Npas4aexpression in the teleost forebrain is associated with stress coping style differences in fear learning

Abstract

Learning to anticipate potentially dangerous contexts is an adaptive behavioral response to coping with stressors. An animal’s stress coping style (e.g. proactive-reactive axis) is known to influence how it encodes salient events. However, the neural and molecular mechanisms underlying these stress coping style differences in learning are unknown. Further, while a number of neuroplasticity-related genes have been associated with alternative stress coping styles, it is unclear if these genes may bias the development of conditioned behavioral responses to stressful stimuli, and if so, which brain regions are involved. Here, we trained adult zebrafish to associate a naturally aversive olfactory cue with a given context. Next, we investigated if expression of two neural plasticity and neurotransmission-related genes (npas4a and gabbr1a) were associated with the contextual fear conditioning differences between proactive and reactive stress coping styles. Reactive zebrafish developed a stronger conditioned fear response and showed significantly higher npas4a expression in the medial and lateral zones of the dorsal telencephalon (Dm, Dl), and the supracommissural nucleus of the ventral telencephalon (Vs). Our findings suggest that the magnitude of expression of activity-dependent genes like npas4a may be differentially expressed across several interconnected forebrain regions in response to fearful stimuli and promote biases in fear learning among different stress coping styles.

Interactions between neuroanatomy, cognition, and ecology in Anolis lizards

“…Another study found upregulation of genes related to learning and memory, synaptic plasticity, and neurogenesis in the hippocampus of poison frogs, which may be related to their increased spatial cognitive abilities (Liu et al 2020). In zebrafish, differences in fear learning between fish with different stress coping styles are associated with differences in the expression of the plasticity related gene npas4a in the basolateral amygdala, hippocampus, and bed nucleus of the stria terminalis (Baker and Wong 2020). These studies demonstrate the detail with which we are beginning to understand the proximate neural mechanisms of cognition in a comparative context.…”