Endomorphin1-like immunoreactivity in the limbic system of Syrian hamsters (Mesocricetus auratus).
Recently, endomorphin-1 (Tyr-Pro-Trp-Phe-NH2; EM1), an endogenous peptide that has high affinity and selectivity for the mu-opiate receptor, has been shown to modulate emotional behavior in mice and social behavior in Syrian hamsters. Endomorphin-1 (EM1) is present throughout the central nervous system in rats, mice, and guinea pigs; however, the distribution of EM1 in hamsters has not been described. The purpose of the present study was to investigate the distribution of EM1-like immunoreactivity (EM1L-IR) in the limbic system of Syrian hamsters using immunocytochemistry. Perikarya containing EM1L-IR were present in the anterior area, dorsomedial, ventromedial, periventricular, posterior, and arcuate nuclei of the hypothalamus. Fibers expressing EM1L-IR were present in the nucleus accumbens, caudate putamen, septum, bed nucleus of the stria terminalis, amygdaloid complex, and hypothalamus. The distribution of EM1 suggests a potential endogenous role for this peptide in major processes modulated by opiates, including affective states and social behavior.
Whitten
R D
RD
Center for Behavioral Neuroscience, Department of Psychology, Georgia State University, Atlanta, GA 30303, USA.
Martin-Schild
S
S
Zadina
J E
JE
Albers
H E
HE
D000818:Animals; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D001522:Behavior, Animal / Q000502:physiology; D006224:Cricetinae; D004644:Emotions / Q000502:physiology; D007150:Immunohistochemistry; D008032:Limbic System / Q000166:cytology / Q000378:metabolism*; D008647:Mesocricetus / Q000033:anatomy & histology / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009842:Oligopeptides / Q000378:metabolism*; D012919:Social Behavior
D009842:Oligopeptides; C105293:endomorphin 1