Given the functional implications of our previous work, we designed experiments aimed at global inhibition of myosin activity to test whether any myosin was in fact involved in driving retrograde F-actin flow in growth cones
. All known myosins have an evolutionarily conserved N-terminal head domain containing the site for ATP and F-actin binding as well as force generation (Mooseker and Cheney, 1995).
Several properties of this compound - its high affinity for [Ca.sup.2+] (6), the approximately 10,000-fold decrease in its affinity for [Ca.sup.2+] upon photolysis (6), its weak fluorescence (6), and its persistence and low toxicity in the teleost embryo (this study) - appear to make it particularly suitable for studying events that have been linked to elevations in cytosolic [[Ca.sup.2+]]: egg activation (12, 13), ooplasmic segregation (9, 10), nuclear envelope breakdown (14), mitosis (15, 16, 17), cytokinesis (8, 18), and neuronal growth cone
motility (19, 20).
Kater, "Role of intracellular calcium in NI-35-evoked collapse of neuronal growth cones
," Science, vol.
To maintain synaptic balance, both ROCK1 and 2 transduce signals to retract the growth cones
and dendritic spines (for review see ).
These phases of neuromuscular synapse formation are known to involve the elevation of resting calcium, voltage-activated calcium influx, and neurotransmitter release following contact of growth cones
with muscle targets (Zoran et al, 1993; Funte and Haydon, 1993; Zoran and Poyer, 1996).
Actin-binding proteins in nerve cell growth cones
. J Pharmacol Sci 2007; 105(1):6-11.
Forscher, "Myosin II functions in actin-bundle turnover in neuronal growth cones
," Nature Cell Biology, vol.
(44) Conversely, overexpression of MLK-1 improves the frequency and timing of growth cone
formation, as well as the rate of successful migration of growth cones
to their target sites.
were fine, appeared delicate structures and had fine filopodial-like processes (Fig.
Neurons synthesize and transport MMPs to their growth cones
, where they are released and inactivate CSPG (49, 91, 159, 176, 184, 185).
Typically, pioneering axons have larger growth cones
to guide themselves to their targets.
Because activated FAK is important in cell adhesion, we hope to observe active FAK located within the neurite extensions, primarily in the growth cones
, where it would be important in regulating neurite adhesion and projection.