Stimuli that possess inherently rewarding or aversive qualities elicit emotional responses and also induce learning by imparting valence upon neutral sensory cues. Evidence has accumulated ...implicating the amygdala as a critical structure in mediating these processes. We have developed a genetic strategy to identify the representations of rewarding and aversive unconditioned stimuli (USs) in the basolateral amygdala (BLA) and have examined their role in innate and learned responses. Activation of an ensemble of US-responsive cells in the BLA elicits innate physiological and behavioral responses of different valence. Activation of this US ensemble can also reinforce appetitive and aversive learning when paired with differing neutral stimuli. Moreover, we establish that the activation of US-responsive cells in the BLA is necessary for the expression of a conditioned response. Neural representations of conditioned and unconditioned stimuli therefore ultimately connect to US-responsive cells in the BLA to elicit both innate and learned responses.
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•ChR2 was expressed in unconditioned stimulus (US) representations in the BLA•Activation of US representations elicits innate responses and drives learning•Inhibition of US representations prevents the expression of learned behavior•Conditioned stimuli activate US representations in BLA to elicit learned behavior
Neurons in the basolateral amygdala that mediate responses to intrinsically rewarding or aversive stimuli also elicit learned responses, indicating that associative learning is funneled through innate behavioral circuits to assign positive or negative emotions to neutral sensory stimuli.
OBJECTIVE To study the clinical results of surgical management in patients with right upper quadrant pain, a positive hepatobiliary iminodiacetic acid (HIDA) scan result, and no gallstones. DATA ...SOURCES Health care databases and gray literature. STUDY SELECTION Each article was scrutinized to determine whether it met inclusion criteria. Only abstracts, full articles, and gray literature that passed the detailed screening procedure were included. Case reports, letters, comments, reviews, and abstracts with insufficient details to meet inclusion criteria were excluded. Gallbladder ejection fraction assessed by means other than cholecystokinin HIDA scan were also excluded. DATA EXTRACTION Three reviewers independently abstracted the following data from each article: first author, year of publication, journal, type of study, location of study population, institution where the study was conducted, symptoms recorded, imaging modality used to establish the absence of gallstones, HIDA scan ejection fraction, number of cases and controls, number of males and females in each group, method of follow-up, and number of cases lost to follow-up. DATA SYNTHESIS Ten studies met inclusion criteria (N = 615). Follow-up ranged from 3 to 64 months. Surgical treatment was 15-fold more likely than medical treatment to result in symptom improvement, with 4% of patients reporting no symptom improvement with surgery. Sensitivity analysis in patients with complete symptom relief following surgery revealed an 8-fold greater odds difference than those treated medically (indicating variation in study reporting). CONCLUSIONS Patients without gallstones who have right upper quadrant pain and a positive HIDA scan result are more likely to experience symptom relief following cholecystectomy than those treated medically. There is, however, wide variability in data reporting, particularly with respect to symptom relief and duration of follow-up. Cholecystectomy is indicated in symptomatic patients without gallstones who have a low–ejection fraction HIDA scan.Arch Surg. 2009;144(2):180-187-->
The fabrication of integrated grating couplers for planar optical waveguides is presented. Holographic gratings with spatial period of 300-400 nm are produced in photoresist films using a Lloyd's ...mirror setup. The periodic modulations of the gratings are transferred to soda-lime glass and fused silica substrates through deep reactive-ion etching with a depth of approximately 70 nm. A single-mode waveguide (in the visible region) is created by depositing a film of Al 2 O 3 (180 nm) using an atomic layer deposition process. Characterization of several steps of the device fabrication was done by spectophotometry, atomic force microscope, and measurements of diffraction efficiency.
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