arousal related hormone affects memory processing

A significant number of animal and human studies demonstrate that memories for new experiences are encoded more effectively under environmental or laboratory conditions which elevate peripheral concentrations of the hormone epinephrine and in turn, induce emotional arousal. Although this phenomenon has been replicated across several learning paradigms, understanding of how this arousal related hormone affects memory processing remains obscure because epinephrine does not freely enter into the central circulation to produce any direct effects on the brain. This study examined whether epinephrine’s actions on the CNS may be mediated by the initial activation of peripheral vagal fibers that project to the brain.

Epinephrine administration increases neural impulses propagated along the vagus nerve: Role of peripheral β-adrenergic receptors

T. Miyashita^a and C.L. Williams^b,

^aDepartment of Neurosciences, University of New Mexico, Albuquerque, NM 87131, USA

^bDepartment of Psychology, The University of Virginia, Charlottesville, VA 22904, USA

Received 9 June 2005;

revised 17 August 2005;

accepted 29 August 2005.

Available online 17 October 2005.