Loss of CELF6 RNA binding protein impairs cocaine conditioned place preference and contextual fear conditioning

Abstract

In addition to gene expression differences in distinct cell types, there is substantial post‐transcriptional regulation driven in part by RNA binding proteins (RBPs). Loss‐of‐function RBP mutations have been associated with neurodevelopmental disorders, such as Fragile‐X syndrome and syndromic autism. Work performed in animal models to elucidate the influence of neurodevelopmental disorder‐associated RBPs on distinct behaviors has showed a connection between normal post‐transcriptional regulation and conditioned learning. We previously reported cognitive inflexibility in a mouse model null for the RBP CUG‐BP, Elav‐like factor 6 (CELF6), which we also found to be associated with human autism. Specifically, these mice failed to potentiate exploratory hole‐poking behavior in response to familiarization to a rewarding stimuli. Characterization of Celf6 gene expression showed high levels in monoaminergic populations such as the dopaminergic midbrain populations. To better understand the underlying behavioral disruption mediating the resistance to change exploratory behavior in the holeboard task, we tested three hypotheses: Does Celf6 loss lead to global restricted patterns of behavior, failure of immediate response to reward or failure to alter behavior in response to reward (conditioning). We found the acute response to reward was intact, yet Celf6 mutant mice exhibited impaired conditioned learning to both reward and aversive stimuli. Thus, we found that the resistance to change by the Celf6 mutant in the holeboard was most parsimoniously explained as a failure of conditioning, as the mice had blunted responses even to potent rewarding stimuli such as cocaine. These findings further support the role of RBPs in conditioned learning.

DNMT3A Haploinsufficiency Results in Behavioral Deficits and Global Epigenomic Dysregulation Shared across Neurodevelopmental Disorders

“…Marble burying is a natural murine behavior and has been used to indicate repetitive digging as well as anxiety-related behaviors. Protocol was adapted from previously published methods (Lazic, 2015;Maloney et al, 2019a). In brief, 8-week old mice were placed in a transparent enclosure (28.5 cm x 17.5 cm x 12 cm) with clean aspen bedding and 20 dark blue marbles evenly spaced in a 4 3 5 grid on top of the bedding.…”

“…Fear conditioning was done as previously described (Maloney et al, 2019a(Maloney et al, , 2019b. Mice were habituated to an acrylic chamber (26 cm x 18 cm x 18 cm) containing a metal grid floor and an odorant and was illuminated by LED light which remained on for the Cell Reports 33, 108416, November 24, 2020 e6 Article ll OPEN ACCESS duration of the trial.…”

CLIP and Massively Parallel Functional Analysis of CELF6 Reveal a Role in Destabilizing Synaptic Gene mRNAs through Interaction with 3′ UTR Elements

“…CELF6 showed expression in the hypothalamus and in several monoaminergic cell populations commonly targeted in psychiatry ( Maloney et al, 2016 ). Likely as a consequence of its role in those cells, it is also associated with conditioned behaviors: Celf6- knockout (KO) mouse pups show altered ultrasonic vocalization, while adults exhibit deficits in fear conditioning and loss of conditioned place preference to cocaine ( Dougherty et al, 2013 ; Maloney et al, 2019 ). Although capable of regulating splicing in vitro ( Ladd et al, 2004 ), CELF6 has recently been shown to interact with the 3′ untranslated region (UTR) as well, allowing it to stabilize p21 mRNA in colorectal cancer cells ( Liu et al, 2019 ).…”

DNMT3A haploinsufficiency results in behavioral deficits and global epigenomic dysregulation shared across neurodevelopmental disorders

“…Marble burying is a natural murine behavior and has been used to indicate repetitive digging as well as anxiety-related behaviors. Protocol was adapted from previously published methods (Lazic, 2015;Maloney et al, 2019a). In brief, 8-week old mice were placed in a transparent enclosure (28.5 cm x 17.5 cm x 12 cm) with clean aspen bedding and 20 dark blue marbles evenly spaced in a 4 x 5 grid on top of the bedding.…”

“…Fear conditioning was done as previously described (Maloney et al, 2019a(Maloney et al, , 2019b. Mice were habituated to an acrylic chamber (26 cm x 18 cm x 18 cm) containing a metal grid floor and an odorant and was illuminated by LED light which remained on for the duration of the trial.…”