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.

The whole-body withdrawal response of Lymnaea stagnalis. II. Activation of central motoneurones and muscles by sensory input

1991 ◽  
Vol 158 (1) ◽  
pp. 97-116 ◽  
Author(s):  
G. P. Ferguson ◽  
P. R. Benjamin
Keyword(s):  
Action Potentials ◽  
Sensory Input ◽  
Lymnaea Stagnalis ◽  
Intact Animal ◽  
The Body ◽  
Resting Potential ◽  
Whole Body ◽  
Withdrawal Response ◽  
Stimulation Of

The role of centrally located motoneurones in producing the whole-body withdrawal response of Lymnaea stagnalis (L.) was investigated. The motoneurones innervating the muscles used during whole-body withdrawal, the columellar muscle (CM) and the dorsal longitudinal muscle (DLM) were cells with a high resting potential (−60 to −70 mV) and thus a high threshold for spike initiation. In both semi-intact and isolated brain preparations these motoneurones showed very little spontaneous spike activity. When spontaneous firing was seen it could be correlated with the occurrence of two types of spontaneous excitatory postsynaptic potential (EPSP). One was a unitary EPSP that occasionally caused the initiation of single action potentials. The second was a larger-amplitude, long-duration (presumably compound) EPSP that caused the motoneurones to fire a burst of high-frequency action potentials. This second type of EPSP activity was associated with spontaneous longitudinal contractions of the body in semi-intact preparations. Tactile stimulation of the skin of Lymnaea evoked EPSPs in the CM and DLM motoneurones and in some other identified cells. These EPSPs summated and usually caused the motoneurone to fire action potentials, thus activating the withdrawal response muscles and causing longitudinal contraction of the semi-intact animal. Stimulating different areas of the body wall demonstrated that there was considerable sensory convergence on the side of the body ipsilateral to stimulation, but less on the contralateral side. Photic (light off) stimulation of the skin of Lymnaea also initiated EPSPs in CM and DLM motoneurones and in some other identified cells in the central nervous system (CNS). Cutting central nerves demonstrated that the reception of this sensory input was mediated by dermal photoreceptors distributed throughout the epidermis. The activation of the CM and DLM motoneurones by sensory input of the modalities that normally cause the whole-body withdrawal of the intact animal demonstrates that these motoneurones have the appropriate electrophysiological properties for the role of mediating whole-body withdrawal.

Motivation for electrical stimulation of the brain and for natural reinforcement in mice

1972 ◽  
Vol 35 (2) ◽  
pp. 366-377 ◽  
Author(s):  
Clark T. Randt ◽  
David Quartermain
Keyword(s):  
Electrical Stimulation ◽  
The Brain ◽  
Stimulation Of

Electroencephalographic Changes During Plateau Waves — Plateau Waves Induced by Electrical Stimulation of the Brain Stem

1989 ◽  
pp. 235-237
Author(s):  
Y. Kogure ◽  
H. Fujii ◽  
S. Higashi ◽  
M. Hashimoto ◽  
K. Tokuda ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Brain Stem ◽  
Plateau Waves ◽  
The Brain ◽  
Stimulation Of

Brain stem responses to electrical stimulation of ventral vagal gastric fibers

1989 ◽  
Vol 257 (1) ◽  
pp. G24-G29
Author(s):  
W. D. Barber ◽  
C. S. Yuan
Keyword(s):  
Electrical Stimulation ◽  
Brain Stem ◽  
Time Of Arrival ◽  
Neuronal Responses ◽  
Proximal Stomach ◽  
Afferent Fibers ◽  
Sensory Modalities ◽  
The Mean ◽  
The Brain ◽  
Stimulation Of

The brain stem neuronal responses to electrical stimulation of gastric branches of the ventral vagal trunk serving the proximal stomach were localized and evaluated in anesthetized cats. The responses were equally distributed bilaterally in the region of nucleus solitarius in the caudal brain stem. The mean latency of the response was 289 +/- 46 (SD) ms, which translated into a conduction velocity of less than 1 m/s based on the distance between the stimulating and recording electrodes. The responses consisted of single and multiple spikes that showed slight variability in the latency, indicating orthodromic activation via a synapse in approximately 98% of the responses recorded. Forty two percent of the units tested showed evidence of convergence of input from vagal afferent fibers in different branches of the ventral vagal trunk that served the proximal stomach. The resultant activity pattern of the unitary response appeared to be the product of 1) the gastric sensory input or modality conveyed by the afferent source and 2) the time of arrival and diversity of modalities served by other gastric afferents impinging on the unit. This provides a mechanism capable of responding on the basis of specific sensory modalities that dynamically reflect ongoing events monitored and conveyed by other gastric afferents in the region.

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