June-Seek Choi

In a natural environment, foragers constantly face the risk of encountering predators. Fear is a defensive mechanism evolved to protect animals from danger by balancing the animals' needs for primary resources with the risk of predation, and the amygdala is implicated in mediating fear responses. However, the functions of fear and amygdala in foraging behavior are not well characterized because of the technical difficulty in quantifying prey-predator interaction with real (unpredictable) predato

Using a two-way signaled active avoidance (2-AA) learning procedure, where rats were trained in a shuttle box to avoid a footshock signaled by an auditory stimulus, we tested the contributions of the lateral (LA), basal (B), and central (CE) nuclei of the amygdala to the expression of instrumental active avoidance conditioned responses (CRs). Discrete or combined lesions of the LA and B, performed after the rats had reached an asymptotic level of avoidance performance, produced deficits in the C

Bilateral amygdala (AM) lesions prevent the acquisition of fear-related conditional responses (CRs) in rats, a result that is most commonly concluded to reflect a learning or memory deficit. An alternative hypothesis is that AM-lesioned animals fail to acquire certain fear CRs simply because they cannot perform these behaviors. This performance-deficit hypothesis is usually invoked in regard to studies in which the CR is freezing, the most commonly measured behavior. Here we explore this interpr

A tone conditioned stimulus (CS) previously paired with a grid shock unconditioned stimulus (US) can greatly enhance the early electromyographic (EMG) component (R1) of the rat eyeblink reflex. The hypothesis that the central nucleus of the amygdala (ACe) is an essential part of the circuitry mediating conditioned R1 enhancement was tested. After bilateral ACe lesions (L) or a sham operation (S), rats received paired presentations of the CS and US (P) or explicitly unpaired CS and US presentatio

Pavlovian eyeblink conditioning is a useful model system for studying how the temporal relationship between a conditioned stimulus and an unconditioned stimulus is represented in the brain. As an example, the response topography formed under a complex conditioning paradigm, involving 2 randomly alternating interstimulus intervals (ISIs), manifests a conditioned response (CR) with 2 distinctive peaks that correspond to the 2 ISIs. The authors present the first full report of neuronal activities i

A 29-year-old woman was given isotretinoin for severe, recalcitrant acne. During the first 3 months of treatment, she was taking an oral contraceptive agent that she had started at the same time as the isotretinoin. After deciding she wanted to become pregnant, the patient stopped taking the

Plasticity in two input pathways into the lateral nucleus of the amygdala (LA), the medial prefrontal cortex (mPFC) and the sensory thalamus, have been suggested to underlie extinction, suppression of a previously acquired conditioned response (CR) following repeated presentations of the conditioned stimulus (CS). However, little is known about the joint dynamics of the relevant synaptic changes within the LA that accompany fear extinction. Employing a novel training procedure, in which stimulat

<b>Background:</b> Developing valid emotional facial stimuli for specific ethnicities creates ample opportunities to investigate both the nature of emotional facial information processing in general and clinical populations as well as the underlying mechanisms of facial emotion processing within and across cultures. Given that most entries in emotional facial stimuli databases were developed with western samples, and given that very few of the eastern emotional facial stimuli sets were based str

Use-dependent synaptic modifications in the lateral nucleus of the amygdala (LA) have been suggested to be the cellular analog of memory trace after pavlovian fear conditioning. However, whether neurophysiological changes in the LA are produced as a direct consequence of associative learning awaits additional proof. Using microstimulation of the medial geniculate nucleus of the thalamus as the conditioned stimulus (CS), we demonstrated that contingent pairings of the brain-stimulation CS and a f

Maternal intake of licorice from dietary sources has been associated with adverse maternal and fetal outcomes. We prospectively studied the outcome of 185 singleton pregnancies who took over-the-counter or naturopathic formulations containing licorice during their pregnancy, and 370 age-matched singleton pregnant controls that were not exposed to any potential teratogen. The indication in 56.8% of the women taking licorice was for cough and cold control, with the maximum dose of 2104 mg/day and

The present study was designed to investigate if exposure to dried ginger during pregnancy would increase the risk of adverse fetal and neonatal outcomes. Participants consisted of 159 singleton pregnant women who received dried ginger as a herbal medication. We also included a control group of 306 pregnant women who had not been exposed to any herbal medication or any known teratogen. No increased risk of major malformations was detected in exposed women (OR = 4.9; 95% CI 0.9-25.5; p = 0.051).

We thank Dumont and Black[1][1] for further raising the issue of the need for effective contraception in order to prevent pregnancies during isotretinoin treatment. Our report[2][2] included only the typical-use contraception failure rates. Please note that Box 1 in our manuscript provides the same

We tested whether a conditioned emotional stimulus could facilitate visual processing when presented subliminally. Participants received Pavlovian conditioning in which a fearful expression (conditioned stimulus) was paired with electric finger shock (unconditioned stimulus). In a subsequent session, they were subject to a simple perceptual task involving subliminal presentation of facial expressions followed by a simple color patch. Although none of the participants reported conscious detection