Event Title

Quantifying Changes in Dorsal and Ventral Hippocampus Immediate Early Gene Expression as a Function of Aging Related Cognitive Decline

Presenter Information

Mariah Linske
Savanna Leigh Shuster

Mentor 1

James Moyer Jr.

Location

Union Wisconsin Room

Start Date

27-4-2018 1:00 PM

Description

Due to the growing portion of the population that is expected to reach old age in the coming years, incidences of aging-related neurodegenerative disorders like Alzheimer's disease are also expected to increase. To determine areas of the brain that may be functionally impaired, the expression of immediate early genes (IEGs) such as c-Fos and Zif-268 were studied. Changes in the expression of IEGs within a neuron indicates that the neuron was recently activated. A combination of behavior and IEG-immunohistochemistry was used to study both learning- and aging-related changes in key brain regions known to be important for learning and memory. In the present experiment, rats were subjected to either (a) trace fear conditioning, (b) trace fear conditioning followed by extinction, (c) pseudo-conditioning, or (d) were left naïve and thus remained in their home cage. Prior analyses illustrated that adult rats showed increased levels of c-Fos and Zif-268 in the prelimbic and infralimbic medial prefrontal cortex after training, and this increase was less pronounced in aged animals. Additionally, training resulted in an increased expression of c-Fos in the lateral amygdala for all age groups, while no changes were observed after extinction for aged or middle aged rats. In the dorsal and ventral hippocampus, adult and middle-aged rats generally showed an increase in c-Fos expression after training, but no increase was seen in aged animals. There was no significant increase of zif-268 expression across any region of the hippocampus or age group. No discrepancy between age groups and their ability to acquire the training was found, but variation in IEG expression suggests differences in brain function between groups. Ongoing research is studying other brain regions implicated in learning and memory, and other markers of neuronal activity. Studying aging-related changes in expression of IEGs in conjunction with their learning-dependent changes should allow for the identification of how information processing changes across the lifespan.

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Apr 27th, 1:00 PM

Quantifying Changes in Dorsal and Ventral Hippocampus Immediate Early Gene Expression as a Function of Aging Related Cognitive Decline

Union Wisconsin Room

Due to the growing portion of the population that is expected to reach old age in the coming years, incidences of aging-related neurodegenerative disorders like Alzheimer's disease are also expected to increase. To determine areas of the brain that may be functionally impaired, the expression of immediate early genes (IEGs) such as c-Fos and Zif-268 were studied. Changes in the expression of IEGs within a neuron indicates that the neuron was recently activated. A combination of behavior and IEG-immunohistochemistry was used to study both learning- and aging-related changes in key brain regions known to be important for learning and memory. In the present experiment, rats were subjected to either (a) trace fear conditioning, (b) trace fear conditioning followed by extinction, (c) pseudo-conditioning, or (d) were left naïve and thus remained in their home cage. Prior analyses illustrated that adult rats showed increased levels of c-Fos and Zif-268 in the prelimbic and infralimbic medial prefrontal cortex after training, and this increase was less pronounced in aged animals. Additionally, training resulted in an increased expression of c-Fos in the lateral amygdala for all age groups, while no changes were observed after extinction for aged or middle aged rats. In the dorsal and ventral hippocampus, adult and middle-aged rats generally showed an increase in c-Fos expression after training, but no increase was seen in aged animals. There was no significant increase of zif-268 expression across any region of the hippocampus or age group. No discrepancy between age groups and their ability to acquire the training was found, but variation in IEG expression suggests differences in brain function between groups. Ongoing research is studying other brain regions implicated in learning and memory, and other markers of neuronal activity. Studying aging-related changes in expression of IEGs in conjunction with their learning-dependent changes should allow for the identification of how information processing changes across the lifespan.