caa a22 4500 469118466 CHVBK 20180323133131.0 cr unu---uuuuu 170328e19921101xx s 000 0 eng 10.1007/BF02245883 doi (NATIONALLICENCE)springer-10.1007/BF02245883 Peripheral modulation of learning and memory: enkephalins as a model system [Elektronische Daten] [Gery Schulteis, Joe Martinez Jr] Extensive research on the effects of enkephalins on conditioning is reviewed and used as the basis for a model of peripheral modulation of learning and memory. An overall theme emphasized throughout our discussion is that these peptides can influence the strength with which a memory is acquired and stored by acting outside the blood-brain barrier. This assertion is supported by research on the behavioral effects of systemically administered enkephalins and opioid antagonists, the rapid hydrolysis of circulating enkephalins in vivo, and the limited ability of these peptides to penetrate the blood-brain barrier. A consideration of the extensive distribution of enkephalins throughout peripheral autonomic systems leads to the proposal that enkephalins may act to modulate learning and memory by altering peripheral autonomic function; autonomic afferents may then communicate with the memory trace in the CNS through a central modulatory pathway outlined herein. Evidence that some stressful experiences may lead to increases in circulating enkephalins also is discussed. The sites of action of these circulating enkephalins may involve peripheral autonomic sites, or additionally may involve the circum-ventricular organs. As a further regulatory mechanism, circulating enkephalin levels may be controlled by experience-dependent alterations of the activity of enzyme systems that participate in their breakdown. Finally, it is emphasized that the mechanisms of enkephalin action postulated herein may be applicable to the actions of other peripheral hormones, peptides, and neurotransmitters that participate in the modulation of learning and memory storage processes. Springer-Verlag, 1992 Modulation nationallicence Learning nationallicence Memory nationallicence Enkephalins nationallicence Autonomic systems nationallicence Circumventricular organs nationallicence Blood-brain barrier nationallicence Schulteis Gery Department of Psychology, University of California, 94720, Berkeley, CA, USA aut Martinez Jr Joe Department of Psychology, University of California, 94720, Berkeley, CA, USA aut Psychopharmacology Springer-Verlag 109/3(1992-11-01), 347-364 0033-3158 109:3<347 1992 109 213 https://doi.org/10.1007/BF02245883 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02245883 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Schulteis Gery Department of Psychology, University of California, 94720, Berkeley, CA, USA aut NATIONALLICENCE 700 1- Martinez Jr Joe Department of Psychology, University of California, 94720, Berkeley, CA, USA aut NATIONALLICENCE 773 0- Psychopharmacology Springer-Verlag 109/3(1992-11-01), 347-364 0033-3158 109:3<347 1992 109 213 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer