Age-dependent effects of conditioning on cholinergic and vasopressin systems in the rat suprachiasmatic nucleus

B A M Biemans*, E A van der Zee, S Daan

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

10 Citaten (Scopus)
284 Downloads (Pure)


Active shock avoidance was used to explore the impact of behavioural stimulation on the neurochemistry of the suprachiasmatic nucleus. We have found previously that the expression of muscarinic acetylcholine receptors in the suprachiasmatic nucleus of young rats was significantly enhanced 24 hours after fear conditioning. Here, we investigated whether this observation is age-dependent. We used 26 month-old Wistar rats with a deteriorated circadian system, and compared them with young rats (4 months of age) with an intact circadian system. Vasopressin, representing a major output system of the suprachiasmatic nucleus, was studied in addition to muscarinic receptors. Young rats showed a significant increase in immunostaining for muscarinic acetylcholine receptors 24 h after training, corroborating earlier observations. Aged rats did hot show such an increase. In contrast, aged rats did show an increase in vasopressin immunoreactivity 24 h after fear conditioning, both at the level of content and cell number, while young rats did not reveal a significant rise. Thus, it seems that these two neurochemical systems in the suprachiasmatic nucleus are regulated independently. The results further demonstrate that the circadian pacemaker is influenced by fear conditioning in an age-dependent manner.

Originele taal-2English
Pagina's (van-tot)729-736
Aantal pagina's8
TijdschriftBiological Chemistry
Nummer van het tijdschrift5
StatusPublished - mei-2003

Citeer dit