Increase of Dialysate Dopamine in the Bed Nucleus of Stria Terminalis by Clozapine and Related Neuroleptics

A systematic microdialysis study of dopamine transmission in the accumbens shell/core and prefrontal cortex after acute antipsychotics

“…of amperozide increased to 400 % dialysate DA in the PFCX and at 6 mg/kg i.p. up to 300 % in the bed nucleus stria terminalis (Carboni et al 2000). Amperozide is a weak D2 ligand but a strong 5HT2A receptor ligand (Svartengren and Simonsson 1990).…”

Implicit and explicit learning in schizophrenics treated with olanzapine and with classic neuroleptics

“…Reduced attention span in schizophrenic patients is not a likely explanation for the effect, as response accuracy was above 90% in all groups. As lesions of the dopaminergic innervation of the PFC/NA impair implicit learning (Williams and Goldman-Rakic 1995;Fletcher and Higgins 1997), the effect may be explained by increased DA output in the NA shell under olanzapine (and also risperidone and clozapine) as compared with haloperidol (Carboni et al 2000). Moreover, olanzapine and clozapine, but not the classic NL haloperidol increase DA turnover in the PFC (Nomikos et al 1994;Volontè et al 1997).…”

“…These features may explain the lower incidence of extrapyramidal symptoms (EPS) with novel NL, but they also suggest different effects on operant conditioning, hedonia, implicit and explicit learning. Of particular interest are findings that novel, but not classic NL increase DA turnover in the prefrontal cortex (PFC) and nucleus accumbens (NA) shell (Deutch et al 1991;Fibiger 1992, 1996;Carboni et al 2000). The PFC/NA-shell system is relevant for both the hedonic experience and at least some kinds of implicit learning.…”

Characterization of Inhibition by Risperidone of the Inwardly Rectifying K+ Current in Pituitary GH3 Cells

“…Metoclopramide was also reported to antagonize at dopamine receptor; 2) in GH 3 cells preincubated with dopamine (10 M), the inhibitory effect of risperidone on I K(IR) was unaffected; and 3) risperidone at a higher concentration (10 M) applied intracellularly also suppressed the activity of BK Ca channels. Therefore, the carefulness may need to be made in ascribing the risperidone-mediated prolactin release to those caused by the blockade of dopamine receptors in vivo or in vitro (Bowden et al 1992;Breier et al 1999;Kim et al 1999;Petty 1999;Carboni et al 2000).…”