In vivo synaptic transmission in young and aged amyloid precursor protein transgenic mice

Alzheimer's disease (AD) is characterized by progressive neurodegeneration and cognitive impairment. We examined in vivo alterations in hippocampal ne urotransmission in both young and aged PDAPP transgenic mice and nontransge nic littermates. We now report that in vivo abnormal neurotransmission in h ippocampal circuits of PDAPP mice precedes beta deposition and neurodegener ation. These in vivo data provide the first evidence that dysfunction in hi ppocampal neuronal circuits may not be correlated with age-related extracel lular beta plaque deposition. (C) 2000 Elsevier Science B.V. All rights res erved.