radula/serotonin

We observed fibers immunoreactive (IR) to serotonin (5-HT), the myomodulins (MMs), and FMRFamide on the I7-I10 complex in the marine mollusk Aplysia californica. The I7-I10 muscle complex, which produces radula opening, is innervated primarily by one motor neuron, B48. B48 is MM-IR and synthesizes

Ion currents and mechanisms of modulation in the radula opener muscles of Aplysia. J. Neurophysiol. 78: 2372-2387, 1997. Numerous studies of plasticity in the feeding behavior of Aplysia have shown that substantial plasticity is due to peripheral neuromodulation of the feeding musculature. Extensive

The serotonergic metacerebral cells (MCCs) and homologous neurons in related mollusks have been extensively investigated within the context of feeding. Although previous work has indicated that the MCCs exert widespread actions, MCC modulation of sensory neurons has not been identified. We

A major goal of neuroscience is to identify the neural and cellular mechanisms of behavior and its plasticity. Progress toward this goal has come particularly from work with a small number of tractable model preparations. One of these is the simple neuromuscular circuit consisting of the accessory

The neural and cellular mechanisms of plasticity apparent in the feeding behavior of the mollusk Aplysia californica have been extensively studied in a simple neuromuscular circuit consisting of the accessory radula closer (ARC) muscle and its innervating motor and modulatory neurons. In this

The neuropeptide designated SCPB (small cardioactive peptide B), the sequence of which has recently been determined, was found in the accessory radula closer muscle, a muscle involved in biting movements. The ganglia and nerves that innervate the accessory radula closer muscle also contain SCPB. At

Hexamethonium bromide (Hex. Br.) blocks acetylcholine (ACh) elicited contractions but not electrically elicited contractions of isolated preparations of Aplysia californica dorsal extrinsic muscle. Serotonin (5-hydroxytryptamine, 5-HT) enhances both magnitude and relaxation rate of ACh and

Serotonin (10(-8) M) produced opposite long-lasting (up to 10 min) effects on acetylcholine-elicited contractions of different buccal mass muscles of Aplysia. Contractions of the dorsal extrinsic muscle and accessory radula closer muscle were enhanced by serotonin; whereas contractions of the

A detailed biochemical and pharmacological analysis of the dopaminergic (DAergic) and serotonergic (5-HTergic) systems was performed during the embryogenesis of Lymnaea stagnalis, to monitor their role in development and different behaviors. The dopamine (DA) level and the synthesizing decarboxylase

The buccal ganglia of Aplysia contain a central pattern generator (CPG) that mediates rhythmic movements of the buccal apparatus during feeding. Activity in this CPG is believed to be regulated, in part, by extrinsic serotonergic inputs and by an intrinsic and extrinsic system of putative

Serotonergic and peptidergic modulation of buccal muscle contraction at an identified neuromuscular synapse in the African giant snail Achatina fulica was examined. A pair of excitatory motoneurons of the radula protractor was identified in the buccal ganglia and these were named B10 neurons.

Plasticity of Aplysia feeding has largely been measured by noting changes in radula protraction. On the basis of previous work, it has been suggested that peripheral modulation may contribute to behavioral plasticity. However, peripheral plasticity has not been demonstrated in the neuromuscular

Hatching is an important phase of the development of pulmonate gastropods followed by the adult-like extracapsular foraging life. Right before hatching the juveniles start to display a rhythmic radula movement, executed by the buccal complex, consisting of the buccal musculature (mass) and a pair of

When Aplysia are initially exposed to food stimuli, their biting responses show progressive increases in speed and strength. The accessory radula closer (ARC) buccal muscles have been used to study this phenomenon, and it has been shown that changes in ARC muscle contraction are partially due to