Central pathways of the nerves of the arms and mantle of Octopus

1985 ◽  
Vol 310 (1143) ◽  
pp. 109-122 ◽  
Keyword(s):  
Frontal Lobes ◽  
Learning System ◽  
Lower Edge ◽  
Optic Lobes ◽  
Basal Lobe ◽  
Tactile Learning

Centripetal cobalt filling of a brachial nerve of Octopus gave further information about the organization of its tactile learning system. Efferent fibres pass from the posterior buccal and subvertical lobes direct to the arms. Afferent fibres from the arms pass to the lateral and median inferior frontal lobes, others to the lateral and median superior frontal lobes, and a third set to the subvertical lobe. None reach to the vertical or subfrontal lobes. Many somata and afferent fibres were filled in the magnocellular lobes after filling either the brachial or pallial nerves. This is probably a region from which escape reactions are initiated. The lower part of the median basal lobe also receives afferents from both these nerves and a few somata were filled at the lower edge of this lobe. It probably controls the magnocellular lobe, lying below it. After filling of a brachial nerve, or the pallial nerve, somata were filled in both the anterior and posterior chromatophore lobes, but few or no afferent fibres were filled in these lobes. After filling of a brachial nerve many somata and afferent fibres were filled in the prebrachial and brachial lobes and in the anterior pedal lobe, and many fine afferent fibres and a few somata were filled in the superior buccal lobe. After filling of the pallial nerve some filled fibres run forwards to the brachial lobe, but no somata were filled there. No filled fibres from either the brachial or pallial nerves were seen proceeding towards the optic lobes.

The Median Inferior Frontal Lobe and Touch Learning in the Octopus

1972 ◽  
Vol 56 (2) ◽  
pp. 381-402
Author(s):  
M. J. WELLS ◽  
J. Z. YOUNG
Keyword(s):  
Frontal Lobe ◽  
Visual Learning ◽  
Frontal Lobes ◽  
Learning System ◽  
The Other ◽  
Reverse Direction ◽  
Tactile Learning ◽  
Smooth Objects ◽  
Smooth Sphere ◽  
Do So

1. After removal of the median inferior frontal lobe, blinded octopuses already trained to discriminate by touch between rough and smooth spheres continued to do so, but at a lower level of accuracy. 2. Animals without pre-training showed a strong tendency to take rough objects after this operation and learned to discriminate well only when trained to take rough and reject smooth. 3. When animals with intact inferior frontal lobes were given food in the presence of a smooth sphere they learned to take the smooth; in subsequent extinction tests they continued to take the smooth but soon ceased to take rough objects. 4. Animals without median inferior frontal lobes also increased their tendency to take a smooth object associated with food. But they did not behave in the same way as controls in extinction tests; they continued to take the rough objects even if they had not been rewarded for doing so. 5. Operated animals thoroughly pre-trained to take smooth objects showed some capacity to discriminate these from rough objects in subsequent successive training with food and shock, though continuing to take the rough far more than control animals. 6. Animals without brain damage could be taught to take smooth rather than rough objects on one side, and continued to do so when trained in the reverse direction on the other. There was, however, some lateral interference; performance on the unreversed side was worse after the introduction of reversed training. 7. Animals with lesions to the median inferior frontal lobe failed to learn on the reversal (rough+/smooth-) side, responses to both objects declining progressively as training continued. At the same time as this discrimination by the non-reversal (smooth+/rough-) side continued to develop. There was thus no evidence of lateral transfer in these animals. 8. It was confirmed that tactile learning is still possible after removal of the vertical and basal lobes, but with some decrease in the normal preference for smooth objects. 9. The median inferior frontal is thus not essential for tactile learning, but greatly facilitates it, making some contribution to the acquisition of both positive and negative responses, perhaps by spreading information through both sides of the touch-learning system. The effect of its removal in touch learning can be compared with the effect of vertical lobe removal on visual learning. It is concluded that one function of these parts is to compensate for the intensity of stimulation so that animals do not pay undue attention to brightly reflective or texturally rough objects.

A memory system in Octopus vulgaris Lamarck

1955 ◽  
Vol 143 (913) ◽  
pp. 449-480 ◽  
Keyword(s):  
Optic Lobe ◽  
Complete Removal ◽  
Frontal Lobes ◽  
Octopus Vulgaris ◽  
Partial Removal ◽  
Retinal Surface ◽  
Optic Lobes ◽  
Neural Activities ◽  
Inhibitory Region ◽  
Set Up

An octopus that has attacked a crab shown with a square and received a shock rapidly learns not to attack when this situation appears again, while continuing to attack crabs shown alone. The memory preventing attack on crabs shown with a white square may last for 2 or 3 days if the crab and square are not shown during that period. If the situation is shown three times a day the memory may last for 6 days or longer. The memory is not erased by anaesthesia nor by electrical stimulation of the supra-oesophageal lobes. After complete removal of the vertical lobe, or of the medial superior frontal lobe, or section of the tract between the two, the memory preventing attack is lost and cannot again be acquired. Animals operated in this way attack a crab and square if shown at 2-hourly intervals in spite of the numerous shocks they receive. A transitory memory lasting a few minutes can still be set up if the frequency of presentation is increased to about once every 5 min. Partial removal of the vertical lobe system does not interrupt the memory. A memory set up by the use of one eye is not abolished if the optic lobe of that side is later removed. The memory is not interrupted by slashes in both optic lobes. After lesions to the lateral parts of the superior frontal lobes an octopus makes few or no further attacks on crabs, unless these are placed close to the animal. The effect of such an operation is to upset the balance of central neural activities in such a way that a region responsible for inhibiting attacks on distant objects assumes control. This inhibitory region may be the first subvertical lobe, whose action is normally balanced by the lateral superior frontal lobes and the vertical lobe. The tangle of fibre bundles within the optic lobes allows for a wide degree of interaction between impulses arriving from different parts of the retinal surface. In addition, these lobes receive afferent fibres from the arms. They thus provide a system within which associations between given sets of inputs can be set up in such a way as to ensure that there is no attack when a similar set of inputs occurs again. Further plexiform arrangements are found in the pathway from the optic to the superior frontal lobes and from the latter to the vertical lobe. These plexuses make possible the interaction in each succeeding lobe of impulses arriving from distant parts of the preceding lobe. Each lobe can thus serve to record the pattern of associations present in the previous one. Since the arrangement is circular the pattern originating in the optic lobe is then re-presented back to it. It is suggested that the vertical lobe system serves to prolong memories set up in the optic lobes by re-presenting them from within, and thus allowing them to persist for long enough to produce some change of a more permanent nature.

The nervous system of Loligo , III. Higher motor centres: the basal supraoesophageal lobes

1977 ◽  
Vol 276 (948) ◽  
pp. 351-398 ◽  
Keyword(s):  
Functional Organization ◽  
Tracking System ◽  
Efference Copy ◽  
Small Cells ◽  
Similar System ◽  
Optic Lobes ◽  
First Order ◽  
Basal Lobe ◽  
Parallel Fibres ◽  
Tracking Movements

The three main basal lobes are orientated in different planes set approximately at right angles. The components of each are similar and based on an organization reminiscent of a cerebellum, like that of the peduncle lobes. They all have large cells and fibres ventrally and numerous small cells dorsally. Each of the two parts of the anterior basal lobe contains a region with numerous very fine parallel fibres, similar to the ‘spine’ of the peduncle lobes. The dorsal basal lobes contain a similar system, but less regular. The three main parts of the basal lobe system all send fibres to the oculomotor centres of the lateral pedal lobes. The two parts of the anterior basal lobe also send fibres to the centres controlling arm movements in the anterior pedal lobe. The median basal lobe sends large tracts to the posterior pedal lobe, controlling movement of the funnel and fins. It also sends a large tract to the region of the first order giant cell, initiating the jet. There is a further massive system of descending fibres from all the basal lobes (and the precommissural lobe) sending branches to all parts of the magnocellular and palliovisceral lobes. The functional organization of the basal and peduncle lobes can be understood as follows. They all receive visual and static inputs and send large outputs to the oculomotor centre and back to the optic lobes. The oculomotor centre also receives direct inputs from the statocyst. The control of eye movements is thus organized in cephalopods in the same way as it is in vertebrates: there is a direct static input to the oculomotor centre, which also receives indirect static influences combined with visual ones, by way of the cerebellum in vertebrates, or basal and peduncle lobes in cephalopods. The basal and peduncle lobes show further similarity to the cerebellum in the presence of the numerous parallel fibres of various diameters, some very fine. These lobes receive dorsal and ventral sets of visual fibres and a set from the magnocellular lobes. The dorsal visual fibres follow the topology of the optic lobes and it is suggested that they provide a tracking system. The numerous fibres passing back from the basal lobes to the optic lobes, allow for a ‘corollary discharge’ (‘efference copy’). The ventral set of large fibres from the optic lobes to the basal lobes may serve to promote the final attack, after the smaller fibres have produced the preliminary tracking movements. The system of large fibres from the magnocellular to the basal lobes are perhaps concerned with avoiding reactions. Each of the large fibres of both of these sets gives branches to all parts of the basal lobes. All the basal lobes contain many microneurons with trunks limited to the lobes. Some of these are very short amacrines. The median basal and dorsal basal lobes contain especially numerous small cells, perhaps neurosecretory and related to reproduction by way of the optic gland, whose nerve arises nearby.

Paired centres for the control of attack by Octopus

1964 ◽  
Vol 159 (977) ◽  
pp. 565-588 ◽  
Keyword(s):  
Visual Field ◽  
Visual System ◽  
Frontal Lobes ◽  
Adaptive Behaviour ◽  
Optic Lobes ◽  
In Series ◽  
Pain Receptors ◽  
Set Up ◽  
Lower Loop

The vertical lobe system in Octopus is concerned in the regulation of the tendency to attack. It receives impulses from the optic lobes, from touch and chemoreceptors and from pain receptors. The visual part of the system is organized into lower and upper loops. The lower loop leads from the optic lobes, through two centres and back to the optic lobes. The upper loop also consists of two centres, superposed in parallel above the lower ones. Each of the two loops thus contains two centres in series and it is suggested that the first centre of each pair tends to promote attack and the second to restrain or prevent it. The net effect of the two centres of each pair together is to increase the probability of attack, unless pain intervenes. After any interruption of the lower loop an octopus does not launch out to attack a crab moving in its visual field, although it still puts out an arm to take a crab that is within reach. The impulses set up in the visual system cannot release an attack without the 'amplification’ produced by the centres of the lower loop. After interruption of the upper loop the octopus is still able to attack but the animals make errors both in failure to attack when rewarded with food and in continuing to attack in spite of shocks. Individual untrained octopuses were found to show consistent differences, in tendency to attack crabs, and these differences survived anaesthesia and dummy operation. However, any interruption of the upper loop tended to reverse the previous attack tendency. When the tendency to attack was high it was decreased by removal of the median superior frontal but not by removal of the vertical lobes. Removal of the median superior frontal after the vertical leads to a reduction in attacks, but removing the vertical after the superior frontal was followed by an increase. This evidence that the median superior frontal increases the tendency to attack and the vertical lobe reduces it was confirmed at longer periods after operation. Attacks at crabs in spite of shocks continued longer after removal of either lobe than in controls, but more attacks were made by animals without vertical than without median superior frontal lobes. The main output of the superior frontal is through the vertical and thus any injury affects both functions. However, severing the tract between them or removing both of them produced effects different from removing either alone. Each therefore has some effect when acting in isolation, though they normally operate together to influence the attack behaviour. There was greatly increased variability between individuals and within the performance of each individual after any interference with the vertical lobe system. This upper loop thus serves to produce stable and consistently adaptive behaviour, in addition to other effects that it may have in the process of learning.

The nervous system of Loligo . V. The vertical lobe complex

1979 ◽  
Vol 285 (1009) ◽  
pp. 311-354 ◽  
Keyword(s):  
Nervous System ◽  
Frontal Lobe ◽  
Frontal Lobes ◽  
Optic Lobes ◽  
Buccal Mass ◽  
Large Neurons ◽  
Skin Receptors ◽  
Large Output

The vertical lobe system is described in Loligo and Sepia . It receives inputs from the optic lobes, arms, mouth and skin receptors. These inputs are combined and passed through a system with several superimposed loops. The output includes large neurons reaching to control centres for the arms and mantle, which initiate movements of attack or retreat. Another part of the output passes back to the optic lobes. The vertical lobe system receives no input from the statocyst and has few connections with the basal lobes. The inferior frontal lobe allows interaction of impulses from the arms, mouth, mantle and skin. Its outputs pass to the buccal mass and arms and upwards to the superior frontal lobe. The latter has two parts comparable to those found in octopods, communicating with the vertical and subvertical lobes. The inferior and superior frontal lobes contain no microneurons with axons restricted to the lobe. The vertical lobes are strikingly different from those of octopods. They are not divided into lobules, they have many large cells and an extensive neuropil. Numerous microneurons, with axons not leaving the lobe, arise in the peripheral parts of the vertical lobe. The organization of the neuropil differs in the six lobes that make up the system. In the inferior frontal lobe all the inputs can influence any of the cells. In the superior frontal lobe the neuropil is layered and the topology of the optic lobes is probably preserved. In the vertical lobe large neurons are scattered throughout the neuropil among the processes of the microneurons. The subvertical and precommissural lobe neuropils allow many influences to converge on large output cells, which are also accompanied by microneurons.

Simultaneous Shape Discrimination in Octopus after Removal of the Vertical Lobe

1962 ◽  
Vol 39 (4) ◽  
pp. 557-566
Author(s):  
W. R. A. MUNTZ ◽  
N. S. SUTHERLAND ◽  
J. Z. YOUNG
Keyword(s):  
Frontal Lobes ◽  
Simultaneous Discrimination ◽  
Shape Discrimination ◽  
Visual Responses ◽  
Optic Lobes ◽  
Previous Evidence

1. Octopuses from which the vertical or median superior frontal lobes had been removed were able to discriminate between objects shown simultaneously, although they could not distinguish them when shown successively. 2. Discrimination by operated animals was however always less accurate than by controls. 3. A very difficult simultaneous discrimination could not be performed without the vertical lobes (although the same animal was able to make it before operation). 4. A discrimination learned by the simultaneous method before operation continues to appear (though less accurately) after vertical lobe removal. 5. The experiments therefore confirm previous evidence that the representations that ensure correct visual responses do not lie mainly in the vertical lobes, but else-where (probably in the optic lobes). 6. The function of the vertical lobes is considered to be to stabilize and perhaps lower the level of tendency to attack.

The functional organization of the brain of the cuttlefish Sepia officinalis

1961 ◽  
Vol 153 (953) ◽  
pp. 503-534 ◽  
Keyword(s):  
Electrical Stimulation ◽  
Functional Organization ◽  
Anterior Part ◽  
Visceral Ganglion ◽  
Optic Lobes ◽  
Basal Lobe ◽  
The Brain ◽  
Motor Centre ◽  
Stimulation Of

The functional organization of the brain of Sepia has been investigated by electrical stimulation. As a result several new divisions of the brain have been made. The pedal ganglion has been shown to consist of four parts: (1) the anterior chromatophore lobes innervating the skin and muscles of the anterior part of the head and arm s; (2) the anterior pedal lobe innervating the arms and tentacles; (3) the posterior pedal lobe innervating the funnel, collar and retractor muscles of the head; (4) the lateral pedal lobes innervating the muscles of the eyes and tissues of the orbits. The palliovisceral (or visceral) ganglion, apart from the magnocellular lobe demonstrated by Young (1939), is shown here to consist of (1) a central palliovisceral lobe innervating the mantle, funnel and viscera ; (2) a pair of lobes innervating the muscles of the fins; (3) a pair of posterior chromatophore lobes innervating the muscles of the chromatophores and skin of the mantle, fin and back of the head; (4) a pair of vasomotor lobes. Because of these new divisions the three main groupings of the suboesophageal neural tissue are now referred to as the anterior, middle and posterior suboesophageal masses corresponding to the old brachial, pedal and palliovisceral divisions. The suboesophageal centres are classified as lower motor centres and intermediate motor centres, depending on the kind of response they give to electrical stimulation and their peripheral connexions. In the supraoesophageal lobes, higher motor centres and silent areas are recognized. The silent areas include the vertical, superior frontal, subvertical, precommissural and dorsal basal lobes. Of the higher motor centres the anterior basal lobe is primarily concerned with the positioning of the head, arms and eyes, particularly during movements involving changes in direction while swimming. Such manoeuvres are brought about by the anterior basal lobe control over the fins and position of the funnel. The posterior basal lobe is here shown to consist of six main divisions: (1) the sub vertical lobe; (2) the dorsal basal lobes; (3) the precommissural lobe; (4) the medial basal lobe; (5) the lateral basal lobe; (6) the interbasal lobe. The medial, lateral and interbasal lobes are higher motor centres. The lateral and medial basal lobes control movements of the chromatophores and skin; the medial basal lobe controls swimming, breathing, fin movements and various visceral functions. The interbasal lobe controls the movements of the tentacles. The optic nerves and the optic lobes, at their periphery, are electrically inexcitable. Electrical stimulation of the centre of the optic lobes evokes all the responses that can be obtained from the other higher m otor centres. The results are discussed in term s of Sanders & Young’s (1940) physiological classification of the brain. A further category intermediate motor centre is recognized. Summary lists of the responses of each lobe are given on pages 516, 520, 525.

An Adaptive and Learning System for Feedback-Controlled Evoked Response Studies

1981 ◽  
Vol 20 (03) ◽  
pp. 169-173
Author(s):  
J. Wagner ◽  
G. Pfurtscheixer
Keyword(s):  
Brain Activity ◽  
Evoked Response ◽  
Learning System ◽  
Time Interval ◽  
Electrical Brain Activity ◽  
Long Time ◽  
The Subject ◽  
Eeg Power ◽  
Stimulation System ◽  
Background Eeg

The shape, latency and amplitude of changes in electrical brain activity related to a stimulus (Evoked Potential) depend both on the stimulus parameters and on the background EEG at the time of stimulation. An adaptive, learnable stimulation system is introduced, whereby the subject is stimulated (e.g. with light), whenever the EEG power is subthreshold and minimal. Additionally, the system is conceived in such a way that a certain number of stimuli could be given within a particular time interval. Related to this time criterion, the threshold specific for each subject is calculated at the beginning of the experiment (preprocessing) and adapted to the EEG power during the processing mode because of long-time fluctuations and trends in the EEG. The process of adaptation is directed by a table which contains the necessary correction numbers for the threshold. Experiences of the stimulation system are reflected in an automatic correction of this table. Because the corrected and improved table is stored after each experiment and is used as the starting table for the next experiment, the system >learns<. The system introduced here can be used both for evoked response studies and for alpha-feedback experiments.

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