Experience-Dependent Induction of Hippocampal ΔFosB Controls Learning.

Autor:	Eagle AL; Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan 48824., Gajewski PA; Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan 48824., Yang M; Department of Anatomy, School of Medicine, Wonkwang University, Iksan, Jeonbuk, 570-749, South Korea, and., Kechner ME; Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan 48824., Al Masraf BS; Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan 48824., Kennedy PJ; Department of Psychology, University of California Los Angeles, Los Angeles, California 90095., Wang H; Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan 48824., Mazei-Robison MS; Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan 48824., Robison AJ; Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan 48824, robiso45@msu.edu.
Jazyk:	angličtina
Zdroj:	The Journal of neuroscience : the official journal of the Society for Neuroscience [J Neurosci] 2015 Oct 07; Vol. 35 (40), pp. 13773-83.
DOI:	10.1523/JNEUROSCI.2083-15.2015
Abstrakt:	The hippocampus (HPC) is known to play an important role in learning, a process dependent on synaptic plasticity; however, the molecular mechanisms underlying this are poorly understood. ΔFosB is a transcription factor that is induced throughout the brain by chronic exposure to drugs, stress, and variety of other stimuli and regulates synaptic plasticity and behavior in other brain regions, including the nucleus accumbens. We show here that ΔFosB is also induced in HPC CA1 and DG subfields by spatial learning and novel environmental exposure. The goal of the current study was to examine the role of ΔFosB in hippocampal-dependent learning and memory and the structural plasticity of HPC synapses. Using viral-mediated gene transfer to silence ΔFosB transcriptional activity by expressing ΔJunD (a negative modulator of ΔFosB transcriptional function) or to overexpress ΔFosB, we demonstrate that HPC ΔFosB regulates learning and memory. Specifically, ΔJunD expression in HPC impaired learning and memory on a battery of hippocampal-dependent tasks in mice. Similarly, general ΔFosB overexpression also impaired learning. ΔJunD expression in HPC did not affect anxiety or natural reward, but ΔFosB overexpression induced anxiogenic behaviors, suggesting that ΔFosB may mediate attentional gating in addition to learning. Finally, we found that overexpression of ΔFosB increases immature dendritic spines on CA1 pyramidal cells, whereas ΔJunD reduced the number of immature and mature spine types, indicating that ΔFosB may exert its behavioral effects through modulation of HPC synaptic function. Together, these results suggest collectively that ΔFosB plays a significant role in HPC cellular morphology and HPC-dependent learning and memory. Significance Statement: Consolidation of our explicit memories occurs within the hippocampus, and it is in this brain region that the molecular and cellular processes of learning have been most closely studied. We know that connections between hippocampal neurons are formed, eliminated, enhanced, and weakened during learning, and we know that some stages of this process involve alterations in the transcription of specific genes. However, the specific transcription factors involved in this process are not fully understood. Here, we demonstrate that the transcription factor ΔFosB is induced in the hippocampus by learning, regulates the shape of hippocampal synapses, and is required for memory formation, opening up a host of new possibilities for hippocampal transcriptional regulation. (Copyright © 2015 the authors 0270-6474/15/3513773-11$15.00/0.)
Databáze:	MEDLINE
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