Search results for "Thalamic Nuclei"
showing 10 items of 10 documents
Letter: Thalamotomy-Like Effects From Partial Removal of a Ventral Intermediate Nucleus Deep Brain Stimulator Lead in a Patient With Essential Tremor…
2017
Afferent and efferent projections of the dorsal anterior thalamic nuclei in the lizard Podarcis hispanica (Sauria, Lacertidae).
2002
The aim of this study was to investigate the afferent and efferent connections of the anterior thalamic nuclei in the lizard Podarcis hispanica. To identify potential sources of sensory inputs and to determine the fine organization of the projections of these thalamic nuclei to the telencephalon, we injected the sensitive tracer biotinylated dextran amine (BDA) into different nuclei of the anterior dorsal thalamus. We also injected BDA into several telencephalic areas in order to corroborate the results of thalamic injections. Our results show that the anterior thalamic nuclei receive projections from multiple areas and nuclei distributed throughout most of the brain, from rhombencephalon t…
Transient cortical circuits match spontaneous and sensory-driven activity during development.
2020
At the earliest developmental stages, spontaneous activity synchronizes local and large-scale cortical networks. These networks form the functional template for the establishment of global thalamocortical networks and cortical architecture. The earliest connections are established autonomously. However, activity from the sensory periphery reshapes these circuits as soon as afferents reach the cortex. The early-generated, largely transient neurons of the subplate play a key role in integrating spontaneous and sensory-driven activity. Early pathological conditions—such as hypoxia, inflammation, or exposure to pharmacological compounds—alter spontaneous activity patterns, which subsequently in…
Functional Plasticity after Unilateral Vestibular Midbrain Infarction in Human Positron Emission Tomography.
2016
The aim of the study was to uncover mechanisms of central compensation of vestibular function at brainstem, cerebellar, and cortical levels in patients with acute unilateral midbrain infarctions presenting with an acute vestibular tone imbalance. Eight out of 17 patients with unilateral midbrain infarctions were selected on the basis of signs of a vestibular tone imbalance, e.g., graviceptive (tilts of perceived verticality) and oculomotor dysfunction (skew deviation, ocular torsion) in F18-fluordeoxyglucose (FDG)-PET at two time points: A) in the acute stage, and B) after recovery 6 months later. Lesion-behavior mapping analyses with MRI verified the exact structural lesion sites. Group su…
Unconditioned stimulus pathways to the amygdala: Effects of lesions of the posterior intralaminar thalamus on foot-shock-induced c-Fos expression in …
2008
The lateral nucleus of the amygdala (LA) is a site of convergence for auditory (conditioned stimulus) and foot-shock (unconditioned stimulus) inputs during fear conditioning. The auditory pathways to LA are well characterized, but less is known about the pathways through which foot shock is transmitted. Anatomical tracing and physiological recording studies suggest that the posterior intralaminar thalamic nucleus, which projects to LA, receives both auditory and somatosensory inputs. In the present study we examined the expression of the immediate-early gene c-fos in the LA in rats in response to foot-shock stimulation. We then determined the effects of posterior intralaminar thalamic lesio…
Electrophysiological investigations on the central innervation of the rat and guinea-pig pineal gland
1984
The possible influence of central nervous structures on the electrical activity of single pineal cells was investigated in rat and guinea-pig. In the rat electrical stimulation of the hippocampal formation elicited both single cell responses with different latencies and mostly long-term excitations in single pineal cells, while stimulation of the habenular nuclei caused clear orthodromical responses with different latencies, alterations in the rate of spontaneous electrical activity and evoked discharges of "silent" units. In the guinea-pig electrical stimulation of the paraventricular nucleus influenced predominantly cells in the deeper layers of the posterior part of the pineal gland. Ele…
Identification of the reptilian basolateral amygdala: an anatomical investigation of the afferents to the posterior dorsal ventricular ridge of the l…
1998
The presence of multimodal association in the telencephalon of reptiles has been investigated by tracing the afferent connections to the posterior dorsal ventricular ridge (PDVR) of the lizard Podarcis hispanica. The PDVR receives telencephalic afferents from the lateral (olfactory) and dorsal cortices, and from the three unimodal areas of the anterior dorsal ventricular ridge, in a convergent manner. From the diencephalon, it receives afferents from the dorsomedial anterior and medial posterior thalamic nuclei, and from several hypothalamic nuclei. Brainstem afferents to the PDVR originate in the dorsal interpeduncular nucleus, the nucleus of the lateral lemniscus and parabrachial nucleus.…
Restoring Neurological Physiology: The Innovative Role of High-Energy MR-Guided Focused Ultrasound (HIMRgFUS). Preliminary Data from a New Method of …
2017
Background Tremor is a disabling condition, common to several neurodegenerative diseases. Lesioning procedures and deep brain stimulation, respectively, of the ventralis intermedius nucleus for intentional tremor, and of the subthalamic nucleus for parkinsonian resting tremor, have been introduced in clinical practice for patients refractory to medical treatment. The combination of high-energy focused ultra-sound (HIFUS) with sophisticated magnetic resonance (MR) instrumentation, together with accurate knowledge of the stereotactic brain coordinates, represents a revolution in neuromodulation. Methods At the Neurosurgical Clinic and the Radiology Department of the University of Palermo,, tw…
Antiabsence effects of carbenoxolone in two genetic animal models of absence epilepsy (WAG/Rij rats and lh/lh mice).
2005
Carbenoxolone (CBX), the succinyl ester of glycyrrhetinic acid, is an inhibitor of gap junctional intercellular communication. We have tested its possible effects upon two genetic animal models of epilepsy (WAG/Rij rats and lethargic (lh/lh) mice). Systemic administration of CBX was unable to significantly affect the occurrence of absence seizures in WAG/Rij rats. In particular, intravenous (5-40 mg/kg) or intraperitoneal (i.p.; 10-80 mg/kg) administration of CBX was unable to significantly modify the number and duration of spike-wave discharges (SWDs) in WAG/Rij rats, whereas the bilateral microinjection (0.05, 0.1, 0.5 and 1 microg/0.5 microl) of CBX into nucleus reticularis thalami (NRT)…
Thalamic Network Oscillations Synchronize Ontogenetic Columns in the Newborn Rat Barrel Cortex
2013
Neocortical areas are organized in columns, which form the basic structural and functional modules of intracortical information processing. Using voltage-sensitive dye imaging and simultaneous multi-channel extracellular recordings in the barrel cortex of newborn rats in vivo, we found that spontaneously occurring and whisker stimulation-induced gamma bursts followed by longer lasting spindle bursts were topographically organized in functional cortical columns already at the day of birth. Gamma bursts synchronized a cortical network of 300-400 µm in diameter and were coherent with gamma activity recorded simultaneously in the thalamic ventral posterior medial (VPM) nucleus. Cortical gamma b…