華盛頓大學(xué)的研究人員利用分子成像技術(shù)跟蹤大鼠大腦神經(jīng)活動，發(fā)現(xiàn)位于大腦側(cè)腦室下角前端上方的杏仁體(amygdala)是恐懼記憶存儲的地方,。
神經(jīng)學(xué)家以前認為杏仁體和海馬體都與恐懼情感產(chǎn)生有關(guān),，但是新的研究表明海馬體只負責處理和傳輸信息，不能產(chǎn)生恐懼感,。
最新研究中,，研究人員將大鼠分為四組，把其中三組放在一個陌生環(huán)境中,，并施予不同的電刺激,。反復(fù)試驗，通過觀察大鼠行為確定產(chǎn)生恐懼記憶后將大鼠殺死,。取腦切片成像后發(fā)現(xiàn)大腦中杏仁體是產(chǎn)生恐懼記憶的部位,。（生物谷Bioon.com）
生物谷推薦原始出處：
PLoS ONE 4(7): e6156. doi:10.1371/journal.pone.0006156
Functional Imaging of Stimulus Convergence in Amygdalar Neurons during Pavlovian Fear Conditioning
Sabiha K. Barot1,2, Ain Chung2, Jeansok J. Kim1,2, Ilene L. Bernstein1,2*
1 Program in Neurobiology & Behavior, University of Washington, Seattle, Washington, United States of America, 2 Department of Psychology, University of Washington, Seattle, Washington, United States of America
Background
Associative conditioning is a ubiquitous form of learning throughout the animal kingdom and fear conditioning is one of the most widely researched models for studying its neurobiological basis. Fear conditioning is also considered a model system for understanding phobias and anxiety disorders. A fundamental issue in fear conditioning regards the existence and location of neurons in the brain that receive convergent information about the conditioned stimulus (CS) and unconditioned stimulus (US) during the acquisition of conditioned fear memory. Convergent activation of neurons is generally viewed as a key event for fear learning, yet there has been almost no direct evidence of this critical event in the mammalian brain.
Methodology/Principal Findings
Here, we used Arc cellular compartmental analysis of temporal gene transcription by fluorescence in situ hybridization (catFISH) to identify neurons activated during single trial contextual fear conditioning in rats. To conform to temporal requirements of catFISH analysis we used a novel delayed contextual fear conditioning protocol which yields significant single- trial fear conditioning with temporal parameters amenable to catFISH analysis. Analysis yielded clear evidence that a population of BLA neurons receives convergent CS and US information at the time of the learning, that this only occurs when the CS-US arrangement is supportive of the learning, and that this process requires N-methyl-D-aspartate receptor activation. In contrast, CS-US convergence was not observed in dorsal hippocampus.
Conclusions/Significance
Based on the pattern of Arc activation seen in conditioning and control groups, we propose that a key requirement for CS-US convergence onto BLA neurons is the potentiation of US responding by prior exposure to a novel CS. Our results also support the view that contextual fear memories are encoded in the amygdala and that the role of dorsal hippocampus is to process and transmit contextual CS information.
