Acute THPVP inactivation decreases the glucagon and sympathoadrenal responses to recurrent hypoglycemia

The posterior paraventricular nucleus of the thalamus (THPVP) has been identified as a forebrain region that modulates the central nervous system (CNS) response to recurrent experiences of stressors. The THPVP is activated in response to a single (SH) or recurrent (RH) experience of the metabolic stress of hypoglycemia. In this study, we evaluated whether temporary experimental inactivation of the THPVP would modify the neuroendocrine response to SH or RH. Infusion of lidocaine (LIDO) or vehicle had no effect on the neuroendocrine response to SH, comparable to findings with other stressors. THPVP vehicle infusion concomitant with RH resulted in a prevention of the expected impairment of neuroendocrine responses, relative to SH. LIDO infusion with RH resulted in significantly decreased glucagon and sympathoadrenal responses, relative to SH. These results suggest that the THPVP may contribute to the sympathoadrenal stimulation induced by hypoglycemia; and emphasizes that the THPVP is a forebrain region that may contribute to the coordinated CNS response to metabolic stressors. (c) 2008 Published by Elsevier B.V.