In the healthy human brain, evidence for dissociable memory networks along the anterior-posterior axis of the hippocampus suggests that this structuremaynot function as a unitary entity. Failure to consider these functional divisionsmayexplain diverging resultsamong studies of memory adaptation in disease. Using task-based and resting functional MRI, we show that chronic seizures disrupting the anterior medial temporal lobe (MTL) preserve anterior and posterior hippocampal-cortical dissociations, but alter signaling between these and other key brain regions. During performance of a memory encoding task, we found reduced neural activity in human patients with unilateral temporal lobe epilepsy relative to age-matched healthy controls, but no upregulation of fMRI signal in unaffected hippocampal subregions. Instead, patients showed aberrant resting fMRI connectivity within anterior and posterior hippocampal-cortical networks, which was associated with memory decline, distinguishing memory-intact from memory-impaired patients. Our results highlight a critical role for intact hippocampo-cortical functional communication in memory and provide evidence that chronic injuryinduced functional reorganization in the diseased MTL is behavioral inefficient. © 2014 the authors.

Aberrant functional connectivity in dissociable hippocampal networks is associated with deficits in memory / Voets, Natalie L.; Zamboni, Giovanna; Stokes, Mark G.; Carpenter, Katherine; Stacey, Richard; Adcock, Jane E.. - In: THE JOURNAL OF NEUROSCIENCE. - ISSN 0270-6474. - 34:14(2014), pp. 4920-4928. [10.1523/JNEUROSCI.4281-13.2014]

Aberrant functional connectivity in dissociable hippocampal networks is associated with deficits in memory

ZAMBONI, Giovanna;
2014

Abstract

In the healthy human brain, evidence for dissociable memory networks along the anterior-posterior axis of the hippocampus suggests that this structuremaynot function as a unitary entity. Failure to consider these functional divisionsmayexplain diverging resultsamong studies of memory adaptation in disease. Using task-based and resting functional MRI, we show that chronic seizures disrupting the anterior medial temporal lobe (MTL) preserve anterior and posterior hippocampal-cortical dissociations, but alter signaling between these and other key brain regions. During performance of a memory encoding task, we found reduced neural activity in human patients with unilateral temporal lobe epilepsy relative to age-matched healthy controls, but no upregulation of fMRI signal in unaffected hippocampal subregions. Instead, patients showed aberrant resting fMRI connectivity within anterior and posterior hippocampal-cortical networks, which was associated with memory decline, distinguishing memory-intact from memory-impaired patients. Our results highlight a critical role for intact hippocampo-cortical functional communication in memory and provide evidence that chronic injuryinduced functional reorganization in the diseased MTL is behavioral inefficient. © 2014 the authors.
2014
34
14
4920
4928
Aberrant functional connectivity in dissociable hippocampal networks is associated with deficits in memory / Voets, Natalie L.; Zamboni, Giovanna; Stokes, Mark G.; Carpenter, Katherine; Stacey, Richard; Adcock, Jane E.. - In: THE JOURNAL OF NEUROSCIENCE. - ISSN 0270-6474. - 34:14(2014), pp. 4920-4928. [10.1523/JNEUROSCI.4281-13.2014]
Voets, Natalie L.; Zamboni, Giovanna; Stokes, Mark G.; Carpenter, Katherine; Stacey, Richard; Adcock, Jane E.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11380/1108771
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