Chemo- and optogenetic activation of hypothalamic -expressing neurons and their terminal endings in the rostral-dorsolateral PAG leads to tachypnea, bradycardia, and immobility.

-expressing neurons occur in the dorsal premammillary nucleus (PMd) and further rostrally in the parvafox nucleus, a longitudinal cluster of neurons in the lateral hypothalamus of rodents. The descending projection of these neurons end in the dorsolateral part of the periaqueductal gray (dlPAG). The functional role of the neuronal subpopulation in the PMd and the parvafox nucleus remains elusive.

The PV2 cluster of parvalbumin neurons in the murine periaqueductal gray: connections and gene expression.

The PV2 (Celio 1990), a cluster of parvalbumin-positive neurons located in the ventromedial region of the distal periaqueductal gray (PAG) has not been previously described as its own entity, leading us to study its extent, connections, and gene expression. It is an oval, bilateral, elongated cluster composed of approximately 475 parvalbumin-expressing neurons in a single mouse hemisphere. In its anterior portion it impinges upon the paratrochlear nucleus (Par4) and in its distal portion it is harbored in the posterodorsal raphe nucleus (PDR).

Gene expression analysis in the mouse brainstem identifies Cart and Nesfatin as neuropeptides coexpressed in the Calbindin-positive neurons of the Nucleus papilio.

Study Objectives: The brainstem contains several neuronal populations, heterogeneous in terms of neurotransmitter/neuropeptide content, which are important for controlling various aspects of the rapid eye movement (REM) phase of sleep. Among these populations are the Calbindin (Calb)-immunoreactive NPCalb neurons, located in the Nucleus papilio, within the dorsal paragigantocellular nucleus (DPGi), and recently shown to control eye movement during the REM phase of sleep.

Methods: We performed in-depth data mining of the in situ hybridization data collected at the Allen Brain Atlas, in order to identify potentially interesting genes expressed in this brainstem nucleus.

Laughter is in the air: involvement of key nodes of the emotional motor system in the anticipation of tickling.

In analogy to the appreciation of humor, that of tickling is based upon the re-interpretation of an anticipated emotional situation. Hence, the anticipation of tickling contributes to the final outburst of ticklish laughter. To localize the neuronal substrates of this process, functional magnetic resonance imaging (fMRI) was conducted on 31 healthy volunteers.

The orbitofrontal cortex projects to the parvafox nucleus of the ventrolateral hypothalamus and to its targets in the ventromedial periaqueductal grey matter.

Although connections between the orbitofrontal cortex (OFC)-the seat of high cognitive functions-the lateral hypothalamus and the periaqueductal grey (PAG) have been recognized in the past, the precise targets of the descending fibres have not been identified. In the present study, viral tracer-transport experiments revealed neurons of the lateral (LO) and the ventrolateral (VLO) OFC (homologous to part of Area 13 in primates) to project to a circumscribed region in the ventrolateral hypothalamus, namely, the horizontally oriented, cylindrical parvalbumin- and Foxb1-expressing (parvafox) nucleus. The fine collaterals stem from coarse axons in the internal capsule and form excitatory synapses specifically with neurons of the parvafox nucleus, avoiding the rest of the hypothalamus.

Eliminating the VGlut2-Dependent Glutamatergic Transmission of Parvalbumin-Expressing Neurons Leads to Deficits in Locomotion and Vocalization, Decreased Pain Sensitivity, and Increased Dominance.

The calcium-binding protein parvalbumin (PV) is a recognized marker of short-axon GABA-ergic neurons in the cortex and the hippocampus. However in addition, PV is expressed by excitatory, glutamatergic neurons in various areas of the brain and spinal cord. Depending on the location of these neurons, loading of their synaptic vesicles with glutamate is mediated by either of three vesicular glutamate transporters (VGlut): VGlut1, VGlut2, or VGlut3.

Parvalbumin-expressing ependymal cells in rostral lateral ventricle wall adhesions contribute to aging-related ventricle stenosis in mice.

Aging-associated ependymal-cell pathologies can manifest as ventricular gliosis, ventricle enlargement, or ventricle stenosis. Ventricle stenosis and fusion of the lateral ventricle (LV) walls is associated with a massive decline of the proliferative capacities of the stem cell niche in the affected subventricular zone (SVZ) in aging mice. We examined the brains of adult C57BL/6 mice and found that ependymal cells located in the adhesions of the medial and lateral walls of the rostral LVs upregulated parvalbumin (PV) and displayed reactive phenotype, similarly to injury-reactive ependymal cells.

Parvalbumin-Neurons of the Ventrolateral Hypothalamic Parvafox Nucleus Receive a Glycinergic Input: A Gene-Microarray Study.

The ventrolateral hypothalamic parvafox (formerly called PV1-Foxb1) nucleus is an anatomical entity of recent discovery and unknown function. With a view to gaining an insight into its putative functional role(s), we conducted a gene-microarray analysis and, armed with the forthcoming data, controlled the results with the Allen databases and the murine BrainStars (B) database. The parvafox nucleus was specifically sampled by laser-capture microdissection and the transcriptome was subjected to a microarray analysis on Affymetrix chips.

The Foxb1-expressing neurons of the ventrolateral hypothalamic parvafox nucleus project to defensive circuits.

The parvafox nucleus is an elongated structure that is lodged within the ventrolateral hypothalamus and lies along the optic tract. It comprises axially located parvalbumin (Parv)-positive neurons and a peripheral cuff of Foxb1-expressing ones. In the present study, injections of Cre-dependent adenoviral constructs were targeted to the ventrolateral hypothalamus of Foxb1/Cre mice to label specifically and map the efferent connections of the Foxb1-expressing subpopulation of neurons of the parvafox nucleus.

Birthdate of parvalbumin-neurons in the Parvafox-nucleus of the lateral hypothalamus.

The Parvafox-nucleus in the lateral hypothalamus is characterized by the presence of two distinct neural populations, the Parvalbumin (Parv) and the Foxb1-expressing ones. Foxb1-neurons are born at day 10 in the subventricular zone of the mouse mammillary region. It would be interesting to know if the subpopulation of Parv- neurons develop independently at different times and then meet the Foxb1- expressing neurons in the lateral hypothalamus, their final settling place.

Reduction in 50-kHz call-numbers and suppression of tickling-associated positive affective behaviour after lesioning of the lateral hypothalamic parvafox nucleus in rats.

The parvafox nucleus is located ventrolaterally in the lateral hypothalamic area (LHA). Its core and shell are composed of neurons expressing the calcium-binding protein parvalbumin (PV) and the transcription factor Foxb1, respectively. Given the known functions of the LHA and that the parvafox nucleus receives afferents from the lateral orbitofrontal cortex and projects to the periaqueductal gray matter, a functional role of this entity in the expression of positive emotions has been postulated.

Insular cortex activity and the evocation of laughter.

The insular cortex is fundamentally involved in the processing of interoceptive information. It has been postulated that the integrative monitoring of the bodily responses to environmental stimuli is crucial for the recognition and experience of emotions. Because emotional arousal is known to be closely coupled to functions of the anterior insula, we suspected laughter to be associated primarily with neuronal activity in this region.

The ventrolateral hypothalamic area and the parvafox nucleus: Role in the expression of (positive) emotions?

The lateral hypothalamus has been long suspected of triggering the expression of positive emotions, because stimulations of its tuberal portion provoke bursts of laughter. Electrophysiological studies in various species have indeed confirmed that the lateral hypothalamus contributes to reward mechanisms. However, only the rudiments of the neural circuit underlying the expression of positive emotions are known.

De novo expression of parvalbumin in ependymal cells in response to brain injury promotes ependymal remodeling and wound repair.

The calcium-binding protein parvalbumin (PV) hallmarks subpopulations of interneurons in the murine brain. We serendipitously observed the de novo expression of PV in ependymal cells of the lateral ventricle wall following in vivo lesioning and brain slicing for the preparation of organotypic hippocampal slice cultures (OHSCs). In OHSCs, de novo PV-expression begins shortly after the onset of culturing, and the number of ependymal cells implicated in this process increases with time.

Coaxiality of Foxb1- and parvalbumin-expressing neurons in the lateral hypothalamic PV1-nucleus.

In the ventrolateral hypothalamus, the PV1-nucleus is defined by its population of parvalbumin-expressing neurons. During embryogenesis, the ventrolateral hypothalamus is colonized also by Foxb1-expressing neurons. In adult Foxb1-EGFP mice, many immunofluorescent neurons were found within the region that is occupied by the PV1-nucleus.

Efferent connections of the parvalbumin-positive (PV1) nucleus in the lateral hypothalamus of rodents.

A solitary cluster of parvalbumin-positive neurons--the PV1 nucleus--has been observed in the lateral hypothalamus of rodents. In the present study, we mapped the efferent connections of the PV1 nucleus using nonspecific antero- and retrograde tracers in rats, and chemoselective, Cre-dependent viral constructs in parvalbumin-Cre mice. In both species, the PV1 nucleus was found to project mainly to the periaqueductal grey matter (PAG), predominantly ipsilaterally.

Exploration of the neural correlates of ticklish laughter by functional magnetic resonance imaging.

The burst of laughter that is evoked by tickling is a primitive form of vocalization. It evolves during an early phase of postnatal life and appears to be independent of higher cortical circuits. Clinicopathological observations have led to suspicions that the hypothalamus is directly involved in the production of laughter.

The lateral hypothalamic parvalbumin-immunoreactive (PV1) nucleus in rodents.

In the lateral hypothalamus, groups of functionally related cells tend to be widely scattered rather than confined to discrete, anatomically distinct units. However, by using parvalbumin (PV)-specific antibodies, a solitary, compact cord of PV-immunoreactive cells (the PV1-nucleus) has been identified in the ventrolateral tuberal hypothalamus in various species. Here we describe the topography, the chemo-, cyto-, and myeloarchitectonics, and the ultrastructure of this PV1-nucleus in rodents.

The human lateral tuberal nucleus: Immunohistochemical characterization and analogy to the rodent PV1-nucleus.

The lateral tuberal nucleus (LTN) is a hypothalamic region that has been identified with certainty only in humans and primates. It is composed of three small round globular units which protrude the basal surface of the brain along the optic tract. The function of the LTN is unknown.

Differences in locomotor behavior revealed in mice deficient for the calcium-binding proteins parvalbumin, calbindin D-28k or both.

We investigated the role of the two calcium-binding proteins parvalbumin (PV) and calbindin D-28k (CB) in the locomotor activity and motor coordination using null-mutant mice for PV (PV-/-), CB (CB-/-) or both proteins (PV-/-CB-/-). These proteins are expressed in distinct, mainly non-overlapping populations of neurons of the central and peripheral nervous system and PV additionally in fast-twitch muscles. In a test measuring repeated locomotor activity during 18-20 days, the analysis revealed a slightly increased activity in mice lacking either protein, while the lack of both decreased the number of beams crossed during active periods.

Identification of calretinin and the alternatively spliced form calretinin-22k in primary pleural mesotheliomas and in their metastases.

Background: Antibodies against calretinin represent an established, powerful and reliable immunohistochemical marker in the differential diagnosis between mesothelioma and adenocarcinomas. However, in studies published so far, the exact molecular identity of the immunoreactive protein(s) detected in mesothelioma sections has not yet been determined.

Materials And Methods: Tissue biopsies from ten mesothelioma samples, primary and metastatic, were analyzed by Western blot analysis and reverse transcriptase-polymerase chain reaction (RT-PCR), in addition to immunohistochemical staining.

Parvalbumin-deficiency facilitates repetitive IPSCs and gamma oscillations in the hippocampus.

In the hippocampus, the calcium-binding protein parvalbumin (PV) is expressed in interneurons that innervate perisomatic regions. PV in GABAergic synaptic terminals was proposed to limit repetitive GABA release by buffering of "residual calcium." We assessed the role of presynaptic PV in Ca(2+)-dependent GABA release in the hippocampus of PV-deficient (PV-/-) mice and wild-type (PV+/+) littermates.