Stress-induced Fos-like Immunoreactivity in the Pons and the Medulla Oblongata of Rats

Immunoreactivity of the immediate early gene c-fos was used to investigate changes in the activity of brainstem neurons in response to acute stressors like immobilization, formalin-induced pain, cold exposure, hemorrhage and insulin-induced hypoglycemia. Different stressors induced Fos-like immunoreactivity in different pontine and medullary neurons. A single, 3 hour immobilization was found to be a very strong stimulus that activated brainstem catecholaminergic (tyrosine hydroxylase-immunopositive) neurons and cells in the raphe and certain pontine tegmental nuclei, as well as in the reticular formation. Pain, induced by a subcutaneous injection of formalin was also effective on catecholamine-synthesizing neurons and on others cells in the nucleus of the solitary tract. Cold exposure activated cells mainly in the sensory spinal trigeminal and parabrachial nuclei and in the so-called "pontine thermoregulatory area". Moderate Fos-like immunoreactivity was induced by a hypotonic (25%) hemorrhage in medullary catecholaminergic neurons, the nucleus of the solitary tract and the Barrington nucleus. Among stressful stimuli used, insulin-induced hypoglycemia elicited the smallest Fos activation in the lower brainstem. The present observations indicate that different stressors may use different neuronal pathways in the central organization of the stress response.     

FACTORS INFLUENCING EMPLOYEES' PROPENSITY TO USE AN EMPLOYEE ASSISTANCE PROGRAM

Using data collected from 1,987 employees at several locations of a large firm, this study investigates relationships between these employees' cognitive and attitudinal perceptions of an employee assistance program (EAP) and their propensity to use it. Familiarity with the program, perceived accessibility of it, and perceived managerial support for it are hypothesized to affect both employees' confidence in the program and their propensity to use it, and confidence in the EAP is further hypothesized to affect propensity to use. LISREL analysis supported the overall model, but the direct paths from the cognitive variables to propensity to use were not supported and confidence in the program was therefore indicated to be an essential mediating variable. Propensity to use an EAP is argued to be an important indicator of effective EAP implementation and suggestions are offered to management for promoting employee confidence in an EAP and ultimately their propensity to use it.