Transfer of habituation between stimulation sites of the siphon withdrawal reflex in Aplysia californica

1983 ◽  
Vol 61 (7) ◽  
pp. 749-755 ◽  
Author(s):  
Jeff I. Goldberg ◽  
Ken Lukowiak
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Neurons ◽  
Aplysia Californica ◽  
Test Site ◽  
Excitatory Input ◽  
Common Mechanism ◽  
Large Decrease ◽  
Withdrawal Reflex ◽  
Tactile Stimuli

Habituation of the siphon withdrawal reflex (SWR) can be evoked by iterative tactile stimuli presented to one of several sites, including the siphon and gill. The SWR evoked at an arbitrary "test" site did not habituate when stimuli were presented at 20-min intervals. However, there was a large decrease in the reflex evoked at the test site when the trial was preceded by 10 repetitive stimuli (interstimuli interval = 30 s) presented to the opposite "habituation" site. Transfer of habituation occurred from gill to siphon stimulation sites, and vice versa. There was a concomitant decrease in the excitatory input evoked in the central siphon motor neurons LDS1 and LDS3. Moreover, transfer of habituation occurred after the abdominal ganglion (central nervous system) was removed. There was little change in the magnitude of the control responses or transfer of habituation after deganglionation. Since transfer of habituation between stimulation sites of the SWR was similar to that reported previously for the gill withdrawal reflex, it was suggested that a common mechanism may underlie the two behaviors.

The gill withdrawal reflex is suppressed in sexually active Aplysia

1983 ◽  
Vol 61 (7) ◽  
pp. 743-748 ◽  
Author(s):  
Ken Lukowiak ◽  
Lee Freedman
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Peripheral Nervous System ◽  
Motor Neurons ◽  
Tactile Stimulation ◽  
Excitatory Input ◽  
Integrated System ◽  
Sexually Active ◽  
Withdrawal Reflex ◽  
The Central Nervous System

In Aplysia, the central nervous system and peripheral nervous system interact and form an integrated system that mediates adaptive gill withdrawal reflex behaviours evoked by tactile stimulation of the siphon. The central nervous system (CNS) exerts suppressive and facilitatory control over the peripheral nervous system (PNS) in the mediation of these behaviours. We found that the CNS's suppressive control over the PNS was increased significantly in animals engaged in sexual activity as either a male or female. In control animals, the evoked gill withdrawal reflex met a minimal response amplitide criterion, while in sexually active animals the reflex did not meet this criterion. At the neuronal level, the increased CNS suppressive control was manifested as a decrease in excitatory input to the central gill motor neurons.

Dopamine modulation of gill reflex behavior in Aplysia

1979 ◽  
Vol 57 (3) ◽  
pp. 329-332 ◽  
Author(s):  
Peter Ruben ◽  
Ken Lukowiak
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Neuron ◽  
Peripheral Nervous System ◽  
Motor Neurons ◽  
Withdrawal Reflex ◽  
Dopaminergic Pathway ◽  
The Central Nervous System ◽  
Dopamine Modulation

We have studied the effects of dopamine on the gill withdrawal reflex evoked by tactile siphon stimulation in the margine mollusc Aplysia. Physiological concentrations of dopamine (diluted in seawater) were perfused through the gill during siphon stimulation series. The amplitude of the reflex was potentiated by dopamine and habituation of the reflex was prevented. This occurred with no change in the activity evoked in central motor neurons. These results lead us to conclude that the dopaminergic motor neuron L9 is modulating habituation in the periphery and that the central nervous system facilitatory control of the peripheral nervous system may act via a dopaminergic pathway.

The development of central nervous system control of the gill withdrawal reflex evoked by siphon stimulation in Aplysia

1979 ◽  
Vol 57 (9) ◽  
pp. 987-997 ◽  
Author(s):  
Ken Lukowiak
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Abdominal Ganglion ◽  
System Control ◽  
Reflex Amplitude ◽  
Withdrawal Reflex ◽  
Reflex Latency ◽  
Neural Processes ◽  
The Central Nervous System ◽  
Cns Control

In older Aplysia, the central nervous system (CNS) (abdominal ganglion) exerts suppressive and facilitatory control over the peripheral nervous system (PNS) which initially mediates the gill withdrawal reflex and its subsequent habituation evoked by tactile stimulation of the siphon. In young animals, both the suppressive and facilitatory CNS control were found to be absent. In older animals, removal of branchial nerve (Br) input to the gill resulted in a significantly reduced reflex latency and, with ctenidial (Ct) and siphon (Sn) nerves intact, a significantly increased reflex amplitude and an inability of the reflex to habituate with repeated siphon stimulation. In young animals, removal of Br had no effect on reflex latency and with Ct and Sn intact, the reflex amplitude latency was not increased and the reflex habituated. Older animals can easily discriminate between different intensity stimuli applied to the siphon as evidenced by differences in reflex amplitude, rates of habituation, and evoked neural activity. On the other hand, young animals cannot discriminate well between different stimulus intensities. The lack of CNS control in young animals was found to be due to incompletely developed neural processes within the abdominal ganglion and not the PNS. The lack of CNS control in young Aplysia results in gill reflex behaviours being less adaptive in light of changing stimulus conditions, but may be of positive survival value in that the young will not habituate as easily. The fact that CNS control is present in older animals strengthens the idea that in any analysis of the underlying neural mechanisms of habituation the entire integrated CNS–PNS must be taken into account.

Sensitization of the gill and siphon withdrawal reflex of Aplysia: multiple sites of change in the neuronal network

1993 ◽  
Vol 70 (3) ◽  
pp. 1210-1220 ◽  
Author(s):  
L. E. Trudeau ◽  
V. F. Castellucci
Keyword(s):  
Sensory Neuron ◽  
Sensory Neurons ◽  
Motor Neurons ◽  
Neuronal Network ◽  
Feedback Inhibition ◽  
Excitatory Input ◽  
Major Mechanism ◽  
Withdrawal Reflex ◽  
The Difference ◽  
Central Synapses

1. Recent studies have emphasized the major contribution of interneuronal transmission to the mediation and learning-associated modulation of the gill and siphon withdrawal (GSW) reflex of Aplysia. We wish to provide more direct support for the hypothesis that inhibitory junctions are crucial sites of plasticity. 2. In parallel experiments we investigated modulation at five major sites of synaptic transmission in the GSW network: 1) from sensory neurons to motor neurons, 2) from sensory neurons to excitatory interneurons (INTs+) 3) from INTs+ to motor neurons (MNs), 4) from inhibitory interneurons (INTs-) to INTs+, and 5) from INTs+ to INTs-. 3. While recording simultaneously from a single sensory neuron of the LE cluster, an INT+, and a MN, we found that both LE-MN and LE-INTs+ synapses were facilitated by the activation of modulator neurons by stimulation of the left pleuroabdominal connective (185 and 93%, respectively) as well as by serotonin (5-HT) (191 and 84%). Junctions of the second type were therefore less facilitated. The difference in the magnitude of facilitation at these two sites is an indication of a branch-specific, differential efficacy in the modulation of different central synapses made by a single neuron. 4. Although INT(+)-MN junctions have the capacity to display marked posttetanic potentiation, they are not significantly potentiated after connective stimulation. Sensitization of the GSW reflex is therefore not necessarily accompanied by a modification of transmission at these synapses. 5. Inhibitory transmission to INTs+ is significantly reduced by connective stimulation (36%) and by 5-HT (71%). This supports the hypothesis that a reduction of feedback inhibition into INTs+ is a major mechanism of reflex sensitization and may account for the increased evoked firing of INTs+ that is observed after connective stimulation. 6. The excitatory input to INTs- is selectively decreased by 5-HT (50%) and by the molluscan neuropeptide small cardioactive peptide B (38%). This latter effect, which could produce disinhibition of INTs+, may explain the previous observation that this peptide is able to potentiate the evoked input to MNs of the reflex at a concentration (1 microM) that fails to modify monosynaptic sensory-motor transmission. 7. These results indicate that transmission through a small neuronal network that mediates a withdrawal reflex in Aplysia may be modulated at multiple sites and by different mechanisms. These mechanisms include: 1) branch-specific facilitation of sensory neuron outputs and 2) inhibition of INT(-)-INT+ inhibitory postsynaptic potentials by endogenous modulatory neurons and by 5-HT.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Loss of the nucleoporin Aladin in central nervous system and fibroblasts of Allgrove Syndrome

2019 ◽  
Vol 28 (23) ◽  
pp. 3921-3927 ◽  
Author(s):  
Giacomo Bitetto ◽  
Dario Ronchi ◽  
Sara Bonato ◽  
Alessandra Pittaro ◽  
Giacomo Monzio Compagnoni ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Purkinje Cells ◽  
Motor Neurons ◽  
Nuclear Membrane ◽  
Nucleocytoplasmic Transport ◽  
Neurological Involvement ◽  
Nuclear Pore ◽  
Striatal Neurons ◽  
Allgrove Syndrome

Abstract Allgrove syndrome (AS) is a rare disease with broad neurological involvement. Neurodegeneration can affect spinal motor neurons, Purkinje cells, striatal neurons and the autonomic system. The mechanisms that lead to neuronal loss are still unclear. Recessive mutations in the AAAS gene affect the encoded protein Aladin, which would normally localize to the cytoplasmic face of the nuclear membrane as part of the nuclear pore complex (NPC). While the NPC is known to be a key factor for nucleocytoplasmic transport, the precise role of Aladin has not been elucidated yet. Here, we explored the consequences of the homozygous AAAS mutation c.464G>A (p.R155H) in central nervous system tissues and fibroblasts of a novel AS patient presenting motor neuron disease, cerebellar ataxia and autonomic dysfunction. Neuropathological analyses showed severe loss of motor neurons and Purkinje cells, with significant reduction in the perinuclear expression of Aladin. A reduced amount of protein was detected in the nuclear membrane fraction of the patient’s brain. RNA analysis revealed a significant reduction of the transcript AAAS-1, while the AAAS-2 transcript was upregulated in fibroblasts. To our knowledge, this is the first study to demonstrate the effects of AAAS mutations in the human central nervous system.

scholarly journals Metabolism of acetylcholine in the nervous system of Aplysia californica. I. Source of choline and its uptake by intact nervous tissue.

1975 ◽  
Vol 65 (3) ◽  
pp. 255-273 ◽  
Author(s):  
J H Schwartz ◽  
M L Eisenstadt ◽  
H Cedar
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nervous Tissue ◽  
Aplysia Californica ◽  
The Other ◽  
Michaelis Constant ◽  
High Affinity ◽  
The Central Nervous System

Although acetylcholine is a major neurotransmitter in Aplysia, labeling studies with methionine and serine showed that little choline was synthesized by nervous tissue and indicated that the choline required for the synthesis of acetylcholine must be derived exogenously. Aanglia in the central nervous system (abdominal, cerebral, and pleuropedals) all took up about 0.5 nmol of choline per hour at 9 muM, the concentration of choline we found in hemolymph. This rate was more than two orders of magnitude greater than that of synthesis from the labeled precursors. Ganglia accumulated choline by a process which has two kinetic components, one with a Michaelis constant between 2-8 muM. The other component was not saturated at 420 muM. Presumably the process with the high affinity functions to supply choline for synthesis of transmitter, since the efficiency of conversion to acetylcholine was maximal in the range of external concentrations found in hemolymph.

Conopressin G, a molluscan vasopressin-like peptide, alters gill behaviors in Aplysia

1992 ◽  
Vol 70 (2) ◽  
pp. 259-267 ◽  
Author(s):  
Manuel Martínez-Padrón ◽  
William R. Gray ◽  
Ken Lukowiak
Keyword(s):  
Motor Neuron ◽  
Motor Neurons ◽  
Aplysia Californica ◽  
Behavioral Effects ◽  
Behavioral State ◽  
Neural Correlate ◽  
Structural Analogue ◽  
Withdrawal Reflex ◽  
Similar Peptide

Superfusion of an invertebrate vasopressin structural analogue, conopressin G, over the abdominal ganglion of an in vitro preparation of Aplysia californica has significant neurophysiological and behavioral effects. Both the amplitude of the siphon-evoked gill withdrawal reflex and concomitant activity in gill motor neurons are reduced in the presence of conopressin G. Moreover, the frequency of spontaneous gill movements and their neural correlate, interneuron II activity, are increased. These behavioral modifications strongly resemble those that occur during the food-aroused behavioral state in intact Aplysia. In addition, conopressin G superfusion reduces both the excitability of gill motor neurons and the strength of gill contractions in response to gill motor neuron discharges elicited by direct depolarizing current. A role for conopressin G or a similar peptide in the modulation of gill behaviors associated with the food-aroused state is suggested.Key words: Aplysia californica, conopressin G, gill withdrawal reflex, spontaneous gill movements.

Photic sensitivity of the rhinophore in Aplysia

1979 ◽  
Vol 57 (3) ◽  
pp. 698-701 ◽  
Author(s):  
Ronald Chase
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Circadian Rhythm ◽  
Locomotor Activity ◽  
Peripheral Nerve ◽  
Aplysia Californica ◽  
Optic Nerves ◽  
Peripheral Location ◽  
The Central Nervous System

A response to the onset of light was recorded electrophysiologically from the rhinophore nerve of Aplysia californica. Except for the optic nerves, no other peripheral nerve is known to carry photic information to the central nervous system. The result suggests a peripheral location for the extraocular photoreceptors which are known to be capable of controlling the circadian rhythm of locomotor activity.

Urotensin I-like immunoreactivity in the central nervous system of Aplysia californica

Peptides ◽  
1991 ◽  
Vol 12 (4) ◽  
pp. 787-793 ◽  
Author(s):  
G.C. Gonzalez ◽  
M. Martinez-Padron ◽  
D. Ko ◽  
K. Lukowiak ◽  
K. Lederis
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Aplysia Californica ◽  
The Central Nervous System
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