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Zebrafish are an established and widely utilized developmental genetic model system, but limitations in developed behavioral assays have meant that their potential as a model in behavioral neuroscience has yet to be fully realized. Here, we describe the development of a novel operant behavioral assay to examine a variety of aspects of stimulus control in(More)
The potential of zebrafish as a comparative model in behavioural neuroscience is currently hampered only by the lack of reliable and validated behavioural assays available to researchers. In the present experiment, we describe the performance of zebrafish in a test of attentional set formation. The fish were initially trained on a two-choice colour(More)
In Xenopus tadpoles, all retinal ganglion cells (RGCs) send axons contralaterally across the optic chiasm. At metamorphosis, a subpopulation of EphB-expressing RGCs in the ventrotemporal retina begin to project ipsilaterally. However, when these metamorphic RGCs are grafted into embryos, they project contralaterally, suggesting that the embryonic chiasm(More)
Addiction is a complex psychiatric disorder considered to be a disease of the brain's natural reward reinforcement system. Repeated stimulation of the 'reward' pathway leads to adaptive changes in gene expression and synaptic organization that reinforce drug taking and underlie long-term changes in behaviour. The primitive nature of reward reinforcement(More)
BACKGROUND During somitogenesis, segmental patterns of gene activity provide the instructions by which mesenchymal cells epithelialize and form somites. Various members of the Eph family of transmembrane receptor tyrosine kinases and their Ephrin ligands are expressed in a segmental pattern in the rostral presomitic mesoderm. This pattern establishes a(More)
Abstract We have examined the expression of Eph receptors and their ephrin ligands in adult rat spinal cord before and after lesion. Neurons in adult motor cortex express EphA4 mRNA, but the protein is undetectable in uninjured corticospinal tract. In contrast, after dorsal column hemisection EphA4 protein accumulates in proximal axon stumps. One of the(More)
Due to their well-characterized neural development and high genetic homology to mammals, zebrafish (Danio rerio) have emerged as a powerful model organism in the field of biological psychiatry. Here, we discuss the molecular psychiatry of zebrafish, and its implications for translational neuroscience research and modeling central nervous system (CNS)(More)
Eph receptor tyrosine kinases (RTK) and their ephrin ligands are involved in the transmission of signals which regulate cytoskeletal organisation and cell migration, and are expressed in spatially restricted patterns at discrete phases during embryogenesis. Loss of function mutants of Eph RTK or ephrin genes result in defects in neuronal pathfinding or cell(More)
Spinal cord injury often leads to permanent incapacity because long axons cannot regenerate in the CNS. Eph receptors inhibit axon extension through an effect on the actin cytoskeleton. We have previously reported that after injury EphA4 appears at high levels in stumps of corticospinal axons, while a cognate ligand, ephrinB2, is upregulated at the lesion(More)
The ability to visualise neural circuits in zebrafish in vivo is one of the most useful aspects of this model organism in neuroscience. To maintain the transparency of embryos, however, drugs, such as 1-pheyl-2-thiourea (PTU) must be added, or researchers can use mutants that do not develop pigment (e.g., the casper). The behavioural characteristics of such(More)