Prefrontal Cortical Synaptic Plasticity: The Roles of Dopamine and Implication for Schizophrenia
The prefrontal cortex (PFC) is central in mediating executive functions in goaldirected behavior, for which proper dopamine (DA) actions of information processing modulation is essential in this area. It is now evident that, as in the case of the hippocampus, the PFC undergoes neuronal adaptation processes in its networks with induction of synaptic plasticity such as long-term potentiation (LTP) and short-term potentiation (STP). A prominent characteristic of synaptic plasticity in the PFC is that its induction mechanisms involve DA as an essential modulatory molecule. As such, DA-dependent plastic changes occurring in PFC network have important roles for PFC-mediated cognitive functions. Nevertheless, little attempt has been made to characterize the nature of PFC neuronal adaptation by synaptic plasticity, given that the PFC is thought to be the area of temporary storage and manipulation of information, known as working memory. However, accumulating evidences now indicate that the functions of the PFC cannot be fully explained just as the region of an online representation and handling of information. Importance of DA-dependent synaptic plasticity is further encouraged by possible disruption of synaptic plasticity mechanism in the PFC in psychiatric disorders such as schizophrenia, drug addiction, and depression.
In this chapter, we describe the underlying cellular mechanisms of DA action on synaptic plasticity induction in the PFC, and possible roles of PFC synaptic plasticity in executive functions as well as its disruptions in the pathophysiology of schizophrenia.
KeywordsPrefrontal Cortex Synaptic Plasticity Ventral Tegmental Area Tetanic Stimulation Trace Fear Conditioning
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