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Ventroanterior thalamus

Clinton B McCracken, Zelma H T Kiss
High-frequency electrical stimulation of specific brain structures, known as deep brain stimulation (DBS), is an effective treatment for movement disorders, but mechanisms of action remain unclear. We examined the time-dependent effects of DBS applied to the entopeduncular nucleus (EP), the rat homolog of the internal globus pallidus, a target used for treatment of both dystonia and Parkinson's disease (PD). We performed simultaneous multi-site local field potential (LFP) recordings in urethane-anesthetized rats to assess the effects of high-frequency (HF, 130 Hz; clinically effective), low-frequency (LF, 15 Hz; ineffective) and sham DBS delivered to EP...
2014: PloS One
Hyeon-Ae Jeon, Alfred Anwander, Angela D Friederici
Despite myriads of studies on a parallel organization of cortico-striatal-thalamo-cortical loops, direct evidence of this has been lacking for the healthy human brain. Here, we scrutinize the functional specificity of the cortico-subcortical loops depending on varying levels of cognitive hierarchy as well as their structural connectivity with high-resolution fMRI and diffusion-weighted MRI (dMRI) at 7 tesla. Three levels of cognitive hierarchy were implemented in two domains: second language and nonlanguage...
July 9, 2014: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Christian Pifl, Oleh Hornykiewicz, Javier Blesa, Rebeca Adánez, Carmen Cavada, José A Obeso
We recently found severe noradrenaline deficits throughout the thalamus of patients with Parkinson's disease [C. Pifl, S. J. Kish and O. Hornykiewicz Mov Disord. 27, 2012, 1618.]. As this noradrenaline loss was especially severe in nuclei of the motor thalamus normally transmitting basal ganglia motor output to the cortex, we hypothesized that this noradrenaline loss aggravates the motor disorder of Parkinson's disease. Here, we analysed noradrenaline, dopamine and serotonin in motor (ventrolateral and ventroanterior) and non-motor (mediodorsal, centromedian, ventroposterior lateral and reticular) thalamic nuclei in MPTP-treated monkeys who were always asymptomatic; who recovered from mild parkinsonism; and monkeys with stable, either moderate or severe parkinsonism...
June 2013: Journal of Neurochemistry
Christian Pifl, Stephen J Kish, Oleh Hornykiewicz
The thalamus occupies a pivotal position within the corticobasal ganglia-cortical circuits. In Parkinson's disease (PD), the thalamus exhibits pathological neuronal discharge patterns, foremost increased bursting and oscillatory activity, which are thought to perturb the faithful transfer of basal ganglia impulse flow to the cortex. Analogous abnormal thalamic discharge patterns develop in animals with experimentally reduced thalamic noradrenaline; conversely, added to thalamic neuronal preparations, noradrenaline exhibits marked antioscillatory and antibursting activity...
November 2012: Movement Disorders: Official Journal of the Movement Disorder Society
Emer J Hughes, Jacqueline Bond, Patricia Svrckova, Antonis Makropoulos, Gareth Ball, David J Sharp, A David Edwards, Joeseph V Hajnal, Serena J Counsell
The thalamus undergoes significant volume loss and microstructural change with increasing age. Alterations in thalamo-cortical connectivity may contribute to the decline in cognitive ability associated with aging. The aim of this study was to assess changes in thalamic shape and in the volume and diffusivity of thalamic regions parcellated by their connectivity to specific cortical regions in order to test the hypothesis age related thalamic change primarily affects thalamic nuclei connecting to the frontal cortex...
November 15, 2012: NeuroImage
Jun Kunimatsu, Masaki Tanaka
Although the roles of the thalamocortical pathways in somatic movements are well documented, their roles in eye movements have only recently been examined. The oculomotor-related areas in the frontal cortex receive inputs from the basal ganglia and the cerebellum via the thalamus. Consistent with this, neurons in the paralaminar part of the ventrolateral (VL), ventroanterior (VA), and mediodorsal (MD) nuclei and those in the intralaminar nuclei exhibit a variety of eye movement-related responses. To date, the thalamocortical pathways are known to play at least 2 roles in eye movements...
August 2011: Brain and Nerve, Shinkei Kenkyū No Shinpo
Masaki Tanaka, Jun Kunimatsu
Lesions in the motor thalamus can cause deficits in somatic movements. However, the involvement of the thalamus in the generation of eye movements has only recently been elucidated. In this article, we review recent advances into the role of the thalamus in eye movements. Anatomically, the anterior group of the intralaminar nuclei and paralaminar portion of the ventrolateral, ventroanterior and mediodorsal nuclei of the thalamus send massive projections to the frontal eye field and supplementary eye field. In addition, these parts of the thalamus, collectively known as the 'oculomotor thalamus', receive inputs from the cerebellum, the basal ganglia and virtually all stages of the saccade-generating pathways in the brainstem...
June 2011: European Journal of Neuroscience
Christophe Lopez, Olaf Blanke
The vestibular system provides the brain with sensory signals about three-dimensional head rotations and translations. These signals are important for postural and oculomotor control, as well as for spatial and bodily perception and cognition, and they are subtended by pathways running from the vestibular nuclei to the thalamus, cerebellum and the "vestibular cortex." The present review summarizes current knowledge on the anatomy of the thalamocortical vestibular system and discusses data from electrophysiology and neuroanatomy in animals by comparing them with data from neuroimagery and neurology in humans...
June 24, 2011: Brain Research Reviews
Ian G M Cameron, Masayuki Watanabe
Our knowledge of thalamus function comes largely from anatomical studies showing, for example, that the ventroanterior (VA) and ventrolateral (VL) nuclei are connected to "motor" regions, whereas the mediodorsal (MD) nucleus is connected to prefrontal "executive" regions. Interestingly, Kunimatsu and Tanaka recently showed that preparatory signals for antisaccades (a motor response requiring executive control) were enhanced compared with prosaccades in the VA/VL but not in the MD, which is surprising given MD's connection to executive regions...
November 2010: Journal of Neurophysiology
Manoj Mittal, Saud Khan
A 19-year-old female presented with acute onset of bizarre behavior, confusion, auditory hallucinations, and delusions after two weeks on a 100 kcal/day diet. She had a normal neurological examination. Urinalysis showed ketones 4+. She had elevated antinuclear antibody (ANA) (320) and positive heterozygous factor V Leiden mutation. Magnetic resonance imaging brain scan showed hyperintensity in the ventroanterior nucleus of the left thalamus. Ventroanterior thalamic stroke has been associated with personality changes...
July 2010: Southern Medical Journal
Jun Kunimatsu, Masaki Tanaka
In response to changes in our environment, we select from possible actions depending on the given situation. The underlying neural mechanisms for this flexible behavioral control have been examined using the antisaccade paradigm. In this task, subjects suppress saccades to the sudden appearance of visual stimuli (prosaccade) and make a saccade in the opposite direction. Because recent imaging studies showed enhanced activity in the thalamus and basal ganglia during antisaccades, we hypothesized that the corticobasal ganglia loop may be involved...
April 7, 2010: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Masaki Tanaka
We often generate movements without any external event that immediately triggers them. How the brain decides the timing of self-initiated movements remains unclear. Previous studies suggest that the basal ganglia-thalamocortical pathways play this role, but the subcortical signals that determine movement timing have not been identified. The present study reports that a subset of thalamic neurons predicts the timing of self-initiated saccadic eye movements. When monkeys made a saccade in response to the fixation point (FP) offset in the traditional memory saccade task, neurons in the ventrolateral and the ventroanterior nuclei of the thalamus exhibited a gradual buildup of activity that peaked around the most probable time of the FP offset; however, neither the timing nor the magnitude of neuronal activity correlated with saccade latencies, suggesting that the brain is unlikely to have used this information to decide the times of saccades in the traditional memory saccade task...
October 31, 2007: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Nobuhiko Hatanaka, Hironobu Tokuno, Ikuma Hamada, Masahiko Inase, Yumi Ito, Michiko Imanishi, Naomi Hasegawa, Toshikazu Akazawa, Atsushi Nambu, Masahiko Takada
Although there has been an increasing interest in motor functions of the cingulate motor areas, data concerning their input organization are still limited. To address this issue, the patterns of thalamic and cortical inputs to the rostral (CMAr), dorsal (CMAd), and ventral (CMAv) cingulate motor areas were investigated in the macaque monkey. Tracer injections were made into identified forelimb representations of these areas, and the distributions of retrogradely labeled neurons were analyzed in the thalamus and the frontal cortex...
July 14, 2003: Journal of Comparative Neurology
S Kakei, J Na, Y Shinoda
We investigated the axonal morphology of single corticothalamic (CT) neurons of the motor cortex (Mx) in the cat thalamus, using a neuronal tracer, biotinylated dextran amine (BDA). After localized injection of BDA into the Mx, labeled CT axons were found ipsilaterally in the thalamic reticular nucleus (TRN), the ventroanterior-ventrolateral complex (VA-VL), the central lateral nucleus (CL), the central medial nucleus, and the centromedian nucleus, but with the primary focus in the VA-VL. The terminals in the VA-VL formed a large laminar cluster, which extended approximately in parallel with the internal medullary lamina...
August 20, 2001: Journal of Comparative Neurology
S de las Heras, E Mengual, J L Velayos, J M Giménez-Amaya
The distribution of thalamic neurons projecting directly to the caudate nucleus (CN) was examined using the retrograde labeling method. Horseradish peroxidase conjugated with wheat germ agglutinin (HRP-WGA) or a fluorescent tracer (either Fast Blue (FB) or Diamidino Yellow (DY)) was injected into various parts of the CN. The main findings were as follows: (1) labeled neurons were distributed most densely in the intralaminar nuclei, midline thalamic nuclei and centre median-parafascicular complex, and less densely in the ventroanterior (VA), ventrolateral (VL) and ventromedial (VM) nuclei...
August 1998: Neuroscience Research
J Na, S Kakei, Y Shinoda
To investigate whether corticothalamic (CT) neurons in the motor cortex (Mx) receive cerebellar input via the ventroanterior-ventrolateral nucleus of the thalamus (VA-VL), we recorded intracellular potentials from neurons in the Mx of anesthetized cats and examined effects of stimulation of the VA-VL and the brachium conjunctivum on them. After this electrophysiological identification, horseradish peroxide (HRP) was injected iontophoretically into the recorded neurons for morphological analysis. We identified 34 neurons as CT neurons by their antidromic response to stimulation of the VA-VL, of which 13 were layer VI CT neurons and 21 were layer V CT neurons...
May 1997: Neuroscience Research
M Inase, H Tokuno, A Nambu, T Akazawa, M Takada
The presupplementary motor area (pre-SMA) is a recently defined cortical motor area that is located immediately rostral to the supplementary motor area (SMA) and is considered to play more complex roles in motor control than the SMA. In the present study, we examined the distribution of cells of origin of thalamocortical projections to the pre-SMA in the macaque monkey. Under the guidance of intracortical microstimulation mapping, the retrograde tracer biotinylated dextran amine was injected into the pre-SMA...
July 1996: Neuroscience Research
D I Finkelstein, A K Reeves, M K Horne
The entopeduncular (EP) nucleus is considered to be the major outflow nucleus of the basal ganglia (BG). The anterograde tracer dextran biotin was injected into EP to investigate its connections with the thalamus. Terminals from EP were found in the ipsilateral ventroanterior-ventrolateral (VAL) and ventromedial thalamic nuclei (VM), lateral habenular and centromedian-parafascicular complex. Electron microscopy of the terminals in VAL/VM revealed densely labelled small synapses that had prominent post-synaptic densities and round vesicles...
June 14, 1996: Neuroscience Letters
R Töpper, J Gehrmann, M Schwarz, F Block, J Noth, G W Kreutzberg
Intrastriatal injection of quinolinic acid (QA) in the rat leads to several structural and biochemical events which resemble neuropathological changes seen in the striatum of Huntington's disease patients. In the present experiment the accompanying microglial response in striatal projection areas following QA injection was studied immunocytochemically using monoclonal macrophage/microglial markers. After injection of 240 nmol of QA a marked microglial reaction was observed in the entire striatum, whereas injection of the same amount of solvent resulted only in a local microglial reaction around the injection site...
October 1993: Experimental Neurology
Y Shinoda, S Kakei, T Futami, T Wannier
In the cat, the cerebellum projects via the ventroanterior-ventrolateral (VA-VL) complex of the thalamus to the motor and premotor cortices and also to the parietal association cortex. Cerebellar inputs to each of these regions have been characterized electrophysiologically by depth profiles of cortical potentials following stimulation of the brachium conjunctivum and of the VA-VL complex, and morphologically by the laminar distribution of thalamocortical (TC) terminations, in aggregate and at the single-axon level...
September 1993: Cerebral Cortex
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