The Effects of Hippocampal Ablation on the Behavior in the Rat

Niki, Hiroaki

doi:10.4992/psycholres1954.4.139

Cited by 61 publications

(36 citation statements)

References 21 publications

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“…In contrast to rhese findings, however, are the more recently published results of Niki (1962) and Karmos and Grasryan (1962) who demonstrated severe impairment on delayed response tasks following hippocampal lesions. Niki found that hippocampectomized rats were significantly inferior to unoperated and neocortex ablated controls in the acquisition of a 3-sec.…”

contrasting

confidence: 62%

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Hippocampal Theta Activity and Learning: A Reply to Douglas

Bennett

1969

Psychol Rep

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Sunzmasy.-Adey and his associates have asserted that theta electrical activity recorded from the hippocampus during learning and performance reflects the role of this structure in information processing, decision making and memory consolidation. This notion was recently quesrioned by Douglas (1967) who concluded that the tasks employed by Adey and his associates to assess theta activity were tasks which the lesion literature indicated do not require hippocampal functioning to be learned. The present paper questions Douglas' assertion by describing studies in the lesion literature which demonstrate that the tasks used by Adey and his co-workers may actually require hippocampal functioning to be learned. During depth recording from unanesthetized animals, a prominent theta rhythm of approximately 4 to 7 c/sec. can be recorded from the hippocampus, particularly from the dorsal portion of this structure. Hippocampal theta activity is relatively easy to record in the rabbit, more difficult in the cat, and extremely difficult to observe in the monkey and in man (Green, 1960). This does not necessarily mean that the function of the hippocampus which is correlated with theta activity is absent in higher animals. Rather, it may simply mean that the EEG concomitants of this function are different in different animals.In an attempt to define the possible significance of hippocampal theta activity as a correlate of the functional role played by the hippocampus in mediating behavior, Adey and his associates have carried out a number of studies (e.g., Adey, et al., 1960;Elazar & Adey, 1967;Holmes & Adey. 1960) which carefully examined the electrical activity of the hippocampal system during acquisition and performance of a simultaneous visual discrimination task or a delayed response task.Using the visual discrimination task, Adey, et al. (1960) found that with every training trial, including the first, a very regular train of high amplimde theta activity appeared in the hippocampus as the animal approached the food reward. These high amplitude slow wave trains occurred regardless of whether the performance was correct or incorrect, and they persisted throughout acquisition and overtraining. Similar findings concerning the EEG concomitants of learning were obtained when the delayed response task was used.In light of these findings, Adey and his co-workers have concluded that theta activity reflects the role of the hippocampus in information processing, decision making and memory consolidation during learning and performance.In a recently published review on the hippocampus and behavior, Douglas (1967) questioned Adey's hypothesis because he concluded that the tasks Adey and his associates employed in assessing theta activity during learning and performance were "tasks which the lesion literature indicates do not require hippocampal functioning" (p. 421). As stated previously, Adey and his associates used two tasks, ( 1 ) delayed response and ( 2 ) simultaneous visual discrimination. The present author has examined the hippocam...

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contrasting

confidence: 62%

“…Niki ( 1962) found that hippocampecromized rats were significantly retarded, while Kimble (1963) reported that hippocampal animals were no different in the acquisition of this rype of task in comparison to the learning rate exhibited by control animals. Future research must resolve this contradiction.…”

mentioning

confidence: 96%

Hippocampal Theta Activity and Learning: A Reply to Douglas

Bennett

1969

Psychol Rep

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“…In addition to the passive avoidance deficits, hippocampal ablations had a profound effect on reversal training, even when the pre-reversal response was readily acquired (Douglas & Pribram, 1966; Kimble & Kimble, 1965; Niki, 1966; Teitelbaum, 1964; Thompson & Langer, 1963; Webster & Voneida, 1964). Further, rats with hippocampal lesions were consistently found to be highly resistant to extinction (Isaacson et al, 1961; Jarrard, Isaacson, & Wickelgren, 1964; Niki, 1962, 1965; Raphelson, Isaacson, & Douglas, 1966). …”

Section: Efforts To Develop An Animal Model Of Medial Temporal Lobmentioning

confidence: 99%

An animal model of recognition memory and medial temporal lobe amnesia: History and current issues

Clark

Squire

2010

Neuropsychologia

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The medial temporal lobe includes a system of anatomically connected structures that are essential for declarative memory (conscious memory for facts and events). A prominent form of declarative memory is recognition memory (the ability to identify a recently encountered item as familiar). Recognition memory has been frequently assessed in humans and in the experimental animal. This article traces the successful development of an animal model of human medial temporal lobe amnesia, which eventually identified the structures in the medial temporal lobe important for memory. Attention is given to two prominent behavioral paradigms (delayed nonmatching to sample and tests of spontaneous novelty preference).

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“…Although there is a great deal of evidence to indicate that animals with lesions of the hippocampus are deficient in the performance of passive avoidance tasks, there has been little systematic work comparing the performance of these animals across the two types of active avoidance tasks. What evidence there is, indicates that in active avoidance tasks which can be classified as "one-way tasks," rats with hippocampal damage are impaired in both acquisition [l, 2, 3, 16] and retention [22], although one exception can be found in the literature [17]. In two-way active avoidance tasks, on the other hand, rats with hippocampal lesions show enhanced performance during acquisition [8,10].…”

mentioning

confidence: 99%