Mineralocorticoid receptors in the ventral hippocampus are involved in extinction memory in rats

作者：Xiaoli, Xing; Hongbo, Wang; Jing, Liang; Yunjing, Bai; Zhengkui, Liu; Xigeng, Zheng

来源：PsyCh Journal, 2014, 3(3): 201-213.

DOI：10.1002/pchj.58

<jats:title>Abstract</jats:title><jats:p><jats:italic>Fear extinction decreases conditioned fear responses that normally occur when a conditioned stimulus (<jats:styled-content style="fixed-case">CS</jats:styled-content>) is repeatedly presented in the absence of an aversive unconditioned stimulus (<jats:styled-content style="fixed-case">US</jats:styled-content>), which is the behavioral basis of exposure therapy for posttraumatic stress disorder (<jats:styled-content style="fixed-case">PTSD</jats:styled-content>). However, knowledge about the neurobiology of extinction is insufficient. The present study investigated changes in the protein expression of mineralocorticoid receptors (<jats:styled-content style="fixed-case">MRs</jats:styled-content>) and glucocorticoid receptors (<jats:styled-content style="fixed-case">GRs</jats:styled-content>) in the dorsal hippocampus (<jats:styled-content style="fixed-case">DH</jats:styled-content>)and ventral hippocampus (<jats:styled-content style="fixed-case">VH</jats:styled-content>), induced by extinction and return of conditioned fear responses to an auditory signal. Western blot analysis indicated that shock stress enhanced the expression of <jats:styled-content style="fixed-case">MRs</jats:styled-content> in only the <jats:styled-content style="fixed-case">DH</jats:styled-content>, whereas extinction selectively increased the expression of <jats:styled-content style="fixed-case">MRs</jats:styled-content> in the <jats:styled-content style="fixed-case">VH</jats:styled-content>. The infusion of <jats:styled-content style="fixed-case">MRs</jats:styled-content> antagonist spironolactone in the <jats:styled-content style="fixed-case">VH</jats:styled-content> indicated that <jats:styled-content style="fixed-case">MRs</jats:styled-content> in the <jats:styled-content style="fixed-case">VH</jats:styled-content> did not affect the retrieval of fear and extinction memories, but facilitated the formation of extinction memory. However, no changes in <jats:styled-content style="fixed-case">GRs</jats:styled-content> in either the <jats:styled-content style="fixed-case">DH</jats:styled-content> or <jats:styled-content style="fixed-case">VH</jats:styled-content> were observed in each phase of auditory fear conditioning. These results suggest that <jats:styled-content style="fixed-case">MRs</jats:styled-content> in the <jats:styled-content style="fixed-case">DH</jats:styled-content> and <jats:styled-content style="fixed-case">VH</jats:styled-content> have differential functions in the extinction of auditory fear conditioning. <jats:styled-content style="fixed-case">MRs</jats:styled-content> in the <jats:styled-content style="fixed-case">DH</jats:styled-content> appear to be related to only stressful experiences, whereas <jats:styled-content style="fixed-case">MRs</jats:styled-content> in the <jats:styled-content style="fixed-case">VH</jats:styled-content> are involved in extinction formation. The enhancement of <jats:styled-content style="fixed-case">MRs</jats:styled-content> in the <jats:styled-content style="fixed-case">VH</jats:styled-content> might be necessary to improve <jats:styled-content style="fixed-case">PTSD</jats:styled-content>.</jats:italic></jats:p>

• 出版日期2014-9
• 单位中国科学院大学