title: Diminished perisomatic GABAergic terminals on cortical neurons adjacent to amyloid plaques.
abstract: One of the main pathological hallmarks of Alzheimer's disease (AD) is the accumulation of plaques in the cerebral cortex, which may appear either in the neuropil or in direct association with neuronal somata. Since different axonal systems innervate the dendritic (mostly glutamatergic) and perisomatic (mostly GABAergic) regions of neurons, the accumulation of plaques in the neuropil or associated with the soma might produce different alterations to synaptic circuits. We have used a variety of conventional light, confocal and electron microscopy techniques to study their relationship with neuronal somata in the cerebral cortex from AD patients and APP/PS1 transgenic mice. The main finding was that the membrane surfaces of neurons (mainly pyramidal cells) in contact with plaques lack GABAergic perisomatic synapses. Since these perisomatic synapses are thought to exert a strong influence on the output of pyramidal cells, their loss may lead to the hyperactivity of the neurons in contact with plaques. These results suggest that plaques modify circuits in a more selective manner than previously thought.
authors: Laboratorio de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid Madrid, Spain.
authors: Virginia
authors: V
authors: Garcia-Marin
authors: Lidia
authors: L
authors: Blazquez-Llorca
authors: José-Rodrigo
authors: JR
authors: Rodriguez
authors: Susana
authors: S
authors: Boluda
authors: Gerard
authors: G
authors: Muntane
authors: Isidro
authors: I
authors: Ferrer
authors: Javier
authors: J
authors: Defelipe