show changes in dendritic spine properties including spine size and density using the same techniques time lapse studies in the brains of living animals have shown that spines come and go with the larger mushroom spines being the most stable over time several proteins are markers for dendritic spine formation spinophilin for example is highly enriched in dendritic spines and has been shown to regulate the formation and function of dendritic spines elav proteins are one of the earliest markers of neuronal differentiation elav proteins are generally involved in the post transcriptional regulation of gene expression specimens of hermissenda crassicornis were maintained in artificial sea water asw at 15 u00b0 for three days in perforated 50 ml conical centrifuge tubes before starting experiments bryostatin purified from the marine bryozoan bugula neritina was dissolved in etoh and diluted to its final concentration in asw animals were incubated with bryostatin in asw for 4 hr then rinsed with normal asw for selected experiments lactacysteine 10 u03bcm or anisomycin was added to the asw bryostatin effects on hermissenda behavior and biochemistry were produced by adding the drug to the bathing medium within an 8 cm long 1 cm diameter test tube housing each individual animal following experimental treatments and testing animals were rapidly decapitated the central nervous systems cns removed and then fixed in 4 para formaldehyde in 20 mm tris buffered ph 8 natural seawater nsw 0 2 u03bcm micropore filtered the cnss were then.