Increase in cyclic AMP concentration in a cerebral giant interneuron mimics part of a memory trace for conditioned taste aversion of the pond snail.
Increase in cyclic AMP concentration in a cerebral giant interneuron mimics part of a memory trace for conditioned taste aversion of the pond snail.
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DOI：
10.2142/biophysics.9.161
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发表时间：
2013-01-01
期刊：
影响因子：
--
通讯作者：
Ito, Etsuro
中科院分区：
文献类型：
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作者：
Otsuka, Emi;Matsunaga, Miho;Ito, Etsuro
条件性味觉厌恶(CTA)可以在池塘蜗牛Lymneea stagnaris中经典地受到条件反射，然后被巩固到长期记忆(LTM)中。CTA-LTM的神经痕迹可概括为：条件钉螺由于大脑巨细胞(CGC)的激活，在神经元1内侧(N1M)细胞记录到的多突触抑制性突触后电位比对照钉螺更大且持续时间更长。N1M细胞最终由CGC通过神经元3强直(N3T)细胞激活。也就是说，促进了从N3T细胞到N1M细胞的抑制性单突触输入。N1M和N3T细胞是摄食中枢模式生成器的成员，而CGC是一个被认为在摄食行为中起关键作用的多模式中间神经元。在这里，我们研究了第二个信使cAMP在记忆痕迹的建立中的参与。我们将cAMP注入CGC，并监测由CGC激活的B3运动神经元的电位。B3活性被用作从N3T细胞到N1M细胞的突触输入的指标。我们发现B3的电势在瞬间增大。因此，当通过味觉厌恶训练提高CGC中cAMP浓度时，cAMP诱导的变化可能在N3T细胞中记忆痕迹的建立中起关键作用。
Conditioned taste aversion (CTA) can be classically conditioned in the pond snail Lymnaea stagnalis and subsequently be consolidated into long-term memory (LTM). The neural trace that subserves CTA-LTM can be summarized as follows: A polysynaptic inhibitory postsynaptic potential recorded in the neuron 1 medial (N1M) cell in the conditioned snails as a result of activation of the cerebral giant cell (CGC) is larger and lasts longer than that in control snails. The N1M cell is ultimately activated by the CGC via the neuron 3 tonic (N3t) cell. That is, the inhibitory monosynaptic inputs from the N3t cell to the N1M cell are facilitated. The N1M and N3t cells are the members of feeding central pattern generator, whereas the CGC is a multimodal interneuron thought to play a key role in feeding behavior. Here we examined the involvement of a second messenger, cAMP, in the establishment of the memory trace. We injected cAMP into the CGC and monitored the potentials of the B3 motor neuron activated by the CGC. B3 activity is used as an index for the synaptic inputs from the N3t cell to the N1M cell. We found that the B3 potentials were transiently enlarged. Thus, when the cAMP concentration is increased in the CGC by taste aversion training, cAMP-induced changes may play a key role in the establishment of a memory trace in the N3t cell.