一般口演
学習、記憶および可塑性 1
Learning, Memory and Plasticity 1
座長：笠井 淳司（大阪大学大学院薬学研究科） |
|---|
| 2022年7月2日 9:00～9:15 沖縄コンベンションセンター 会議場B2 第5会場
3O05m1-01
文脈依存的恐怖条件付け学習におけるマウス海馬CA1細胞のカルシウムイメージング
Calcium imaging of mouse hippocampal CA1 cells during a contextual fear conditioning paradigm
*小林 曉吾(1)、髙島 魁斗(2)、寺前 順之介(2)、松尾 直毅(1)
1. 九州大学大学院理学研究院、2. 京都大学大学院情報学研究科
*Kyogo Kobayashi(1), Kaito Takashima(2), Jun-nosuke Teramae(2), Naoki Matsuo(1)
1. Faculty of Sci, Kyushu Univ, Fukuoka, Japan, 2. Grad Sch Info, Kyoto Univ, Kyoto, Japan
Keyword: CALCIUM IMAGING, FEAR CONDITIONING, HIPPOCAMPUS, MEMORY
Animals acquire a fear memory upon encounter a dangerous situation, and they make full use of the memory upon re-encounter the same situation to survive. Contextual fear conditioning is a powerful behavioral paradigm to study the neural mechanism of learning and memory. In this paradigm, a mouse is placed in a neutral context, which is characterized by a variety of environmental cues, such as floor textures, lighting intensity, background noise, odors of the chamber. Several minutes later, electrical foot shock is administered and the mouse is removed from the context. When the mouse is returned to the same context, it exhibits freezing behavior as a result of fear memory retrieval. Subsequent repeated re-exposure to the context without foot shocks eventually results in an attenuation of freezing behavior. Thus, contextual fear conditioning is useful for the analysis of memory encoding, retrieval, and extinction. Although a number of studies have demonstrated that the hippocampus is indispensable for contextual learning, a number of mysteries still remain unexplained: (1) what kind of cell would become a memory engram cell, (2) how hippocampal neurons encode contextual information, and (3) how hippocampal context representations are affected by fear memory extinction. To tackle these issues, we monitored calcium dynamics of more than 1,000 hippocampal CA1 pyramidal cells from 8 mice using a head-mounted microendoscope at single-cell resolution during contextual fear learning. We thereby analyzed the activity of each neuron at different time points (before, during, or after foot shocks), different contexts (fear-conditioned context, distinct context, or home cage), and different behavioral states (freezing or non-freezing). In this meeting, we will present our recent findings about the neuronal activity patterns observed in the CA1 and discuss the association between the neural activity and behavior. | | 2022年7月2日 9:15～9:30 沖縄コンベンションセンター 会議場B2 第5会場
3O05m1-02
ニコチンによる物体認知記憶増強作用に対する内側前頭前野-嗅周皮質経路の関与
The involvement of the medial prefrontal cortex-perirhinal cortex pathway in the nicotine-induced enhancement of object recognition memory in mice
*江崎 博仁(1)、深尾 朱里(2)、桂 あやの(2)、北中 貴紀(2)、泉 翔馬(1)、犬束 歩(3)、山中 章弘(4)、永安 一樹(5)、金子 周司(5)、西谷 直也(1,2)、出山 諭司(1,2)、金田 勝幸(1,2)
1. 金沢大院医薬保健薬理、2. 金沢大医薬保健薬理、3. 自治医大医神経脳生理、4. 名古屋大学環境医学研究所、5. 京大院薬生体機能解析
*Hirohito Esaki(1), Akari Fukao(2), Ayano Katsura(2), Takanori Kitanaka(2), Shoma Izumi(1), Ayumu Inutsuka(3), Akihiro Yamanaka(4), Kazuki Nagayasu(5), Shuji Kaneko(5), Naoya Nishitani(1,2), Satoshi Deyama(1,2), Katsuyuki Kaneda(1,2)
1. Lab Mol Pharmacol, Inst Med Pharmaceut Health Sci, Kanazawa Univ, Kanazawa, Japan, 2. Lab Mol Pharmacol, Sch Pharmaceut Sci, Kanazawa Univ, Kanazawa, Japan, 3. Dept Physiol, Jichi Med Univ, Tochigi, Japan, 4. Res Inst Envron Med, Nagoya Univ, Aichi, Japan, 5. Dept Mol Pharm, Grad Sch Pharm Sci, Kyoto Univ, Kyoto, Japan
Keyword: Object Recognition Memory, medial prefrontal cortex, perirhinal cortex, Nicotine
We have previously reported that nicotine enhances object recognition memory by acting on the medial prefrontal cortex (mPFC) in mice. In the present study, we firstly examined whether the activation of mPFC neurons mediates the nicotine-induced memory enhancement by performing the novel object recognition test (NOR) in combination with adeno-associated virus (AAV) vector-mediated designer receptors exclusively activated by designer drugs (DREADD) techniques in male C57BL/6J mice (7 – 12 weeks old). Systemic nicotine (0.1 mg/kg, s.c.) injection 10 min before the training session of the NOR significantly enhanced object recognition memory. Chemogenetic silencing of mPFC excitatory neurons, which express inhibitory DREADD hM4Di, by clozapine-N-oxide (CNO, 0.5 mg/kg, i.p.) administration 30 min before nicotine injection inhibited the enhanced memory. Conversely, chemogenic activation of mPFC excitatory neurons expressing hM3Dq by CNO before the training session enhanced object recognition memory. We next examined whether the excitatory transmission from the mPFC to the perirhinal cortex (PRH), a brain region associated with recognition memory, is involved in the nicotine-induced memory enhancement. Unilateral intra-mPFC nicotine (0.3 μg) infusion immediately before the training session was sufficient to enhance object recognition memory. This enhancement was blocked by the unilateral intra-PRH infusion of an AMPA receptor antagonist NBQX (0.05 μg) 5 min before ipsilateral intra-mPFC nicotine infusion. To investigate the role of the mPFC-PRH pathway in the nicotine-induced memory enhancement more directly, we selectively expressed hM4Di in PRH-projecting mPFC neurons by injecting retrograde AAV vector carrying Cre recombinase into the PRH and AAV-DIO-hM4Di into the mPFC. Silencing of PRH-projecting mPFC neurons before systemic nicotine administration attenuated the nicotine-induced enhancement of object recognition memory. Although we found that mPFC-PRH projection neurons send axon collaterals to the basolateral nucleus of the amygdala (BLA), unilateral intra-BLA infusion of NBQX had no effect on the ipsilateral intra-mPFC nicotine infusion-induced enhancement of object recognition memory, indicating that the mPFC-BLA pathway is not involved in the nicotine-induced memory enhancement. Collectively, these findings suggest that nicotine enhances object recognition memory via activating PRH-projecting mPFC neurons. | | 2022年7月2日 9:30～9:45 沖縄コンベンションセンター 会議場B2 第5会場
3O05m1-03
Neural circuit mechanisms of second-order conditioning in Drosophila
*Yoshinori Aso(1), Daichi Yamada(2), Toshihide Hige(2)
1. Janelia Research Campus, Ashburn, Virginia, 2. Univ of North Carolina, Chapel Hill, North Carolina, USA
Keyword: Dopamine, Associative learning, Neural circuit, EM connectome
Reward-predicting cues can promote learning of new associations without actual rewards in second-order conditioning. Here, we examined how interaction between heterogeneous types of dopamine neurons support second-order conditioning in Drosophila by developing new driver lines and an EM connectome map with machine learning based neurotransmitter prediction. We found that a mushroom body compartment that slowly forms a stable memory can instruct “student” compartments with fast and transient memory dynamics. This hierarchical interaction is mediated by the key excitatory interneuron that acquires enhanced response to a reward-predicting odor, evokes dopamine release in five compartments and promotes upwind steering upon activation. Our results reveal the origin of action-correlate in dopamine neurons and how memory subsystems with distinct dynamics concertedly synthesize transient nature of second-order memory long known by behavioral psychologists and theorists. | | 2022年7月2日 9:45～10:00 沖縄コンベンションセンター 会議場B2 第5会場
3O05m1-04
マウスにおける直接経験なしに新規知識を獲得する行動解析系の確立
Social transmission of food finding: a novel task for new knowledge learning without firsthand experience in mice
*金 亮(1,2)、尾藤 晴彦(2)、北村 貴司(1,3)
1. テキサス大学サウスウェスタン医学センター精神神経科、2. 東京大学大学院医学系研究科神経生化学、3. テキサス大学サウスウェスタン医学センター神経科学科
*Ryang Kim(1,2), Haruhiko Bito(2), Takashi Kitamura(1,3)
1. Dep. of Psychiatry, Univ of Texas Southwestern Medical Center, Dallas, US, 2. Dep. of Neurochemistry, Grad Sch Med, Univ of Tokyo, Tokyo, Japan, 3. Dep. of Neuroscience, Univ of Texas Southwestern Medical Center, Dallas, US
Keyword: social learning, hippocampus
Animals can acquire new knowledge by two types of learning: firsthand experiences such as classical conditioning or secondhand experiences through observing and listening to the other animal’s experience such as observational learning (social learning). The mechanism of the former has been well studied, while that of social learning is not well understood. The social transmission of food preference (STFP) task in rodents is one of the behavioral models for social learning. In this task, the animals (observer) can learn that an unknown odor is safe by smelling another animal (demonstrator) that has eaten the food with the same odor. Then, the observer shows a “preference” to the food with a familiar odor (smelled from the observer) than the same food with a novel odor. However, since the normal protocol of STFP requires habituating the observer with a food-filled cup, the observer has already known that the food is in the cup by observer’s firsthand experience so that we cannot understand whether the observer has acquired “the new knowledge” which the unknown odor from the demonstrator relates to the food or not at the behavioral level. Therefore, we established a new experimental model that is more suitable for social learning (social transmission of food finding; STFF) by modification of STFP. In STFF, we excluded the habituation session from the protocol, and we evaluated whether the observer acquired the knowledge about which an unknown odor relates to the food by the latency to eat the food in the cup. We found that when the observer smelled an unknown odor from the demonstrator, the latency to eat was faster than in the control animal which did not smell it, suggesting that the observer socially learned an association that an unknown odor relates to the food. Also, we found that 1) smelling an unknown odor itself (without interaction with demonstrator) was enough to establish STFP in keeping with previous reports, whereas a direct interaction with the demonstrator was required for establishing STFF, and 2) the hippocampus is necessary for recall in STFP, but not in STFF. These results suggested that STFF is a task for a social learning in which mice can learn new knowledge without firsthand experience. This new model may shed new light on key circuit differences between episodic and semantic memories in mice. | |
|
|
