Date of Award
Bachelor of Science
J. Harry Blaise
A leading neurocircuitry model of emotional regulation points to the pathway from the medial prefrontal cortex (mPFC) to the basolateral amygdala (BLA). This pathway has been implicated in fear conditioning and extinction studies and its malfunction is hypothesized to underlie affective disorders such as PTSD and anxiety. Interestingly, the mPFC-BLA pathway shows delayed maturation in both humans and rats, rendering it vulnerable to early life stress (ELS). Indeed, several studies have linked ELS to emotional dysregulation as well as changes in the amygdala and PFC. However, no study has ever been done on the effect of ELS on long-term potentiation (LTP) in this pathway. In fact, very few studies on LTP in the mPFC-BLA pathway have been conducted at all which is surprising given LTP’s role in learning and memory and given the mPFC-BLA pathway’s proposed role in fear conditioning/extinction. Therefore, using electrophysiological methods in awake, freely behaving rats, the current study examined whether ELS in the form of neonatal isolation (ISO) affects LTP in the mPFC-BLA pathway. Results indicate that the mPFC-BLA pathway is resistant to LTP in both control and ISO rats following both sustained and theta burst high frequency stimulation (HFS). In fact, rats showed a tendency toward long-term depression (LTD) especially following sustained stimulation at 200 Hz. Small sample sizes prevented a meaningful comparison of LTD across ISO and control groups.
Gitchell, Thomas, "THE EFFECTS OF EARLY LIFE STRESS ON LONG-TERM POTENTIATION IN PATHWAY FROM THE MEDIAL PREFRONTAL CORTEX TO THE BASOLATERAL AMYGDALA". Senior Theses, Trinity College, Hartford, CT 2018.
Trinity College Digital Repository, https://digitalrepository.trincoll.edu/theses/736