The puzzle of how complex nervous systems emerged remains unsolved. Comparative
studies of neurodevelopment in cnidarians and bilaterians suggest that this process began …

Surprisingly little is known about the nature and function of neurohormones in molluscs
despite the fact that many of the neurotransmitters, including serotonin, catecholamines and …

Background Invertebrate nervous systems are highly disparate between different taxa. This
is reflected in the terminology used to describe them, which is very rich and often confusing …

The use of polymerase chain reaction (PCR) to generate large amounts of a desired product
can be a double-edged sword. Failure to amplify under optimum conditions can lead to the …

The littorinimorph gastropod Crepidula fornicata shows a spiralian cleavage pattern and has
been the subject of studies in experimental embryology, cell lineage, and the organization of …

Ctenophores are non-bilaterian animals sharing with cnidarians and bilaterians the
presence of sensory receptors, nerve cells, and synapses, absent in placozoans and …

Morphology, the description and analysis of organismal form, is one of the oldest biological
disciplines that has significantly contributed to our understanding as to how animals function …

Highlights•The two signalling systems that pattern the bilaterian forebrain evolved on
opposite body sides.•These systems initially specified two spatially separate condensations …

Abstract Background The polychaete annelid Capitella teleta (formerly Capitella sp. I)
develops by spiral cleavage and has been the focus of several recent developmental …

The embryology of sipunculans, entoprocts, nemertines, platyhelminths (excluding
acoelomorphs), rotifers, ectoprocts, phoronids, brachiopods, echinoderms and …