Tph2 gene deletion enhances amphetamine-induced hypermotility: effect of 5-HT restoration and role of striatal noradrenaline release.

Variants of tryptophan hydroxylase-2 (Tph2), the gene encoding enzyme responsible for the synthesis of brain serotonin (5-HT), have been associated with neuropsychiatric disorders, substance abuse and addiction. This study assessed the effect of Tph2 gene deletion on motor behavior and found that motor activity induced by 2.5 and 5 mg/kg amphetamine was enhanced in Tph2(-/-) mice.

Dopamine D1-like and D2-like receptors in the dorsal striatum control different aspects of attentional performance in the five-choice serial reaction time task under a condition of increased activity of corticostriatal inputs.

We investigated the interaction between the corticostriatal glutamatergic afferents and dopamine D1-like and D2-like receptors in the dorsomedial striatum (dm-STR) in attention and executive response control in the five-choice serial reaction time (5-CSRT) task. The competitive NMDA receptor antagonist 3-(R)-2-carboxypiperazin-4-propyl-1-phosphonic acid (CPP) injected in the mPFC impaired accuracy and increased premature and perseverative responding, raising GLU, DA, and GABA release in the dm-STR. The D1-like antagonist SCH23390 injected in the dm-STR reversed the CPP-induced accuracy deficit but did not affect the increase in perseverative responding.

Distinct Changes in CREB Phosphorylation in Frontal Cortex and Striatum During Contingent and Non-Contingent Performance of a Visual Attention Task.

The cyclic-adenosine monophosphate response element-binding protein (CREB) family of transcription factors has been implicated in numerous forms of behavioral plasticity. We investigated CREB phosphorylation along some nodes of corticostriatal circuitry such as frontal cortex (FC) and dorsal (caudate-putamen, CPu) and ventral (nucleus accumbens, NAC) striatum in response to the contingent or non-contingent performance of the five-choice serial reaction time task (5-CSRTT) used to assess visuospatial attention. Three experimental manipulations were used; an attentional performance group (contingent, "master"), a group trained previously on the task but for whom the instrumental contingency coupling responding with stimulus detection and reward was abolished (non-contingent, "yoked") and a control group matched for food deprivation and exposure to the test apparatus (untrained).

Effects of aripiprazole, olanzapine, and haloperidol in a model of cognitive deficit of schizophrenia in rats: relationship with glutamate release in the medial prefrontal cortex.

Rationale: Disruption in cognition is characteristic of psychiatric illnesses such as schizophrenia. Studies of drugs that improve cognition might provide a better insight into the mechanisms underlying cognitive deficits.

Objectives: We compared the effects of the antipsychotic drugs aripiprazole, olanzapine, and haloperidol on performance deficit in a test of divided and sustained visual attention, the five-choice serial reaction time task (5-CSRTT), which provides information on attentional functioning (accuracy of visual discrimination), response control (measured by anticipatory and perseverative responses) and speed.