Analysis of Mutants Suggests Kamin Blocking in C. elegans is Due to Interference with Memory Recall Rather than Storage

Abstract

Higher-order conditioning phenomena, including context conditioning and blocking, occur when conditioning to one set of stimuli interacts with conditioning to a second set of stimuli to modulate the strength of the resultant memories. Here we analyze higher-order conditioning in the nematode worm Caenorhabditis elegans, demonstrating for the first time the presence of blocking in this animal, and dissociating it from context conditioning. We present an initial genetic dissection of these phenomena in a model benzaldehyde/NH4Cl aversive learning system, and suggest that blocking may involve an alteration of memory retrieval rather than storage. These findings offer a fundamentally different explanation for blocking than traditional explanations, and position C. elegans as a powerful model organism for the study of higher order conditioning.

A NovelC. elegansMemory Type Mediated by an Insulin/Phospholipase C Pathway

“…We find that crh-1(tz2) mutants exhibit slightly impaired naïve approach to odorants, as has been reported previously (Dahiya et al, 2019), but see no evidence of a benzaldehyde/starvation learning deficit ( Fig. 3B ), consistent with our previous observations on these mutants in more complex memory paradigms (Merritt et al, 2019). Since the crh-1(tz2) allele deletes most of the bZIP domain of C. elegans CREB1 (Fig.…”

Agency rescues competition for credit assignment among predictive cues from adverse learning conditions

“…Credit assignment among environmental cues has traditionally been regarded as a competitive process in which the best predictor of the outcome acquires substantial credit over the course of learning at the expense of other predictors 1 , 5 , 6 . In support of this notion is evidence that cues compete for credit in a range of tasks 7 – 10 and species, from C. elegans to humans 11 – 16 . However, it has also long been known that cue competition is not ubiquitous 17 – 19 and can be disrupted across multiple learning conditions 20 – 22 .…”

The Conscious Nematode: Exploring Hallmarks of Minimal Phenomenal Consciousness in Caenorhabditis Elegans

“…Ardiel & Rankin, 2010;Ghosh et al, 2017;Guillermin et al, 2017;Dekkers et al, 2021;Merritt et al, 2019 Embodiment and self Perhaps. There is an efferent copy of motor commands.…”

“…Induction of diapause is pheromone-dependent and thus, C. elegans can recognize its community. tioning and blocking conditioning, which are second order paradigms (Merritt et al, 2019). Most importantly, C. elegans can transiently change its behavior towards NaCl concentration gradients from attraction to strong repulsion when a NaCl (aq) gradient is presented to a naïve C. elegans in absence of food (bacteria) for 15 minutes or longer (Hukema et al, 2008).…”