Disease relevance of Entopeduncular Nucleus

• Lesions of the entopeduncular nucleus and the subthalamic nucleus reduce dopamine receptor antagonist-induced catalepsy in the rat [1].
• In a rat model of Parkinson's disease, unilateral 6-hydroxydopamine lesion in the substantia nigra, [3H]AA acid incorporation from blood was increased in cerebral cortex, caudate putamen, globus pallidus, entopeduncular nucleus, subthalamic nucleus and substantia nigra pars reticulata ipsilateral to the lesion [2].

Psychiatry related information on Entopeduncular Nucleus

• Microinjection of muscimol into entopeduncular nucleus suppresses pilocarpine but not maximal electroshock seizures in rats [3].
• The two other sites tested, the entopeduncular nucleus and subthalamic nucleus, do not receive projections from the accumbens; in these two structures, muscimol enhanced locomotor activity but abolished self-stimulation; picrotoxin was without significant effect, or was disruptive [4].

High impact information on Entopeduncular Nucleus

• The anticonvulsant action of N-Me-D-Asp in the caudate-putamen was reversed by blocking gamma-aminobutyrate-mediated inhibition in the substantia nigra pars reticulata or in the entopeduncular nucleus [5].
• In contrast, the role of the entopeduncular nucleus in response initiation and its control through GABA and glutamate is at variance with this hypothesis, suggesting functional differences of the output structures [6].
• Nigrostriatal dopamine (DA) lesions lead to changes of neuronal activity in basal ganglia nuclei such as the globus pallidus (GP, the rodent homolog of lateral globus pallidus), entopeduncular nucleus (EP, the rodent homolog of medial globus pallidus), substantia nigra pars reticulata (SNR), and subthalamic nucleus (STN) [7].
• In addition, the lesion decreased substance P mRNA in the ipsilateral striatum compared to the contralateral side, and GAD mRNA in the contralateral entopeduncular nucleus [8].
• Confirming previous results, nigrostriatal dopaminergic lesions caused contraversive rotation after apomorphine injection, and increased enkephalin mRNA in the striatum, GAD mRNA in the globus pallidus, and somatostatin mRNA in the entopeduncular nucleus (internal pallidum) ipsilateral to the lesion [8].

Chemical compound and disease context of Entopeduncular Nucleus

• Microinjection of muscimol (406 pmol) into the rat entopeduncular nucleus, the analogue of the primate globus pallidus pars interna, significantly suppressed pilocarpine but not maximal electroshock seizures in a spatially specific manner [3].

Biological context of Entopeduncular Nucleus

• Our previous studies showed that the opioid peptide dynorphin regulates that subtype of projection neurons which sends axons to the substantia nigra/entopeduncular nucleus, as indicated by an inhibitory action of dynorphin/agonists on D1 dopamine receptor-mediated immediate-early gene induction in these neurons [9].
• Normalization of glutamate decarboxylase gene expression in the entopeduncular nucleus of rats with a unilateral 6-hydroxydopamine lesion correlates with increased GABAergic input following intermittent but not continuous levodopa [10].
• These studies show that clozapine and haloperidol, both of which increase the occurrence of VCM, differentially modulate the neurochemistry of the entopeduncular nucleus [11].

Anatomical context of Entopeduncular Nucleus

• In the substantia nigra pars reticulata, internal pallidal segment/entopeduncular nucleus, and subthalamic nucleus, activation of AMPA/kainate and metabotropic receptors but not of NMDA receptors led to parkinsonian rigidity [12].
• Effect of subthalamic nucleus or entopeduncular nucleus lesion on levodopa-induced neurochemical changes within the basal ganglia and on levodopa-induced motor alterations in 6-hydroxydopamine-lesioned rats [13].
• The entopeduncular nucleus and zona incerta contained many positive neurons, and the lateral habenula had a dense terminal field suggesting a pallidohabenula somatostatin pathway [14].
• Pretreatment with the noncompetitive N-methyl-D-aspartate receptor antagonist MK-801 (0.1 mg/kg, i.v.), which had little effect on cerebral metabolism by itself, reduced the effect of SKF 38393 in entopeduncular nucleus and substantia nigra pars reticulata and prevented the effect of quinpirole in nucleus accumbens [15].
• D1 receptors were found throughout the forebrain and were concentrated in the substantia nigra pars reticulata, accumbens nucleus, caudate putamen, entopeduncular nucleus, olfactory tubercle and the major island of Calleja [16].

Associations of Entopeduncular Nucleus with chemical compounds

• However, the effects of STN or entopeduncular nucleus (EP) lesion on levodopa-related motor fluctuations and on neurochemical changes induced by levodopa remain largely unknown [13].
• Intrastriatal Mn2+ (0.4 mumol) produced time-dependent 45Ca2+ accumulation in striatum, globus pallidus, entopeduncular nucleus, several thalamic nuclei, and substantia nigra pars reticulata ipsilateral to the injection site [17].
• All changes in the background activity and reactions to cerebellothalamic or nucleus entopeduncularis stimulation developing under the influence of D2 receptor antagonist haloperidol (1.5-1.7 mg/kg, i.v.) have been studied in the same cell [18].
• Injections of muscimol into the entopeduncular nucleus (25-100 ng) failed to have any significant effects on tacrine-induced vacuous jaw movements [19].
• Behavioural and electrographic signs of limbic seizures following pilocarpine (380 mg/kg) are suppressed by the focal microinjection into the entopeduncular nucleus of the N-methyl-D-aspartate antagonist, 2-amino-7-phosphonoheptanoate (0.02 nmol) or the kainate antagonist, gamma-D-glutamylamino-methylsulphonate (40 nmol) [20].

Gene context of Entopeduncular Nucleus

• At gestational days 16-17 (14-17-mm embryo, SRIF-positive cells appear in the developing piriform cortex and entopeduncular nucleus [21].
• In the basal ganglia and related nuclei, cadherin-8 is expressed by parts of the striatum, globus pallidus, substantia nigra, entopeduncular nucleus, subthalamic nucleus, zona incerta, and pedunculopontine nuclei [22].
• Furthermore, CB-1 receptor density in the hippocampus, nucleus accumbens and entopeduncular nucleus was significantly inversely correlated with intake of palatable food (r(2)=0.25-0.35; all P<0.05) [23].
• Unilateral depletion of striatal dopamine resulted in a moderate increase in GAD67 messenger RNA levels within the ipsilateral entopeduncular nucleus, along with a substantial decrease in GAD67 levels within the contralateral nucleus [24].
• Amphetamine-induced Fos expression is evident in gamma-aminobutyric acid neurons in the globus pallidus and entopeduncular nucleus in rats treated with intrastriatal c-fos antisense oligodeoxynucleotides [25].

Analytical, diagnostic and therapeutic context of Entopeduncular Nucleus

• This study utilized microdialysis in conscious rats to investigate dopaminergic control of excitatory amino acid release in the entopeduncular nucleus (EPN), and glutamatergic control of dopamine release in the substantia nigra pars reticulata (SNr) [26].
• The purpose of the present experiment was to describe the distribution of glutamic acid decarboxylase-65 and glutamic decarboxylase-67 messenger RNAs throughout the entopeduncular nucleus using recently developed oligodeoxynucleotide probes and in situ hybridization histochemical methods [27].
• We injected ibotenate into the striatum of adult rats and performed Nissl and silver staining of the substantial nigra, the globus pallidus and the entopeduncular nucleus at multiple times up to postlesion day 28 [28].
• The striatum and the globus pallidus send convergent synaptic inputs onto single cells in the entopeduncular nucleus of the rat: a double anterograde labelling study combined with postembedding immunocytochemistry for GABA [29].
• The resulting autoradiography showed ibotenate-induced losses of cannabinoid, D1 and D2 receptors in the caudate-putamen and topographic losses of cannabinoid and D1 receptors in the globus pallidus, entopeduncular nucleus, and substantia nigra pars reticulata at both survivals [30].

References