ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Electronic Resource

Multimodal motor-innervation of the gill of the aplysiid gastropods,Aplysia kurodai andAplysia Juliana (1985)

Kurokawa, Makoto ; Kuwasawa, Kiyoaki

Springer

Journal of comparative physiology 157 (1985), S. 483-489

add to mindlist on the mindlist

Details

ISSN: 1432-1351

Source: Springer Online Journal Archives 1860-2000

Topics: Biology , Medicine

Notes: Summary 1. Electrophysiological methods were used to study the neural mechanisms of both centrally and peripherally induced gill movements in two species ofAplysia. 2. Excitatory junctional potentials (EJPs), recorded from pinnule muscle, corresponded one-to-one to impulses in the branchio-ganglionic neurons (BGNs) with a constant latency. This may confirm that the branchial ganglion contains motor neurons for the gill. 3. Longitudinal shortening of the gill evoked by branchial nerve stimulation was only slightly affected when the branchial ganglion was perfused with high Mg2+ saline. This may show that the branchial nerve contains a motor pathway passing through the branchial ganglion, which extends directly to the gill musculature. 4. Pinnule contraction evoked by branchial nerve stimulation was blocked by perfusing the branchial ganglion with high Mg2+ saline. This shows that the contraction was mediated by BGNs. 5. A neuron was identified in the abdominal ganglion, which induced both the pinnule contraction and the longitudinal shortening. 6. The same identified neuron also elicited EPSPs in BGNs. The pinnule contraction was prevented by blockage of the EPSPs in BGNs with high Mg2+ saline, but the longitudinal shortening was not. 7. These results may show that the identified neuron has dual functions, serving both as an interneuron to activate the BGNs which excite the pinnule contractions and also as a motor neuron to produce the longitudinal gill shortening.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00615149

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

2

Electronic Resource

Electrophysiological studies on the branchial ganglion in the opisthobranch molluscs (Aplysia andDolabella) (1985)

Kurokawa, Makoto ; Kuwasawa, Kiyoaki

Springer

Journal of comparative physiology 156 (1985), S. 35-44

add to mindlist on the mindlist

Details

ISSN: 1432-1351

Source: Springer Online Journal Archives 1860-2000

Topics: Biology , Medicine

Notes: Summary 1. The branchial ganglion of the gills ofAplysia kurodai, A. juliana andDolabella auricularia were investigated, using electrophysiological techniques. 2. The branchio-ganglionic neurons (BGNs) generated spontaneous tonic impulses with superimposed pacemaker potentials and mainly periodic bursting impulses superimposed on slow sustained depolarizing potentials. 3. BGNs were synchronously active, coupled one to another through bidirectional electrical synapses. 4. Electrical stimulation of the branchial nerve elicited excitatory postsynaptic potentials (EPSPs), in BGNs, which showed facilitation and summation and were blocked with high Mg2+ sea water, indicating that the EPSPs were chemically mediated. 5. Electrical stimulation of a nerve extending posterior to the ganglion also produced EPSPs in BGNs. These EPSPs showed summation (but not facilitation), and were blocked with high Mg2+ sea water, indicating that the EPSPs were chemically mediated. 6. Tactile stimulation to the pinnule exerted excitatory transmission of EPSPs which caused BGNs to fire a burst of impulses, and resulting in a reflexive pinnule contraction. 7. Electrical stimulation applied to a nerve of the branchial ganglion produced inhibitory postsynaptic potentials (IPSPs) which showed summation and had a reversal potential at a level slightly higher than the resting membrane potential. The inhibitory transmission seems to be from the mechanoproprioceptor in the gill, since it was elicited by a spontaneous gill contraction or by perfusion of the branchial vasculature with sea water. 8. When either spontaneous bursts of the BGNs occurred, or bursts of BGNs were induced by intracellular current application, EJPs were evoked in the pinnule muscle. Thus, the peripheral nervous system including the branchial ganglion may contain motor neurons of the pinnule muscle. 9. The branchial ganglion had functions of the peripheral reflex center and the distributing center of central motor influence to the branchial muscle.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00610664

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

3

Electronic Resource

Multimodal inhibitory innervation of the gill ofAplysia Juliana (1988)

Kurokawa, Makoto ; Kuwasawa, Kiyoaki

Springer

Journal of comparative physiology 162 (1988), S. 533-541

add to mindlist on the mindlist

Details

ISSN: 1432-1351

Source: Springer Online Journal Archives 1860-2000

Topics: Biology , Medicine

Notes: Summary 1. The excitatory and inhibitory influences on the gill ofAplysia Juliana, which are mediated by the branchial nerve, were studied by means of electrophysiological techniques. Excitatory and inhibitory pathways in the nerve were stimulated simultaneously or selectively. 2. The branchial nerve was found to contain both excitatory and inhibitory pathways which did not contain synapses in the branchial ganglion. The excitatory pathways caused longitudinal shortening of the gill along the efferent branchial vessel and the inhibitory pathways were modulatory, depressing the longitudinal shortening. 3. Branchial nerve stimulation elicited two types of excitatory junctional potential (EJP), which were not mediated by the branchial ganglion, in a muscle cell of the efferent branchial vessel. One type was attributed to the central motor neuron and the other type to a motor neuron which is probably situated in the neural plexus of the gill periphery. 4. Four inhibitory pathways from the central nervous system to the gill were found. 5. Inhibitory junctional potentials (IJPs) recorded from muscle cells of the efferent branchial vessel in response to branchial nerve stimulation did not have monosynaptic characteristics. It is thought that inhibitory motor neurons which were activated by the branchial nerve might exist at the neural plexus of the gill. 6. A single EJP which has been induced by a stimulus pulse applied to the excitatory pathway of the branchial nerve may be depressed in an all-or-none manner by a stimulus pulse applied to the inhibitory pathway, if this is done within a distinct short period prior to or after the stimulus inducing the EJP. This indicates that the central motor neuron receives presynaptic inhibition at its periphery. 7. The motor neurons of the neural plexus seem to receive inhibitory innervation. Suppression of endogenous EJPs in the efferent vessel persisted for a long period even after cessation of stimulation. 8. A certain branchioganglionic neuron (BGN) was found to receive inhibitory postsynaptic potential (IPSP) inputs from the branchial nerve. 9. The multimodality of both the excitatory and the inhibitory pathways in the branchial nerve may explain the compound neural modulations of gill movements.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00612518

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

4

Electronic Resource

Mosaic arrangement of SCPb-, FMRFamide-, and histamine-like immunoreactive sensory hair cells in the statocyst of the gastropod mollusc Pleurobranchaea japonica (2000)

Ohsuga, Kenji ; Kurokawa, Makoto ; Kuwasawa, Kiyoaki

Springer

Cell & tissue research 300 (2000), S. 165-172

add to mindlist on the mindlist

Details

ISSN: 1432-0878

Keywords: SCPb FMRFamide Histamine Immunocytochemistry Statocyst Pleurobranchaea japonica (Mollusca)

Source: Springer Online Journal Archives 1860-2000

Topics: Biology , Medicine

Notes: Abstract. A pair of statocysts are located in the periganglionic connective tissue of the pedal ganglia of the opisthobranch mollusc Pleurobranchaea japonica. Light- and electron-microscopic observations show that the sensory epithelium of the statocyst consists of 13 disk-shaped hair cells. Each hair cell sends a single axon to the cerebral ganglion through the static nerve. Neurotransmitters in the hair cells were examined by means of immunocytochemistry. Our results show that the 13 sensory hair cells include two SCPb-, three FMRFamide-, and eight histamine-like immunoreactive cells. One hair cell contains a transmitter substance other than SCPb-, FMRFamide, histamine, serotonin, or GABA. One of the two SCPb-like immunoreactive cells, located in the ventral region of the statocyst, is the largest cell in the statocyst. The other, located in the anterodorsal region, shows co-immunoreactivity to both SCPb and FMRFamide antisera. Among the three FMRFamide-like immunoreactive hair cells, one is located in the posteroventral region, separated from the other two, which are adjacent to each other in the anterodorsal region. All the eight histamine-like immunoreactive hair cells are adjacent to one another, occupying the remainder of a triangular pyramid-shaped region. These immunoreactive cells are symmetrically placed in the right and left statocysts. This mosaic arrangement was identical among specimens. Thus the static nerve may code information about position or movement of the statoliths, with the use of different transmitters in the mosaic arrangement of the hair cells.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s004410000186

Permalink