Search results for "thalamus"
showing 10 items of 280 documents
Essential thalamic contribution to slow waves of natural sleep
2013
Slow waves represent one of the prominent EEG signatures of non-rapid eye movement (non-REM) sleep and are thought to play an important role in the cellular and network plasticity that occurs during this behavioral state. These slow waves of natural sleep are currently considered to be exclusively generated by intrinsic and synaptic mechanisms within neocortical territories, although a role for the thalamus in this key physiological rhythm has been suggested but never demonstrated. Combining neuronal ensemble recordings, microdialysis, and optogenetics, here we show that the block of the thalamic output to the neocortex markedly (up to 50%) decreases the frequency of slow waves recorded dur…
Functional Inactivation of the Genome-Wide Association Study Obesity Gene Neuronal Growth Regulator 1 in Mice Causes a Body Mass Phenotype
2012
To date, genome-wide association studies (GWAS) have identified at least 32 novel loci for obesity and body mass-related traits. However, the causal genetic variant and molecular mechanisms of specific susceptibility genes in relation to obesity are yet to be fully confirmed and characterised. Here, we examined whether the candidate gene NEGR1 encoding the neuronal growth regulator 1, also termed neurotractin or Kilon, accounts for the obesity association. To characterise the function of NEGR1 for body weight control in vivo, we generated two novel mutant mouse lines, including a constitutive NEGR1-deficient mouse line as well as an ENU-mutagenised line carrying a loss-of-function mutation …
The LIM Homeodomain Factor Lhx2 Is Required for Hypothalamic Tanycyte Specification and Differentiation
2014
Hypothalamic tanycytes, a radial glial-like ependymal cell population that expresses numerous genes selectively enriched in embryonic hypothalamic progenitors and adult neural stem cells, have recently been observed to serve as a source of adult-born neurons in the mammalian brain. The genetic mechanisms that regulate the specification and maintenance of tanycyte identity are unknown, but are critical for understanding how these cells can act as adult neural progenitor cells. We observe that LIM (Lin-11, Isl-1, Mec-3)-homeodomain geneLhx2is selectively expressed in hypothalamic progenitor cells and tanycytes. To test the function ofLhx2in tanycyte development, we used an intersectional gene…
Lateral differences in GABA binding sites in rat brain.
1988
An asymmetric distribution of GABA binding sites was found in the cerebral cortex, hippocampus, cerebellar hemispheres, striatum, and thalamus. Higher levels of [3H]GABA binding were observed in the left-side of most brain areas and in a greater percentage of adult rats, but the opposite asymmetry was found in the thalamus. A similar left-right difference in cerebral hemispheres was also found in five day-old rats, suggesting the genetic predetermination of asymmetry.
Anterograde tracing of retinal afferents to the tree shrew hypothalamus and raphe
2000
The anterograde neuronal transport of Cholera toxin B subunit (CTB) was used in this study to label the termination of retinal afferents in the hypothalamus of the tree shrew Tupaia belangeri. Upon pressure-injection of the substance into the vitreous body of one eye, a major projection of the retinohypothalamic tract (RHT) was found to the hypothalamic suprachiasmatic nuclei (SCN). Although the innervation pattern was bilateral, the ipsilateral SCN received a somewhat stronger projection. Labeling was also found in the supraoptic nucleus and its perinuclear zone, respectively, mainly ipsilaterally as well as in the bilateral para- and periventricular hypothalamic regions without lateral pr…
Thalamic relay or cortico-thalamic processing? Old question, new answers.
2013
Ascending and descending information is relayed through the thalamus via strong, “driver” pathways. According to our current knowledge, different driver pathways are organized in parallel streams and do not interact at the thalamic level. Using an electron microscopic approach combined with optogenetics and in vivo physiology, we examined whether driver inputs arising from different sources can interact at single thalamocortical cells in the rodent somatosensory thalamus (nucleus posterior, POm). Both the anatomical and the physiological data demonstrated that ascending driver inputs from the brainstem and descending driver inputs from cortical layer 5 pyramidal neurons converge and interac…
Subthalamic deep brain stimulation improves time perception in Parkinson's disease.
2004
Alterations in temporal estimation have been observed in Parkinson's disease (PD) and have been associated with dopaminergic dysfunction. To investigate whether deep brain stimulation might reverse these abnormalities in PD, patients treated with electrode implantation for subthalamic deep brain stimulation were required to reproduce time intervals in different experimental conditions (off deep brain stimulation/off therapy, on deep brain stimulation/off therapy, on therapy/off deep brain stimulation). Patients treated with deep brain stimulation in off deep brain stimulation/off therapy displayed the anomalous pattern of responses typically observed in PD. When subthalamic deep brain stimu…
Importance of mitochondrial dynamin-related protein 1 in hypothalamic glucose sensitivity in rats.
2012
International audience; AIMS: Hypothalamic mitochondrial reactive oxygen species (mROS)-mediated signaling has been recently shown to be involved in the regulation of energy homeostasis. However, the upstream signals that control this mechanism have not yet been determined. Here, we hypothesize that glucose-induced mitochondrial fission plays a significant role in mROS-dependent hypothalamic glucose sensing. RESULTS: Glucose-triggered translocation of the fission protein dynamin-related protein 1 (DRP1) to mitochondria was first investigated in vivo in hypothalamus. Thus, we show that intracarotid glucose injection induces the recruitment of DRP1 to VMH mitochondria in vivo. Then, expressio…
Transcriptional profiling of rat hypothalamus response to 2,3,7,8-tetrachlorodibenzo-ρ-dioxin
2015
In some mammals, halogenated aromatic hydrocarbon (HAH) exposure causes wasting syndrome, defined as significant weight loss associated with lethal outcomes. The most potent HAH in causing wasting is 2,3,7,8-tetrachlorodibenzo-r-dioxin (TCDD), which exerts its toxic effects through the aryl hydrocarbon receptor (AHR). Since TCDD toxicity is thought to predominantly arise from dysregulation of AHR-transcribed genes, it was hypothesized that wasting syndrome is a result of to TCDD-induced dysregulation of genes involved in regulation of food-intake. As the hypothalamus is the central nervous systems' regulatory center for food-intake and energy balance. Therefore, mRNA abundances in hypothala…
Efferent connections of the "olfactostriatum": a specialized vomeronasal structure within the basal ganglia of snakes.
2005
Abstract The olfactostriatum is a portion of the basal ganglia of snakes that receives substantial vomeronasal afferents through projections from the nucleus sphericus. In a preceding article, the olfactostriatum of garter snakes (Thamnophis sirtalis) was characterized on the basis of chemoarchitecture (distribution of serotonin, neuropeptide Y and tyrosine hydroxylase) and pattern of afferent connections [Martinez-Marcos, A., Ubeda-Banon, I., Lanuza, E., Halpern, M., 2005. Chemoarchitecture and afferent connections of the “olfactostriatum”: a specialized vomeronasal structure within the basal ganglia of snakes. J. Chem. Neuroanat. 29, 49–69]. In the present study, its efferent connections …