Sign and goal tracker rats process differently the incentive salience of a conditioned stimulus

Abstract

Sign and goal tracker animals show different behavioral patterns in response to conditioned stimuli, which may be driven by different neural circuits involved in processing stimuli. Here, we explored whether sign and goal-tracker profiles implicated different brain regions and responses to incentive salience of stimuli. We performed three experiments using male Wistar rats. Experiment 1 showed that lesioning the medial prefrontal cortex increased the prevalence of the goal-tracker phenotype. Experiment 2 assessed the developmental trajectory of the salience incentive attribution to a conditioned stimulus, showing that increased incentive salience of stimuli increased the prevalence of the sign-tracker phenotype in mature, but not preadolescent rats. In experiment 3, the functional impact of the medial prefrontal cortex circuits was analyzed with a latent inhibition procedure. Sign tracker rats showed a reduced latent inhibition to stimuli previously exposed when compared to goal tracker or intermediate rats. The overall results of this study highlight a key role of the medial prefrontal cortex for sign tracking behavior. The expression of sign and goal tracker phenotypes changed after lesion to the medial prefrontal cortex (experiment 1), differed across development (experiment 2), and showed differences in the attentional processes to previously exposed stimuli, as preexposure to CS was ineffective in sign tracker animals (experiment 3). These data indicate that the responses to the incentive salience of stimuli in sign tracker and goal tracker profiles are likely driven by different neural circuitry, with a different role of prefrontal cortical function.

Prelimbic prefrontal cortical encoding of reward predictive cues

“…autoshaping, learning, reward the mPFC (Batten et al, 2018;Tomie et al, 2014), and lesions of the mPFC reduce cue approach behavior (Serrano-Barroso et al, 2019), there is little evidence that the mPFC encodes such Pavlovian cues.…”

Traditional Scales Diagnosis and Endophenotypes in Attentional Deficits Disorders: Are We on the Right Track?

“…In fact, nucleus accumbens shows higher levels of dopamine release in the presence of a CS [142]. Besides, D2 dopamine receptors stimulation reduces ST behavior selectively, in a similar way to medial prefrontal cortex lesion [140,141]. Thus, this model integrates information at different level from this animal model that cover biochemical, anatomical and behavioral level.…”

“…Using the same paradigm, Serrano et al [141] found processing differences of a CS in latent inhibition (LI), other easily quantifiable procedure. LI is a learning process associated to selective attention assessment.…”

Detecting Attention Levels in ADHD Children with a Video Game and the Measurement of Brain Activity with a Single-Channel BCI Headset

“…Taken as a whole, we propose that levels of attention and behavioural measures could help us characterise our participants in different populations. Studies carried out by our research group have shown a clear correlation between attention deficit and levels of impulsivity in an animal model [ 39 ]. These endophenotypes are based in different cue processing, predict vulnerability to behavioural disorders [ 40 ], and could work as a model to evaluate individual differences regarding impulsivity and attention factors [ 7 ].…”