Brain : a journal of neurology
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In order to understand the complex functional organization of the motor system, it is essential to know the anatomical and functional connectivity among individual motor areas. Clinically, knowledge of these cortico-cortical connections is important to understand the rapid spread of epileptic discharges through the network underlying ictal motor manifestation. In humans, however, knowledge of neuronal in vivo connectivity has been limited. ⋯ The same findings were observed in MMCx (82%) upon stimulation of LMCx. In four subjects in whom bi-directional connectivity was investigated by stimulating both MMCx and LMCx, reciprocality was observed in the majority of connections (78-94%). In conclusion, the present study demonstrated a human motor cortico-cortical network connecting (i) anatomically homologous areas of LMCx and MMCx along the rostrocaudal cognitive-motor gradient; and (ii) somatotopically homologous regions in LMCx and MMCx in a reciprocal manner.
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Using results from cortical stimulations, as well as the symptoms of spontaneous epileptic seizures recorded by stereoelectroencephalography we re-studied the phenomenon of the dreamy state, as described by Jackson (Jackson JH. Selected writings of John Hughlins Jackson. Vol 1. ⋯ Given the role of the amygdala and hippocampus in autobiographic memory, their pathological activation during seizures may trigger memory recall. This study of the dreamy state is in keeping with other evidence demonstrating the constant and central role of the amygdala and hippocampus (right as much as left) in the recall of recent and distant memories. It demonstrates the existence of large neural networks that produce recall of memories via activation of the hippocampus, amygdala and rhinal cortex.