title: Evidence for cholecystokinin-dopamine receptor interactions in the central nervous system of the adult and old rat. Studies on their functional meaning.
abstract: Evidence has been presented for the existence of interactions between CCK and DA receptors both in striatal and limbic membranes. A similar type of modulation by CCK-8 of DA receptors also exists after chronic neuroleptic treatment indicating that supersensitive DA receptors are also modulated by this peptide. As seen from simulation curves, CCK-8 increases the binding of [3H]DA agonists and reduces the binding of [3H]DA antagonists in striatal membranes, suggesting that CCK-8 may increase striatal DA transmission. Results of this type may underlie some of the non-neuroleptic effects of CCK-8. In the aged brain, the ability of CCK-8 to modulate DA antagonist binding sites is changed such that the binding of [3H]DA antagonists is increased. Thus, in the aged brain, receptor-receptor interactions may be altered, leading to a derangement of heterostatic mechanisms (mechanisms changing chemical transmission without interfering with synaptic homeostasis). It was also demonstrated that during aging there is a preferential disappearance of CCK-like immunoreactivity versus TH immunoreactivity in the nigral DA neurons, especially in the medially located nigral DA cells; furthermore, co-existence in the TH/CCK co-storing terminals in the nucleus accumbens was reduced during aging. Such alterations should also lead to changes in heterostatic regulation because the CCK co-modulation line controlling the DA receptors may be preferentially affected.
authors.forename: L F
authors.initials: LF
authors.lastname: Agnati
authors.forename: K
authors.initials: K
authors.lastname: Fuxe
authors.forename: L
authors.initials: L
authors.lastname: Giardino
authors.forename: L
authors.initials: L
authors.lastname: Calza
authors.forename: M
authors.initials: M
authors.lastname: Zoli
authors.forename: N
authors.initials: N
authors.lastname: Battistini
authors.forename: F
authors.initials: F
authors.lastname: Benfenati
authors.forename: J J
authors.initials: JJ
authors.lastname: Vanderhaeghen
authors.forename: D
authors.initials: D
authors.lastname: Guidolin
authors.forename: M
authors.initials: M
authors.lastname: Ruggeri
mesh_terms: D000375:Aging; D000818:Animals; D001058:Apomorphine / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000187:drug effects*; D002766:Cholecystokinin / Q000032:analysis; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D009474:Neurons / Q000032:analysis; D009714:Nucleus Accumbens / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000032:analysis / Q000187:drug effects* / Q000502:physiology; D012844:Sincalide / Q000494:pharmacology* / Q000502:physiology; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis
chemical_list: D011954:Receptors, Dopamine; C009074:N-n-propylnorapomorphine; D002766:Cholecystokinin; D014446:Tyrosine 3-Monooxygenase; D006220:Haloperidol; D012844:Sincalide; D001058:Apomorphine