The orbitofrontal cortex (OFC) and basolateral nucleus of the amygdala (BLA) share many reciprocal connections, and a functional interaction between these regions is important in controlling goal-directed behavior. However, their relative roles have proved hard to dissociate. Although injury to these brain regions can cause similar effects, it has been suggested that the resulting impairments a...

The amygdala is known to play a role in learning about motivationally significant events. We investigated this role further by examining the effects of excitotoxic lesions of the basolateral amygdala on the ability of rats to use instrumental outcomes to direct responding (the differential outcomes effect) and on the ability of Pavlovian cues to modulate instrumental performance based on shared...

Prediction about outcomes constitutes a basic mechanism underlying informed economic decision making. A stimulus constitutes a reward predictor when it provides more information about the reward than the environmental background. Reward prediction can be manipulated in two ways, by varying the reward paired with the stimulus, as done traditionally in neurophysiological studies, and by varying t...

Why are emotionally arousing experiences well-remembered? Since the amygdala and hippocampus play pivotal roles in emotion and memory, respectively, the interaction between these brain regions may underlie the formation of enhanced memory for emotionally arousing events. Behavioral experiments using animals have demonstrated that lesions of the amygdaloid nuclei or infusions of drugs into the a...

Basolateral amygdala and orbitofrontal cortex are implicated in cue-outcome learning. In this issue of Neuron, Schoenbaum et al. show that, following basolateral amygdala lesions, cue-selective neurons in orbitofrontal cortex are more sensory driven and less sensitive to the motivational value of an outcome, suggesting that predictive value coding in orbitofrontal cortex is dependent on input f...

Rorick-Kehn and Steinmetz (2005) report that neurons in the central and basolateral nuclei of the amygdala exhibit learning-related spike firing to conditional stimuli associated with shock in 3 different aversive conditioning paradigms: eyeblink conditioning, fear conditioning, and signaled avoidance conditioning. Central nucleus neurons responded in all 3 tasks, whereas basolateral nucleus ne...

To confirm that an increase in blood pressure induced by ketamine is mediated through the central nervous system, we examined effect of ketamine, applied directly to amygdala, on pressure. Six male Sprague-Dawley rats were used study. Under head-restrained and unanesthetized condition, 0.2 μl (5 mg/ml) was injected around amygdala at a flow rate μl/min glass pipette, recorded while monitoring s...

Neurogenesis in the rat amygdala was examined with 3H-thymidine radiography. The animals were the offspring of pregnant females given two injections of 3H-thymidine on consecutive days in an overlapping series: Embryonic day (E) 12 + E13, E l 3 + E14. . . E21 + E22. On 60 days of age, the percentage of labelled cells and the proportion of cells added during each day of formation were determined...

Introduction: Aggressive behavior is a major issue in the field of mental health. Pharmacotherapy is often used for the treatment of violent individuals. A neurochemical system most consistently linked with aggression is the GABAergic system. The aim of the present investigation was to examine the effect of muscimol (GABAA agonist) 250 and 500 ng/rat and picrotoxin (GABAA antagonist) 1.5 and...