Clonazepam Effects on Brain Oscillations and Cognition in Schizophrenia

Schizophrenia is a common, disabling mental illness with a considerable public health impact. Cognitive dysfunction (e.g in attention, memory, etc.) is an enduring feature of the illness, a strong predictor of functional outcome, and presently has no established treatment. Therefore, advances in treatment of cognition in schizophrenia are likely to alleviate a significant health burden. Deficits in executive control functions, such as those measurable on task-switching paradigms, are among the most important cognitive deficits in schizophrenia, and arise from disturbances in distributed neural networks operated by the prefrontal cortex. An important phenomenon that underpins cortical information processing are oscillations in brain activity that can be measured both with intracranial electrical recordings and at the scalp with EEG. These networks and their cortical oscillatory signatures are also strongly modulated by cortical interneurons that use gamma-amino butyric acid (GABA) as a neurotransmitter. Post-mortem evidence suggests that GABAergic neurons are altered in schizophrenia. Furthermore, studies in animals, using optogenetic manipulations that are restricted to a subset of cortical GABA neurons, also suggest that GABA neurons can be selectively modulated to improve PFC-dependent cognition in animal models of schizophrenia. This includes experiments that involve administration of sub-sedating doses of clonazepam, a representative FDA-approved medication from the benzodiazepine class.

Therefore, this neurochemical system represents a novel set of candidate treatment targets that are both implicated in the pathophysiology of schizophrenia and the potential remediation of associated cognitive dysfunction.