Heterochronic Parabiosis
Objective: To assess whether exposure of aged animals to young blood can reverse age-related cognitive impairments and improve synaptic plasticity through heterochronic parabiosis
Protocol Steps
Heterochronic Parabiosis Surgery
Surgical connection of circulatory systems between young and aged animals
Note: This creates heterochronic parabionts where blood circulation is shared between animals of different ages
View evidence from paper
“circulatory systems of young and aged animals are connected”
Genome-wide Microarray Analysis
Analysis of transcriptional changes in the hippocampus of aged heterochronic parabionts to identify synaptic plasticity-related gene expression changes
Note: Performed on hippocampal tissue from aged animals in parabiotic pairs
View evidence from paper
“Genome-wide microarray analysis of heterochronic parabionts identified synaptic plasticity-related transcriptional changes in the hippocampus of aged mice”
Dendritic Spine Density Assessment
Measurement of dendritic spine density of mature neurons in the hippocampus of aged heterochronic parabionts
Note: Structural analysis of neuronal changes
View evidence from paper
“Dendritic spine density of mature neurons increased and synaptic plasticity improved in the hippocampus of aged heterochronic parabionts”
Contextual Fear Conditioning Test
Cognitive assessment of aged mice exposed to young blood using contextual fear conditioning paradigm
Note: Measures cognitive function improvement in aged animals
View evidence from paper
“systemic administration of young blood plasma into aged mice improved age-related cognitive impairments in both contextual fear conditioning and spatial learning and memory”
Spatial Learning and Memory Test
Cognitive assessment of aged mice exposed to young blood using spatial learning and memory tasks
Note: Measures spatial cognition improvement in aged animals
View evidence from paper
“systemic administration of young blood plasma into aged mice improved age-related cognitive impairments in both contextual fear conditioning and spatial learning and memory”
Young Blood Plasma Administration
Systemic administration of young blood plasma into aged mice
Note: Alternative to full parabiosis - direct plasma transfer to assess cognitive and structural improvements
View evidence from paper
“systemic administration of young blood plasma into aged mice improved age-related cognitive impairments”
CREB Activation Analysis
Assessment of cyclic AMP response element binding protein (CREB) activation in the aged hippocampus
Note: Identifies molecular mechanism mediating cognitive and structural enhancements
View evidence from paper
“Structural and cognitive enhancements elicited by exposure to young blood are mediated, in part, by activation of the cyclic AMP response element binding protein (Creb) in the aged hippocampus”