olanzapine and Perceptual-Disorders

Deficits in olfactory abilities are frequently observed in schizophrenia patients. However, whether olfactory dysfunction is found in animal models is not known. Here, we examined whether two well-established schizophrenia rat models exhibit olfactory-relevant dysfunction that is similar to schizophrenia patients. Olfactory sensitivity was tested in rats that were acutely (3.3mg/kg) or postnatally (10mg/kg, at postnatal day 7, 9 and 11) treated with phencyclidine (PCP) as schizophrenia models. Electrophysiological recordings were conducted to measure the olfactory-relevant local field potential after acute PCP treatment. Olfactory-relevant neural connections were tested via virus tracing in rats postnatally treated with PCP. We also assessed the reversal effects of olanzapine (OLZ) treatment on both models. We found that acute PCP treatment induced a decline in olfactory sensitivity (p=0.01) and significantly lower beta- and higher gamma-band oscillations (p=0.03, and p=0.00 respectively) which were partly attenuated by OLZ treatment (2mg/kg and 4mg/kg). Postnatal PCP exposure also resulted in an olfactory sensitivity deficit during adulthood (p=0.012 for males and p=0.009 for females), and an abnormal development of neural circuits (p=0.000). Together, our research indicated that olfactory dysfunction found in schizophrenia patients can also be observed on animal models.

Topics: Animals; Antipsychotic Agents; Brain; Disease Models, Animal; Female; Male; Neurons; Olanzapine; Olfactory Bulb; Olfactory Perception; Perceptual Disorders; Phencyclidine; Rats, Sprague-Dawley; Schizophrenia; Sex Factors

In this study we report the results of two experiments on visual attention conducted with patients with early-onset schizophrenia. These experiments investigated the effect of irrelevant spatial-scale information upon the processing of relevant spatial-scale information, and the ability to shift the spatial scale of attention, across consecutive trials, between different levels of the hierarchical stimulus. Twelve patients with early-onset schizophrenia and matched controls performed local-global tasks under: (1) directed attention conditions with a consistency manipulation and (2) divided-attention conditions. In the directed-attention paradigm, the early-onset patients exhibited the normal patterns of global advantage and interference, and were not unduly affected by the consistency manipulation. Under divided-attention conditions, however, the early-onset patients exhibited a local-processing deficit. The source of this local processing deficit lay in the prolonged reaction time to local targets, when these had been preceded by a global target, but not when preceded by a local target. These findings suggest an impaired ability to shift the spatial scale of attention from a global to a local spatial scale in early-onset schizophrenia.

Topics: Adolescent; Affect; Antipsychotic Agents; Attention; Benzodiazepines; Clopenthixol; Diazepam; Female; Flupenthixol; Frontal Lobe; Humans; Male; Olanzapine; Parietal Lobe; Perceptual Disorders; Pirenzepine; Reaction Time; Risperidone; Schizophrenia; Space Perception; Time Factors

The aim of this paper is to document regular nocturnal intensification of delusional nihilistic and persecutory ideas (Cotard delusion) linked with extreme depersonalisation and hypervivid dreaming.. A 17-year-old man presented with Cotard and Capgras delusions after sustaining multiple cognitive impairments secondary to traumatic brain injury.. Delusional ideation fully resolved within 14 days of commencement of olanzapine 5 mg daily.. This patient's experience of perceptual abnormalities and impairments in meta-abilities related to self-monitoring and critical inferencing lends support to multicomponent sensory processing accounts of brain injury related, content-specific delusional syndromes.

Topics: Adolescent; Antipsychotic Agents; Benzodiazepines; Brain Injuries; Capgras Syndrome; Circadian Rhythm; Delusions; Humans; Male; Olanzapine; Perceptual Disorders; Pirenzepine; Syndrome