A genetic-correlational study of hippocampal structural variation and variation in exploratory activities of mice.
Our previous work provided evidence that hippocampal opioid peptides form an important neurochemical substrate underlying the gene-dependent exploratory behavior of mice. A prominent hippocampal opioid is dynorphin B, which resides in the mossy fibers exclusively. In order to seek support for causal relationships between dynorphinergic hippocampal mechanisms and exploration, a quantitative-genetic method was chosen. For this purpose, mice from the inbred strains C57BL/6, DBA/2, BLN, and CPB-K were used. Their hippocampal mossy fiber projections were visualized by means of immunohistochemistry, using a highly specific anti-dynorphin B antiserum. The additive-genetic correlations that were estimated suggest pleiotropic gene effects on locomotion, rearing-up, wall-leaning, and several intra- and infrapyramidal mossy fiber (iipMF) variables. Long iipMF, in particular, were found to be associated with high exploratory activity.
Department of Animal Physiology, University of Nijmegen, The Netherlands.
J H
JH
van Daal
P J
PJ
Herbergs
W E
WE
Crusio
H
H
Schwegler
B G
BG
Jenks
W A
WA
Lemmens
J H
JH
van Abeelen
D000818:Animals; D001143:Arousal / Q000235:genetics / Q000502:physiology; D001931:Brain Mapping; D004399:Dynorphins / Q000502:physiology; D004723:Endorphins / Q000502:physiology; D005106:Exploratory Behavior / Q000502:physiology*; D014644:Genetic Variation / Q000235:genetics*; D006624:Hippocampus / Q000033:anatomy & histology* / Q000502:physiology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains / Q000033:anatomy & histology / Q000235:genetics* / Q000502:physiology; D009043:Motor Activity / Q000235:genetics / Q000502:physiology; D009412:Nerve Fibers / Q000502:physiology / Q000648:ultrastructure; D012931:Social Environment; D013045:Species Specificity
D004723:Endorphins; D004399:Dynorphins; C036200:rimorphin