University of Kentucky
PRENATAL ALCOHOL EXPOSURE IMPAIRS PERFORMANCE ON SPATIAL AND TACTILE SERIAL DISCRIMINATION TASK IN JUVENILE RATS
Grade Level at Time of Presentation
Senior
Major
Neuroscience
Minor
Pharmacology, Spanish
KY House District #
79
KY Senate District #
13
Faculty Advisor/ Mentor
Mark Prendergast
Department
Psychology Department
Abstract
Alcohol use disorder has many ramifications which, unfortunately, can be exacerbated by alcohol consumption during pregnancy. Children prenatally-exposed to alcohol (PAE) present with learning, memory, and attention impairments resulting in exaggerated deficits in executive function leading to incompetency in problem-solving, concept formation, and planning to achieve goal-directed behaviors. These cognitive deficits are often observed in humans using methods including working-memory tasks and neuroimaging techniques. These measures typically point to deficits in the hippocampus and prefrontal cortex, among other central nervous system structures in humans. Rodent models of fetal alcohol spectrum disorders (FASDs) particularly focus on spatial and working memory tasks but less experimental attention is dedicated to non-spatial, hippocampal-dependent tasks. Of this work, most procedures involve conditioned fear tasks relying on spatial recognition and negative reinforcement. Some Y- and T-maze tasks incorporate positive reinforcement, although these paradigms are specifically spatially oriented and rarely employ non-spatial dimensions, which may permit greater sensitivity to cognitive deficits in FASDs. To address this gap in FASDs research, we developed a T-maze paradigm that incorporates both spatial and non-spatial dimensions in a sequential discrimination task. Specifically, rats are asked to discriminate the dimension that predicts a Cheerio when exposed to 4 different stimuli: left-turn, right-turn, sandpaper-floor, smooth-floor. This task requires rodents to tend to relevant spatial and non-spatial stimuli to earn a Cheerio. Our sequential discrimination task reveals robust deficits in rats prenatally-exposed to alcohol in the human 2nd-trimester equivalent. Shifting contingencies appears to disrupt the PAE rats’ ability to tend to the relevant dimensions when simultaneously presented with all four stimuli. We suspect that these sequential discrimination deficits will be associated with hippocampal dysfunction, evidenced by exaggerated structural complications of the microtubule-associated “tau” protein. This discovery has the capacity to change how we study and treat FASDs.
PRENATAL ALCOHOL EXPOSURE IMPAIRS PERFORMANCE ON SPATIAL AND TACTILE SERIAL DISCRIMINATION TASK IN JUVENILE RATS
Alcohol use disorder has many ramifications which, unfortunately, can be exacerbated by alcohol consumption during pregnancy. Children prenatally-exposed to alcohol (PAE) present with learning, memory, and attention impairments resulting in exaggerated deficits in executive function leading to incompetency in problem-solving, concept formation, and planning to achieve goal-directed behaviors. These cognitive deficits are often observed in humans using methods including working-memory tasks and neuroimaging techniques. These measures typically point to deficits in the hippocampus and prefrontal cortex, among other central nervous system structures in humans. Rodent models of fetal alcohol spectrum disorders (FASDs) particularly focus on spatial and working memory tasks but less experimental attention is dedicated to non-spatial, hippocampal-dependent tasks. Of this work, most procedures involve conditioned fear tasks relying on spatial recognition and negative reinforcement. Some Y- and T-maze tasks incorporate positive reinforcement, although these paradigms are specifically spatially oriented and rarely employ non-spatial dimensions, which may permit greater sensitivity to cognitive deficits in FASDs. To address this gap in FASDs research, we developed a T-maze paradigm that incorporates both spatial and non-spatial dimensions in a sequential discrimination task. Specifically, rats are asked to discriminate the dimension that predicts a Cheerio when exposed to 4 different stimuli: left-turn, right-turn, sandpaper-floor, smooth-floor. This task requires rodents to tend to relevant spatial and non-spatial stimuli to earn a Cheerio. Our sequential discrimination task reveals robust deficits in rats prenatally-exposed to alcohol in the human 2nd-trimester equivalent. Shifting contingencies appears to disrupt the PAE rats’ ability to tend to the relevant dimensions when simultaneously presented with all four stimuli. We suspect that these sequential discrimination deficits will be associated with hippocampal dysfunction, evidenced by exaggerated structural complications of the microtubule-associated “tau” protein. This discovery has the capacity to change how we study and treat FASDs.