Specific behavioural responses triggered by identified mechanosensory receptor cells in the apical field of the giant rotifer Asplanchna sieboldi.

1998 ◽  
Vol 201 (2) ◽  
pp. 169-177
Author(s):  
K D Joanidopoulos ◽  
W Marwan
Keyword(s):  
Behavioural Response ◽  
Sensory Receptor ◽  
Receptor Specificity ◽  
Free Swimming ◽  
Behavioural Responses ◽  
Receptor Cells ◽  
Mechanical Interference ◽  
Different Types ◽  
Males And Females ◽  
Stimulation Of

The giant rotifer Asplanchna sieboldi swims by the propulsive effect of thousands of cilia arrayed in clusters around the apical field, which has several mechanosensory structures (sensilla) located at defined positions. Males and females differ in both their patterns of behaviour and their sensory receptor equipment. Unstimulated males swim straight with occasional spontaneous changes in direction until they hit an obstacle with their apical field. Depending on the direction and the strength of the mechanical interference, the animals show different behavioural responses. To analyse the effect of excitation of the apical mechanosensitive sensilla on these responses, males were held on microcapillaries, and the sensitivity of individual sensilla was assayed using micromanipulator-mediated mechanical stimulation. Stimulation of each of the four different types of sensillum triggered a specific and well-defined initial behavioural response. Individual animals behaved identically with respect to the receptor specificity of the responses. The behaviour of free-swimming males upon contact with obstacles or females is discussed on the basis of these results.

Developing guidelines for the use of traps to capture koalas

2020 ◽  
Vol 42 (3) ◽  
pp. 380 ◽  
Author(s):  
Kita R. Ashman ◽  
Desley A. Whisson
Keyword(s):  
Behavioural Response ◽  
Motion Sensing ◽  
Behavioural Responses ◽  
Cost Efficacy ◽  
Males And Females ◽  
The Cost

Capture of wildlife is essential both for research and management, and minimising the amount of stress an animal experiences during capture is important. We examined the behavioural response of koalas to cage traps to improve protocols for trapping koalas. We used heat- and motion-sensing cameras to record the behaviour of koalas in traps, and the duration spent in traps. Behavioural responses were scored on a scale of 0 (no apparent response) to 3 (heightened response) from videos. We successfully trapped a koala in 19 of 21 attempts. For 12 occasions when traps were monitored with cameras, koalas spent 6.3–181.2min in traps and 8 of 12 koalas displayed heightened behavioural responses (score of ≥2). The frequency of response scores did not vary between males and females and was not influenced by trapped duration. We found that traps were effective for capturing koalas; however, to minimise overt behavioural responses by trapped koalas, trap-check intervals need to be as short as possible. We recommend the use of trap-trigger devices to alert personnel when a koala is trapped. The addition of such devices in trapping practices may reduce potential for adverse behavioural responses and improve the cost-efficacy of trapping.

Movements and Motor Patterns of the Buccal Mass of Pleurobranchaea During Feeding, Regurgitation and Rejection

1982 ◽  
Vol 98 (1) ◽  
pp. 195-211
Author(s):  
ANDREW D. McCLELLAN
Keyword(s):  
Motor Activity ◽  
Motor Pattern ◽  
Pattern Generator ◽  
Behavioural Response ◽  
Rhythmic Movements ◽  
Motor Patterns ◽  
Jaw Muscles ◽  
Behavioural Responses ◽  
Buccal Mass ◽  
Different Types

Feeding, regurgitation, and rejection in the marine gastropod Pleurobranchaea all involve similar but not identical rhythmic movements of buccal mass structures such as the radula, jaws and lips. The part of the motor pattern which produces rhythmic radula movement, as recorded in the major external muscles of the buccal mass of behaving semi-intact preparations, was similar during the three different types of behaviour, suggesting that they share a common motor-pattern generator. Other parts of the motor pattern were only obviously different during the vomiting phase of regurgitation. Differences in the function and motor patterns of feeding and rejection are presumably accounted for by differences in the activity of muscles which could not be recorded from in this study (e.g. jaw muscles). A general conclusion is that buccal rhythms in gastropods cannot automatically be assumed to underlie feeding, and this is particularly true for dissected preparations which do not execute a clear behavioural response. It would be necessary either to record motor activity that is unique for a given behaviour, or to employ preparations which execute unambiguous behavioural responses.

Neuronal Mechanisms for the Control of Body Orientation inClione II. Modifications in the Activity of Postural Control System

2000 ◽  
Vol 83 (1) ◽  
pp. 367-373 ◽  
Author(s):  
T. G. Deliagina ◽  
G. N. Orlovsky ◽  
A. I. Selverston ◽  
Y. I. Arshavsky
Keyword(s):  
Defense Reaction ◽  
Postural Control System ◽  
Receptor Cells ◽  
Complete Inactivation ◽  
Reflex Pathways ◽  
Neuronal Mechanisms ◽  
Different Types ◽  
Different Temperatures ◽  
Higher Temperature ◽  
Stimulation Of

The marine mollusk Clione limacina, when swimming, can stabilize different body orientations in the gravitational field. The stabilization is based on the reflexes initiated by activation of the statocyst receptor cells and mediated by the cerebro-pedal interneurons that produce excitation of the motoneurons of the effector organs; tail and wings. Here we describe changes in the reflex pathways underlying different modes of postural activity; the maintenance of the head-up orientation at low temperature, the maintenance of the head-down orientation at higher temperature, and a complete inactivation of the postural mechanisms during defense reaction. Experiments were performed on the CNS-statocyst preparation. Spike discharges in the axons of different types of neurons were recorded extracellularly while the preparation was rotated in space through 360° in different planes. We characterized the spatial zones of activity of the tail and wing motoneurons and the CPB3 interneurons mediating the effects of statocyst receptor cells on the tail motoneurons. This was done at different temperatures (10 and 20°C). The “fictive” defense reaction was evoked by electrical stimulation of the head nerve. At 10°C, a tilt of the preparation evoked activation in the tail motoneurons and wing retractor motoneurons contralateral to the tilt and in the wing locomotor motoneurons ipsilateral to the tilt. At 20°C, the responses in the tail motoneurons and in the wing retractor motoneurons occurred reversed; these neurons were now activated with the ipsilateral tilt. In the wing locomotor motoneurons the responses at 20°C were suppressed. During the defense reaction, gravitational responses in all neuron types were suppressed. Changes in the chains of tail reflexes most likely occurred at the level of connections from the statocyst receptor cells to the CPB3 interneurons. The changes in gravitational reflexes revealed in the present study are sufficient to explain the corresponding modifications of the postural behavior in Clione.

Behavioural responses of wintering black-faced spoonbills (Platalea minor) to disturbance

2014 ◽  
Vol 41 (6) ◽  
pp. 465 ◽  
Author(s):  
Chang-Yong Choi ◽  
Hyun-Young Nam ◽  
Woo-Shin Lee
Keyword(s):  
Management Strategies ◽  
Warning System ◽  
Breeding Site ◽  
Sympatric Species ◽  
Management Plan ◽  
Behavioural Response ◽  
Motor Vehicles ◽  
Behavioural Responses ◽  
Threat Level ◽  
Different Types

Context Behavioural responses can be used to understand the impacts of disturbance on animals and to develop management strategies, and there is considerable conservation interest in quantifying the effects of disturbances on wild animals. Aims We seek to formulate a management plan for the endangered black-faced spoonbills (Platalea minor) in a non-breeding ground, on the basis of their behavioural responses to different types of stimulus categorised by threat level (threatening vs non-threatening) and human involvement (anthropogenic vs natural). Methods We documented 16 stimuli from 379 disturbance events through continuous observation on 31 daily selected focal individuals, and estimated flight distances caused by human approach under different conditions at a non-breeding site in Korea. Key results The spoonbills showed the strongest behavioural response to the non-threatening anthropogenic stimuli, and human approach followed by motor vehicles caused longer responses per event than did any other type of disturbing stimulus. Flight distance caused by human approach varied depending on conditions; inactive spoonbills in mixed-species associations started to flee at the greatest distance (197.4 m, with a 50% probability), whereas the spoonbills in a single conspecific flock were the most tolerant of human approaches, regardless of their activeness (61.0–61.7 m, with a 50% probability). Conclusions Human approach had been identified as the most important disturbing stimulus that should be controlled as a priority. We also suggest that black-faced spoonbills benefit from the presence of other waterbirds and exploit them as an early warning system. Implications The tolerance of sympatric species as well as the behavioural response of target species should be considered when a buffer area for wildlife management, particularly against human disturbance, is planned. How the site has been used and what the species composition is are still important components for the design of safe refuges and roosts.

Properties of Unitary IPSCs in Hippocampal Pyramidal Cells Originating From Different Types of Interneurons in Young Rats

1997 ◽  
Vol 77 (4) ◽  
pp. 1939-1949 ◽  
Author(s):  
Mohamed Ouardouz ◽  
Jean-Claude Lacaille
Keyword(s):  
Reversal Potential ◽  
Pyramidal Cells ◽  
Mean Amplitude ◽  
Paired Pulse ◽  
Young Rats ◽  
Different Types ◽  
The Mean ◽  
Paired Pulse Depression ◽  
Types Of Interneurons ◽  
Stimulation Of

Ouardouz, Mohamed and Jean-Claude Lacaille. Properties of unitary IPSCs in hippocampal pyramidal cells originating from different types of interneurons in young rats. J. Neurophysiol. 77: 1939–1949, 1997. Whole cell recordings were used in hippocampal slices of young rats to examine unitary inhibitory postsynaptic currents (uIPSCs) evoked in CA1 pyramidal cells at room temperature. Loose cell-attached stimulation was applied to activate single interneurons of different subtypes located in stratum oriens (OR), near stratum pyramidale (PYR), and at the border of stratum radiatum and lacunosum-moleculare (LM). uIPSCs evoked by stimulation of PYR and OR interneurons had similar onset latency, rise time, peak amplitude, and decay. In contrast, uIPSCs elicited by activation of LM interneurons were significantly smaller in amplitude and had a slower time course. The mean reversal potential of uIPSCs was −53.1 ± 2.1 (SE) mV during recordings with intracellular solution containing potassium gluconate. With the use of recording solution containing the potassium channel blocker cesium, the reversal potential of uIPSCs was not significantly different (−58.5 ± 2.6 mV), suggesting that these synaptic currents were not mediated by potassium conductances. Bath application of the γ-aminobutyric acid-A (GABAA) receptor antagonist bicuculline (25 μM) reversibly blocked uIPSCs evoked by stimulation of all interneuron subtypes. In bicuculline, the mean peak amplitude of uIPSCs recorded with potassium gluconate was reduced to 3.5 ± 4.4% of control ( n = 7). Similarly, with cesium methanesulfonate, the mean amplitude in bicuculline was 2.9 ± 3.1% of control ( n = 13). Application of the GABAB receptor antagonist CGP 55845A (5 μM) resulted in a significant and reversible increase in the mean amplitude of uIPSCs recorded with cesium-containing intracellular solution. Thus uIPSCs from all cell types appeared under tonic presynaptic inhibition by GABAB receptors. Paired stimulation of individual interneurons at 100- to 200-ms intervals did not result in paired pulse depression of uIPSCs. For individual responses, a significant negative correlation was observed between the amplitude of the first and second uIPSCs. A significant paired pulse facilitation (154.0 ± 8.0%) was observed when the first uIPSC was smaller than the mean of all first uIPSCs. A small, but not significant, paired pulse depression (90.8 ± 4.0%) was found when the first uIPSC was larger than the mean of all first uIPSCs. Our results indicate that these different subtypes of hippocampal interneurons generate Cl−-mediated GABAA uIPSCs. uIPSCs originating from different types of interneurons may have heterogeneous properties and may be subject to tonic presynaptic inhibition via heterosynaptic GABAB receptors. These results suggest a specialization of function for inhibitory interneurons and point to complex presynaptic modulation of interneuron function.

scholarly journals At a snail’s pace: the influence of habitat disturbance on terrestrial snail movement using experimentally manipulated mesocosms

2021 ◽  
Author(s):  
Emily E. Denief ◽  
Julie W. Turner ◽  
Christina M. Prokopenko ◽  
Alec L. Robitaille ◽  
Eric Vander Wal
Keyword(s):  
Experimental Approach ◽  
Movement Ecology ◽  
Behavioural Response ◽  
Habitat Alteration ◽  
Movement Behaviour ◽  
Physical Disturbance ◽  
Behavioural Responses ◽  
Cepaea Nemoralis ◽  
Experimental Mesocosms ◽  
Step Selection

AbstractThe Anthropocene marks great changes to environments and the animals that inhabit them. Changes, such as disturbance, can affect the manner in which animals interact with their environments, such as moving and selecting habitats. To test how animals might respond to changing disturbance regimes, we employ an experimental approach to movement ecology. We used integrated step selection analysis (iSSA) to test the behavioural responses of individually-marked grove snails (Cepaea nemoralis) exposed to a gradient of physical disturbance in their habitat. We used a before-after control-impact (BACI) experimental design within semi-controlled mesocosms to manipulate edge and disturbance variables by altering the area of the mesocosm covered by bricks. We showed that grove snails perceive edges of enclosures and edges of bricks as risks, and responded to such risks by altering their movement. Grove snails displayed a bimodal response to risk by taking shelter in place or moving faster to be farther from the disturbance. Furthermore, individuals tended to modulate their behavioural response to the degree of risk. Our study highlights the usefulness of experimental mesocosms in movement ecology and in determining the effects of habitat alteration and human-imposed risk on movement behaviour.

scholarly journals Electrical Stimulation for Immune Modulation in Cancer Treatments

2022 ◽  
Vol 9 ◽  
Author(s):  
Ritopa Das ◽  
Sofia Langou ◽  
Thinh T. Le ◽  
Pooja Prasad ◽  
Feng Lin ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Immune System ◽  
Immune Modulation ◽  
Cancer Treatments ◽  
Different Types ◽  
Specific Antigens ◽  
High Doses ◽  
T Cell Transfer ◽  
Deficient Mice ◽  
Stimulation Of

Immunotherapy is becoming a very common treatment for cancer, using approaches like checkpoint inhibition, T cell transfer therapy, monoclonal antibodies and cancer vaccination. However, these approaches involve high doses of immune therapeutics with problematic side effects. A promising approach to reducing the dose of immunotherapeutic agents given to a cancer patient is to combine it with electrical stimulation, which can act in two ways; it can either modulate the immune system to produce the immune cytokines and agents in the patient’s body or it can increase the cellular uptake of these immune agents via electroporation. Electrical stimulation in form of direct current has been shown to reduce tumor sizes in immune-competent mice while having no effect on tumor sizes in immune-deficient mice. Several studies have used nano-pulsed electrical stimulations to activate the immune system and drive it against tumor cells. This approach has been utilized for different types of cancers, like fibrosarcoma, hepatocellular carcinoma, human papillomavirus etc. Another common approach is to combine electrochemotherapy with immune modulation, either by inducing immunogenic cell death or injecting immunostimulants that increase the effectiveness of the treatments. Several therapies utilize electroporation to deliver immunostimulants (like genes encoded with cytokine producing sequences, cancer specific antigens or fragments of anti-tumor toxins) more effectively. Lastly, electrical stimulation of the vagus nerve can trigger production and activation of anti-tumor immune cells and immune reactions. Hence, the use of electrical stimulation to modulate the immune system in different ways can be a promising approach to treat cancer.

Response of western diamondback rattlesnakesCrotalus atroxto airborne sounds

2002 ◽  
Vol 205 (19) ◽  
pp. 3087-3092 ◽  
Author(s):  
Bruce A. Young ◽  
Amie Aguiar
Keyword(s):  
Experimental Evidence ◽  
Frequency Modulation ◽  
Stimulus Presentation ◽  
Behavioural Response ◽  
Acoustic Energy ◽  
Body Movements ◽  
Perception Threshold ◽  
Behavioural Responses ◽  
Acoustic Chamber ◽  
Tongue Flicking

SUMMARYIn order to test the hypothesis that snakes can not only perceive airborne sounds, but also respond to them, an acoustic isolation chamber was designed and constructed to perform best within the 150-450 Hz range in which snakes perceive sound. Suspended within this acoustic chamber was a steel mesh basket designed to minimize the potential for groundborne vibrations. A synthesized tone was created out of 20 different 150 ms sounds, each separated by a 50 ms period of silence; the acoustic energy of each of the 20 sounds was concentrated between 200-400 Hz, and each sound included frequency modulation. The trial stimuli were presented to western diamondback rattlesnakes Crotalus atrox at a level 5-10 dB above their perception threshold. Four significant behavioural responses were observed upon stimulus presentation: cessation of body movements, reduction or cessation of tongue flicking, rapid jerks of the head and rattling. At least one significant behavioural response was observed in 92% of the behavioural trials. This study provides the first experimental evidence that snakes can respond behaviourally to airborne sounds.

Modulation of Hydra attenuata rhythmic activity: phase response curve

1976 ◽  
Vol 65 (3) ◽  
pp. 737-751
Author(s):  
C. Taddei-Ferretti ◽  
L. Cordella
Keyword(s):  
Response Curve ◽  
Phase Response Curve ◽  
Rhythmic Activity ◽  
Light Stimulation ◽  
Pulse Trains ◽  
Activity Phase ◽  
Photic Stimulus ◽  
Different Types ◽  
Hydra Attenuata ◽  
Stimulation Of

We investigated the effect of photic stimulation on the frequency of Hydra attenuata column contractions. We used positive or negative abrupt light transitions, single or repetitive light or darkness pulses, and alternation of light and darkness periods. The main results are: (a) The frequency of the contraction pulse trains (CPTs) varies transiently in response to an abrupt variation of the light intensity. (b) CPTs in progress can be inhibited by different types of photic stimuli. (c) The response time to a single photic stimulus varies during the inter-CPT interval and depends also on the polarity of the stimulus. (d) The CPTs are entrainable with repetitive light stimulation of various frequencies. (e) Long-lasting variations of the frequency of CPTs occur after the end of a repetitive light stimulation. We suggest that the mechanism responsible for the rhythym of column contractions is quite similar to that on which other biological rhythmic phenomena are based.

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