Retrieval-Induced Forgetting in a Pentylenetetrazole-Induced Epilepsy Model in the Rat

Abstract

The selective retrieval of some information may lead to the forgetting of related, but non-retrieved information. This memory phenomenon is termed retrieval-induced forgetting (RIF). Active inhibition is thought to function to resolve interference from competing information during retrieval, which results in forgetting. Epilepsy is associated with impaired inhibitory control that contributes to executive dysfunction. The purpose of this study is to investigate whether rats in a kindling model of epilepsy demonstrate normal levels of RIF. Rats were divided into two groups: saline and kindling. Pentylenetetrazole was injected intraperitoneally until the rats kindled. RIF was tested using a modified version of the spontaneous object recognition test, consisting of a sample phase, retrieval or interference phase, and a test phase. Exploration time for each object was analyzed. RIF was demonstrated in the saline group when rats subjected to the retrieval phase failed to discriminate between the familiar object and the novel object later in the test phase. Kindled rats, on the other hand, did not suffer forgetting even when they were subjected to the retrieval phase, as they spent significantly longer times exploring the novel rather than the familiar object in the test phase. Therefore, RIF was not observed in the kindling group. These findings indicate impaired retrieval-induced forgetting in kindled rats, which may be suggestive of a deficit in the inhibitory control of memory.

Inhibition as a cause of forgetting

“…Paralleling findings in humans Kuhl et al (2007), cFos imaging showed declining pre-frontal control demands over retrieval practice trials, indicating reduced competition as memories were inhibited. Other rodent studies have also reported RIF for odours associated with food rewards Wu et al, (2014), and RIF of objects (Yamada et al, 2014;Almahozi et al, 2018). Similarly, the effect could be abolished with mPFC or hippocampal lesions (Wu et al, 2014).…”

Neuroprotective role of chrysin‐loaded poly(lactic‐co‐glycolic acid) nanoparticle against kindling‐induced epilepsy through Nrf2/ARE/HO‐1 pathway

“…Furthermore, Nrf2/ARE/HO‐1 activation has an important role in neurodegenerative diseases, including Alzheimer's, Parkinson's disease, and epilepsy model for animals and cell cultures. [ 5,6 ]…”