I.P. Pavlov Journal of Higher Nervous ActivityI.P. Pavlov Journal of Higher Nervous ActivityЖурнал высшей нервной деятельности им. И.П. Павлова0044-46773034-5316The Russian Academy of Sciences68758110.31857/S0044467725040086ФИЗИОЛОГИЧЕСКИЕ МЕХАНИЗМЫ ПОВЕДЕНИЯ ЖИВОТНЫХ: ВОСПРИЯТИЕ ВНЕШНИХ СТИМУЛОВ, ДВИГАТЕЛЬНАЯ АКТИВНОСТЬ, ОБУЧЕНИЕ И ПАМЯТЬФИЗИОЛОГИЧЕСКИЕ МЕХАНИЗМЫ ПОВЕДЕНИЯ ЖИВОТНЫХ: ВОСПРИЯТИЕ ВНЕШНИХ СТИМУЛОВ, ДВИГАТЕЛЬНАЯ АКТИВНОСТЬ, ОБУЧЕНИЕ И ПАМЯТЬResearch ArticleThe effects of the early pro-inflammatory stress on reconsolidation and extinction of fear memory in male Wistar ratsВлияние раннего провоспалительного стресса на реконсолидацию и угашение памяти о страхе у самцов крыс ВистарGrigoryanGrigory A.ГригорьянГригорий А.
Russian Federation
grigorygrigoryan@hotmail.comPavlovaIrina V.ПавловаИрина В.
Russian Federation
grigorygrigoryan@hotmail.comBroshevitskayaNadezda D.БрошевицкаяНадежда Д.
Russian Federation
grigorygrigoryan@hotmail.comShvadchenkoAnastasia A.ШвадченкоАнастасия А.
Russian Federation
grigorygrigoryan@hotmail.comInstitute of Higher Nervous Activity and Neurophysiology RASИнститут высшей нервной деятельности и нейрофизиологии РАН150820257544834971507202515072025Copyright ©; 2025, Russian Academy of SciencesCopyright ©; 2025, Российская академия наук2025Russian Academy of SciencesРоссийская академия наукhttps://innoscience.ru/0044-4677/article/view/687581

The influence of neuroinflammation on the reconsolidation of fear memory is poorly studied, using only acute but not the remote effects of intoxication. In the present work, we investigated the influence of remote pro-inflammatory lipopolysaccharide (LPS) stress on the reconsolidation and extinction of fear memory in adult male Wistar rats. On the 3rd and 5th PND, during the critical period of postnatal ontogenesis, the rats received subcutaneous injections of LPS (50 μg/kg) or saline. At 120 PND, the rats acquired a fear conditioning by the use of three pairings of tone presentations and shock. Twenty-four hours after training, one group of rats was reactivated in the same context and by a single tone presentation (Re+), while the other group remained in the home cages, (Re‒). A day later, in retention test 1, the freezing reaction was measured in all groups. After test 1, the groups underwent extinction for two days with 10 tones on each day, followed by retention test 2. In test 1, the contextual memory of the Re+ vs. Re‒ saline groups were impaired as opposed to cue memory. The early LPS stress equalized the level of freezing of both Re+ and Re‒ groups, indicating that early neuroinflammation impairs the updating of the contextual fear memory. The differences in the level of freezing between the Re+ and Re‒ groups persisted during extinction and in test 2. The extinction of the LPS group was slower than that in the SAL group. Thus, remote neuroinflammation impairs the process of memory updating and extinction of conditioned fear.

Влияние нейровоспаления на реконсолидацию памяти о страхе слабо изучено, исследовались только острые, но не отдаленные эффекты интоксикации. В настоящей работе мы изучали влияние отдаленного провоспалительного липополисахаридного (ЛПС) стресса на реконсолидацию и угашение памяти о страхе у взрослых самцов крыс Вистар. На 3-й и 5-й постнатальный день (ПНД), во время критического периода постнатального онтогенеза, крысам подкожно вводили ЛПС (50 мкг/кг, группа LPS) или физиологический раствор (группа SAL). На 120 ПНД у крыс вырабатывали условнорефлекторный страх с помощью трех сочетаний звукового тона и удара током по лапам. Через 24 час после обучения у одной группы крыс проводили реактивацию памяти, помещая их в ту же обстановку и давая одно применение тона (Re+), другая группа крыс оставалась в домашней клетке (Re‒). Через 24 час в тесте 1 на сохранность памяти во всех группах определяли время замирания. После теста 1 в течение двух дней проводили угашение реакции, давая по 10 тонов каждый день, после чего следовал тест 2. В тесте 1 у крыс, получавших SAL, в группе Re+ по сравнению с группой Re‒ была нарушена память об обстановке, но не память о сигнале. После раннего LPS стресса уровень замирания на обстановку в группах Re+ и Re‒ не различался, что свидетельствовало о том, что раннее нейровоспаление ослабляло обновление контекстуальной памяти о страхе. Различия в уровне замирания в группах Re+ и Re‒ сохранялись во время угашения и в тесте 2. В группе LPS угашение реакции было более медленное, чем в группе SAL. Таким образом, отдаленное нейровоспаление нарушает процесс обновления и угашения памяти о страхе.

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