Mental Phenomena Evoked by Electrical Stimulation of the Human Hippocampal Formation and Amygdala

Halgren, Eric; Walter, Richard D.; Cherlow, Diana G.; Crandall, Paul H.

doi:10.1093/brain/101.1.83

Cited by 536 publications

(289 citation statements)

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“…The finding of selective ER activation during intentional retrieval is consistent with the observation that powerful feelings of familiarity (déjà vu) as well as intense reminiscences of previous events can be evoked by electrical stimulation of the human avTL (Bancaud et al, 1994;Halgren et al, 1978b), and perhaps especially ER (Bartolomei et al, 2004). These phenomena imply an active role of ER in shifting the mode of cerebral processing from one of identifying external stimuli to one of retrieving internal representations.…”

Section: Repetition and Retrieval Effectssupporting

confidence: 85%

“…This increasing complexity lies on an unbroken continuum of visual processing with the more posterior visual areas. In contrast, the vivid memories evoked by avTL hyperactivation (Halgren et al, 1978b), as well as its crucial anatomical position relaying hippocampal formation output to association cortex, suggests a countercurrent return of information during memory retrieval from more medial structures (Buzsaki, 1996;Halgren, 1984;Merker, 2004;Qin et al, 1997).…”

Section: Introductionmentioning

confidence: 97%

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Processing stages underlying word recognition in the anteroventral temporal lobe

et al. 2006

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The anteroventral temporal lobe integrates visual, lexical, semantic and mnestic aspects of wordprocessing, through its reciprocal connections with the ventral visual stream, language areas, and the hippocampal formation. We used linear microelectrode arrays to probe population synaptic currents and neuronal firing in different cortical layers of the anteroventral temporal lobe, during semantic judgments with implicit priming, and overt word recognition. Since different extrinsic and associative inputs preferentially target different cortical layers, this method can help reveal the sequence and nature of local processing stages at a higher resolution than was previously possible.The initial response in inferotemporal and perirhinal cortices is a brief current sink beginning at 120ms, and peaking at ~170ms. Localization of this initial sink to middle layers suggests that it represents feedforward input from lower visual areas, and simultaneously increased firing implies that it represents excitatory synaptic currents. Until ~800ms, the main focus of transmembrane current sinks alternates between middle and superficial layers, with the superficial focus becoming increasingly dominant after ~550ms. Since superficial layers are the target of local and feedback associative inputs, this suggests an alternation in predominant synaptic input between feedforward and feedback modes. Word repetition does not affect the initial perirhinal and inferotemporal middle layer sink, but does decrease later activity. Entorhinal activity begins later (~200ms), with greater apparent excitatory postsynaptic currents and multiunit activity in neocortically-projecting than hippocampal-projecting layers. In contrast to perirhinal and entorhinal responses, entorhinal responses are larger to repeated words during memory retrieval.These results identify a sequence of physiological activation, beginning with a sharp activation from lower level visual areas carrying specific information to middle layers. This is followed by feedback and associative interactions involving upper cortical layers, which are abbreviated to repeated words. Following bottom-up and associative stages, top-down recollective processes may be driven by entorhinal cortex. Word processing involves a systematic sequence of fast feedforward information transfer from visual areas to anteroventral temporal cortex, followed by prolonged interactions of this feedforward information with local associations, and feedback mnestic information from the medial temporal lobe.

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Section: Repetition and Retrieval Effectssupporting

confidence: 85%

Section: Introductionmentioning

confidence: 97%

Processing stages underlying word recognition in the anteroventral temporal lobe

et al. 2006

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“…These findings are also in keeping with our intraoperative stimulation results under local anaesthesia where the patient's habitual aura, psychic phenomena, automatisms and after discharges were mainly obtained from stimulation through the deepest contacts of depth electrodes corresponding to the amygdala and hippocampus (unpublished observations). They are also in keeping with the original work of Feindel et al 6,7 on the peroperative stimulation of the amygdala region in man and with the results of Halgren 35 using strictly limbic stimulation. That these phenomena can also be triggered by neocortical stimulation has also been shown by Penfield et al 8 Imaging studies of the past, such as pneumoencephalography very often showed enlargement of one temporal horn in temporal lobe epilepsy.…”

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confidence: 82%

Transcortical Selective Amygdalohippocampectomy in Temporal Lobe Epilepsy

Olivier

2000

Can J Neurol Sci.

133

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Suppl. 1 -S68Insight in the role played by the mesio-temporal structures in human epilepsy is derived from various sources. Hughlings Jackson 1 was the first to describe the autopsy findings showing a mesio-temporal lesion as the cause of psychomotor seizures. Echoing the original observations of Jackson, the many experimental studies of the 1950s such as those of Kaada, 2 Vigouroux, 3 Gastaut, 4 Green, 5 and the observations in the human by Feindel,6,7 Penfield and Jasper, 8 and Morris 9 pointed to a very important role of the mesiobasal temporal structures in experimental and human epilepsies.There is a large collection of data describing striking neuropathological changes in the mesio-temporal area in patients with temporal epilepsy. The hippocampal sclerosis and mesiotemporal sclerosis, including changes in the amygdala, were reviewed in detail in a series of excellent studies. [10][11][12] More recent work has shed light on the basic physiopathological mechanisms responsible for mesio-temporal epilepsy. [13][14][15][16][17][18][19][20] Studies on mesio-temporal kindling have brought further ABSTRACT: Numerous studies of the electrophysiology and neuropathology of temporal lobe epilepsy have demonstrated the mesial temporal structures to be the site of seizure origin in the majority of cases. This is the rationale for a transcortical selective approach, first introduced by Niemeyer, for removal of the hippocampus and amygdala. Series from a number of centers have demonstrated the efficacy of selective amygdalohippocampectomy compared to a more traditional resection. The technique described here and used at the Montreal Neurological Institute (MNI) utilizes a strictly endopial resection of the hippocampal formation and amygdala in addition to computer image guidance to perform the procedure. Ninety-five percent of patients at the MNI who underwent selective amygdalohippocampectomy realized a cessation of seizures, or greater than 90% reduction, with minimal risk of complications.

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“…Furthermore, the right amygdala blood flow correlated with the degree of affective arousal, while the left amygdala CBF correlated positively with the degree of dysphoria and negatively with the degree of euphoria (Ketter et al, 1996). The experiences described by the subjects in these procaine studies are reminiscent of those reported after direct stimulation of limbic cortex during epilepsy surgery (Gloor et al, 1982;Halgren et al, 1978;Penfield and Jasper, 1954). The emotional and endocrine changes also resemble the effects of acute challenge with the anticholinesterase drug physostigmine (Janowsky et al, 1986).…”

Section: Introductionmentioning

confidence: 74%

A Potential Cholinergic Mechanism of Procaine's Limbic Activation

Benson

Carson

Kiesewetter

et al. 2004

Neuropsychopharmacol

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The local anesthetic procaine, when administered to humans intravenously (i.v.), yields brief intense emotional and sensory experiences, and concomitant increases in anterior paralimbic cerebral blood flow, as measured by positron emission tomography (PET). Procaine's high muscarinic affinity, together with the distribution of muscarinic receptors that overlaps with brain regions activated by procaine, suggests a muscarinic contribution to procaine's emotional and sensory effects. This study evaluates the effects of procaine on cerebral muscarinic cholinergic receptors in the anesthetized rhesus monkey. Whole brain and regional muscarinic receptor binding was measured before and after procaine administration on the same day in three anesthetized rhesus monkeys with PET and the radiotracer 3-(3-(3[ 18 F]fluoropropylthio)-1,2,5-thiadiazol-4-yl)-1,2,5,6-tetrahydro-1-methylpyridine ([ 18 F]FP-TZTP), a cholinergic ligand that has preferential binding to muscarinic (M 2 ) receptors. On separate days each animal received six different doses of i.v. procaine in a randomized fashion. Procaine blocked up to B90% of [ 18 F]FP-TZTP specific binding globally in a dose-related manner. There were no regional differences in procaine's inhibitory concentration for 50% blockade (IC 50 ) for [ 18 F]FP-TZTP. Tracer delivery, which was highly correlated to cerebral blood flow in previous monkey studies, was significantly increased at all doses of procaine with the greatest increases occurring near procaine's IC 50 for average cortex. Furthermore, anterior limbic regions showed greater increases in tracer delivery than nonlimbic regions. Procaine has high affinity to muscarinic M 2 receptors in vivo in the rhesus monkey. This, as well as a preferential increase of tracer delivery to paralimbic regions, suggests that action at these receptors could contribute to i.v. procaine's emotional and sensory effects in man. These findings are consistent with other evidence of cholinergic modulation of mood and emotion.

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Mental Phenomena Evoked by Electrical Stimulation of the Human Hippocampal Formation and Amygdala

Cited by 536 publications

References 0 publications

Processing stages underlying word recognition in the anteroventral temporal lobe

Processing stages underlying word recognition in the anteroventral temporal lobe

Transcortical Selective Amygdalohippocampectomy in Temporal Lobe Epilepsy

A Potential Cholinergic Mechanism of Procaine's Limbic Activation

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