radula/ganglion cysts

The buccal ganglion of Aplysia contains a heterogeneous population of peptidergic, radula mechanoafferent (RM) neurons. To investigate their function, two of the larger RM cells (B21, B22) were identified by morphological and electrophysiological criteria. Both are low-threshold, rapidly adapting,

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

1. We have studied the neural circuitry mediating ingestion and rejection in Aplysia using a reduced preparation that produces ingestion-like and rejection-like motor patterns in response to physiological stimuli. 2. We have characterized 3 buccal ganglion motor neurons that produce specific

1. Recently a cluster of sensory neurons (peptidergic radula mechanoafferents) has been identified in the buccal ganglion of Aplysia that is likely to play an important role in influencing the activity of feeding motor programs. All of the neurons of this cluster, which includes the identified cells

Acetone extract of the ganglia of Fusinus ferrugineus was applied to C-18 cartridges, and the flowthrough and retained materials were bioassayed on the radula retractor muscle of the animal. The flowthrough was found to have a potent contractile action and the retained material a potent

Rhythmic activities of two feeding structures of the pteropod mollusk Clione limacina, redula and hooks, controlled by the neural networks in the buccal ganglia must be coordinated in order to produce a meaningful feeding response. Optical recording from the buccal ganglia, which allows the

Rhythmic activity in two independent structures of the digestive apparatus of Clione limacina--the radula and the hooks--is coordinated by neural networks in the buccal ganglion during feeding behavior. Optical recording of neuron activity in the buccal ganglion, which allows simultaneous recording

Complex behaviors often require coordinated movements of dissimilar motor structures. The underlying neural mechanisms are poorly understood. We investigated cycle-by-cycle coordination of two dissimilar feeding structures in Aplysia californica: the external lips and the internal radula. During

The cellular and synaptic morphology of a component of the feeding motor circuit in Aplysia californica was examined with light and electron microscopic techniques. The circuit consists of a pair of inhibitory premotor interneurons, B4 and B5, as well as two motoneurons, B15 and B16, which innervate

The buccal ganglion of Aplysia contains a central pattern generator (CPG) that organizes sequences of radula protraction and retraction during food ingestion and egestion. Neurons B63 and B34 have access to, or are elements of, the CPG. Both neurons are depolarized along with B31/B32 during the

The head ganglia from 350 Aplysia brasiliana were extracted and purified by gel (Sephadex G-15) and cation exchange (CM-Sephadex) chromatography; the fractions were examined with radioimmunoassays (RIA) for the molluscan neuropeptides, FMRFamide and SCPB. Immunoreactive (ir-) FMRFamide (but not

We have used intracellular recording from groups of interneurons in the feeding system of the pond snail, Lymnaea stagnalis, to examine the connections of a modulatory interneuron, the slow oscillator (SO), with the network of pattern-generating interneurons (N1, N2, and N3). The SO is an

Previous studies have shown that each buccal ganglion in Aplysia contains two B52 neurons, one in each hemiganglion. We now show that there are two B52 neurons in a single buccal hemiganglion and four cells in an animal. We also show that the B52 neurons are histamine-immunoreactive and use reverse

We have photoinactivated identified feeding interneurons known as N1 and N2 neurons. These are pattern-generating neurons that are active in the protraction of the radula and rasping phases, respectively, of the feeding cycle of the pond snail. The N1 or N2 feeding interneurons in the buccal ganglia

FMRFamide immunoreactivity was detected in all regions of the Limulus nervous system, including the brain (6.5 +/- 0.6 pg FMRFamide/mg), cardiac ganglion (2.06 +/- 0.67 pg FMRFamide/mg), and ventral nerve cord (5.8 +/- 0.7 pg FMRFamide/mg). The distribution of immunoreactive FMRFamide (irFMRFamide)