Central projections of the stretch receptor neurons of crayfish: structure, variation, and postembryonic growth

Journal ArticleEach stretch receptor neuron (SR) of the crayfish abdomen projects from its peripherally located soma an axon that enters the CNS through the second nerve (N2) of its segmental ganglion. CoZ+ backfills of N2 revealed that this axon bifurcates, sending one branch to the brain and the other to the terminal abdominal ganglion

Developmental expression and biochemical analysis of Conulin, a protein secreted from a subset of neuronal growth cones

Journal ArticleIn this report, we analyze the developmental pattern of expression of a new grasshopper protein, Conulin, using the monoclonal antibody 7D2 on whole-mount embryos and dissociated neurons. We also have examined its biochemical properties by immunoblot analysis. Conulin is a protein expressed by a subset of neurons in the grasshopper embryo

Central projections of the stretch receptor neurons of crayfish: segmental gradients of synaptic probability and strength

Journal ArticleThe 20 stretch receptor neurons (SRs) of the crayfish abdomen send axons into the CNS that then project both to the brain and to the last abdominal ganglion, G6 (Bastiani and Mulloney, 1988). In G6, we recorded intracellularly from different kinds of neurons postsynaptic to SR axons

Guidance of neuronal growth cones: selective fasciculation in the grasshopper embryo

Journal ArticleOne of the central questions of developmental neurobiology concerns how the diversity and specificity of individual neurons are generated during embryonic development. One major component of neuronal diversity is the complex axonal morphology of individual neurons, largely generated early in development and intimately involved in the ability of neurons to find their correct synaptic targets

Pathfinding by growth cones in the central nervous system of the grasshopper embryo

Journal ArticleIn the grasshopper embryo the morphological development of individually identified neurons can be traced prior to the onset of axonogenesis on through maturity (eg., Goodman and Spitzer, 1979). The behavior of individual growth cones can be characterized in their natural environment as they extend towards their targets

Guidance of neuronal growth cones in the grasshopper embryo. II. Recognition of a specific axonal pathway by the aCC neuron

Journal ArticleIn the previous paper, we experimentally analyzed the selective affinity of the pCC growth cone for the MP1/dMP2 fascicle in the grasshopper embryo. Here we describe a similar experimental analysis demonstrating the selective affinity of the aCC growth cone for the U fascicle. These results support the labeled-pathways hypothesis

Pathfinding by neuronal growth cones in grasshopper embryos I. Divergent choices made by the growth cones of sibling neurons

Journal ArticleWe are interested in how the growth cones of identified neurons navigate in the central nervous system of the grasshopper embryo. The behavior of identified growth cones was observed as a function of developmental time by (i) periodically removing embryos from synchronized clutches of eggs and (ii) filling identified neurons in the central nervous system with the fluorescent dye Lucifer Yellow

Cell-cell interactions during the migration of an identified commissural growth cone in the embryonic grasshopper

Journal ArticleOne of the fascicles of the posterior commissure of the embryonic grasshopper is pioneered by an individually identifiable neuron named Q1. Q1 initially grows along a longitudinal pathway established by another pioneer neuron, MPl, and then crosses to the midline, where it meets and fasciculates with the axon of the contralateral Q1

Targeted mutagenesis by homologous recombination in D. melanogaster

Journal ArticleWe used a recently developed method to produce mutant alleles of five endogenous Drosophila genes, including the homolog of the p53 tumor suppressor. Transgenic expression of the FLP site-specific recombinase and the I-SceI endonuclease generates extrachromosomal linear DNA molecules in vivo

Pathfinding by neuronal growth cones in grasshopper embryo: III. Selective affinity of the G growth cone for the P cells within the A/P fascicle

Journal ArticleThe growth cone of the G neuron selectively fasciculates upon specific axon bundles in a stereotypic sequence as it navigates through the developing central nervous system of the grasshopper embryo. It turns and extends anteriorly in the contralateral neuropil of the second thoracic ganglion at a specific choice point where it fasciculates with the A/P axon bundle which contains the axons of the A1, A2, P1, and P2 neurons