Biology Project Abstract
AFFERENT AND EFFERENT CONNECTIONS OF THE CAUDAL MEDIAL PREFRONTAL CORTEX IN RABBIT: A PROPOSED CIRCUIT MEDIATING EARLY ACQUISITION OF THE TRACE EYEBLINK CONDITIONED REFLEX
Presenter:
Darrel Saldanha, Illinois Mathematics and Science Academy, 1500 West Sullivan Road, Aurora, IL 60506; djs85@imsa.edu
Mentor:
Aldis Weible, Northwestern University Medical School, 303 E. Chicago Ave, M211, Chicago, IL 60611
Abstract:
The caudal medial prefrontal cortex (cmPFC) is a component of the circuitry mediating forebrain-dependent trace eyeblink conditioning, a task involving the association of a conditioned stimulus (CS) with an unconditioned stimulus (US). Lesions of the cmPFC disrupt learning of the trace conditioned reflex. Robust modulation of cmPFC neuronal activity specific to trace conditioning has been reported during the first two days of training. Because these changes occurred early in conditioning, we hypothesize that the cmPFC is involved in forming the association between the CS and US. In this study, using the anterograde and retrograde neuronal tracer wheatgerm agglutinated horseradish peroxidase, we examined the afferent and efferent projections of the cmPFC so as to identify those structures directly connected with the cmPFC that may also be involved in trace eyeblink conditioning. The cmPFC may serve as a hub where information pertaining to the external environment is gathered from each of the primary sensory cortices. Furthermore, other connections provide a means to pass the newly established association on to other structures involved in eyeblink conditioning such as the hippocampal formation and lateral pontine nucleus. These structures have been shown to be involved in an assortment of associative learning paradigms, including trace eyeblink conditioning.