Search results for "Striosome"
showing 2 items of 2 documents
Intermittent cortical stimulation evokes sensitization to cocaine and enduring changes in matrix and striosome neuron responsiveness
2005
Both the behavioral sensitization syndrome and the changes in the responsiveness of striatal neurons evoked by chronic cocaine exposure may be linked to enhanced neocortical activity, yet a direct demonstration of the effects of cortical stimulation on these parameters is lacking. We have found that repeated stimulation of the rat prelimbic cortex with picrotoxin (0.25 microg/0.25 microl, five injections on alternate days followed by 7-day withdrawal) contributed to increase c-Fos protein expression in the striosomes of the dorsolateral striatum, while producing the opposite effect in the matrix compartment, after a single exposure to cocaine (25 mg/kg). Moreover, rats exposed to cortical s…
Stimulant-induced adaptations in neostriatal matrix and striosome systems: Transiting from instrumental responding to habitual behavior in drug addic…
2005
Abstract Converging evidence indicates that repeated exposure to motor stimulants such as cocaine and amphetamine produces marked alterations in network responsiveness of striatal neurons to subsequent challenge with the same stimulant drug. Such alterations, which correlate with persistent patterns of repetitive behavior, associate with distinct compartmental changes in the neostriatum. Striatal matrix system neurons undergo “silencing” following repeated drug challenges, allowing striosome system neurons to exhibit preferential activation. Matrix neurons are innervated by sensory and motor areas of neocortex and are activated in the course of on-going, adaptive behavior. Inactivation of m…