Theory suggests R&D intensity and acquisition activity may be either directly or inversely related. However, we know relatively little about which firms are responsible for acquisition activity in high‐technology industries, which are not only R&D‐intensive, but also have substantial acquisition activity in the United States. Using a panel of 217 US electronic and electrical equipment firms from 1985–93 and limited dependent variable estimation techniques, we find a substantial negative correlation between R&D‐intensity and a firm’s propensity to acquire. This result is surprisingly robust to numerous sensitivity tests and is significant in both the ‘within’ and ‘between’ dimensions of our data.

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Previous investigation by our laboratory found that acute hypernatremia potentiates an oxytocinergic tone that inhibits parvocellular neurosecretory neurons in the paraventricular nucleus of the hypothalamus (PVN), attenuates restraint-induced surges in corticosterone (CORT), and reduces anxiety-like behavior in male rats. To investigate the neural mechanisms mediating these effects and extend our findings to a more versatile species, we repeated our studies using laboratory mice. In response to 2.0 M NaCl injections, mice had increased plasma sodium concentrations which were associated with a blunted rise in CORT subsequent to restraint challenge relative to 0.15 M NaCl injected controls. Immunofluorescent identification of the immediate early gene product Fos found that 2.0 M NaCl treatment increased the number of activated neurons producing oxytocin in the PVN. To evaluate the effect of acute hypernatremia on PVN neurons producing corticotropin-releasing hormone (CRH), we used the Cre-lox system to generate mice that produced the red fluorescent protein, tdTomato, in cells that had Cre-recombinase activity driven by CRH gene expression. Analysis of brain tissue from these CRH-reporter mice revealed 2.0 M NaCl treatment caused a dramatic reduction in Fos-positive nuclei specifically in CRH-producing PVN neurons. This altered pattern of activity was predictive of alleviated anxiety-like behavior as mice administered 2.0 M NaCl spent more time exploring the open arms of an elevated-plus maze than 0.15 M NaCl treated controls. Taken together, these results further implicate an oxytocin-dependent inhibition of CRH neurons in the PVN and demonstrate the impact that slight elevations in plasma sodium have on hypothalamic-pituitary-adrenocortical axis output and anxiety-like behavior.