Although central pattern generators (CPGs) can produce rhythmic activity in isolation, it is now generally accepted that under physiological conditions information from the external and internal environment is incorporated into CPG-induced motor programs. Experimentally advantageous invertebrate preparations may be particularly useful for studies that seek to characterize the cellular mechanism...

Coordination of two sets of movements, protraction-retraction versus opening-closing, of the feeding apparatus (the radula) in ingestive and egestive motor programs of Aplysia resembles vertebrate intralimb coordination in that the relative timing of the two sets of movements differs in the two motor programs. In both ingestion and egestion, radula protraction and retraction alternate, whereas ...

Aplysia feeding is striking in that it is executed with a great deal of plasticity. At least in part, this flexibility is a result of the organization of the feeding neural network. To illustrate this, we primarily discuss motor programs triggered via stimulation of the command-like cerebral-buccal interneuron 2 (CBI-2). CBI-2 is interesting in that it can generate motor programs that serve opp...

The rostral cluster of SCP-immunoreactive cells, originally identified in each buccal hemiganglion of juvenile Aplysia, was examined in mature specimens. Immunohistochemical and dye-fill experiments showed that each rostral cluster consists of approximately 40 cells. Although these neurons exhibit heterogeneity of size and shape, all cells project an axon into the radula nerve. Tracing of dye-f...

The Aplysia multifunctional feeding central pattern generator (CPG) produces at least two types of motor programs, ingestion and egestion, that involve two sets of radula movements, protraction-retraction and opening-closing movements. In ingestion, the radula closes during retraction to pull food in, whereas in egestion, the radula closes during protraction to push inedible objects out. Thus, ...

Limpets are a class of marine mollusks that use mineralized teeth, one the hardest and strongest biological materials, to feed on algae rocks. By combining proteomics RNA-seq analysis limpet radula, we identified novel chitin-binding protein (CtCBP-1) may play regulatory role in radula mineralization Cellana toreuma . In this study, full-length cDNA CtCBP-1 gene was cloned for first time, succe...

When first secreted the radula consists of chitin and protein. In the bases and cusps of the teeth the reactions for tyrosine, tryptophane, and chitin become negative, and are replaced by reactions for amino groups and argentaffin material. The bases of the teeth become impregnated with iron. Subsequently the reactions for amino groups and argentaffin material become negative in the cusps and t...

The present paper describes a new record of Morula anaxares (Kiener 1835) (Muricidae) from Goa, Central West coast of India aided by spiral cord ontogeny, aperture morphology of shell and SEM of radula. This species was previously reported from Andaman, Nicobar, Lakshadweep and Madras coasts. In addition, detailed structures of radula of other three species namely Orania subnodulosa (Melvill 18...

A manipulation often used to determine whether a neuron plays a role in the generation of a motor program involves injecting current into the cell during rhythmic activity to determine whether activity is modified. We perform this type of manipulation to study the impact of afferent activity on feeding-like motor programs in Aplysia. We trigger biting-like programs and manipulate sensory neuron...