Differential behavioral effects of TFF peptides: injections of synthetic TFF3 into the rat amygdala.
TFF peptides (formerly named P-domain peptides or trefoil factors) are also released from the brain as well as being secreted typically by mucin producing cells. The amygdala, besides the hypothalamus, represents a defined neuronal locality of TFF3 synthesis. In a passive avoidance test synthetic TFF3/monomer or 0.9% sodium chloride (control) was injected bilaterally into the basolateral nucleus of the amygdala of male rats either immediately (consolidation test) or 23 h after a footshock (retrieval test). Application of a low TFF3 dose (2 x 6 pg) decreased avoidance latency in a time dependent manner. In contrast, a high dose (2 x 60 pg) increased avoidance latency. Maximal effects of TFF3 were observed about 24 h after the injection. This bidirectional effect was also observed using the elevated plus-maze test. The locomotor activity on the open arms was significantly increased 24 h after a low dose injection of TFF3 into the amygdala. In contrast, a high-dose injection significantly decreased the activity on the open arms. The results of both tests can be explained by an anxiolytic effect at a low dose and an anxiogenic effect at a high dose of synthetic TFF3/monomer.
Schwarzberg
H
H
Institut für Neurophysiologie, Otto-von-Guericke-Universität, Magdeburg, Germany.
Kalbacher
H
H
Hoffmann
W
W
D000679:Amygdala / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D006133:Growth Substances / Q000378:metabolism / Q000494:pharmacology*; D007275:Injections, Intravenous; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects; D009077:Mucins; D009124:Muscle Proteins; D009479:Neuropeptides; D010455:Peptides / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D000071164:Trefoil Factor-2; D000071165:Trefoil Factor-3