Electrophysiology of rat perirhinal cortex.

摘要

Perirhinal cortex has received much attention recently for its purported role in learning and memory. Despite scores of lesion and behavioral studies, relatively little has been done to explore the electrophysiology of this region. In order to construct a plausible circuit-level model of how perirhinal cortex might contribute to mnemonic function, it was essential to first answer several questions in the domain of electrophysiology: (1) What are the intrinsic properties of the different cell types in perirhinal cortex? (2) How do perirhinal neurons respond to synaptic inputs? (3) Does this system exhibit synaptic plasticity? (4) How could input from the amygdala, another structure implicated in memory, influence synaptic plasticity in perirhinal cortex?;The experiments in this thesis were performed to seek answers to the questions posed above. After a general introduction in section 1, section 2 explores the intrinsic electrophysiology of neurons in perirhinal cortex, noting their spiking patterns, morphologies, and locations. Section 3 investigates how two of these cell types process synaptic inputs, leading to very different spiking outputs. Section 4 presents the perirhinal-amygdala slice preparation with amygdala and intracortical inputs. Plasticity is found in each of these inputs, and they are both found to converge in perirhinal layer II/III. The interaction of these inputs is studied, and associative LTP is found in the intracortical pathways when the amygdala is stimulated as a strong input. The implications of this result are discussed in section 5, and it is argued that the amygdala may serve to gate or trigger synaptic plasticity in perirhinal cortex.