Specific Re-Innervation of Limbs Transplanted between Segments in the Cockroach, Periplaneta Americana

1972 ◽  
Vol 57 (2) ◽  
pp. 305-309
Author(s):  
D. YOUNG
Keyword(s):  
Cell Body ◽  
Motor Neurons ◽  
Periplaneta Americana ◽  
Thoracic Ganglia ◽  
Morphological Criteria ◽  
Procion Yellow ◽  
Limb Muscles ◽  
Intracellular Stimulation

1. The connexions of single, identified motor neurons have been studied in the thoracic ganglia of the cockroach, Periplaneta americana. Selected cell bodies were identified on purely morphological criteria from one animal to another. Similarly, serially homologous cell bodies were identified from one ganglion to another. Their connexions to particular limb muscles were demonstrated by intracellular stimulation through the cell body and infsequent marking with procion yellow dye. 2. Serially homologous cell bodies in the mesothoracic and metathoracic ganglia innervate serially homologous muscles in the mesothoracic and metathoracic limbs. 3. Metathoracic limbs transplanted to the mesothoracic segment retain their metathoracic characteristics. They become functionally incorporated in the mesothoracic segment and are used normally during walking movements. 4. These transplanted metathoracic limbs become re-innervated from the mesothoracic ganglion. Identified mesothoracic cell bodies make specific connexions with those metathoracic muscles which are the serial homologues of their own muscles.

Structure and Synaptic Activation of the Fast Coxal Depressor Motoneurone of the Cockroach, Periplaneta Americana

1972 ◽  
Vol 56 (3) ◽  
pp. 647-656
Author(s):  
J. F. ILES
Keyword(s):  
Cell Body ◽  
Periplaneta Americana ◽  
Excitatory Input ◽  
Synaptic Activation ◽  
Synaptic Response ◽  
Metathoracic Ganglion ◽  
Procion Yellow ◽  
Giant Fibres

1. Using Procion Yellow dye injection the structure of the fast coxal depressor motoneurone was determined. 2. The cell body of the slow depressor motoneurone was located within the metathoracic ganglion. 3. Intracellular records from the fast motoneurone failed to reveal any post-synaptic response when the largest abdominal giant fibres were stimulated. 4. Smaller abdominal afferent fibres gave an excitatory input.

The functional organization of motor neurons in an insect ganglion

1967 ◽  
Vol 252 (781) ◽  
pp. 561-569 ◽  
Keyword(s):  
Peripheral Nerve ◽  
Nerve Cell ◽  
Cell Body ◽  
Motor Neurons ◽  
Periplaneta Americana ◽  
Functional Organization ◽  
Motor Nerve ◽  
Nerve Trunk ◽  
Three Dimensions ◽  
Nerve Cell Body

The distribution of motor nerve cell bodies in the metathoracic ganglion of the cockroach Periplaneta americana was mapped and displayed in three dimensions. A dense ring of ribonucleic acid ( RNA ) appears in the perinuclear cytoplasm of a nerve cell body whose axon has been cut in a peripheral nerve trunk. Using this RNA ring as the primary marker, 5 cell maps of ganglia from different animals were constructed to indicate which motor nerve cell body sends its axon out a particular peripheral nerve trunk. We count about 3000 neurons in the ganglion, and of these about 230 are above 20 /an in diameter. About 100 of these larger cells are generally arranged in bilaterally symmetrical pairs. These cell pairs have been assigned numbers and can be identified from one animal to another. Nerve cell bodies associated with nerves 3 through 6 send their axons out the ipsilateral nerve trunks. Cells associated with nerve 2 send their axons out the contralateral nerve trunk. This study may provide a basis for understanding the structural and metabolic organization responsible for the particular behavioural capacities of certain populations of neurons.

Levels of tryptophan, 5-hydroxytryptamine, and dopamine in some tissues of the cockroach Periplaneta americana

1986 ◽  
Vol 64 (12) ◽  
pp. 2669-2673 ◽  
Author(s):  
B. Duff Sloley ◽  
Roger G. H. Downer ◽  
Cedric Gillott
Keyword(s):  
Nervous Tissue ◽  
High Performance ◽  
Periplaneta Americana ◽  
Corpora Allata ◽  
Suboesophageal Ganglion ◽  
Corpora Cardiaca ◽  
Thoracic Ganglia ◽  
Frontal Ganglion ◽  
Low Levels ◽  
Immunohistochemical Studies

Tryptophan, 5-hydroxytryptamine, and dopamine were measured in the frontal ganglion, corpora cardiaca, corpora allata, nerves of the suboesophageal ganglion, nerves of the thoracic ganglia, gut, testes, and ovaries of the cockroach Periplaneta americana using high performance liquid chromatography with electrochemical detection. 5-Hydroxytryptamine was demonstrated in the frontal ganglion, corpora cardiaca, corpora allata, and nerves of the suboesophageal ganglion but not in the gut, testes, ovaries, or nerves of the thoracic ganglia. These results quantitatively confirm immunohistochemical studies of 5-hydroxytryptamine in neurohaemal and nonneuronal tissues of the cockroach. Dopamine was found in all neurohaemal and nervous tissue examined. Dopamine was also found at low levels in the rectum. Tryptophan was found in all tissues examined.

Regulation of motor neuron dendrite growth by NMDA receptor activation

Development ◽  
1994 ◽  
Vol 120 (11) ◽  
pp. 3063-3071 ◽  
Author(s):  
R.G. Kalb
Keyword(s):  
Nmda Receptor ◽  
Motor Neuron ◽  
Cell Body ◽  
Motor Neurons ◽  
Receptor Activation ◽  
Dendrite Growth ◽  
Postnatal Life ◽  
Receptor Antagonism ◽  
Neuron Cell Body ◽  
Early Postnatal Life

Spinal motor neurons undergo great changes in morphology, electrophysiology and molecular composition during development. Some of this maturation occurs postnatally when limbs are employed for locomotion, suggesting that neuronal activity may influence motor neuron development. To identify features of motor neurons that might be regulated by activity we first examined the structural development of the rat motor neuron cell body and dendritic tree labeled with cholera toxin-conjugated horseradish peroxidase. The motor neuron cell body and dendrites in the radial and rostrocaudal axes grew progressively over the first month of life. In contrast, the growth of the dendritic arbor/cell and number of dendritic branches was biphasic with overabundant growth followed by regression until the adult pattern was achieved. We next examined the influence of neurotransmission on the development of these motor neuron features. We found that antagonism of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptor inhibited cell body growth and dendritic branching in early postnatal life but had no effect on the maximal extent of dendrite growth in the radial and rostrocaudal axes. The effects of NMDA receptor antagonism on motor neurons and their dendrites was temporally restricted; all of our anatomic measures of dendrite structure were resistant to NMDA receptor antagonism in adults. These results suggest that the establishment of mature motor neuron dendritic architecture results in part from dendrite growth in response to afferent input during a sensitive period in early postnatal life.

A Time-Dependent Excitability change in the soma of an identified Insect Motoneurone

1992 ◽  
Vol 162 (1) ◽  
pp. 251-263
Author(s):  
JULES C. HANCOX ◽  
ROBERT M. PITMAN
Keyword(s):  
Cell Body ◽  
Action Potentials ◽  
Periplaneta Americana ◽  
Channel Blocker ◽  
Time Dependent ◽  
Sodium Channel Blocker ◽  
Plateau Potentials ◽  
Excitability Change ◽  
Membrane Oscillations

Long-term, current-clamp recordings were made from the cell body of the fast coxal depressor motoneurone (Df) of the third thoracic ganglion of the cockroach Periplaneta americana. In freshly dissected preparations the response to shortduration, suprathreshold, depolarising current pulses was a graded series of damped membrane oscillations similar to those reported previously in this neurone. The response to current injection changed, however, with increasing time after setting up the preparation: cells developed the ability to exhibit all-ornone action potentials. Their amplitude, however, was usually insufficient to overshoot 0 m V. Our observations suggest that the enhancement in excitability is dependent on time following dissection rather than on time following impalement. Recordings taken from neurone somata mechanically divided from their processes indicated that the time-dependent changes in excitability were not attributable to changes in synaptic input to the neurone and, moreover, that the cell body was involved in action potential genesis. The action potentials were resistant to treatment with the sodium channel blocker tetrodotoxin (up to 10−5 mol l−1), but were reversibly abolished when preparations were bathed in saline containing cadmium ions (1 mmol l−1) or manganese ions (20 or 40 mmol l−1) and, therefore, the inward current underlying these events was largely, if not entirely, carried by calcium ions. These time-dependent action potentials can co-exist with plateau potentials. In neurones giving both plateau potentials and time-dependent action potentials, plateau potentials can drive action potentials in bursts.

Analysis of decreased conductance serotonergic response in Aplysia ink motor neurons

1985 ◽  
Vol 53 (2) ◽  
pp. 590-602 ◽  
Author(s):  
J. P. Walsh ◽  
J. H. Byrne
Keyword(s):  
Cell Body ◽  
Motor Neurons ◽  
Potassium Conductance ◽  
Membrane Conductance ◽  
Resting Potential ◽  
Slow Inward Current ◽  
Equilibrium Potential ◽  
Voltage Sensitivity ◽  
Inward Current ◽  
Bath Application

Micropressure ejection of serotonin (5-hydroxytryptamine, 5-HT) produced excitatory responses in the L14 ink motor neurons of Aplysia that depended on the site of application. Ejection of 5-HT onto the cell body produced a slow response that showed variability in voltage sensitivity between preparations. In contrast, ejection of 5-HT onto the neuropil underneath the cell body produced a response whose amplitude was consistently a linear function of the holding potential, reversing near the predicted potassium equilibrium potential. Subsequent analyses focused on this second response. The neuropil response induced by 5-HT had a linear current-voltage relationship (reversing at ca. -80 mV), was associated with a decrease in input conductance, and was sensitive to changes in the concentration of extracellular K+. Serotonin application in artificial seawater (ASW) containing 30 mM K+ produced a response that reversed close to the altered Nernst potential for K+. The 5-HT response did not appear to be due to secondary activation of interneurons or to depend primarily on extracellular Ca2+, since ejection of 5-HT onto cells bathed in ASW containing 30 mM Co2+ produced responses comparable to, although somewhat attenuated from, those observed in ASW. Serotonin responses similar to those produced in ASW were obtained after perfusing the ganglion with ASW containing Co2+, 4-aminopyridine (4-AP), and tetraethylammonium (TEA). This suggests that the 5-HT-sensitive current is separate from the Ca2+-activated, fast, and delayed rectifying K+ currents. The 5-HT response appeared to be mediated by changes in levels of cAMP. Bath application of the phosphodiesterase inhibitors IBMX (3-isobutyl-1-methylxanthine) or Ro 20-1724, or the adenylate cyclase activator forskolin mimicked the 5-HT response by producing a slow inward current associated with a decrease in membrane conductance. Alteration of cellular cAMP metabolism modulated the response to 5-HT. Exposure of the ganglion to low concentrations of either Ro 20-1724 or forskolin potentiated the 5-HT response. Higher concentrations of these agents largely blocked the response to subsequent 5-HT applications. Bath application of the 8-bromo derivative of either cAMP or cGMP produced a slow inward current associated with a decrease in membrane conductance in cells voltage clamped at the resting potential. Responses to 5-HT were blocked, however, after exposure to 8-bromo-cAMP, but not to 8-bromo-cGMP. These results suggest that 5-HT produces a voltage-independent decrease in a steady-state potassium conductance that may be mediated by cAMP.(ABSTRACT TRUNCATED AT 400 WORDS)

Ultrastructure of a sensillum associated with the pharynx of the cockroach Periplaneta americana

1996 ◽  
Vol 74 (11) ◽  
pp. 1999-2008
Author(s):  
R. Gary Chiang ◽  
K. G. Davey
Keyword(s):  
Electron Microscopy ◽  
Cell Body ◽  
Extracellular Space ◽  
Direct Contact ◽  
Periplaneta Americana ◽  
Sensory Cell ◽  
Sensory Cells ◽  
Osmotic Concentration ◽  
Sensory Cilia ◽  
Ultrathin Sections

A sensillum associated with the pharynx of the cockroach Periplaneta americana was examined in serial ultrathin sections using electron microscopy. This sensillum consisted of a group of 10–20 similar sensillar subunits. Each sensillar subunit possessed one 60- to 70-μm long dendritic sheath that made direct contact with the cuticle. The dendritic sheath enclosed 3–5 sensory cilia arising from 3–5 sensory cells located in a cluster approximately 30 μm proximal to the base of the sheath. Between the sensory cell body and the base of the sheath the dendrites were wrapped by the sheath-forming cell. Before entering the dendritic sheath itself, the dendrites crossed through an extracellular space, the ciliary sinus. No cuticular specializations, such as a well-defined sensory hair or pore, were observed. The structure of this sensillum suggests that it responds poorly to mechanical distortion of its surroundings. This characteristic supports the hypothesis that this sensillum measures the osmotic concentration of the ingested food.

Response properties and synaptic connections of mechanoafferent neurons in cerebral ganglion of Aplysia

1979 ◽  
Vol 42 (4) ◽  
pp. 954-974 ◽  
Author(s):  
S. C. Rosen ◽  
K. R. Weiss ◽  
I. Kupfermann
Keyword(s):  
Receptive Field ◽  
Motor Neurons ◽  
Receptive Fields ◽  
Cerebral Ganglion ◽  
The Body ◽  
Sensory Response ◽  
Tactile Stimuli ◽  
Dorsal Portion ◽  
Intracellular Stimulation ◽  
Stimulation Of

1. The cells of two clusters of small neurons on the ventrocaudal surface of each hemicerebral ganglion of Aplysia were found to exhibit action potentials following tactile stimuli applied to the skin of the head. These neurons appear to be mechanosensory afferents since they possess axons in the nerves innervating the skin and tactile stimulation evokes spikes with no prepotentials, even when the cell bodies are sufficiently hyperpolarized to block some spikes. The mechanosensory afferents may be primary afferents since the sensory response persists after chemical synaptic transmission is blocked by bathing the ganglion and peripheral structures in seawater with a high-Mg2+ and low-Ca2+ content. 2. The mechanosensory afferents are normally silent and are insensitive to photic, thermal, and chemical stimuli. A punctate tactile stimulus applied to a circumscribed region of skin can evoke a burst of spikes. If the stimulus is maintained at a constant forces, the mechanosensory response slowly adapts over a period of seconds. Repeated brief stimuli have little or no effect on spike frequency within a burst. 3. Approximately 81% of the mechanoafferent neurons have a single ipsilateral receptive field. The fields are located on the lips, the anterior tentacles, the dorsal portion of the head, the neck, or the perioral zone. Because many cells have collateral axons in the cerebral connectives, receptive fields elsewhere on the body are a possibility. The highest receptive-field density was associated with the lips. Within each area, receptive fields vary in size and shape. Adjacent fields overlap and larger fields frequently encompass several smaller ones. The features of some fields appear invariant from one animal to the next. A loose form of topographic organization of the mechanoafferent cells was observed. For example, cells located in the medial cluster have lip receptive fields, and most cells in the posterolateral portion of the lateral clusters have tentacle receptive fields. 4. Intracellular stimulation of individual mechanoafferents evokes short and constant-latency EPSPs in putative motor neurons comprising the identified B-cell clusters of the cerebral ganglion. On the basis of several criteria, these EPSPs appear to be several criteria, these EPSPs appear to be chemically mediated and are monosynaptic. 5. Repetitive intracellular stimulation of individual mechanoafferent neurons at low rates results in a gradual decrement in the amplitude of the EPSPs evoked in B cluster neurons. EPSP amplitude can be restored following brief periods of rest, but subsequent stimulation leads to further diminution of the response. 6. A decremented response cannot be restored by strong mechanical stimulation outside the receptive field of the mechanoafferent or by electrical stimulation of the cerebral nerves or connectives...

scholarly journals Higher-order assembly of Sorting Nexin 16 controls tubulation and distribution of neuronal endosomes

2019 ◽  
Vol 218 (8) ◽  
pp. 2600-2618 ◽  
Author(s):  
ShiYu Wang ◽  
Zechuan Zhao ◽  
Avital A. Rodal
Keyword(s):  
Cell Body ◽  
Motor Neurons ◽  
Coiled Coil ◽  
Higher Order ◽  
Synaptic Growth ◽  
Sorting Nexin ◽  
Protein Receptors ◽  
Self Association ◽  
Signaling Receptors

The activities of neuronal signaling receptors depend heavily on the maturation state of the endosomal compartments in which they reside. However, it remains unclear how the distribution of these compartments within the uniquely complex morphology of neurons is regulated and how this distribution itself affects signaling. Here, we identified mechanisms by which Sorting Nexin 16 (SNX16) controls neuronal endosomal maturation and distribution. We found that higher-order assembly of SNX16 via its coiled-coil (CC) domain drives membrane tubulation in vitro and endosome association in cells. In Drosophila melanogaster motor neurons, activation of Rab5 and CC-dependent self-association of SNX16 lead to its endosomal enrichment, accumulation in Rab5- and Rab7-positive tubulated compartments in the cell body, and concomitant depletion of SNX16-positive endosomes from the synapse. This results in accumulation of synaptic growth–promoting bone morphogenetic protein receptors in the cell body and correlates with increased synaptic growth. Our results indicate that Rab regulation of SNX16 assembly controls the endosomal distribution and signaling activities of receptors in neurons.

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