnitude and probability of rewards and penalties. In order to address the roles of the RAIC and CGIC in established choice behavior, pharmacological inactivations of these two subregions via local infusions of GABA receptor agonists were performed following 30 rGT training sessions. The contribution made by the RAIC or CGIC to the acquisition of choice behavior was also determined by lesioning these areas before behavioral training. Inactivation of the RAIC, but not of the CGIC, shifted rats’ preference toward options with greater reward frequency and lower punishment. Before rGT acquisition, lesions of the RAIC, but not the CGIC, likewise resulted in a higher preference for options with greater reward frequency and lower punishment, and this persisted throughout the 30 training sessions. Our results provide confirmation of the involvement of the RAIC in rGT choice behavior and suggest that the RAIC may mediate detrimental risky decision-making behavior, such as that associated with addiction and gambling disorder.
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Involvement of the caudal Granular Insular Cortex in alcohol self-administration in rats.
Behavioural brain research, 2015Co-Authors: Abhiram Pushparaj, Bernard Le FollAbstract:Animal models of substance abuse have established a role for the caudal Granular Insular Cortex (CGIC) in drug taking behaviour for several addictive substances, yet nothing has thus far been reported for alcohol. The current research was undertaken to examine the involvement of the CGIC in a rat model of alcohol self-administration. We investigated the inactivating effects of local infusions of a γ-aminobutyric acid agonist mixture (baclofen/muscimol) into the CGIC on alcohol self-administration under a fixed ratio-3 (FR-3). This inactivation of the CGIC decreased operant responding for alcohol along with a corresponding decrease in oral alcohol intake. Our results demonstrate the involvement of the CGIC in alcohol taking behaviour and suggest future studies examine the differential involvement of the various subregions of the Insular Cortex in various aspects of alcohol consumption.
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differential involvement of the aGranular vs Granular Insular Cortex in the acquisition and performance of choice behavior in a rodent gambling task
Neuropsychopharmacology, 2015Co-Authors: Abhiram Pushparaj, Aaron Kim, Martin Musiol, Abraham Zangen, Zafiris J Daskalakis, Martin Zack, Catharine A Winstanley, Bernard Le FollAbstract:Differential Involvement of the AGranular vs Granular Insular Cortex in the Acquisition and Performance of Choice Behavior in a Rodent Gambling Task
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Electrical Stimulation of the Insular Region Attenuates Nicotine-Taking and Nicotine-Seeking Behaviors
Neuropsychopharmacology, 2013Co-Authors: Abhiram Pushparaj, Clement Hamani, Damian S Shin, Bin Kang, José N Nobrega, Bernard Le FollAbstract:Pharmacological inactivation of the Granular Insular Cortex is able to block nicotine-taking and -seeking behaviors in rats. In this study, we explored the potential of modulating activity in the Insular region using electrical stimulation. Animals were trained to self-administer nicotine (0.03 mg/kg per infusion) under a fixed ratio-5 (FR-5) schedule of reinforcement followed by a progressive ratio (PR) schedule. Evaluation of the effect of stimulation in the Insular region was performed on nicotine self-administration under FR-5 and PR schedules, as well on reinstatement of nicotine-seeking behavior induced by nicotine-associated cues or nicotine-priming injections. The effect of stimulation was also examined in brain slices containing Insular neurons. Stimulation significantly attenuated nicotine-taking, under both schedules of reinforcement, as well as nicotine-seeking behavior induced by cues and priming. These effects appear to be specific to nicotine-associated behaviors, as stimulation did not have any effect on food-taking behavior. They appear to be anatomically specific, as stimulation surrounding the Insular region had no effect on behavior. Stimulation of brain slices containing the Insular region was found to inactivate Insular neurons. Our results suggest that deep brain stimulation to modulate Insular activity should be further explored.
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Granular Insular Cortex inactivation as a novel therapeutic strategy for nicotine addiction
Biological Psychiatry, 2010Co-Authors: Benoit Forget, Abhiram Pushparaj, Bernard Le FollAbstract:Background Nicotine is the principal component of tobacco smoke, resulting in addiction, and recent evidence suggests that damage to the Insular Cortex (insula) disrupts tobacco addiction in human smokers. However, the effect of an inactivation of this structure in an animal model of nicotine addiction has yet to be evaluated. Methods To study this question, we investigated the effects of reversible inactivation of the Granular insula by local injection of a γ-aminobutyric acid agonists mixture (baclofen/muscimol) on nicotine self-administration (SA) under fixed and progressive ratio and on reinstatement of nicotine seeking induced by nicotine priming or nicotine-associated cues in rats. We also evaluated the effects of Granular insula inactivation on food SA and relapse as a control. Results The inactivation of the Granular insula decreased nicotine SA under both fixed and progressive ratios without affecting the SA of food under the same schedules of reinforcement. This inactivation also prevented the reinstatement, after extinction, of nicotine seeking induced by nicotine-associated cues or nicotine priming without modifying the reinstatement of food seeking. Conclusions Our study indicates that the integrity of the Granular insula is necessary for exhibiting motivation to take nicotine and to relapse to nicotine seeking but not for consuming food pellets or to relapse for food seeking. Indeed, it might be interesting to study the effect of methods that are able to modulate the activity of the insula—such as repetitive transcranial magnetic stimulation or deep brain stimulation—on tobacco addiction and relapse in humans.
Bernard Le Foll - One of the best experts on this subject based on the ideXlab platform.
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Differential Involvement of the AGranular vs Granular Insular Cortex in the Acquisition and Performance of Choice Behavior in a Rodent Gambling Task
Neuropsychopharmacology, 2015Co-Authors: Abhiram Pushparaj, Martin Musiol, Abraham Zangen, Zafiris J Daskalakis, Martin Zack, Catharine A Winstanley, Aaron S Kim, Bernard Le FollAbstract:Substance-related and addictive disorders, in particular gambling disorder, are known to be associated with risky decision-making behavior. Several neuroimaging studies have identified the involvement of the Insular Cortex in decision-making under risk. However, the extent of this involvement remains unclear and the specific contributions of two distinct Insular subregions, the rostral aGranular (RAIC) and the caudal Granular (CGIC), have yet to be examined. Animals were trained to perform a rat gambling task (rGT), in which subjects chose between four options that differed in the magnitude and probability of rewards and penalties. In order to address the roles of the RAIC and CGIC in established choice behavior, pharmacological inactivations of these two subregions via local infusions of GABA receptor agonists were performed following 30 rGT training sessions. The contribution made by the RAIC or CGIC to the acquisition of choice behavior was also determined by lesioning these areas before behavioral training. Inactivation of the RAIC, but not of the CGIC, shifted rats’ preference toward options with greater reward frequency and lower punishment. Before rGT acquisition, lesions of the RAIC, but not the CGIC, likewise resulted in a higher preference for options with greater reward frequency and lower punishment, and this persisted throughout the 30 training sessions. Our results provide confirmation of the involvement of the RAIC in rGT choice behavior and suggest that the RAIC may mediate detrimental risky decision-making behavior, such as that associated with addiction and gambling disorder.
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Involvement of the caudal Granular Insular Cortex in alcohol self-administration in rats.
Behavioural brain research, 2015Co-Authors: Abhiram Pushparaj, Bernard Le FollAbstract:Animal models of substance abuse have established a role for the caudal Granular Insular Cortex (CGIC) in drug taking behaviour for several addictive substances, yet nothing has thus far been reported for alcohol. The current research was undertaken to examine the involvement of the CGIC in a rat model of alcohol self-administration. We investigated the inactivating effects of local infusions of a γ-aminobutyric acid agonist mixture (baclofen/muscimol) into the CGIC on alcohol self-administration under a fixed ratio-3 (FR-3). This inactivation of the CGIC decreased operant responding for alcohol along with a corresponding decrease in oral alcohol intake. Our results demonstrate the involvement of the CGIC in alcohol taking behaviour and suggest future studies examine the differential involvement of the various subregions of the Insular Cortex in various aspects of alcohol consumption.
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Electrical Stimulation of the Insular Region Attenuates Nicotine-Taking and Nicotine-Seeking Behaviors
Neuropsychopharmacology, 2013Co-Authors: Abhiram Pushparaj, Clement Hamani, Damian S Shin, Bin Kang, José N Nobrega, Bernard Le FollAbstract:Pharmacological inactivation of the Granular Insular Cortex is able to block nicotine-taking and -seeking behaviors in rats. In this study, we explored the potential of modulating activity in the Insular region using electrical stimulation. Animals were trained to self-administer nicotine (0.03 mg/kg per infusion) under a fixed ratio-5 (FR-5) schedule of reinforcement followed by a progressive ratio (PR) schedule. Evaluation of the effect of stimulation in the Insular region was performed on nicotine self-administration under FR-5 and PR schedules, as well on reinstatement of nicotine-seeking behavior induced by nicotine-associated cues or nicotine-priming injections. The effect of stimulation was also examined in brain slices containing Insular neurons. Stimulation significantly attenuated nicotine-taking, under both schedules of reinforcement, as well as nicotine-seeking behavior induced by cues and priming. These effects appear to be specific to nicotine-associated behaviors, as stimulation did not have any effect on food-taking behavior. They appear to be anatomically specific, as stimulation surrounding the Insular region had no effect on behavior. Stimulation of brain slices containing the Insular region was found to inactivate Insular neurons. Our results suggest that deep brain stimulation to modulate Insular activity should be further explored.
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Granular Insular Cortex Inactivation as a Novel Therapeutic Strategy for Nicotine Addiction
Biological psychiatry, 2010Co-Authors: Benoit Forget, Abhiram Pushparaj, Bernard Le FollAbstract:Nicotine is the principal component of tobacco smoke, resulting in addiction, and recent evidence suggests that damage to the Insular Cortex (insula) disrupts tobacco addiction in human smokers. However, the effect of an inactivation of this structure in an animal model of nicotine addiction has yet to be evaluated. To study this question, we investigated the effects of reversible inactivation of the Granular insula by local injection of a gamma-aminobutyric acid agonists mixture (baclofen/muscimol) on nicotine self-administration (SA) under fixed and progressive ratio and on reinstatement of nicotine seeking induced by nicotine priming or nicotine-associated cues in rats. We also evaluated the effects of Granular insula inactivation on food SA and relapse as a control. The inactivation of the Granular insula decreased nicotine SA under both fixed and progressive ratios without affecting the SA of food under the same schedules of reinforcement. This inactivation also prevented the reinstatement, after extinction, of nicotine seeking induced by nicotine-associated cues or nicotine priming without modifying the reinstatement of food seeking. Our study indicates that the integrity of the Granular insula is necessary for exhibiting motivation to take nicotine and to relapse to nicotine seeking but not for consuming food pellets or to relapse for food seeking. Indeed, it might be interesting to study the effect of methods that are able to modulate the activity of the insula--such as repetitive transcranial magnetic stimulation or deep brain stimulation--on tobacco addiction and relapse in humans. Copyright 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
Yumi Tsutsumi - One of the best experts on this subject based on the ideXlab platform.
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Widespread corticopetal projections from the oval paracentral nucleus of the intralaminar thalamic nuclei conveying orofacial proprioception in rats
Brain Structure and Function, 2021Co-Authors: Yumi Tsutsumi, Tahsinul Haque, Takahiro Furuta, Masayuki Moritani, Fumihiko Sato, Yuka Mizuno, Ayaka Oka, Yong Chul Bae, Takashi Yamashiro, Yoshihisa TachibanaAbstract:The oval paracentral nucleus (OPC) was initially isolated from the paracentral nucleus (PC) within the intralaminar thalamic nuclei in rats. We have recently shown that the rat OPC receives proprioceptive inputs from jaw-closing muscle spindles (JCMSs). However, it remains unknown which cortical areas receive thalamic inputs from the OPC, and whether the cortical areas receiving the OPC inputs are distinct from those receiving inputs from the other intralaminar nuclei and sensory thalamic nuclei. To address this issue, we injected an anterograde tracer, biotinylated dextranamine (BDA), into the OPC, which was electrophysiologically identified by recording of proprioceptive inputs from the JCMSs. Many BDA-labeled axonal fibers and terminals from the OPC were ipsilaterally observed in the rostral and rostroventral regions of the primary somatosensory Cortex (S1), the rostral region of the secondary somatosensory Cortex (S2), and the most rostrocaudal levels of the Granular Insular Cortex (GI). In contrast, a BDA injection into the caudal PC, which was located slightly rostral to the OPC, resulted in ipsilateral labeling of axonal fibers and terminals in the rostrolateral region of the medial aGranular Cortex and the rostromedial region of the lateral aGranular Cortex. Furthermore, injections of a retrograde tracer, Fluorogold, into these S1, S2, and GI regions, resulted in preferential labeling of neurons in the ipsilateral OPC among the intralaminar and sensory thalamic nuclei. These findings reveal that the rat OPC has widespread, but strong corticopetal projections, indicating that there exist divergent corticopetal pathways from the intralaminar thalamic nucleus, which process JCMS proprioceptive sensation.
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Cortical and Subcortical Projections from Granular Insular Cortex Receiving Orofacial Proprioception.
Neuroscience, 2018Co-Authors: Yumi Tsutsumi, Akiko Tomita, Yoshihisa Tachibana, Takahiro Furuta, Haruka Ohara, Masatoshi Fujita, Masayuki Moritani, Fumihiko Sato, Atsushi YoshidaAbstract:Abstract We have recently revealed that the proprioceptive signal from jaw-closing muscle spindles (JCMSs) is conveyed to the dorsal part of Granular Insular Cortex rostroventrally adjacent to the rostralmost part of secondary somatosensory Cortex (dGIrvs2) via the caudo-ventromedial edge (VPMcvm) of ventral posteromedial thalamic nucleus (VPM) in rats. However, it remains unclear to which cortical or subcortical structures the JCMS proprioceptive information is subsequently conveyed from the dGIrvs2. To test this issue, we injected an anterograde tracer, biotinylated dextranamine, into the electophysiologically identified dGIrvs2, and analyzed the resultant distribution profiles of labeled axon terminals in rats. Labeled terminals were distributed with an ipsilateral predominance. In the cerebral Cortex, they were seen in the primary and secondary somatosensory cortices, lateral and medial aGranular cortices and dorsolateral orbital Cortex. In the basal ganglia, they were found in the caudate putamen, core part of accumbens nucleus, lateral globus pallidus, subthalamic nucleus, and substantia nigra pars compacta and pars reticulata. They were also observed in the central amygdaloid nucleus and extended amygdala (the interstitial nucleus of posterior limb of anterior commissure and the juxtacapsular part of lateral division of bed nucleus of stria terminalis). In the thalamus, they were seen in the reticular nucleus, ventromedial nucleus, core VPM, parvicellular part of ventral posterior nucleus, oval paracentral nucleus, medial and triangular parts of posterior nucleus, and zona incerta as well as the VPMcvm. These data suggest that the JCMS proprioceptive information through the dGIrvs2 is transmitted to the emotional ‘limbic’ regions as well as sensorimotor regions.
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Transcortical descending pathways through Granular Insular Cortex conveying orofacial proprioception.
Brain research, 2018Co-Authors: Etsuko Ikenoue, Yumi Tsutsumi, Katsuro Uchino, Yoshihisa Tachibana, Takahiro Furuta, Haruka Ohara, Fumihiko Sato, F. Akhter, Atsushi YoshidaAbstract:Our motor behavior can be affected by proprioceptive information. However, little is known about which brain circuits contribute to this process. We have recently revealed that the proprioceptive information arising from jaw-closing muscle spindles (JCMSs) is conveyed to the supratrigeminal nucleus (Su5) by neurons in the trigeminal mesencephalic nucleus (Me5), then to the caudo-ventromedial edge of ventral posteromedial thalamic nucleus (VPMcvm), and finally to the dorsal part of Granular Insular Cortex rostroventrally adjacent to the rostralmost part of secondary somatosensory Cortex (dGIrvs2). Our next question is which brain areas receive the information from the dGIrvs2 for the jaw-movements. To test this issue, we injected an anterograde tracer, biotinylated dextranamine, into the dGIrvs2, and analyzed the resultant distribution profiles of the labeled axon terminals. Anterogradely labeled axons were distributed in the pontomedullary areas (including the Su5) which are known to receive JCMS proprioceptive inputs conveyed directly by the Me5 neurons and to contain premotoneurons projecting to the jaw-closing motoneurons in the trigeminal motor nucleus (Mo5). They were also found in and around the VPMcvm. In contrast, no labeled axonal terminals were detected on the cell bodies of Me5 neurons and motoneurons in the Mo5. These data suggest that jaw-movements, which are evoked by the classically defined jaw-reflex arc originating from the peripheral JCMS proprioceptive information, could also be modulated by the transcortical feedback connections from the dGIrvs2 to the VPMcvm and Su5.
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Thalamo-Insular pathway conveying orofacial muscle proprioception in the rat.
Neuroscience, 2017Co-Authors: Fumihiko Sato, Yume Uemura, Chiharu Kanno, Yumi Tsutsumi, Akiko Tomita, Takafumi Kato, Katsuro Uchino, Jumpei Murakami, Tahsinul HaqueAbstract:Abstract Little is known about how proprioceptive signals arising from muscles reach to higher brain regions such as the cerebral Cortex. We have recently shown that a particular thalamic region, the caudo-ventromedial edge (VPMcvm) of ventral posteromedial thalamic nucleus (VPM), receives the proprioceptive signals from jaw-closing muscle spindles (JCMSs) in rats. In this study, we further addressed how the orofacial thalamic inputs from the JCMSs were transmitted from the thalamus (VPMcvm) to the cerebral Cortex in rats. Injections of a retrograde and anterograde neuronal tracer, wheat-germ agglutinin-conjugated horseradish peroxidase (WGA-HRP), into the VPMcvm demonstrated that the thalamic pathway terminated mainly in a rostrocaudally narrow area in the dorsal part of Granular Insular Cortex rostroventrally adjacent to the rostralmost part of the secondary somatosensory Cortex (dGIrvs2). We also electrophysiologically confirmed that the dGIrvs2 received the proprioceptive inputs from JCMSs. To support the anatomical evidence of the VPMcvm–dGIrvs2 pathway, injections of a retrograde neuronal tracer Fluorogold into the dGIrvs2 demonstrated that the thalamic neurons projecting to the dGIrvs2 were confined in the VPMcvm and the parvicellular part of ventral posterior nucleus. In contrast, WGA-HRP injections into the lingual nerve area of core VPM demonstrated that axon terminals were mainly labeled in the core regions of the primary and secondary somatosensory cortices, which were far from the dGIrvs2. These results suggest that the dGIrvs2 is a specialized cortical region receiving the orofacial proprioceptive inputs. Functional contribution of the revealed JCMSs–VPMcvm–dGIrvs2 pathway to Tourette syndrome is also discussed.
Fumihiko Sato - One of the best experts on this subject based on the ideXlab platform.
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Widespread corticopetal projections from the oval paracentral nucleus of the intralaminar thalamic nuclei conveying orofacial proprioception in rats
Brain Structure and Function, 2021Co-Authors: Yumi Tsutsumi, Tahsinul Haque, Takahiro Furuta, Masayuki Moritani, Fumihiko Sato, Yuka Mizuno, Ayaka Oka, Yong Chul Bae, Takashi Yamashiro, Yoshihisa TachibanaAbstract:The oval paracentral nucleus (OPC) was initially isolated from the paracentral nucleus (PC) within the intralaminar thalamic nuclei in rats. We have recently shown that the rat OPC receives proprioceptive inputs from jaw-closing muscle spindles (JCMSs). However, it remains unknown which cortical areas receive thalamic inputs from the OPC, and whether the cortical areas receiving the OPC inputs are distinct from those receiving inputs from the other intralaminar nuclei and sensory thalamic nuclei. To address this issue, we injected an anterograde tracer, biotinylated dextranamine (BDA), into the OPC, which was electrophysiologically identified by recording of proprioceptive inputs from the JCMSs. Many BDA-labeled axonal fibers and terminals from the OPC were ipsilaterally observed in the rostral and rostroventral regions of the primary somatosensory Cortex (S1), the rostral region of the secondary somatosensory Cortex (S2), and the most rostrocaudal levels of the Granular Insular Cortex (GI). In contrast, a BDA injection into the caudal PC, which was located slightly rostral to the OPC, resulted in ipsilateral labeling of axonal fibers and terminals in the rostrolateral region of the medial aGranular Cortex and the rostromedial region of the lateral aGranular Cortex. Furthermore, injections of a retrograde tracer, Fluorogold, into these S1, S2, and GI regions, resulted in preferential labeling of neurons in the ipsilateral OPC among the intralaminar and sensory thalamic nuclei. These findings reveal that the rat OPC has widespread, but strong corticopetal projections, indicating that there exist divergent corticopetal pathways from the intralaminar thalamic nucleus, which process JCMS proprioceptive sensation.
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Cortical and Subcortical Projections from Granular Insular Cortex Receiving Orofacial Proprioception.
Neuroscience, 2018Co-Authors: Yumi Tsutsumi, Akiko Tomita, Yoshihisa Tachibana, Takahiro Furuta, Haruka Ohara, Masatoshi Fujita, Masayuki Moritani, Fumihiko Sato, Atsushi YoshidaAbstract:Abstract We have recently revealed that the proprioceptive signal from jaw-closing muscle spindles (JCMSs) is conveyed to the dorsal part of Granular Insular Cortex rostroventrally adjacent to the rostralmost part of secondary somatosensory Cortex (dGIrvs2) via the caudo-ventromedial edge (VPMcvm) of ventral posteromedial thalamic nucleus (VPM) in rats. However, it remains unclear to which cortical or subcortical structures the JCMS proprioceptive information is subsequently conveyed from the dGIrvs2. To test this issue, we injected an anterograde tracer, biotinylated dextranamine, into the electophysiologically identified dGIrvs2, and analyzed the resultant distribution profiles of labeled axon terminals in rats. Labeled terminals were distributed with an ipsilateral predominance. In the cerebral Cortex, they were seen in the primary and secondary somatosensory cortices, lateral and medial aGranular cortices and dorsolateral orbital Cortex. In the basal ganglia, they were found in the caudate putamen, core part of accumbens nucleus, lateral globus pallidus, subthalamic nucleus, and substantia nigra pars compacta and pars reticulata. They were also observed in the central amygdaloid nucleus and extended amygdala (the interstitial nucleus of posterior limb of anterior commissure and the juxtacapsular part of lateral division of bed nucleus of stria terminalis). In the thalamus, they were seen in the reticular nucleus, ventromedial nucleus, core VPM, parvicellular part of ventral posterior nucleus, oval paracentral nucleus, medial and triangular parts of posterior nucleus, and zona incerta as well as the VPMcvm. These data suggest that the JCMS proprioceptive information through the dGIrvs2 is transmitted to the emotional ‘limbic’ regions as well as sensorimotor regions.
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Transcortical descending pathways through Granular Insular Cortex conveying orofacial proprioception.
Brain research, 2018Co-Authors: Etsuko Ikenoue, Yumi Tsutsumi, Katsuro Uchino, Yoshihisa Tachibana, Takahiro Furuta, Haruka Ohara, Fumihiko Sato, F. Akhter, Atsushi YoshidaAbstract:Our motor behavior can be affected by proprioceptive information. However, little is known about which brain circuits contribute to this process. We have recently revealed that the proprioceptive information arising from jaw-closing muscle spindles (JCMSs) is conveyed to the supratrigeminal nucleus (Su5) by neurons in the trigeminal mesencephalic nucleus (Me5), then to the caudo-ventromedial edge of ventral posteromedial thalamic nucleus (VPMcvm), and finally to the dorsal part of Granular Insular Cortex rostroventrally adjacent to the rostralmost part of secondary somatosensory Cortex (dGIrvs2). Our next question is which brain areas receive the information from the dGIrvs2 for the jaw-movements. To test this issue, we injected an anterograde tracer, biotinylated dextranamine, into the dGIrvs2, and analyzed the resultant distribution profiles of the labeled axon terminals. Anterogradely labeled axons were distributed in the pontomedullary areas (including the Su5) which are known to receive JCMS proprioceptive inputs conveyed directly by the Me5 neurons and to contain premotoneurons projecting to the jaw-closing motoneurons in the trigeminal motor nucleus (Mo5). They were also found in and around the VPMcvm. In contrast, no labeled axonal terminals were detected on the cell bodies of Me5 neurons and motoneurons in the Mo5. These data suggest that jaw-movements, which are evoked by the classically defined jaw-reflex arc originating from the peripheral JCMS proprioceptive information, could also be modulated by the transcortical feedback connections from the dGIrvs2 to the VPMcvm and Su5.
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Thalamo-Insular pathway conveying orofacial muscle proprioception in the rat.
Neuroscience, 2017Co-Authors: Fumihiko Sato, Yume Uemura, Chiharu Kanno, Yumi Tsutsumi, Akiko Tomita, Takafumi Kato, Katsuro Uchino, Jumpei Murakami, Tahsinul HaqueAbstract:Abstract Little is known about how proprioceptive signals arising from muscles reach to higher brain regions such as the cerebral Cortex. We have recently shown that a particular thalamic region, the caudo-ventromedial edge (VPMcvm) of ventral posteromedial thalamic nucleus (VPM), receives the proprioceptive signals from jaw-closing muscle spindles (JCMSs) in rats. In this study, we further addressed how the orofacial thalamic inputs from the JCMSs were transmitted from the thalamus (VPMcvm) to the cerebral Cortex in rats. Injections of a retrograde and anterograde neuronal tracer, wheat-germ agglutinin-conjugated horseradish peroxidase (WGA-HRP), into the VPMcvm demonstrated that the thalamic pathway terminated mainly in a rostrocaudally narrow area in the dorsal part of Granular Insular Cortex rostroventrally adjacent to the rostralmost part of the secondary somatosensory Cortex (dGIrvs2). We also electrophysiologically confirmed that the dGIrvs2 received the proprioceptive inputs from JCMSs. To support the anatomical evidence of the VPMcvm–dGIrvs2 pathway, injections of a retrograde neuronal tracer Fluorogold into the dGIrvs2 demonstrated that the thalamic neurons projecting to the dGIrvs2 were confined in the VPMcvm and the parvicellular part of ventral posterior nucleus. In contrast, WGA-HRP injections into the lingual nerve area of core VPM demonstrated that axon terminals were mainly labeled in the core regions of the primary and secondary somatosensory cortices, which were far from the dGIrvs2. These results suggest that the dGIrvs2 is a specialized cortical region receiving the orofacial proprioceptive inputs. Functional contribution of the revealed JCMSs–VPMcvm–dGIrvs2 pathway to Tourette syndrome is also discussed.
