Plasticity in the prefrontal cortex of adult rats

Abstract

We review the plastic changes of the prefrontal cortex of the rat in response to a wide range of experiences including sensory and motor experience, gonadal hormones, psychoactive drugs, learning tasks, stress, social experience, metaplastic experiences, and brain injury. Our focus is on synaptic changes (dendritic morphology and spine density) in pyramidal neurons and the relationship to behavioral changes. The most general conclusion we can reach is that the prefrontal cortex is extremely plastic and that the medial and orbital prefrontal regions frequently respond very differently to the same experience in the same brain and the rules that govern prefrontal plasticity appear to differ for those of other cortical regions.

Keywords: experience-dependent plasticity; metaplasticity; prefrontal cortex; psychoactive drugs; stress.

Figure 1

The prefrontal cortex. A. Serial sections through a rat brain showing different cytoarchitectonic regions. Dotted areas receive projections from MD; gray areas receive projections from the amygdala. Abbreviations: AC, anterior cingulate; CL, claustrum; gcc, genu of the corpus callousm; IL, infralimbic; lag, lateral agranular; MO, medial orbital; PL, prelimbic; plag, posterior lateral agranular; SEP, septum; TT, tania tecta; vlag, ventral lateral agranular; VLO, ventral lateral orbital; VO, ventral orbital. (Modified and adapted from Reep, 1984).

Figure 2

The medial and orbital prefrontal regions show opposite chronic effects of amphetamine on spine density in adulthood. Abbreviations: UNTR, untreated; SUC, sucrose treated; AMPH, amphetamine treated. (After Crombag et al., 2005). ^*† indicate a significant difference from UNTR and SUC conditions, respectively (P < 0.05).

Figure 3

The medial and orbital prefrontal regions show opposite chronic effects of stress in male rats in adulthood. (After McEwen and Morrison, 2013).