Refinement of neuronal synchronization with gamma oscillations in the medial prefrontal cortex after adolescence

DE ALMEIDA J; JOURDAN I; MURER MG; BELFORTE J

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2013 vol. 8 p. 1 - 9

1932-6203

The marked anatomical and functional changes taking place in the medial prefrontalcortex (PFC) during adolescence set grounds for the high incidence ofneuropsychiatric disorders with adolescent onset. Although circuit refinement throughsynapse pruning may constitute the anatomical basis for the cognitive differencesreported between adolescents and adults, a physiological correlate of circuitrefinement at the level of neuronal ensembles has not been demonstrated. We haverecorded neuronal activity together with local field potentials in the medial PFC ofjuvenile and adult mice under anesthesia, which allowed studying local functionalconnectivity without behavioral or sensorial interference. Entrainment of pyramidalneurons and interneurons to gamma oscillations, but not to theta or beta oscillations,was reduced after adolescence. Interneurons were synchronized to gamma oscillationsacross a wider area of the PFC than pyramidal neurons, and the span of interneuronsynchronization was shorter in adults than juvenile mice. Thus, transition fromchildhood to adulthood is characterized by reduction of the strength and span ofneuronal synchronization specific to gamma oscillations in the mPFC. The morerestricted and weak ongoing synchronization in adults may allow a more dynamicrearrangement of neuronal ensembles during behavior and promote parallelprocessing of information.