NEURAL DEVELOPMENT--INTERCELLULAR AND HUMORAL CONTROL

The three participating research groups share a common interest in
understanding the postembryonic development of neurons, the neural systems
in which they function, and the muscles they control. Growing
collaboration among these groups over the past three years and increasing
mutual focus on the mechanisms that control the developmental plasticity of
nerve and muscle cells have led to the emergence of this new Program
Project. Among the research areas represented by these laboratories are:
the roles and mechanisms of short-distance and contact-mediated
intercellular influences in neural development; hormonally regulated,
postembryonic differentiation and respecification of sensory and motor
neurons and interneurons; ultrastructural and physiological aspects of
synapse formation in developing neural systems; correlation and
coordination of cellular, physiological, and neurochemical events in
neurogenesis; the role of glial cells in the development of organized
neuropil in the central nervous system; and developmental, physiological,
anatomical, and molecular studies of olfactory, visual, mechanosensory, and
motor systems. The participants propose to mount multidisciplinary, highly
collaborative investigations of mechanisms underlying hormonal and trans-
cellular regulation of the survival and development of nerve cells and
muscles during postembryonic life. The five component projects in this
program project probe for cellular and physiological mechanisms of: (1)
influences of primary-sensory neurons, glial cells, and development-
regulating hormones and neurotransmitters ont he development of
arborizations and voltage- and ligand-gated membrane ion channels in
olfactory interneurons in primary cell culture; (2) steroid-hormonal
regulation of development of identified motor neurons in primary cell
culture; (3) influences of steroid hormones on cellular, neurochemical, and
systemic characteristics of the first-order olfactory center in the brain.
All of the proposed studies are based on the use of non-vertebrate model
systems that are economical, readily available, and experimentally
tractable. Because they have been extensively studied by many
investigators, including the participants in this program project, the
insect preparations to be used in the proposed studies are especially well
understood and favorable for these project, the insect preparations to be
used in the proposed studies are especially well understood and favorable
for these experiments. Taking advantage of this background, the component
projects focus on neurons and glial cells that are identifiable as
individuals or as specific functional types from animal. The basic
mechanisms of development have been conserved during evolution. We expect,
therefore, that information obtained in these projects about neural and
muscular development in insects will illuminate related phenomena in other
animals including human beings.