Project description:Despite the advances in our understanding of aging-associated behavioral decline, we know relatively little about how aging affect neural circuits that underlie specific behaviors. Specifically, we know little about how aging affect expression of genes in specific neural circuits. We have now addressed this problem by exploring a cholinergic neuron R15, an identified neuron of marine snail Aplysia. R15 is characterized by bursting action potentials and is implicated in reproduction, osmoregulation and locomotion.
Project description:Despite the advances in our understanding of aging-associated behavioral decline, we know relatively little about how aging affect neural circuits that underlie specific behaviors. Specifically, we know little about how aging affect expression of genes in specific neural circuits. We have now addressed this problem by exploring a cholinergic neuron R15, an identified neuron of marine snail Aplysia. R15 is characterized by bursting action potentials and is implicated in reproduction, osmoregulation and locomotion. We examined changes in gene expression in R15 neurons during aging by microarray analyses of RNAs prepared from two different age groups, mature and old animals. Specifically we find that 1083 ESTs are differentially regulated in mature and old R15 neurons. Bioinformatics analyses of these genes have identified specific biological pathways and molecular processes that are up or down regulated in mature and old neurons. Comparison with human signaling networks using pathway analyses have identified three major networks that are altered in old R15 neurons. Furthermore, by single neuron qRTPCR we examined expression levels of candidate regulators involved in transcription (CREB1) and translation (S6 kinase) and find that aging is associated with a decrease in expression of these regulators. We next studied expression of CREB1 and S6 kinase in two different motor neurons (L7 and L11) and another cholinergic neuron R2 and find that these neurons have characteristic changes in gene expression during aging
