|Chiton Integument: Development of Sensory Organs in Juvenile Mopalia muscosa
||The girdle epidermis of adult Mopalia muscosa secretes several types of structures, including calcareous spicules and innervated hairs. Newly metamorphosed chitons superficially resemble adult animals, but they lack the adult girdle ornaments, shell ...
|Chiton integument: Metamorphic changes in <i>Mopalia muscosa</i> (Mollusca, Polyplacophora)
||The larval integument and juvenile girdle integument of Mopalia muscosa (Mollusca: Polyplacophora) were studied by light microscopy. Within 24 h of settlement, eight distinctive changes occur that characterize metamorphosis: loss of the functional pr...
|Chiton integument: Ultrastructure of the sensory hairs of <i>Mopalia muscosa</i> (Mollusca: Polyplacophora)
||The dorsal integument of the girdle of the chiton Mopalia muscosa is covered by a chitinous cuticle about 0.1 mm in thickness. Within the cuticle are fusiform spicules composed of a central mass of pigment granules surrounded by a layer of calcium ca...
|Diatom cultures exhibit differential effects on larval metamorphosis in the marine gastropod Ilyanassa obsoleta (Say)
||Adult Ilyanassa obsoleta recruit from the plankton to surface sediments of intertidal mudflats along the U.S. East Coast as a result of metamorphic induction of planktonic larvae by environmental cues. A previous researcher discovered that seawater e...
|Evolutionary trends in invertebrate ganglionic structure
||Early Bilateria developed the basic characteristics of ganglionic organization. Features such as the divergence of longitudinal axon bundles into functionally unique tracts, the separation of centers for motor pattern generation and exteroceptive sen...
|Functional Organization of Crayfish Abdominal Ganglia: I. The Flexor Systems
||For insect ganglia, Altman (Advances in Physiological Science, Vol. 23. Neurobiology of Invertebrates. New York: Pergamon Press, pp. 537-555, '81) proposed that individual neuropils control different motor activities. A corollary of this hypothesis i...
|Functional Organization of Crayfish Abdominal Ganglia: II. Sensory Afferents and Extensor Motor Neurons
||Abdominal ganglia of crayfish contain identifiable neuropils, commissures, longitudinal tracts, and vertical tracts. To determine the functional significance of this ganglionic framework, we backfilled the following types of neurons with cobalt chlor...
|Gangliogenesis in the Prosobranch Gastropod Ilyanassa obsoleta
||We determined that the larval nervous system of Ilyanassa obsoleta contains paired cerebral, pleural, pedal, buccal, and intestinal ganglia and unpaired apical, osphradial, and visceral ganglia. We used a modified form of NADPH diaphorase histochemis...
|An Inducer of Molluscan Metamorphosis Transforms Activity Patterns in a Larval Nervous System
|| Larvae of the nudibranch mollusc Phestilla sibogae metamorphose in response to a small organic com-pound released into seawater by their adult prey, the scleractinian coral Porites compressa. The transformations that occur during metamorphosis, incl...
|Induction of Metamorphosis Decreases Nitric Oxide Synthase Gene Expression in Larvae of the Marine
||Many marine organisms spend the early part of their lives as larvae suspended in the water column before metamorphosing into benthic reproductive adults. Metamorphosis does not occur until a larva has become competent to respond to appropriate stimul...
|Induction of metamorphosis in the marine gastropod, Ilyanassa obsoleta: 5HT, NO and Programmed Cell Death.
||The central nervous system (CNS) of a metamorphically competent larva of the caenogastropod Ilyanassa obsoleta contains a medial, unpaired apical ganglion (AG) of approximately 25 neurons that lies above the commissure connecting the paired ce...
|Localization of nitric oxide synthase-like immunoreactivity in the developing nervous system of the snail Ilyanassa obsoleta
|| Production of nitric oxide (NO), an evolutionarily conserved, intercellular signaling molecule, appears to be required for the maintenance of the larval state in the gastropod mollusc Ilyanassa obsoleta. Pharmacological inactivation of endogenous ni...
|Metamorphosis in the marine snail Ilyanassa obsoleta, yes or NO?
||Metamorphosis is a crucial life-history event that can change an organism's form, function, behavior, and ecological interactions. In the Mollusca, several neurotransmitters and neuromodulators play inductive or inhibitory roles in the pathways that ...
|Modeling excitable systems: Reentrant Tachycardia.
Many physics majors are unaware of the important role that physicists play in medical research. Typical coursework for a physics major is removed from real-world applications, especially compared to what they perceive for their premedi...
|Modular construction of nervous systems: a basic principle of design for invertebrates and vertebrates
||As evidenced by the proliferation of papers in the last 30 years it is now well accepted that an iterative columnar or modular organization of the neocortex is characteristic of mammalian sensory, motor and frontal association areas. This does not im...
|NADPH-Diaphorase Activity Changes During Gangliogenesis and Metamorphosis in the Gastropod Mollusc Ilyanassa obsoleta
||Gaseous nitric oxide (NO) is produced through the action of the enzyme nitric oxide synthase (NOS) and acts as a neurotransmitter (Jacklet and Gruhn, 1994b; Elphick et al., 1995a; Jacklet, 1995) in the nervous systems of adult gastropod molluscs. By ...
|Neurotransmitters, Benthic Diatoms and Metamorphosis in a Marine Snail
||Many marine snails have a biphasic life cycle. They may live in diverse habitats on the ocean floor as adults, but are planktonic in the larval phase where they are subject to oceanic tides and currents. The link between these two disparate life hist...
|On Feeding Mechanisms and Clearance Rates of Molluscan Veligers
||The teeth of a mammal or the mouthparts of a copepod can tell a knowledgeable biologist much about that animal's feeding habits. Deductions based on the structure of ciliary bands can be at least as useful. This study is part of a larger effort to re...
|The Osmium-Ethyl Gallate Procedure is Superior to Silver Impregnations for Mapping Neuronal Pathways
||Ganglia processed through the osmium-ethyl gallate procedure (OEG)19 retain more structural integrity than those processed through various silver impregnation methods. However, the OEG method continues to be neglected by most neuroanatomis...
|Postsynaptic Modulation of Rectifying Electrical Synaptic Inputs to the LG Escape Command Neuron in Crayfish
||The lateral giant (LG) tail-flip escape system of crayfish is organized to provide a massive convergence of mechanosensory inputs onto the LG command neuron through electrical synapses from both mechanosensory afferents and interneurons. We used elec...
|Programmed Cell Death in the Apical Ganglion During Larval Metamorphosis of the Marine Mollusc <i>Ilyanassa obsoleta</i>
||The apical ganglion (AG) of larval caenogastropods, such as Ilyanassa obsoleta, houses a sensory organ, contains five serotonergic neurons, innervates the muscular and ciliary components of the velum, and sends neurites into a neuropil that li...
|Selective Retention of the Fluorescent Dye DASPEI in a Larval Gastropod Mollusc After Paraformaldehyde Fixation
||In the vertebrates, the vital mitochondrial dye DASPEI (2-(4-dimethylaminostyryl)-N-ethylpyridinium iodide) has been used for the rapid visualization of several distinct classes of epidermal cells in vivo and in vitro: epidermal electroreceptors, mec...
|Sensory Organs in the Hairy Girdles of Some Mopaliid Chitons
|| The polyplacophoran mantle secretes the shell plates, houses the gills in the pallial grooves, and forms a muscular perinotum or girdle that encircles the shell and viscera. The epidermis of this girdle occurs as papillae of columnar cells dispersed...
|Serotonin and Nitric Oxide Regulate Metamorphosis in the Marine Snail Ilyanassa obsoleta
||Several neuroactive compounds have been implicated as playing roles in the circuitry that controls larval metamorphosis in marine molluscs. For the caenogastropod Ilyanassa obsoleta, results of neuroanatomical studies suggest that the production of n...
|Serotonin Injections Induce Metamorphosis in Larvae of the Gastropod Mollusc Ilyanassa obsoleta
||Bath-applied serotonin (5-HT) induces competent larvae of the marine snail Ilyanassa obsoleta to metamorphose. Previously, the mode of action of 5-HT, whether as an external ligand or as an internal neurotransmitter, was unknown. Larvae were injected...