Briefly, the sound of scratching a blackboard 20 times was recorded binaurally with a dummy head that had recording microphones at the location of the eardrums. In this study, three types of sounds were used as experimental sound stimuli, the details of which are described in a previous study (Ooishi and Kashino, 2012). The experiments were performed in a sound-insulated listening room. Taken together, the amygdala-RVLM relationship might be a neural regulator that induces sound-induced vasoconstriction. When considering the neural mechanism of sound-induced vasoconstriction, it is important to note that the RVLM and the amygdala might be involved in such mechanism. Second, the vasoconstriction of the arterioles at the fingertip is derived from pure noradrenergic activity mediated by α-adrenergic receptors (Grote et al., 2003). It is important to highlight that the production of tears represents only one of several important aspects of human emotional crying. More precisely, crying individuals tend to be seen as more warm and friendly, more sincere and honest, but also as likely to be more emotionally unstable, incompetent, and manipulative. However, given the frequency of emotional crying in adult humans, it must be concluded that we most often cry in relatively mundane situations. Second, whereas in animals crying is limited to vocal forms of expression (i.e., distress vocalizations, separation calls), in humans the shedding of visible tears is an essential additional feature (beginning in infants at approximately 4-8 weeks of age). The difference in effects of the two types of products may reflect that transdermal 17β-estradiol is absorbed directly into the circulation and thus, bypasses immediated degradation in the liver. These differences may reflect other underlying disease processes such as changes in endothelial function in addition to differences in autonomic control. Women with symptoms also showed greater dilatation of the radial artery to nitroglycerin, and more calcification of the coronary arteries than asymptomatic women 76, 79. Vasomotor symptoms were more prominent in women with other conventional risk factors for cardiovascular disease such as higher total cholesterol, elevated systolic and diastolic blood pressure and higher fasting glucose than women without symptoms . Although estrogen treatment reduces the severity and frequency of these periodic episodes, insight into the mechanisms and regulatory pathways involved remains to be clarified as investigative work is hampered by the lack of a robust animal model to study this phenomenon. On the other hand, direct stimulation of the PAG or adjacent tegmentum in adult mammals generally does not result in the production of crying, even in species in which distress calls continue into adulthood (e.g., the squirrel monkey). Electrical and chemical stimulation of this structure in infant guinea pigs and other animals results in the production of distress vocalizations, whereas PAG lesion studies demonstrate a long-lasting elimination or substantial reduction of distress vocalizations in adult squirrel monkeys (see also ). This additionally implies no essential role for the cortex and other structures within the cerebral hemispheres (at least in reflexive crying without an emotional component). For example, case studies have demonstrated that involuntary emotional expressions may occur after particular lesions in certain subcortical brain areas .
