In vivo 2-photon calcium imaging has led to fundamental advances in our understanding of sensory circuits in mammalian species. In contrast, few studies have exploited this methodology in birds, with investigators primarily relying on histological and electrophysiological techniques. Here, we report the development of in vivo 2-photon calcium imaging in awake pigeons.
View Article and Find Full Text PDFCryptochromes (CRY) are highly conserved signalling molecules that regulate circadian rhythms and are candidate radical pair based magnetoreceptors. Birds have at least four cryptochromes (CRY1a, CRY1b, CRY2, and CRY4), but few studies have interrogated their function. Here we investigate the expression, localisation and interactome of clCRY2 in the pigeon retina.
View Article and Find Full Text PDFMagnetoreception is the ability to sense the Earth's magnetic field, which is used for orientation and navigation. Behavioural experiments have shown that it is employed by many species across all vertebrate classes; however, our understanding of how magnetic information is processed and integrated within the central nervous system is limited. In this Commentary, we review the progress in birds and rodents, highlighting the role of the vestibular and trigeminal systems as well as that of the hippocampus.
View Article and Find Full Text PDFThe biophysical and molecular mechanisms that enable animals to detect magnetic fields are unknown. It has been proposed that birds have a light-dependent magnetic compass that relies on the formation of radical pairs within cryptochrome molecules. Using spectroscopic methods, we show that pigeon cryptochrome clCRY4 is photoreduced efficiently and forms long-lived spin-correlated radical pairs via a tetrad of tryptophan residues.
View Article and Find Full Text PDFThe transcription factor ZENK is an immediate early gene that has been employed as a surrogate marker to map neuronal activity in the brain. It has been used in a wide variety of species, however, commercially available antibodies have limited immunoreactivity in birds. To address this issue we generated a new mouse monoclonal antibody, 7B7-A3, raised against ZENK from the rock pigeon (Columba livia).
View Article and Find Full Text PDFA diverse array of vertebrate species employs the Earth's magnetic field to assist navigation. Despite compelling behavioral evidence that a magnetic sense exists, the location of the primary sensory cells and the underlying molecular mechanisms remain unknown [1]. To date, most research has focused on a light-dependent radical-pair-based concept and a system that is proposed to rely on biogenic magnetite (FeO) [2, 3].
View Article and Find Full Text PDFA diverse array of species on the planet employ the Earth's magnetic field as a navigational aid. As the majority of these animals are migratory, their utility to interrogate the molecular and cellular basis of the magnetic sense is limited. Vidal-Gadea and colleagues recently argued that the worm possesses a magnetic sense that guides their vertical movement in soil.
View Article and Find Full Text PDFHair cells are specialized sensors located in the inner ear that enable the transduction of sound, motion, and gravity into neuronal impulses. In birds some hair cells contain an iron-rich organelle, the cuticulosome, that has been implicated in the magnetic sense. Here, we exploit histological, transcriptomic, and tomographic methods to investigate the development of cuticulosomes, as well as the molecular and subcellular architecture of cuticulosome positive hair cells.
View Article and Find Full Text PDFEvolution has equipped life on our planet with an array of extraordinary senses, but perhaps the least understood is magnetoreception. Despite compelling behavioral evidence that this sense exists, the cells, molecules, and mechanisms that mediate sensory transduction remain unknown. So how could animals detect magnetic fields? We introduce and discuss 3 concepts that attempt to address this question: (1) a mechanically sensitive magnetite-based magnetoreceptor, (2) a light-sensitive chemical-based mechanism, and (3) electromagnetic induction within accessory structures.
View Article and Find Full Text PDFThe quantification of salivary oxytocin (OXT) concentrations emerges as a helpful tool to assess peripheral OXT secretion at baseline and after various challenges in healthy and clinical populations. Both positive social interactions and stress are known to induce OXT secretion, but the relative influence of either of these triggers is not well delineated. Choir singing is an activity known to improve mood and to induce feelings of social closeness, and may therefore be used to investigate the effects of positive social experiences on OXT system activity.
View Article and Find Full Text PDFTRPV1 is a polymodally activated cation channel acting as key receptor in nociceptive neurons. Its function is strongly affected by kinase-mediated phosphorylation leading to hyperalgesia and allodynia. We present behavioral and molecular data indicating that TRPV1 is strongly modulated by Cdk5-mediated phosphorylation at position threonine-407(mouse)/T406(rat).
View Article and Find Full Text PDFMotor cortex excitability can be measured by single- and paired-pulse transcranial magnetic stimulation (TMS). Repetitive transcranial magnetic stimulation (rTMS) can induce neuroplastic effects in stimulated and in functionally connected cortical regions. Due to its ability to non-invasively modulate cortical activity, rTMS has been investigated for the treatment of various neurological and psychiatric disorders.
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