David P. Crockett

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The EphA5 receptor tyrosine kinase plays key roles in axon guidance during development. However, the presence of EphA5 protein in the nervous system has not been fully characterized. To examine EphA5 localization better, mutant mice, in which the EphA5 cytoplasmic domain was replaced with beta-galactosidase, were analyzed for both temporal and regional(More)
Dopaminergic (DA) neurons in the substantia nigra (SN) and ventral tegmental area (VTA) of the midbrain project to the dorsolateral caudate/putamen and to the ventromedially located nucleus accumbens, respectively, establishing the mesostriatal and the mesolimbic pathways. Disruptions in this system have been implicated in Parkinson's disease, drug(More)
The A-class of the erythropoietin-producing hepatocellular carcinoma cell-derived (EphA) tyrosine kinase receptors and their ligands, the A-ephrins, play critical roles in the specification of topographic axon projection maps during development. In this study, the role of the EphA subfamily in callosal projections was investigated using transgenic mice(More)
Existing cytochrome oxidase (CO)-staining techniques were modified to enhance sensitivity and contrast in order to examine patterns of CO-activity in the dorsal column nuclei (DCN) of adult Long-Evans rats. Within a rostrocaudally limited region in the middle of the cuneate nucleus (CN) distinctive blotches of intense CO-activity were observed. The(More)
To analyze the patterns of cutaneous primary afferent fibers projecting to the dorsal column nuclei in the rat, horseradish peroxidase (HRP)-based tracers were injected intracutaneously into a number of discrete regions of the forelimbs and hindlimbs. Three-4 days following the HRP injections, the rats were perfused transcardially; 60 microns transverse(More)
Primary afferent projections from cutaneous afferents in the forelimb and hindlimb digits to the dorsal horn (DH) were examined using 4 tracers: (1) 25% free horseradish peroxidase (HRP), (2) 2.5% wheat-germ agglutinin conjugated to horseradish peroxidase (WGA-HRP), (3) a mixture of 25% free HRP and 2.5% WGA-HRP (WGA-HRP/HRP) or (4) 0.1% HRP conjugated to(More)
Recently obtained anatomical evidence supports the division of the rat cuneate nucleus (CN) into three rostrocaudal regions, with the middle region receiving a disproportionately greater share of the primary sensory input. The CN in the rat conforms to the basic rostrocaudal CN pattern described in other mammals, including cat, monkey and raccoon.
The role played by the electric organ discharge (EOD) in eliciting and maintaining social behavior was assessed. First, a description of the motor acts associated with agonistic encounters between resident and intruder Gnathonemus petersii was provided: The temporal distribution of these acts depended on the aggressiveness of the resident. Second, half of(More)
We report on the transient, patterned expression of p75 in the ventrobasal (VB) thalamus, the major thalamic relay for somatosensation. We immunostained the brains of developing rats ranging in age from embryonic day (E) 14.5 to postnatal day (PD) 15 with an antibody against p75. To compare p75 expression with the developing synaptic organization within VB,(More)
Research focused on deciphering the biochemical mechanisms that regulate cell proliferation and function has largely depended on the use of tissue culture methods in which cells are grown on two-dimensional (2D) plastic or glass surfaces. However, the flat surface of the tissue culture plate represents a poor topological approximation of the more complex(More)