Neural control of circulation in Aplysia. III. Neurotransmitters

1975 ◽  
Vol 38 (4) ◽  
pp. 767-779 ◽  
Author(s):  
G. Liebeswar ◽  
J. E. Goldman ◽  
J. Koester ◽  
E. Mayeri
Keyword(s):  
Cell Body ◽  
Neural Control ◽  
Aplysia Californica ◽  
Heart Beat ◽  
Abdominal Ganglion ◽  
Vasomotor Tone ◽  
Aortic Constriction ◽  
Chronotropic Effects ◽  
Inhibitory Motoneuron ◽  
Motor Effects

In the abdominal ganglion of Aplysia californica, seven motoneurons have been described which modulate the myogenic heart beat and vasomotor tone (28). These neurons mediate their motor effects by chemical transmission. In this paper we have attempted to specify the transmitters of six of these motoneurons. We have 1) studied the effects of several common transmitters on the innervated structures and compared these effects with the effects of firing the motoneurons, 2) examined whether blocking agents influence similarly the effect of a putative transmitter applied to the innervated structure and the effect of firing a motoneuron, and 3) tested the capability of the motoneurons to synthesize the putative transmitters from precursors. The positive inotropic and chronotropic effects of firing the excitor motoneuron RB(HE) were mimicked by perfusion of the heart with serotonin at a low concentration. Cinanserin blocked both the effects of motoneuron excitation and serotonin perfusion. RB(HE) was also shown to synthesize [3H]serotonin from L-[3H]tryptophan injected directly into the cell body. The effects of firing the two LD(HI) heart-inhibitory motoneurons were mimicked by perfusion of the heart with acetylcholine. Benzoquinonium blocked the effects of the inhibitory motoneuron and acetylcholine perfusion. Perfusion with arecoline also inhibited the heart beat. Acetylcholine applied to the arteries mimicked the vasoconstriction caused by the LB(VC) motoneurons. Aortic constriction in response to activity in LB(VC) cells or to acetylcholine was blocked by hexamethonium and curare. The heart inhibitor and vasoconstrictor motoneurons synthesized [3H] acetylcholine from [3H] choline injected into their cell bodies. Thus, as in vertebrates, acetylcholine mediates inhibition to the heart. Unlike vertebrates, however, serotonin mediates excitation to the heart and acetylcholine mediates peripheral vasoconstriction.

The role of support cells in the growth and differentiation of neurones in the abdominal ganglion of Aplysia

1981 ◽  
Vol 95 (1) ◽  
pp. 205-214
Author(s):  
S. M. Schacher
Keyword(s):  
Cell Body ◽  
Synapse Formation ◽  
Sea Water ◽  
Secretory Granules ◽  
Body Growth ◽  
Abdominal Ganglion ◽  
Morphological Properties ◽  
High Concentration ◽  
Premature Release

During the late premetamorphic stages of development, the abdominal ganglion of Aplysia is surrounded by a group of support cells which later develop morphological properties characteristic of glial cells. These support cells contain large secretory granules whose contents are released primarily after the onset of the metamorphic phase. The release of the granule contents may signal the burst of neuronal growth and maturation that occurs following metamorphosis. The evidence supporting this idea is the following: (1) The release of the granule material after the onset of metamorphosis coincides with an increase in cell body growth and a more marked increase in the density of synapses within the neuropil. Both release and neuronal maturation can be blocked when metamorphosis is postponed by withholding the appropriate macroalgal substrate. (2) Premature release of the granule contents 2-3 weeks before metamorphosis with artificial sea water containing a high concentration of potassium results in an increase in cell body growth, density of synapses, and the number of spines formed and contacts received by specific identified cells. (3) Artificially inducing the release of the granule material in animals whose metamorphosis has been prevented (by withholding the appropriate substrate) still produces an increase in cell body growth and density of synapses. These results suggest that the release of material from support cell granules provides a general stimulus for neuronal differentiation including cell body growth, spine development, and synapse formation.

Kinematic models of the buccal mass of Aplysia californica.

1998 ◽  
Vol 201 (10) ◽  
pp. 1563-1583 ◽  
Author(s):  
R F Drushel ◽  
D M Neustadter ◽  
I Hurwitz ◽  
P E Crago ◽  
H J Chiel
Keyword(s):  
Neural Control ◽  
Kinematic Model ◽  
Aplysia Californica ◽  
Relative Location ◽  
Marine Mollusc ◽  
Buccal Mass ◽  
Kinematic Models ◽  
Made In

The feeding behavior of the marine mollusc Aplysia californica is an intensively studied model system for understanding the neural control of behavior. Feeding movements are generated by contractions of the muscles of the buccal mass. These muscles are internal and cannot be visualized during behavior. In order to infer the movements of the muscles of the buccal mass, two kinematic models were constructed. The first kinematic model assumed that the complex consisting of the pincer-like radula and the underlying odontophore was spherical in shape. In this model, the radula/odontophore was moved anteriorly or posteriorly and the more superficial buccal muscles (I1/I3 and I2) were fitted around it. Although the overall buccal mass shapes predicted by this model were similar to those observed in vivo during protraction, the shapes predicted during retraction were very different. We therefore constructed a second kinematic model in which the shape of the radula/odontophore was based on the shapes assumed by those structures in vitro when they were passively forced into protraction, rest or retraction positions. As each of these shapes was rotated, the second kinematic model generated overall shapes of the buccal mass that were similar to those observed in vivo during swallowing and tearing, and made predictions about the antero-posterior length of the buccal mass and the relative location of the lateral groove. These predictions were consistent with observations made in vivo and in vitro. The kinematic patterns of intrinsic buccal muscles I1 and I2 in vivo were estimated using the second model. Both models make testable predictions with regard to the functions and neural control of intrinsic buccal muscles I2 and I3.

The time-dependent diffusivity in the abdominal ganglion of Aplysia californica: experiments and simulations

2019 ◽  
Vol 5 (4) ◽  
pp. 045036
Author(s):  
Khieu-Van Nguyen ◽  
Denis Le Bihan ◽  
Luisa Ciobanu ◽  
Jing-Rebecca Li
Keyword(s):  
Aplysia Californica ◽  
Abdominal Ganglion ◽  
Time Dependent

MORPHOLOGICAL AND FUNCTIONAL PROPERTIES OF IDENTIFIED NEURONS IN THE ABDOMINAL GANGLION OF APLYSIA CALIFORNICA

1967 ◽  
Vol 30 (6) ◽  
pp. 1288-1351 ◽  
Author(s):  
Wesley T. Frazier ◽  
Eric R. Kandel ◽  
Irving Kupfermann ◽  
Rafiq Waziri ◽  
Richard E. Coggeshall
Keyword(s):  
Functional Properties ◽  
Aplysia Californica ◽  
Abdominal Ganglion ◽  
Identified Neurons

scholarly journals AXONAL TRANSPORT OF NEWLY SYNTHESIZED GLYCOPROTEINS IN A SINGLE IDENTIFIED NEURON OF APLYSIA CALIFORNICA

1974 ◽  
Vol 61 (3) ◽  
pp. 665-675 ◽  
Author(s):  
Richard T. Ambron ◽  
James E. Goldman ◽  
James H. Schwartz
Keyword(s):  
Axonal Transport ◽  
Cell Body ◽  
Aplysia Californica ◽  
Identified Neuron ◽  
The Right ◽  
Aplysia Neuron

Increasing amounts of glycoprotein synthesized from L-[3H]fucose injected into the cell body of R2, an identified Aplysia neuron, were found in the right pleuro-abdominal connective. Autoradiography revealed that the glycoproteins were localized in the axon of R2. Glycoproteins appearing in the axon presumably were synthesized in the cell body, since no significant incorporation was observed when [3H]fucose was injected directly into the axon. [3H]glycoproteins were detected in the connective after a delay of 1 h after intrasomatic injection. Thereafter, transport from the cell body was rapid, and by 10 h after injection, 45% of the total neuronal [3H]glycoprotein had appeared in the axon. By analysing the radioactivity in cell body and connective 4, 10, and 15 h after injection, we found that [3H]glycoproteins were transported selectively compared to nonmacromolecular material. Sequential sectioning of the connective revealed that [3H]glycoproteins were transported in discrete waves. The population of membrane-associated [3H]glycoproteins in the axon differed from that in the cell body. Two of the five somatic components appeared to be transported preferentially. In addition a new component appeared in the axon 10 h after injection.

Development of neurons in the abdominal ganglion of Aplysia californica

1979 ◽  
Vol 71 (1) ◽  
pp. 176-190 ◽  
Author(s):  
Samuel Schacher ◽  
Eric R. Kandel ◽  
Robert Woolley
Keyword(s):  
Aplysia Californica ◽  
Abdominal Ganglion
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