Update of studies about prepulse inhibition in psychiatric disorders

Abstract

Prepulse inhibition (PPI) is the suppression of the startle reflex when the startling stimulus is preceded by a non-startling stimulus (the prepulse). It is an operational measurement of sensorimotor gating mechanism to help the brain adapt to the complex environment, which could be top-down modulated by attention and other higher cognitive processes. Deficits of PPI and the top-down modulation of PPI are closely related to psychiatric diseases. Research papers published from January 2001 to October 2016 related to PPI in psychiatric disorders were searched in the Chinese and English databases. Results showed that schizophrenic patients and their relatives showed deficits in baseline PPI as well as the attentional modulation of PPI, and more importantly, the attentional modulation of PPI rather than the baseline PPI was more related to the symptom severity. Patients with Tourette’s syndrome showed PPI impairment, while patients with obsessive compulsive disorder had lower levels of PPI. PPI deficits in bipolar disorder patients were gender-dependent. Studying PPI and the top-down modulation of PPI could provide a basis to study the interaction of sensory processing and attention, and facilitate the researches of neural mechanism underlying the deficits of sensory gating. To establish advanced paradigms of PPI, new cognitive components could be introduced, such as attention, emotion, motor control, compulsivity and so on, thus improving the specificity of PPI test and promoting the PPI test as new biomarker and endophenotype in various psychiatric disorders. Key words: Prepulse inhibition; Schizophrenia; Tourette’s syndrome; Obsessive compulsive disorder; Bipolar disorder