Grooming behavior in rats has so far been known to be induced mainly by dopamine agonists type D1. In order to explore the involvement of serotonine (5-HT) and its receptors in such a behavior, rats were exposed to two phases of treatment: to the serotonin neurotoxin 5,7-dihydroxytryptamine (5,7-DHT), injected intraventricularly three days after birth, and to the serotonin partial agonist m-chlorophenylpiperazine (mCPP), administered in two dose levels, two months later. Grooming behavior was monitored immediately before and after the higher dose of mCPP, while brain levels of 5-HT and its major metabolite 5-HIAA were assayed one week after mCPP administration. It is documented that while a low dose of mCPP in the non-lesioned rats increased the grooming-time by 5.7-fold, the higher mCPP dose in the non-lesioned non-primed rats increased grooming behavior by 3.6-fold. The 5,7-DHT lesions caused a 6.7-fold increase in the non-primed rats, and a 4.2-fold increase in the primed ones. These increases were noticeable only in male rats. When a higher dose of mCPP followed its lower dose in the 5,7-DHT-lesioned rats, a 3.6-fold decrease was recorded only in the female rats. A 88% and 94% drop in 5-HT and 5-HIAA levels in the brain neostriatum of the 5,7-DHT-lesioned rats was noticed in both sexes, one week after mCPP administration. These findings are the first to demonstrate that the 5-HT2 partial agonist mCPP is capable of modifying grooming behavior, and that 5,7,-DHT brain lesions increase basal grooming time, suggesting that 5-HT neurons and receptors are involved in grooming behavior in rats.
Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-14867 |
Date | 01 December 1997 |
Creators | Brus, Ryszard, Nowak, Przemyslaw, Szkilnik, Ryszard, Kostrzewa, Richard M., Shani, Jashovam |
Publisher | Digital Commons @ East Tennessee State University |
Source Sets | East Tennessee State University |
Detected Language | English |
Type | text |
Source | ETSU Faculty Works |
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