SEARCH · Search PubMed

Results for “BASAL GANGLIA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40Linked to original sources

PubMed1997

Adenosine-dopamine receptor-receptor interactions as an integrative mechanism in the basal ganglia.

Increasing evidence suggests that antagonistic interactions between specific subtypes of adenosine and dopamine receptors in the basal ganglia are involved in the motor depressant effects of adenosine receptor agonists and the motor stimulant effects of adenosine receptor antagonists, such as caffeine. The GABAergic striatopallidal neurons are regulated by interacting adenosine A2A and dopamine D2 receptors. On the other hand, the GABAergic striatonigral and striatoentopeduncular neurons seem to be regulated by interacting adenosine A1 and dopamine D1 receptors. Furthermore, behavioural studies have revealed interactions between adenosine A2A and dopamine D1 receptors that occur at the network level. These adenosine-dopamine receptor-receptor interactions might offer new therapeutic leads for basal ganglia disorders.

Animals↗

PubMed1987

What do the basal ganglia tell premotor cortical areas?

The defects in execution of simple single arm movements at one joint, and of complex arm movements simultaneously or sequentially at two joints, in Parkinson's disease are analysed as a clue to the formal functions of the basal ganglia in human motor control. Slowness in execution of single movements, due to failure to scale the size of the initial electromyographic burst of activity in the agonist, is one characteristic abnormality. However, patients with Parkinson's disease are also shown to have added difficulty with complex motor tasks. When they attempt to undertake a hand 'squeeze' at the same time as an elbow 'flex', both movements are even slower. When they try to perform an elbow flex as quickly as possible after a hand squeeze with the same or opposite arms, the second movement is slowed and the interval between movements is prolonged. Similar movement abnormalities have been found in patients with Huntington's disease-even in those with chorea alone, and irrespective of drug therapy-and in a patient with an infarct involving the right supplementary motor area. These observations suggest that the basal ganglia in humans are required to set up the correct motor programmes to execute complex simultaneous and sequential movements. It is suggested that the basal ganglia, acting on a read-out of existing sensorimotor cortical activity, direct the premotor cortical areas to select the correct parameters of the motor programmes required for subsequent motor action.

Arm↗

PubMed2003

The striatal GABA-ergic neurons expressing substance P receptors in the basal ganglia of mice.

By using a double immunofluorescence, we have examined the distribution of striatal GABAergic neurons that expressed substance P receptor (SPR) in the basal ganglia of adult C57 mice. The distribution of GABA-immunoreactive neurons completely or partially overlapped with that of SPR-immunoreactive neurons in the striatum (i.e. the caudate-putamen), globus pallidus, ventral pallidum, and nucleus accumbens. Neurons showing both GABA- and SPR-immunoreactivities were, however, predominantly found in the caudate-putamen, and most of them were characterized by their large-sized aspiny neuronal profile. Semi-quantification indicated that only about 13% of the total GABA-immunoreactive neurons (including large and medium-sized) displayed SPR-immunoreactivity, and these double-labeled neurons constituted about 31% of the total SPR-immunoreactive cells in the striatum. Neurons double-labeled with GABA- and SPR-immunoreactivities were hardly detected in other aforementioned regions of the basal ganglia. In addition, double immunofluorescence also showed co-localization of SPR- with glutamic acid decarboxylase-immunoreactivity, but not with parvalbumin-immunoreactivity, in the striatal neurons. Taken together with previous reports, the present study has suggested that a sub-population of striatal GABA-ergic neurons, most possibly GABA-ergic interneurons, may also receive direct physiological modulation by tachykinins through SPR in the basal ganglia of mammals.

Animals↗

PubMedDate not supplied

Neurocircuitry of the basal ganglia studied by monitoring neurotransmitter release. Effects of intracerebral and perinatal asphyctic lesions.

The neurocircuitries of the basal ganglia are studied with in vivo microdialysis, with special consideration to dopamine transmission and its interaction with other neurotransmitter systems. The aim is to develop experimental models to study the pathophysiology and therapy of neurodegenerative disorders of the basal ganglia, as well as to develop models to study the short- and long-term consequences of perinatal asphyctic lesions. A main goal of these studies is to find and to characterize new treatments for these disorders.

Alzheimer Disease↗

PubMed1987

Immunohistochemical and biochemical studies on Lys8-Asn9-neurotensin8-13 (LANT6)-related peptides in the basal ganglia of pigeons, turtles, and hamsters.

The distribution of the neurotensin-related hexapeptide LANT6 within the basal ganglia and its projection targets was studied in turtles, pigeons, and hamsters by using immunohistochemical techniques, radioimmunoassay (RIA), gel chromatography, and high performance liquid chromatography (HPLC). The results in turtles and pigeons were fundamentally similar. Within the basal ganglia, LANT6-like immunoreactivity (LLI) was observed in a population of large striatal neurons (comprising 1-5% of the total number of striatal neurons) and in essentially all of the medium-large pallidal neurons. In addition, LLI was observed in neurons of such other "striatal" and "pallidal" cell groups as the olfactory tubercle and ventral pallidum, respectively. Within the dopaminergic cell fields of the tegmentum, to which the pallidal cell groups project, LLI-containing fibers were abundant. Knife-cut studies confirmed that the majority of these LLI-containing fibers arise from telencephalic levels. Biochemical studies with RIA and HPLC showed large amounts of immunoreactive LANT6 (iLANT6) in the basal telencephalon (477 pmol/g) and tegmentum of pigeons (259 pmol/g), and this material was indistinguishable from the synthetic peptide. Lower levels of iLANT6 were demonstrated in the basal telencephalon (82 pmol/g) and tegmentum (156 pmol/g) of turtles, and the majority of this activity appeared to be associated with larger molecular forms of LANT6 or a peptide related to LANT6. In addition, one or more substances resembling Neuromedin N (NMN), a mammalian counterpart to LANT6, were detected in the turtle nervous system. The labeling patterns in hamsters were similar to those in pigeons and turtles, except that in hamsters fewer neurons were labeled and the labeling was generally lighter. The lighter level of labeling may reflect a difference between the LANT6-like material present in hamster nervous system and authentic LANT6. Biochemical studies revealed that a Neuromedin N-like substance, as well as high molecular weight forms of a LANT6-like substance, are present in hamster brain. In hamsters, neurons within globus pallidus, the entopeduncular nucleus, the ventral pallidum, and the polymorph layer of the olfactory tubercle were labeled for the presence of LANT6. Fiber labeling for LANT6 in the dopaminergic tegmental cell groups that receive pallidal input was, however, light. Thus, the present results establish that LANT6 in pigeons and LANT6-related peptides in turtles and hamsters are present within many pallidal neurons. In pigeons and turtles, these pallidal neurons give rise to a major LLI-containing projection to the dopaminergic cell groups of the tegmentum.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed2002

Distribution of basal ganglia lesions in diffuse neurofibrillary tangles with calcification: a clinicopathological study of five autopsy cases.

We investigated five Japanese autopsy cases of diffuse neurofibrillary tangles with calcification (DNTC), both clinically and pathologically, and examined the degree and distribution of the basal ganglia lesions, especially in the amygdala, striatum, pallidum, and substantia nigra. The lesions in the amygdala, striatum, and pallidum were classified into three categories (mild, moderate, and severe). The lesions in the substantia nigra were qualitatively judged, compared with normal controls. Severe dementia was observed in four cases neuropathologically showing pronounced neuronal loss in the cerebral cortex, but one case without neuronal loss in the cerebral cortex showed mild memory disturbance. Extrapyramidal signs were evident in three cases. Obvious neuronal loss in the substantia nigra with the presence of Lewy bodies was noticed in four cases. Basal ganglia lesions in all five cases were uniform: the amygdala showed severe to moderate lesions, the caudate nucleus moderate to slight lesions, and the putamen and pallidum slight lesions to normal. Furthermore, the lesions in the amygdala were more prominent in the basolateral group than in the corticomedial group, inconsistent with those in the amygdala of Alzheimer's disease. Moderate lesions were evident in the basolateral group of the amygdala in the case without neuronal loss in the cerebral cortex. In DNTC, the degree and distribution of the basal ganglia lesions, except for nigral lesions, were analogous to those found in Pick's disease with Pick bodies. These clinicopathological findings may contribute to the elucidation of the clinicopathological hallmarks in this disorder.

Age of Onset↗

PubMed1991

[Basal ganglia calcifications demonstrated by CT. Is further investigation necessary when this is found incidentally?].

Calcification in the basal ganglia in the brain is, as a rule, asymptomatic and is therefore observed as an incidental finding at CT examination for other cerebral conditions e.g. tumours or haemorrhage. The question is whether incidental finding of calcification in the basal ganglia indicates the need for further supplementary investigations. Three case histories and study of the literature are quoted to illustrate this. It is concluded that investigation is not indicated in patients over the age of 50 years with limited, bilateral, symmetrical calcifications in the globi pallidi. In patients under 50 years, investigation in the form of detailed history taking, neurological examination and haematological investigation is indicated.

Adolescent↗

PubMed1975

Single unit activity in basal ganglia of monkeys during performance of a delayed response task.

Single unit activity was recorded from the basal ganglia (caudate, putamen and globus pallidus) of monkeys during the performance of a delayed-response task. The task was divided into five epochs: stimulus onset, delay, pre-response, post-response and reqard. A high percentage of units recorded from the basal ganglia were found to show significant changes in activity during one or more epochs. Examination of the proportion of units excited or inhibited during a particular epoch indicated that brief increases or decreases in unit firing rates occurred "in phase" in both pallidum and caudate. Longer lasting firing rate changes, however, tended to occur in opposite directions in these two structures. This latter finding is interpreted as representing the consequence of persistent increases or decreases in activity of inhibitory interneurons in the caudate nucleus.

Animals↗

PubMed1995

[Functional magnetic resonance tomography of the basal ganglia. Use of FLASH sequences for mapping activity with BOLD contrast ane high resolution].

The activation pattern of putamen, internal and external division of globus pallidus was investigated during rapid pronation and supination of the right and left hand in 12 normal volunteers using a FLASH sequence with high resolution for functional magnetic resonance imaging (fMRI) at 1.5 T. The chosen paradigm for motor function led to a signal increase within the basal ganglia between 3 and 23%, depending on the structure and individual subject. In all cases significant activation could be found contralateral to the moving hand. In six cases activation was also found on the ipsilateral side. The activated areas within putamen, internal and external division of globus pallidus were less than 5 mm2. These first results indicate that fMRI studies of basal ganglia are feasible and might be suitable for analyzing basal ganglia disorders.

Adult↗

PubMedDate not supplied

Prognosis and MRI after ischemic stroke of the basal ganglia.

The clinical courses and long-term prognoses in 16 young patients with infarctions of the basal ganglia were evaluated and the recent magnetic resonance imaging findings in 9 of them were examined. Only 5 of 14 patients (35%) had motor sequelae, 4 had hemiparesis, and 1 had gait disturbance. Secondary dystonia occurred in 1 patient. Magnetic resonance imaging disclosed a circumscribed lesion in the basal ganglia, as reflected by T2 high- and T1 low-intensity signals, in all patients. The abnormal region on T2-weighted images usually was more extensive than that observed on T1-weighted ones. The hemiplegic patients each had an area of abnormal intensity in the internal capsule or corona radiata with relatively high signals on the T2- and proton-density-weighted images. Mild to moderate asymmetric atrophy of the midbrain on the side ipsilateral to the stroke lesion was observed in 8 of 9 patients. The mechanism involved may be remote transsynaptic neuronal death of the substantia nigra, as well as Wallerian degeneration of the pyramidal tract.

Adolescent↗

PubMed1990

[Massive traumatic hematoma localized in the basal ganglia: treatment by CT-guided stereotactic aspiration surgery].

A case of massive traumatic hematoma of the basal ganglia which was treated successfully by CT-guided stereotactic aspiration surgery, was reported. A 6-year-old boy was admitted 2 hours after a traffic accident. He had no neurological focal signs except for disturbance of consciousness on admission. CT scan revealed a massive hematoma in the right basal ganglia. His neurological status gradually deteriorated 6 hours after the trauma and the size of the hematoma increased on serial CT scan. Then, CT-guided stereotactic aspiration surgery was performed and about 15.5 ml of hematoma clot was successfully evacuated. He made an uneventful recovery from the operation and gradually improved. The final outcome was that he showed moderate disability at 3 months after the trauma. The possible mechanism of development of hematoma in this lesion, and indication of CT-guided stereotactic aspiration surgery were also discussed.

Basal Ganglia Diseases↗

PubMed1993

Basal ganglia intrinsic circuits and their role in behavior.

There have been significant recent advances in the understanding of basal ganglia circuitry and its role in behavior. Important areas of work in the past year include, firstly, the role of striatal neurons in early phases of movement and, secondly, further characterization of the intrinsic circuitry with emphasis on the importance of the subthalamic nucleus and its connections. A conceptual model of basal ganglia inhibition of competing motor programs is discussed.

Animals↗

PubMed1993

NGF receptor (p75)-immunoreactivity in the developing primate basal ganglia.

The distribution of the p75 nerve growth factor receptor (NGFr) was determined within the developing human basal ganglia in specimens between weeks 16 through 40 of gestation, 5 years of age, and adulthood. Although NGFr-immunoreactive neurons were rarely seen in the caudate nucleus, a few such neurons were seen in the putamen between prenatal weeks 16 and 26 of development. At 26 and 40 weeks of gestation, the putamen also displayed NGFr-immunoreactive fibers of putative basal forebrain origin. Some of these fibers coursed through the putamen en route to the cortex while others appeared to remain within the putamen. The external segment of the globus pallidus contained dense collections of NGFr-immunoreactive neurons between 16 and 26 weeks of gestation, whereas the internal segment was devoid of immunoreactive perikarya. A few NGFr-immunoreactive neurons were observed within the globus pallidus at embryonic week 40. The expression of NGFr-immunoreactive neurons within the external segment of the globus pallidus was paralleled by a dense granular NGFr-immunoreactive terminal-like staining pattern within the subthalamic nucleus. This staining pattern was most intense at midgestation (weeks 21-26) and was not observed at 40 weeks of gestation or in adulthood. Interestingly, a similar NGFr-immunoreactive terminal-like pattern was also observed within the monkey subthalamic nucleus at embryonic day 120. These data indicate that NGF receptor mediated mechanisms may underlie developmental processes within the primate basal ganglia. The absence of NGFr-immunoreactive neurons within the caudate nucleus, and the paucity of such neurons in the putamen, suggests that NGF receptors play a limited role in primate neostriatal development. Alternatively, developmental events mediated through NGF receptors may occur prior to embryonic week 16. Furthermore, an NGFr/trophic interaction appears to underlie the development of the pallidal-subthalamic nucleus pathway.

Animals↗

PubMed1991

Three cases of anomic aphasia after lesions in and/or around the basal ganglia.

The present paper reports 3 cases of aphasia with small lesions in the region of the basal ganglia to discuss whether neostrial dysfunction can cause aphasic symptoms. The Standard Language Tests of Aphasia (SLTA) was used to assess the type and degree of aphasia. Two patients with infarction either in the left putamen or in the head of the left caudate nucleus showed severe disturbance only in recalling words, especially nouns. The other patient showed the same symptom, in addition to writing disturbance that developed shortly after surgical extirpation of an arteriovenous malformation (AVM) in the left caudate nuclei. The symptoms common to the 3 patients corresponded well to the "anomic aphasia" proposed by Benson. The aphasic symptoms disappeared completely or largely within several months. This easy reversibility suggests that the aphasic disorder in the three patients was caused by damage not to the basal ganglia themselves, but to the affecting axons passing through or by the nuclei.

Aged↗

PubMed2006

The role of the basal ganglia in exploration in a neural model based on reinforcement learning.

We present a computational model of basal ganglia as a key player in exploratory behavior. The model describes exploration of a virtual rat in a simulated water pool experiment. The virtual rat is trained using a reward-based or reinforcement learning paradigm which requires units with stochastic behavior for exploration of the system's state space. We model the Subthalamic Nucleus-Globus Pallidus externa (STN-GPe) segment of the basal ganglia as a pair of neuronal layers with oscillatory dynamics, exhibiting a variety of dynamic regimes such as chaos, traveling waves and clustering. Invoking the property of chaotic systems to explore state-space, we suggest that the complex exploratory dynamics of STN-GPe system in conjunction with dopamine-based reward signaling from the Substantia Nigra pars compacta (SNc) present the two key ingredients of a reinforcement learning system.

Animals↗

PubMed1999

Modulation of endogenous GABA release by an antagonistic adenosine A1/dopamineD1 receptor interaction in rat brain limbic regions but not basal ganglia.

Behavioral and biochemical studies suggest that a negative interaction exists between adenosine A(1) and dopamine D(1) receptors in the brain and that this may contribute to the psychomotor effects of adenosine receptor agonists and antagonists. We examined the functional significance of A(1) and D(1) receptor subtypes in modulating electrically evoked endogenous GABA release from slices/punches of rat basal ganglia (striatum, globus pallidus, striatum containing globus pallidus, and substantia nigra reticulata) and limbic regions (ventral pallidum and nucleus accumbens). In basal ganglia, stimulation of A(1) receptors with the selective agonist R-PIA (1-100 nM) resulted in a concentration-dependent decrease in GABA release. The selective A(1) antagonist DPCPX (10-100 nM) increased GABA release, suggesting that endogenous adenosine tonically inhibits GABA release. However, in basal ganglia, consistent dopamine D(1) receptor modulation of GABA, release was not observed in response to either D(1) agonists or antagonists. Furthermore, the A(1) receptor-mediated inhibition of GABA release was not changed by concurrent activation of D(1) receptors, thus confirming the lack of D(1) receptor modulation under these conditions. In contrast, in ventral pallidum and nucleus accumbens, stimulation of D(1) receptors with SKF-82958 (1 microM) increased GABA release significantly. The D(1) receptor-mediated increase in GABA release was attenuated by concurrent activation of adenosine A(1) receptors. These results are consistent with the hypothesis that an antagonistic A(1)/D(1) receptor interaction may be important in modulating GABA release in limbic regions.

Adenosine↗

PubMedDate not supplied

Ultrasonographic findings in thalamus and basal ganglia in term asphyxiated infants.

Three severely asphyxiated term neonates demonstrated bilateral hyperechogenicity in the thalamus and basal ganglia. During evolution, areas of attenuated echogenicity appeared in these structures at the same time as periventricular cysts were evident in 2 patients with coexistent periventricular leukomalacia. All 3 patients developed ventricular dilatation; in the 2 patients with periventricular leukomalacia, the ventricular border was irregular in the outer (dorsal) margin, and interhemispheric fissures were widened as a manifestation of cerebral atrophy. Furthermore, the thalamic inner (ventral) margins of the lateral ventricles were irregular in all 3 patients. This previously unrecognized finding points to a particular form of cerebral atrophy localized in the gangliothalamic region that contributes to the development of ventriculomegaly. The reported sonographic sequence implies profound damage in the thalamus and basal ganglia in asphyxiated infants which undoubtedly has contributed to the poor outcomes of our patients.

Asphyxia Neonatorum↗

PubMed1989

Bilateral germ cell tumors involving the basal ganglia and thalamus.

Two cases of a human chorionic gonadotropin-producing germ cell tumor originating bilaterally in the basal ganglia and thalamus are reported. The biological behavior and clinical characteristics were similar to those of unilateral germinomas involving the basal ganglia and thalamus. Common clinical features were slowly progressive unilateral pyramidal signs and bilateral and/or unilateral extrapyramidal signs which occurred either concomitantly or sequentially. Bilateral symmetrical lesions were demonstrated by computed tomography and/or magnetic resonance imaging at an early stage of illness. Serum and cerebrospinal fluid human chorionic gonadotropin levels were elevated (116 and 141 mIU/ml, respectively) but decreased and remained within normal limits after radiation therapy alone. Radiosensitivity was confirmed by repeated computed tomographic scans and tumor marker measurements. Multiple concomitant germ cell tumors is a rare, but interesting lesion, especially considering its pathogenesis and oncogenesis.

Adolescent↗