Model investigation of neuronal mechanisms of discrimination between two tactile stimuli in snails

1984 ◽  
Vol 15 (6) ◽  
pp. 445-450
Author(s):  
D. B. Logunov ◽  
M. I. Konnov
Keyword(s):  
Model Investigation ◽  
Tactile Stimuli ◽  
Neuronal Mechanisms

Neuronal correlates of siphon withdrawal in freely behaving Aplysia

1979 ◽  
Vol 42 (6) ◽  
pp. 1538-1556 ◽  
Author(s):  
J. E. Kanz ◽  
L. B. Eberly ◽  
J. S. Cobbs ◽  
H. M. Pinsker
Keyword(s):  
Low Frequency ◽  
Short Latency ◽  
Moderate Intensity ◽  
Efferent Activity ◽  
Nerve Cuff ◽  
Tactile Stimuli ◽  
Cuff Electrodes ◽  
Neuronal Mechanisms ◽  
Wide Range ◽  
Freely Behaving

1. Central neuronal mechanisms of siphon withdrawal in Aplysia were studied for the first time in intact, freely behaving animals by means of population recordings from implanted whole-nerve cuff electrodes. Intracellular follow-up studies were then conducted when the same animal was reduced to a semi-intact preparation. 2. Background spontaneous activity in the siphon nerve consisted of low-frequency firing of a population of efferent units containing identified siphon motoneurons. 3. Spontaneous patterned bursts of efferent activity occurred irregularly and were associated with all-or-nothing contractions of the parapodia, gill, and siphon. Spontaneous bursts were due to centrally generated activity in the interneuron II (INT II) network, an oscillatory network with endogenous pacemaker properties. 4. In intact animals, even weak tactile stimuli to the siphon typically triggered an INTII burst shortly after the stimulus-locked efferent activity. Thus, the stimulus can phase-advance the INT II oscillator. In semi-intact preparations, short-latency INT II bursts were triggered less less frequently and required more intense stimuli. 5. With weak to moderate-intensity stimuli in intact animals, the presence of short-latency triggered INT II bursts largely determined the duration of the siphon component and amplitude of the gill component of the withdrawal reflex. 6. When stimuli were repeated over a range of interstimulus intervals (from 60 to 1 min), the likelihood of triggering a short-latency INT II burst die not change systematically. Thus, the ability of the siphon stimulus to stably entrain the all-or-none INT II component over a wide range of intervals will interact behaviorally with the decrement of the monosynaptic component of the reflex with repetition.

scholarly journals Serotonergic control in initiating defensive responses to unexpected tactile stimuli in the trap-jaw ant Odontomachus kuroiwae

2020 ◽  
Vol 223 (19) ◽  
pp. jeb228874 ◽  
Author(s):  
Hitoshi Aonuma
Keyword(s):  
Oral Administration ◽  
Defensive Behavior ◽  
Tactile Stimulation ◽  
Defensive Response ◽  
Potential Threat ◽  
Defensive Responses ◽  
Tactile Stimuli ◽  
Neuronal Mechanisms ◽  
The Brain ◽  
Unexpected Stimulus

ABSTRACTThe decision to express either a defensive response or an escape response to a potential threat is crucial for insects to survive. This study investigated an aminergic mechanism underlying defensive responses to unexpected touch in an ant that has powerful mandibles, the so-called trap-jaw. The mandibles close extremely quickly and are used as a weapon during hunting. Tactile stimulation to the abdomen elicited quick forward movements in a dart escape in 90% of the ants in a colony. Less than 10% of the ants responded with a quick defensive turn towards the source of stimulation. To reveal the neuronal mechanisms underlying this defensive behavior, the effect of brain biogenic amines on the responses to tactile stimuli were investigated. The levels of octopamine (OA), dopamine (DA) and serotonin (5HT) in the brain were significantly elevated in ants that responded with a defensive turn to the unexpected stimulus compared with ants that responded with a dart escape. Oral administration of DA and 5HT demonstrated that both amines contributed to the initiation of a defensive response. Oral administration of l-DOPA weakly affected the initiation of the defensive turn, while 5-hydroxy-l-tryptophan (5HTP) strongly affected the initiation of defensive behavior. Oral administration of ketanserin, a 5HT antagonist, inhibited the initiation of the defensive turn in aggressive workers, abolishing the effects of both 5HT and 5HTP on the initiation of turn responses. These results indicate that 5HTergic control in the nervous system is a key for the initiation of defensive behavior in the trap-jaw ant.

scholarly journals The sensory code within sense of time

2021 ◽  
Author(s):  
Sebastian Reinartz ◽  
Arash Fassihi ◽  
Luciano Paz ◽  
Francesca Pulecchi ◽  
Marco Gigante ◽  
...  
Keyword(s):  
Time Perception ◽  
Sensory Cortex ◽  
Process Time ◽  
Sensory Coding ◽  
Causal Function ◽  
Tactile Stimuli ◽  
Primary Sensory Cortex ◽  
Neuronal Mechanisms ◽  
Sense Of Time ◽  
Sensory Code

Sensory experiences are accompanied by the perception of the passage of time; a cell phone vibration, for instance, is sensed as brief or long. The neuronal mechanisms underlying the perception of elapsed time remain unknown1. Recent work agrees on a role for cortical processing networks2,3, however the causal function of sensory cortex in time perception has not yet been specified. We hypothesize that the mechanisms for time perception are embedded within primary sensory cortex and are thus governed by the basic rules of sensory coding. By recording and optogenetically modulating neuronal activity in rat vibrissal somatosensory cortex, we find that the percept of stimulus duration is dilated and compressed by optogenetic excitation and inhibition, respectively, during stimulus delivery. A second set of rats judged the intensity of tactile stimuli; here, optogenetic excitation amplified the intensity percept, demonstrating sensory cortex to be the common gateway to both time and stimulus feature processing. The coding algorithms for sensory features are well established4–10. Guided by these algorithms, we formulated a 3–stage model beginning with the membrane currents evoked by vibrissal and optogenetic drive and culminating in the representation of perceived time; this model successfully replicated rats′ choices. Our finding that stimulus coding is intrinsic to sense of time disagrees with dedicated pacemaker-accumulator operation models11–13, where sensory input acts only to trigger the onset and offset of the timekeeping process. Time perception is thus as deeply intermeshed within the sensory processing pathway as is the sense of touch itself14,15 and can now be treated through the computational language of sensory coding. The model presented here readily generalizes to humans14,16 and opens up new approaches to understanding the time misperception at the core of numerous neurological conditions17,18.

Independent Controls of Attentional Influences in Primary and Secondary Somatosensory Cortex

2005 ◽  
Vol 94 (6) ◽  
pp. 4094-4107 ◽  
Author(s):  
C. Elaine Chapman ◽  
El-Mehdi Meftah
Keyword(s):  
Somatosensory Cortex ◽  
Neuronal Responses ◽  
Directed Attention ◽  
Cell Discharge ◽  
Secondary Somatosensory Cortex ◽  
Tactile Stimuli ◽  
Neuronal Mechanisms ◽  
Additive Increase ◽  
Single Unit Recordings ◽  
Marked Suppression

The neuronal mechanisms underlying enhanced perception of tactile stimuli with directed attention were investigated using single-unit recordings from primary (S1, n = 53) and secondary (S2, n = 50) somatosensory cortex in macaque monkeys. Neuronal responses to textures scanned under the digit tips (spatial periods, SP, of 2, 3.7 or 4.7 mm) were recorded while attention was directed either to discriminating a change in texture or to the reward and also in a neutral no-task condition. Cell discharge was quantified in three periods of the trials: salient Δ texture (directed attention), postreward, and static (both cases, attention directed to the reward). S1 texture- and non-texture-sensitive cells, as well as S2 non-texture-sensitive cells, showed a modest enhancement of discharge during the salient Δ texture period (∼25%) but no change in response gain, consistent with an additive increase in neuronal responsiveness with directed attention. In contrast, S2 texture-related cells showed a larger enhancement with directed attention to salient inputs (82%) and increased response gain, suggesting that directed attention produces a multiplicative increase in S2 responsiveness. During the postreward period, and also in no-task testing, S1 texture-sensitive cells preserved their sensitivity to SP. In contrast, S2 texture-, but not non-texture-, sensitive cells showed a marked suppression of discharge and decreased gain after the discrimination response. Together, the results support the notion that S2 discharge reflects stimulus parameters in relation to ongoing behavioral demands. The results also support the existence of two independent attentional mechanisms in somatosensory cortex, one generalized (S1 and S2), and the other focused on S2 texture-related cells.

scholarly journals Control of Locomotion in the Freshwater Snail Planorbis Corneus: II. Differential Control of Various Zones of the Ciliated Epithelium

1990 ◽  
Vol 152 (1) ◽  
pp. 405-423
Author(s):  
T. G. DELIAGINA ◽  
G. N. ORLOVSKY
Keyword(s):  
Locomotor Activity ◽  
Freshwater Snail ◽  
Ciliated Epithelium ◽  
Small Disk ◽  
Ciliary Beating ◽  
Tactile Stimuli ◽  
Neuronal Mechanisms ◽  
Planorbis Corneus ◽  
Differential Control ◽  
Spontaneous Fluctuations

In the freshwater snail Planorbis corneus, the neuronal mechanisms of the pedal ganglia that control ciliary locomotion were studied. The foot was attached to the bottom of a recording chamber with the ciliated epithelium facing upwards. To record the total motor effect produced by ciliary beating, a small disk with its edge lying on the sole of the foot was used. The ciliary beating forced the disk to rotate. In the pedal ganglia, efferent locomotor neurones (ELNs) were found, which control the locomotor activity of the ciliated epithelium. This locomotor activity increased with excitation of an ELN, and decreased with its inhibition. Axons of the ELNs, controlling the anterior, middle and posterior zones, traverse the corresponding pedal nerves. For the anterior zone, two ELNs were found. For the middle and posterior zones, only one ELN per zone was found. The activity of ELNs correlated with the intensity of ciliary beating during the following central and reflex influences upon the locomotor mechanisms: (1) spontaneous fluctuations of the locomotor activity, (2) changes of temperature, (3) transections of central connections (interganglionic connectives), (4) defensive reactions evoked by tactile stimuli or switching off the light, and (5) activation of feeding behaviour by natural stimuli. The data strongly suggest that ELNs are responsible for the differential control of locomotor activity in various zones of the ciliated epithelium during different behavioural acts.

Somatosensory processing of non-painful tactile stimuli in patients with idiopathic trigeminal neuralgia

2006 ◽  
Vol 33 (S 1) ◽  
Author(s):  
E. Sarpaczki ◽  
M. Blatow ◽  
E. Nennig ◽  
A. Durst ◽  
D. Rasche ◽  
...  
Keyword(s):  
Trigeminal Neuralgia ◽  
Somatosensory Processing ◽  
Tactile Stimuli ◽  
Idiopathic Trigeminal Neuralgia

Evaluation of Body Sway Using Tactile Stimuli on the Body Trunk

2016 ◽  
Vol 136 (8) ◽  
pp. 1135-1141
Author(s):  
Ryo Hasegawa ◽  
Amir Maleki ◽  
Masafumi Uchida
Keyword(s):  
The Body ◽  
Body Sway ◽  
Tactile Stimuli
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