Emotional vocalizations alter behaviors and neurochemical release into the amygdala.

The basolateral amygdala (BLA), a brain center of emotional expression, contributes to acoustic communication by first interpreting the meaning of social sounds in the context of the listener's internal state, then organizing the appropriate behavioral responses. We propose that modulatory neurochemicals such as acetylcholine (ACh) and dopamine (DA) provide internal-state signals to the BLA while an animal listens to social vocalizations. We tested this in a vocal playback experiment utilizing highly affective vocal sequences associated with either mating or restraint, then sampled and analyzed fluids within the BLA for a broad range of neurochemicals and observed behavioral responses of adult male and female mice.

Fluoride-Free Diet Stimulates Pineal Growth in Aged Male Rats.

The pineal gland is a naturally calcifying endocrine organ which secretes the sleep-promoting hormone melatonin. Age-related changes of the pineal have been observed, including decreased pinealocyte numbers, increased calcification, and a reduction in melatonin production. Since fluoride is attracted to calcium within the pineal gland, this study sought to examine the effects of a fluoride-free diet on the morphology of the pineal gland of aged male rats (26 months old).