scholarly journals Operant conditioning of aerial respiratory behaviour in Lymnaea stagnalis

1996 ◽  
Vol 199 (3) ◽  
pp. 683-691 ◽  
Author(s):  
K Lukowiak ◽  
E Ringseis ◽  
G Spencer ◽  
W Wildering ◽  
N Syed
Keyword(s):  
Operant Conditioning ◽  
Tactile Stimulation ◽  
Direct Evidence ◽  
Lymnaea Stagnalis ◽  
Freshwater Snail ◽  
Withdrawal Reflex ◽  
Before And After ◽  
Opening And Closing ◽  
Stimulation Paradigm ◽  
Stimulation Of

In this study, we operantly conditioned the aerial respiratory behaviour of the freshwater snail Lymnaea stagnalis. Aerial respiration in Lymnaea stagnalis is accomplished by the spontaneous opening and closing of its respiratory orifice, the pneumostome, at the water surface. Weak tactile stimulation of the pneumostome area, when the pneumostome is open, evoked only the pneumostome closure response, which is one aspect of the escape-withdrawal reflex. Pneumostome stimulation resulted in its closure and the termination of aerial respiratory activity. A contingent tactile stimulation paradigm was used to operantly condition the animals. Stimulation of the pneumostome whenever the animal attempted to breathe resulted in significantly fewer attempts to open the pneumostome as training progressed. The latency of the first breath (subsequent to stimulation), the number of breaths and the total breathing time were measured before and after each training period. Significant, quantifiable changes in these behavioural parameters were observed only in the operant conditioning group animals. Control animals receiving tactile stimulation to their pneumostome not contingent upon pneumostome opening movements (yoked controls) or those that were physically prevented from surfacing to breathe (hypoxic controls), did not exhibit significant changes in these behavioural parameters. Our data provide the first direct evidence for operant conditioning of respiration in any animal.

scholarly journals Electro-haptic hearing: Speech-in-noise performance in cochlear implant users is enhanced by tactile stimulation of the wrists

2019 ◽  
Author(s):  
Mark D. Fletcher ◽  
Amatullah Hadeedi ◽  
Tobias Goehring ◽  
Sean R Mills
Keyword(s):  
Cochlear Implant ◽  
Speech Intelligibility ◽  
Tactile Stimulation ◽  
Electrical Signal ◽  
Noise Performance ◽  
Speech In Noise ◽  
Non Invasive ◽  
Real World Application ◽  
Before And After ◽  
Stimulation Of

Cochlear implant (CI) users receive only limited sound information through their implant, which means that they struggle to understand speech in noisy environments. Recent work has suggested that combining the electrical signal from the CI with a haptic signal that provides crucial missing sound information (“electro-haptic stimulation”; EHS) could improve speech-in-noise performance. The aim of the current study was to test whether EHS could enhance speech-in-noise performance in CI users using: (1) a tactile signal derived using an algorithm that could be applied in real time, (2) a stimulation site appropriate for a real-world application, and (3) a tactile signal that could readily be produced by a compact, portable device. We measured speech intelligibility in multi-talker noise with and without vibro-tactile stimulation of the wrist in CI users, before and after a short training regime. No effect of EHS was found before training, but after training EHS was found to improve the number of words correctly identified by an average of 8.3 %-points, with some users improving by more than 20 %-points. Our approach could offer an inexpensive and non-invasive means of improving speech-in-noise performance in CI users.

Transfer of Habituation Shows an Interaction Between Neuronal Circuits of the Gill Withdrawal Reflex in Aplysia Californica

1982 ◽  
Vol 96 (1) ◽  
pp. 107-124
Author(s):  
JEFF GOLDBERG ◽  
KEN LUKOWIAK
Keyword(s):  
Tactile Stimulation ◽  
Neural Circuits ◽  
Repetitive Stimulation ◽  
Integrated System ◽  
Neuronal Circuits ◽  
Withdrawal Reflex ◽  
Motor Neurones ◽  
Excitatory Responses ◽  
Lines Of Evidence ◽  
Stimulation Of

The gill withdrawal reflex (GWR) and its subsequent habituation can be evoked by tactile stimulation of the siphon or gill when the CNS is either intact or removed. It has been suggested that the neural circuits that mediate the GWR evoked at these two loci are parallel and independent. We provide three lines of evidence which show that these circuits interact and, therefore, comprise a single integrated system. Firtly, siphon and gill stimulation evoked similar excitatory responses in the central gill motor neurones. Secondly, the GWR habituated by repetitive stimulation at one locus was dishabituated by stimulation of the other locus. Thirdly, transfer of habituation occurred. Although the transfer was seen neurally at the level of central gill motor neurones, transfer of habituation also occurred after the CNS was removed. Therefore, the neuronal circuits mediating the reflexes evoked at the siphon and gill interact within both the CNS and PNS. The PNS is largely responsible for mediating this gill behaviour that is based on such interactions, while the CNS provides suppressive and facilitatory plasticity to these responses to enable Aplysia to better adapt to a changing environment.

Changes in the Activity of a CPG Neuron After the Reinforcement of an Operantly Conditioned Behavior in Lymnaea

2002 ◽  
Vol 88 (4) ◽  
pp. 1915-1923 ◽  
Author(s):  
Gaynor E. Spencer ◽  
Mustapha H. Kazmi ◽  
Naweed I. Syed ◽  
Ken Lukowiak
Keyword(s):  
Operant Conditioning ◽  
Sensory Input ◽  
Lymnaea Stagnalis ◽  
Training Stimulus ◽  
Rhythmic Activity ◽  
Neural Correlates ◽  
Behavioral Changes ◽  
Conditioned Behavior ◽  
Before And After ◽  
Respiratory Behavior

We have previously shown that the aerial respiratory behavior of the mollusk Lymnaea stagnalis can be operantly conditioned, and the central pattern generating (CPG) neurons underlying this behavior have been identified. As neural correlates of operant conditioning remain poorly defined in both vertebrates and invertebrates, we have used the Lymnaea respiratory CPG to investigate neuronal changes associated with the change in behavior after conditioning. After operant conditioning of the intact animals, semi-intact preparations were dissected, so that changes in the respiratory behavior (pneumostome openings) and underlying activity of the identified CPG neuron, right pedal dorsal 1 (RPeD1), could be monitored simultaneously. RPeD1 was studied because it initiates the rhythmic activity of the CPG and receives chemo-sensory input from the pneumostome area. Pneumostome openings and RPeD1 activity were monitored both before and after a reinforcing training stimulus applied to the open pneumostome of operantly conditioned and yoked control preparations. After presentation of the reinforcing stimulus, there was a significant reduction in both breathing behavior and RPeD1 activity in operant preparations but not in yoked and naı̈ve controls. Furthermore these changes were only significant in the subgroup of operantly conditioned animals described as good learners and not in poor learners. These data strongly suggest that changes in RPeD1 activity may underlie the behavioral changes associated with the reinforcement of operant conditioning of the respiratory behavior.

Long-term memory of an operantly conditioned respiratory behaviour pattern in lymnaea stagnalis

1998 ◽  
Vol 201 (6) ◽  
pp. 877-882 ◽  
Author(s):  
K Lukowiak ◽  
R Cotter ◽  
J Westly ◽  
E Ringseis ◽  
G Spencer ◽  
...  
Keyword(s):  
Operant Conditioning ◽  
Lymnaea Stagnalis ◽  
Training Session ◽  
Freshwater Snail ◽  
Behaviour Pattern ◽  
Long Term Memory ◽  
Training Procedure ◽  
Term Memory ◽  
Hypoxic Environment

The freshwater snail Lymnaea stagnalis breaths bimodally either through its skin (cutaneous respiration) or via a rudimentary lung opening called the pneumostome (aerial respiration). Aerial respiratory behaviour can be operantly conditioned. Animals placed in an aquatic, hypoxic environment received a tactile stimulus to the pneumostome area every time they attempted to breathe. Over a period of five training sessions (2.5 days), the animals learned not to breathe, and the number of stimuli received in the fifth session was significantly lower than in the first session. These changes in the respiratory behaviour following the operant paradigm were shown to persist for at least 24 h. We aimed to determine whether the changes in the learned behaviour would persist for longer. We obtained direct evidence that the behavioural changes following operant conditioning persisted for at least 4 weeks following the last training session. However, we found that the persistence of this memory was dependent upon the training procedure used. Memory persisted longer following a spaced training procedure (4 weeks) as opposed to a massed training procedure (2 weeks). Yoked control animals showed no changes in their respiratory behaviour over the same time periods. However, if these yoked control animals were subjected to an operant conditioning procedure, their ability to learn was not impeded. This study demonstrated that operant conditioning of a behaviour pattern in a molluscan preparation can result in long-term memory and that the persistence of the memory is contingent on the training procedure used. <P>

Suppression of gill withdrawal reflex behaviours in Aplysia: the role of acetylcholine

1990 ◽  
Vol 68 (11) ◽  
pp. 1407-1413
Author(s):  
David Cawthorpe ◽  
Ken Lukowiak
Keyword(s):  
Tactile Stimulation ◽  
Aplysia Californica ◽  
Withdrawal Reflex ◽  
Stimulation Of

Acetylcholine (ACh) dissolved in seawater and perfused through the isolated gill of the Aplysia californica produced suppression of the gill withdrawal reflex (GWR) evoked by tactile stimulation of the gill. This suppression was reversible upon washout and was blocked by co-perfusion of curare and α-bungarotoxin. Co-perfusion of atropine did not block the suppression of the GWR produced by ACh. We concluded that the suppressive effects produced by perfusion of ACh through the gill occur as a result of the action of ACh at the nicotinic-like receptors. The role of ACh suppression in the mediation of gill reflex behaviours is discussed.Key words: Aplysia, gill withdrawal reflex, suppression, acetylcholine.

Picrotoxin prevents habituation of the gill withdrawal reflex in Aplysia

1978 ◽  
Vol 56 (6) ◽  
pp. 1079-1082 ◽  
Author(s):  
Ken Lukowiak
Keyword(s):  
Tactile Stimulation ◽  
Aminobutyric Acid ◽  
Adaptive Behaviour ◽  
Repeated Presentation ◽  
Reflex Amplitude ◽  
Repeated Stimulation ◽  
Withdrawal Reflex ◽  
Reflex Latency ◽  
Cns Control ◽  
Stimulation Of

The gill withdrawal reflex evoked by tactile stimulation of the siphon in Aplysia habituates with repeated presentation of the stimulus. This adaptive behaviour is mediated by the integrated activity of the central (CNS) and peripheral (PNS) nervous systems. The PNS mediates the basic reflex and its habituation while the CNS exerts both suppressive and facilitatory control over the PNS. This results in greater adaptability of the reflex behaviours. In young Aplysia the CNS control is absent and this is due to the incomplete development of pathways in the CNS. In an attempt to identify the pathway an attempt was made to manipulate the CNS's suppressive influence by agents which antagonize putative neurotransmitters. The application of picrotoxin-containing seawater over the CNS removed the CNS's suppressive influence but not its facilitatory influence. Thus the reflex amplitude was increased, the reflex latency decreased, and repeated stimulation did not result in habituation. This effect of picrotoxin was completely reversible. It is thus proposed that γ-aminobutyric acid, a putative neurotransmitter, plays an important rote in the mediation of the CNS's suppressive influence.

Contribution of individual mechanoreceptor sensory neurons to defensive gill-withdrawal reflex in Aplysia

1978 ◽  
Vol 41 (2) ◽  
pp. 418-431 ◽  
Author(s):  
J. H. Byrne ◽  
V. F. Castellucci ◽  
E. R. Kandel
Keyword(s):  
Motor Neuron ◽  
Sensory Neuron ◽  
Sensory Neurons ◽  
Motor Neurons ◽  
Tactile Stimulation ◽  
Sensory Cell ◽  
Divalent Cations ◽  
Plastic Properties ◽  
Withdrawal Reflex ◽  
Stimulation Of

1. To evaluate the contribution which mechanoreceptor sensory neurons make to the defensive gill-withdrawal reflex we developed an isolated reflex preparation. We then reduced this isolated reflex to a microcircuit (consisting of a single sensory cell and single motor cell) so as to causally relate the contribution of individual cells to the expression and plastic properties of the behavior. 2. Mechanoreceptor neurons make significant contributions to the amplitude and duration of the complex PSP in the motor neurons. A single spike in a sensory neuron produces an EPSP in the motor neuron which accounts for 7-36% of the complex EPSP produced by weak tactile stimulation of the skin. 3. More than 50% of the synaptic input to the gill motor neurons appears to be monosynaptic. Perfusing the ganglion with solutions of high divalent cations reduced the motor neurons' complex PSP by only 40%. 4. The population response of the mechanoreceptors to a point stimulus can be simulated by repetitively firing a single sensory neuron. Firing a single sensory cell discharges the motor neuron and produces a gill contraction similar to that produced by a natural stimulus. 5. Mechanoreceptors make monosynaptic connections onto gill motor neurons which decrement with repeated stimulation paralleling the decrement of the complex PSP to punctate tactile stimulation of the skin. 6. The results indicate that the known neural elements may quantitatively account for most of the expression of the behavior and its short-term habituation.

Painful Stimuli Evoke Potentials Recorded From the Parasylvian Cortex in Humans

1998 ◽  
Vol 80 (4) ◽  
pp. 2077-2088 ◽  
Author(s):  
F. A. Lenz ◽  
M. Rios ◽  
D. Chau ◽  
G. L. Krauss ◽  
T. A. Zirh ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Direct Evidence ◽  
Indirect Evidence ◽  
Positive Potential ◽  
Cutaneous Stimulation ◽  
The Face ◽  
Ipsilateral Stimulation ◽  
Nociceptive Input ◽  
Stimulation Paradigm ◽  
Stimulation Of

Lenz, F. A., M. Rios, D. Chau, G. L. Krauss, T. A. Zirh, and R. P. Lesser. Painful stimuli evoke potentials recorded from the parasylvian cortex in humans. J. Neurophysiol. 80: 2077–2088, 1998. Cutaneous stimulation of the face and hand with a CO2 laser in three awake patients evoked potentials (LEPs) recorded from the dominant left parasylvian cortex. These were recorded by means of a subdural grid of electrodes implanted for evaluation of epilepsy. Stimulation of the contralateral face resulted in waveforms consisting of a negative potential (N2, 162 ± 5 ms; mean ± SE) followed by a positive potential (P2, 340 ± 18 ms). Both waves occurred at longer latency after hand than after facial stimulation. N2 and P2 potentials recorded from the grid correspond well in morphology to those recorded from the scalp in four additional patients tested with the same stimulation paradigm. The N2 waves recorded from the subdural grid occurred at significantly shorter latencies than did those recorded from the scalp (184 ± 6 ms), but the P2 waves at the grid occurred at significantly longer latencies than did those recorded at the scalp (281 ± 13 ms). The amplitudes of the potentials recorded from the grid were maximal over the parietal operculum both for contralateral stimulation of the face or hand and for ipsilateral stimulation of the face. Potentials also were recorded in this area after stimulation of the ipsilateral hand. The cortical distributions of these potentials suggest that their generators are located in the parietal operculum or in the insula, or in both, consistent with previous PET, magnetoencephalographic, and scalp LEP source analyses. These previous analyses provide indirect evidence of nociceptive input to parasylvian cortex because the interpretation of each analysis incorporates multiple assumptions. The present results are the first direct evidence of nociceptive input to the human parasylvian cortex.

Morphology and electrophysiology of the ovulation hormone producing neuro-endocrine cells of the freshwater snail Lymnaea stagnalis (L.)

1980 ◽  
Vol 84 (1) ◽  
pp. 259-271
Author(s):  
T. A. de Vlieger ◽  
K. S. Kits ◽  
A. ter Maat ◽  
J. C. Lodder
Keyword(s):  
Endocrine Cells ◽  
Lymnaea Stagnalis ◽  
Cerebral Ganglion ◽  
Cell Types ◽  
Freshwater Snail ◽  
Bag Cells ◽  
Repetitive Electrical Stimulation ◽  
The Right ◽  
Dorsal Cells ◽  
Stimulation Of

The ovulation hormone producing neuro-endocrine cells of Lymnaea stagnalis, the caudo-dorsal cells (CDC), are comparable to the bag cells of Aplysia. Both cell types are capable of the production of a long-lasting activity (afterdischarge) during which an ovulation hormone is released. The CDC (30 cells in the left cerebral ganglion and 70 cells in the right) are usually electrically silent but an afterdischarge can be brought about in all cells of both groups by direct, repetitive electrical stimulation of single CDC. This is not possible in every preparation, indicating that the CDC can be in different states of excitability. All cells participate in the afterdischarge and fire approximately synchronously. All CDC are electrotonically connected. Results of experiments in which neurones were injected with horseradish peroxidase suggest that the demonstrated electrotonic connexions between the two opposite groups of CDC are brought about by 10-12 special axons.

The Withdrawal Response of a Freshwater Snail (Lymnaea Stagnalis L.)

1975 ◽  
Vol 62 (3) ◽  
pp. 783-796
Author(s):  
ANTHONY COOK
Keyword(s):  
Electrical Stimulation ◽  
Response Latency ◽  
Lymnaea Stagnalis ◽  
Intact Animal ◽  
Freshwater Snail ◽  
Response Decrement ◽  
Withdrawal Response ◽  
The Brain ◽  
Incremental Process ◽  
Stimulation Of

1. Electrical stimulation of a variety of nerves towards the brain results in movements of the neck of the snail similar to those associated with the withdrawal response of the intact animal. 2. The columellar and cervical nerves mediate most of the movements being measured. 3. Repetition of the stimuli results in a decline in response amplitude which is complicated by a superimposed incremental process which is itself subject to a decremental process as stimuli are repeated. 4. As stimuli are repeated the response latency increases. 5. Consecutive stimulation of pairs of nerves indicates that the response decrement is specific to the nerve being stimulated. 6. The involvement of the pleuro-pedal connectives in the response has been demonstrated both in a semi-intact preparation stimulated electrically and in a free-roaming animal treated surgically and stimulated visually. 7. Visual stimuli associated with the withdrawal response are detected by photoreceptors on the head and in the mantle.

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