The effect of substance P and its fragments on passive avoidance retention and brain monoamine activity.
It has been shown that substance P(SP), as well as its carboxy and amino terminal fragments, affects a wide range of behaviors. In order to test the CNS activity of these fragments, we measured their effects on passive avoidance learning and monoamine activity. Following one-trial passive avoidance training, mice were injected intraventricularly with either a carboxy or amino terminal SP fragment (SP-C or SP-N), SP itself or phosphate-buffered saline (PBS). SP-N enhanced avoidance retention, which was tested 24 h after training. In a second experiment, monoamine activity was measured one hour after intraventricular injection of SP, PBS or SP fragments. SP-C decreased both nigral 5-hydroxyindoleacetic acid/5-hydroxytryptamine (5-HIAA/5-HT) and, to a lesser extent, 3,4-dihydroxyphenylacetic acid/dopamine, while SP-N increased nigral 5-HIAA/5-HT. It was concluded that SP-N and SP-C can exert behavioral and neurochemical effects that may be independent of the parent SP molecule.
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001679:Biogenic Amines / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D008568:Memory / Q000187:drug effects*; D051379:Mice; D010446:Peptide Fragments / Q000494:pharmacology*; D012153:Retention, Psychology / Q000187:drug effects*; D012701:Serotonin / Q000378:metabolism; D013373:Substance P / Q000494:pharmacology*
D001679:Biogenic Amines; D010446:Peptide Fragments; D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D013373:Substance P; D006897:Hydroxyindoleacetic Acid; D004298:Dopamine