a-procedure-to-observe-context-induced-renewal-pavlovian-conditioned

A Procedure to Observe Context-induced Renewal of Pavlovian-conditioned Alcohol-seeking Behavior in Rats

Environmental contexts in which drugs of abuse are consumed can trigger craving, a subjective Pavlovian-conditioned response that can facilitate ...

Concordia University

Many associative learning theories assert that the predictive accuracy of events affects the allocation of attention to them. More reliable predictors of future events are usually more likely to control action based on past learning, but less reliable predictors are often more likely to capture attention when new information is acquired. Previous studies showed that a circuit including the amygdala central nucleus (CEA) and the cholinergic substantia innominata/nucleus basalis magnocellularis (SI/nBM) is important for both sustained attention guiding action in a five-choice serial reaction time (5CSRT) task and for enhanced new learning about less predictive cues in a serial conditioning task. In this study, the authors found that lesions of the cholinergic afferents of the medial prefrontal cortex interfered with 5CSRT performance but not with surprise-induced enhancement of learning, whereas lesions of cholinergic afferents of posterior parietal cortex impaired the latter effects but did not affect 5CSRT performance. CEA lesions impaired performance in both tasks. These results are consistent with the view that CEA affects these distinct aspects of attention by influencing the activity of separate, specialized cortical regions via modulation of SI/nBM.

Dissociation of attention in learning and action: effects of lesions of the amygdala central nucleus, medial prefrontal cortex, and posterior parietal cortex.

Lesions of the rat medial prefrontal cortex (mPFC) produce behavioral impairments in the 5-choice serial reaction time (5CSRT) task, a widely used measure of sustained and selective visual attention. This experiment compared the effects of "dorsal" (centered on prelimbic and infralimbic cortices) and "ventral" (centered on dorsal peduncular cortex and tenia tecta) mPFC lesions on performance in a variant of the 5CSRT task. Because in some associative learning theories, the predictive validity of events determines the allocation of attention to them, we also examined the effects of cue validity in this task. Operant nosepoke responses to some briefly illuminated ports were consistently (100%) reinforced (CRF) with food, whereas for other ports, responding was reinforced on only 50% of the trials (partial reinforcement, PRF). Different patterns of impairment emerged depending on lesion location within the mPFC. Dorsal- and sham-lesioned rats responded more to CRF than to PRF cues, but ventral-lesioned rats responded similarly to CRF and PRF cues. Additionally, under some conditions of increased attentional demands, dorsal-lesioned rats failed to respond on many trials, whereas the impairment in ventral-lesioned rats was manifested as an increase in response errors. These results demonstrate separable roles for dorsal and ventral mPFC subregions in controlling attention.

Effects of dorsal or ventral medial prefrontal cortical lesions on five-choice serial reaction time performance in rats.

The medial prefrontal cortex (mPFC) has been implicated in various attentional functions. This experiment examined the involvement of mPFC subregions in the allocation of attention in learning and action as a function of the predictive accuracy of cues. Rats with dorsal (encompassing anterior cingulate, prelimbic, and infralimbic cortices) or ventral (encompassing mainly infralimbic and dorsopeduncular cortices and tenia tecta) mPFC lesions were trained in a multiple-choice discrimination task in which operant nosepoke responses to some visual cues were consistently (100%) reinforced (CRF) with food, whereas responses to other visual cues were partially (50%) reinforced (PRF). In challenge tests designed to assess attention in the control of action, responding was directed more to CRF cues than to PRF cues in sham and dorsal mPFC-lesioned rats, but ventral mPFC-lesioned rats showed similar levels of responding to both CRF and PRF cues. Nevertheless, when given a choice between simultaneously presented CRF and PRF cues in a cue competition test, all groups responded more to CRF cues. In a subsequent Pavlovian overshadowing phase designed to assess attention in the acquisition of new learning, previously trained CRF cues overshadowed conditioning to novel auditory cues more than did PRF cues in dorsal mPFC-lesioned rats, whereas the opposite pattern was observed in sham and ventral mPFC-lesioned rats. These results suggest a dissociation within the mPFC in the use of reinforcement prediction information to allocate attention for new learning and for the control of action.

Article	Year
Dissociation of attention in learning and action: effects of lesions of the amygdala central nucleus, medial prefrontal cortex, and posterior parietal cortex. Behavioral neuroscience\| PubMed ID: 17324051	2007
Effects of dorsal or ventral medial prefrontal cortical lesions on five-choice serial reaction time performance in rats. Behavioural brain research\| PubMed ID: 21376088	2011
Dissociations between medial prefrontal cortical subregions in the modulation of learning and action. Behavioral neuroscience\| PubMed ID: 21517147	2011
The amygdala central nucleus: a new region implicated in habit learning. The Journal of neuroscience : the official journal of the Society for Neuroscience\| PubMed ID: 22674253	2012

Jean-Marie Maddux

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