Search results for "Subthalamic nucleus"
showing 10 items of 35 documents
Intensity of GABA-evoked responses is modified by nitric oxide-active compounds in the subthalamic nucleus of the rat: a microiontophoretic study.
2009
We have previously described modulatory effects of nitric oxide (NO)-active drugs on subthalamic nucleus (STN) neurons. In this study, the effects of microiontophoretically applied NO-active compounds on GABA-evoked responses were investigated in subthalamic neurons extracellularly recorded from anesthetized rats: 45 of 62 cells were excited by S-nitroso-glutathione (SNOG), an NO donor, whereas 28 of 43 neurons were inhibited by N-nitro-L-arginine methyl ester (L-NAME), a NOS inhibitor. Nearly all neurons responding to SNOG and/or L-NAME showed significant inhibitory responses to the administration of iontophoretic GABA. In these cells, the changes induced by NO-active drugs in the magnitud…
Effects of Substantia Nigra pars compacta lesion on the behavioral sequencing in the 6-OHDA model of Parkinson’s disease
2019
The basal ganglia circuitry plays a crucial role in the sequential organization of behavior. Here we studied the behavioral structure of the animals after 21 days of 6-OHDA-induced lesion of the dopaminergic nigrostriatal system. Frequencies and durations of individual components of the behavioral repertoire were calculated; moreover, whether a temporal organization of the activity was present, it was investigated by using T-pattern analysis, a multivariate approach able to detect the real-time sequential organization of behavior. Six sham-depleted and six rats with unilateral 6−OHDA-lesion of the Substantia Nigra pars compacta were used. As to quantitative evaluations, the comparison betwe…
A Strange Case of Downward Displacement of a Deep Brain Stimulation Electrode 10 Years Following Implantation: The Gliding Movement of Snakes Theory.
2014
Background Despite the best efforts to ensure stereotactic precision, deep brain stimulation (DBS) electrodes can wander from their intended position after implantation. We report a case of downward electrode migration 10 years following successful implantation in a patient with Parkinson disease. Methods A 53-year-old man with Parkinson disease underwent bilateral implantation of DBS electrodes connected to a subclavicular 2-channel pulse generator. The generator was replaced 7 years later, and a computed tomography (CT) scan confirmed the correct position of both leads. The patient developed a gradual worsening affecting his right side 3 years later, 10 years after the original implantati…
Different methods for anatomical targeting.
2003
AIM: Several procedures are used in the different neurosurgical centers in order to perform stereotactic surgery for movement disorders. At the moment no procedure can really be considered superior to the other. We contribute with our experience of targeting method. METHODS: Ten patients were selected, in accordance to the guidelines for the treatment of Parkinson disease, and operated by several methods including pallidotomy, bilateral insertion of chronic deep brain electrodes within the internal pallidum and in the subthalamic nucleus (18 procedures). Interventions: in each patient an MR scan was performed the day before surgery. Scans were performed axially parallel to the intercommissu…
Effects of nitric oxide-active drugs on the discharge of subthalamic neurons: microiontophoretic evidence in the rat.
2006
The presence of nitric oxide (NO) synthase and of soluble guanylyl cyclase, the main NO-activated metabolic pathway, has been demonstrated in many cells of the subthalamic nucleus. In this study, the effects induced on the firing of 96 subthalamic neurons by microiontophoretically administering drugs modifying NO neurotransmission were explored in anaesthetized rats. Recorded neurons were classified into regularly and irregularly discharging on the basis of their firing pattern. Nω-nitro-l-arginine methyl ester (L-NAME; a NO synthase inhibitor), 3-morpholino-sydnonimin-hydrocloride (SIN-1; a NO donor), S-nitroso-glutathione (SNOG; another NO donor) and 8-Br-cGMP (a cell-permeable analogue o…
A basal ganglia-like cortical-amygdalar-hypothalamic network mediates feeding behavior.
2020
International audience; The network connecting the insular cortex, the central nucleus of the amygdala, and a caudal hypothalamic nuclear complex including the parasubthalamic nucleus (PSTN) is of interest due to its role in controlling feeding behavior. Here, we show that the organization of this network is similar to that of the basal ganglia network, implying that both fit within a simplified structural plan of the forebrain. Then, we demonstrate that the PSTN complex modulates behavior in response to hedonic factors normally inducing a “reward effect.” The PSTN complex is involved in a “non-feed” response equivalent of a “non-reward” evaluation: “I don’t want to consume this food, recog…
Chronic l-DOPA treatment increases striatal cannabinoid CB1 receptor mRNA expression in 6-hydroxydopamine-lesioned rats
2000
Abstract The effect of a unilateral 6-hydroxydopamine (6-OHDA) lesion of the left medial forebrain bundle and 3 weeks treatment with l -DOPA of normal and 6-OHDA lesioned rats on CB1r mRNA expression was investigated by in situ hybridization. A 6-OHDA lesion of nigrostriatal pathway alone, confirmed by the loss of nigral tyrosine hydroxylase mRNA, did not alter CB1r mRNA levels in the dopamine depleted striatum. Similarly, chronic l -DOPA treatment of normal rats had no effect on striatal CB1r mRNA expression. In contrast, chronic l -DOPA treatment of 6-OHDA-lesioned rats significantly increased CB1r mRNA expression in the denervated striatum. These results suggest that the CB1r activity ma…
Motor intracortical inhibition in PD: L-DOPA modulation of high-frequency rTMS effects
2007
Dopaminergic drugs and deep brain stimulation restore cortical inhibition in Parkinson disease (PD) patients. High-frequency rTMS was also found to increase cortical inhibition in PD but its therapeutic effect is still controversial. Here we hypothesize that, if dopaminergic drugs reverse to normal cortical excitability in M1, the effect of high-frequency (hf)-rTMS in PD patients could depend on whether they are in a medicated or unmedicated state. The present study aims to explore the lasting effects of sub-threshold hf rTMS trains over M1 on cortical inhibition in patients with "on" and without "off" L-DOPA treatment. Fourteen PD patients were examined twice while "on" and "off" medicatio…
Frequency-specific network activity predicts bradykinesia severity in Parkinson’s disease
2021
Highlights • Parallel subnetworks are affected in bradykinesia. • The primary motor and the premotor cortex are common nodes with task-specificity. • Beta activity decreases, gamma activity increases with improvement of bradykinesia. • Subthalamic stimulation reduces beta, increases gamma power in ipsilateral cortex. • Subnetworks act with frequency-specific oscillations.
Cortical beta burst dynamics are altered in Parkinson's disease but normalized by deep brain stimulation
2022
Funding Information: Amande Pauls was supported by a personal grant from the University of Helsinki . Olesia Korsun was supported by the Päivikki and Sakari Sohlberg Foundation , the Orion Research Foundation , the Finnish Parkinson Foundation and the Finnish Brain Foundation . Mia Liljeström was supported by the Swedish Cultural Foundation in Finland , the Päivikki and Sakari Sohlberg Foundation , and the Finnish Cultural Foundation . Eero Pekkonen was supported by Finnish Government research funding ( TYH- fund ). Hanna Renvall was supported by the Academy of Finland (grant number 321460 ) and Paulo Foundation. Publisher Copyright: © 2022 Exaggerated subthalamic beta oscillatory activity …