Corrigendum: Basolateral amygdala rapid glutamate release encodes an outcome-specific representation vital for reward-predictive cues to selectively invigorate reward-seeking actions (original) (raw)

Proper performance of acquired abilities can be disturbed by the unexpected occurrence of external changes. Rats trained with an operant conditioning task (to press a lever in order to obtain a food pellet) using a fixed-ratio (1:1) schedule were subsequently placed in a Skinner box in which the lever could be removed randomly. Field postsynaptic potentials (fPSPs) were chronically evoked in perforant pathway-hippocampal CA1 (PP-CA1), CA1-subiculum (CA1-SUB), CA1-medial prefrontal cortex (CA1-mPFC), mPFC-nucleus accumbens (mPFC-NAc), and mPFC-basolateral amygdala (mPFC-BLA) synapses during lever IN and lever OUT situations. While lever presses were accompanied by a significant increase in fPSP slopes at the five synapses, the unpredictable absence of the lever were accompanied by decreased fPSP slopes in all, except PP-CA1 synapses. Spectral analysis of local field potentials (LFPs) recorded when the animal approached the corresponding area in the lever OUT situation presented lower spectral powers than during lever IN occasions for all recording sites, apart from CA1. Thus, the unpredictable availability of a reward-related cue modified the activity of cortical and subcortical areas related with the acquisition of operant learning tasks, suggesting an immediate functional reorganization of these neural circuits to address the changed situation and to modify ongoing behaviors accordingly. Cognitive flexibility allows us to respond to changing environmental events (e.g., the presence of new context or cues) leading to the generation of adaptive behaviors 1. These adaptations require the modification of previously acquired stimulus-response associations 2-4. The detection of novel conditions must take place before the adapted behavior occurs, since several psychological factors, like reward 5 , attention 6 and novelty 7 , can modify ongoing cerebral functions 8. Accordingly, it is important to understand brain processes by which changes in the availability of a reward-related cue are compared with the functional states corresponding to previously acquired motor situations and how this detection will modify subsequent behaviors. Neural oscillations emerge from the network of excitatory and inhibitory synaptic connections specific of each neural center and result from the phase synchrony of cell assemblies 9. Neural oscillations are thought to contribute to the dynamic coupling in neural communication between related brain areas underlying different cognitive processes 10-14. One of the most prominent and best studied oscillations is the theta (3-12 Hz) rhythm, which has been shown to play a role in different learning and memory functions 12,15-18. Information flow through theta oscillations between the hippocampus and the neocortex points to this network as a core component in cognitive processes and subsequent behaviors 15,19,20. While the hippocampus has been proposed to create context representation in space and time 21-23 and to facilitate the formation of memory traces important to long-term memory storage 24 , cortical structures such as mPFC have a special role in cognitive processes involved in the selection, timing, and execution of particular behaviors 25-30. Finally, subcortical structures as the NAc and the BLA have been related to different motivational and rewarding learning tasks 16,31-33. Within the hippocampus, the CA1 region has been related to appetitive and consummatory behaviors during operant conditioning tasks 34 , as well as during novelty detection 35,36. The SUB is a hippocampal output structure receiving synaptic excitation from CA1 pyramidal cells, and represents an important connecting node for processing spatial information and body movements. In particular, the dorsal SUB is necessary for the memory of self-motion cues 37 and object recognition 38 , as well as being involved in hippocampal-ventral tegmental area loops for rewarding long-term memories 7,33 .