Effects of pancreatic polypeptide family peptides on feeding and learning behavior in mice.
We studied the effects of intra-third cerebroventricular administration of neuropeptide Y (NPY), peptide YY (PYY) and pancreatic polypeptide (PP) on the locomotor activity and the feeding and learning behavior of mice. NPY (0.3-10 micrograms), PYY (0.1-10 micrograms) and PP (3.0-10 micrograms) produced significant increases in locomotor activity. A significant decrease was then observed 15 min after administration of 10 micrograms of PYY. NPY, PYY and PP significantly increased food intake at 20 min and this effect continued for 2 to 4 hr at the high doses. The feeding response to PP family peptides were quite similar to that in locomotor activity with respect to dose-response, time course and peptide specificity. Learning behaviors were evaluated at three different stages of memory processing, acquisition, consolidation and retrieval, in a battery of step-down type passive avoidance tests. NPY and PYY had no effect on acquisition, but significantly improved consolidation at a dose of 0.03 and 0.3 microgram, respectively. NPY also improved retrieval at a dose of 0.03 microgram. The ranking order of potency in stimulating feeding and locomotor activity was PYY > NPY > PP, and in improving memory consolidation NPY > PYY >> PP. These observations suggest that NPY and PYY influence different neural substrates in the brain involved in feeding and learning.
Nakajima
M
M
Second Department of Internal Medicine, Kobe University School of Medicine, Japan.
Inui
A
A
Teranishi
A
A
Miura
M
M
Hirosue
Y
Y
Okita
M
M
Himori
N
N
Baba
S
S
Kasuga
M
M
D000818:Animals; D004435:Eating / Q000187:drug effects*; D007858:Learning / Q000187:drug effects*; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D009478:Neuropeptide Y / Q000494:pharmacology*; D010191:Pancreatic Polypeptide / Q000494:pharmacology*; D019894:Peptide YY; D010455:Peptides / Q000494:pharmacology*; D011964:Receptors, Gastrointestinal Hormone / Q000502:physiology; D017476:Receptors, Neuropeptide Y / Q000502:physiology
D009478:Neuropeptide Y; D010455:Peptides; D011964:Receptors, Gastrointestinal Hormone; D017476:Receptors, Neuropeptide Y; C082172:peptide YY receptor; D019894:Peptide YY; D010191:Pancreatic Polypeptide