Effects of brexpiprazole on patient life engagement in schizophrenia: analysis of Positive and Negative Syndrome Scale data.

Objective: Patients with schizophrenia value improved life engagement, a term that describes positive health aspects across emotional, physical, social, and cognitive domains. This analysis of clinical trial data aimed to investigate the effect of brexpiprazole on patient life engagement in schizophrenia over the short and long term.

Methods: Data were pooled from three 6-week, randomized, double-blind, placebo-controlled clinical trials (ClinicalTrials.

Assessment of patient life engagement in schizophrenia using items from the Positive and Negative Syndrome Scale.

Background: Improved patient life engagement is a meaningful treatment goal in schizophrenia that cannot be satisfactorily measured using existing tools. This research aimed to determine whether certain items from the Positive and Negative Syndrome Scale (PANSS) can assess patient life engagement in schizophrenia.

Methods: Three approaches were used to identify PANSS items that reflect patient life engagement: (1) a panel discussion with expert psychiatrists (n = 4); (2) interviews with patients with schizophrenia (n = 20); and (3) a principal component analysis to explore clustering of items (n = 954 from three randomized controlled trials).

Bidirectional prefrontal-hippocampal interactions support context-guided memory.

We compared the dynamics of hippocampal and prefrontal interactions in rats as they used spatial contexts to guide the retrieval of object memories. Functional connectivity analysis indicated a flow of contextual information from the hippocampus to prefrontal cortex upon the rat's entry into the spatial context. Conversely, upon the onset of object sampling, the direction of information flow reversed, consistent with prefrontal control over the retrieval of context-appropriate hippocampal memory representations.

Representation of memories in the cortical-hippocampal system: Results from the application of population similarity analyses.

Here we consider the value of neural population analysis as an approach to understanding how information is represented in the hippocampus and cortical areas and how these areas might interact as a brain system to support memory. We argue that models based on sparse coding of different individual features by single neurons in these areas (e.g.

Orbitofrontal cortex encodes memories within value-based schemas and represents contexts that guide memory retrieval.

There are a substantial number of studies showing that the orbitofrontal cortex links events to reward values, whereas the hippocampus links events to the context in which they occur. Here we asked how the orbitofrontal cortex contributes to memory where context determines the reward values associated with events. After rats learned object-reward associations that differed depending on the spatial context in which the objects were presented, neuronal ensembles in orbitofrontal cortex represented distinct value-based schemas, each composed of a systematic organization of the representations of objects in the contexts and positions where they were associated with reward or nonreward.

Amygdala lesions selectively impair familiarity in recognition memory.

A major controversy in the study of memory concerns whether there are distinct medial temporal lobe (MTL) substrates of recollection and familiarity. Studies using receiver operating characteristics analyses of recognition memory indicate that the hippocampus is essential for recollection, but not for familiarity. We found the converse pattern in the amygdala, wherein damage impaired familiarity while sparing recollection.

Distinct roles for dorsal CA3 and CA1 in memory for sequential nonspatial events.

Previous studies have suggested that dorsal hippocampal areas CA3 and CA1 are both involved in representing sequences of events that compose unique episodes. However, it is uncertain whether the contribution of CA3 is restricted to spatial information, and it is unclear whether CA1 encodes order per se or contributes by an active maintenance of memories of sequential events. Here, we developed a new behavioral task that examines memory for the order of sequential nonspatial events presented as trial-unique odor pairings.

Medial prefrontal cortex supports recollection, but not familiarity, in the rat.

There is continuing controversy about the extent to which the rodent medial prefrontal cortical area (mPFC) is functionally homologous to the dorsolateral prefrontal cortex in humans and nonhuman primates. Previous studies have compared the effects of mPFC lesions in rats to those of dorsolateral prefrontal lesions in working memory, strategy switching, and temporal ordering. None, however, has examined the role of the rodent mPFC in recognition memory, wherein, in humans, dorsolateral prefrontal damage results in a deficit in source monitoring resulting in impaired recollection.

Lesions of the dorsal noradrenergic bundle impair attentional set-shifting in the rat.

Rats with medial prefrontal cortex (mPFC) lesions are impaired in attentional set-shifting, when it is required to shift to a previously irrelevant perceptual dimension. The main source of noradrenergic input to the mPFC is from the locus coeruleus via the dorsal noradrenergic ascending bundle (DNAB). This study examined the effects of selective cortical noradrenaline depletion following 6-hydroxydopamine-induced lesions of the DNAB on attentional set-shifting and other aspects of discrimination learning and performance.