Habituation and Prepulse Inhibition of Acoustic Startle in Rodents

Abstract

The acoustic startle response is a protective response, elicited by a sudden and intense acoustic stimulus. Facial and skeletal muscles are activated within a few milliseconds, leading to a whole body flinch in rodents 1 . Although startle responses are reflexive responses that can be reliably elicited, they are not stereotypic. They can be modulated by emotions such as fear (fear potentiated startle) and joy (joy attenuated startle), by non-associative learning processes such as habituation and sensitization, and by other sensory stimuli through sensory gating processes (prepulse inhibition), turning startle responses into an excellent tool for assessing emotions, learning, and sensory gating, for review see 2,3 . The primary pathway mediating startle responses is very short and well described, qualifying startle also as an excellent model for studying the underlying mechanisms for behavioural plasticity on a cellular/molecular level 3 .We here describe a method for assessing short-term habituation, long-term habituation and prepulse inhibition of acoustic startle responses in rodents. Habituation describes the decrease of the startle response magnitude upon repeated presentation of the same stimulus. Habituation within a testing session is called short-term habituation (STH) and is reversible upon a period of several minutes without stimulation. Habituation between testing sessions is called long-term habituation (LTH) 4 . Habituation is stimulus specific 5 . Prepulse inhibition is the attenuation of a startle response by a preceding non-startling sensory stimulus 6 . The interval between prepulse and startle stimulus can vary from 6 to up to 2000 ms. The prepulse can be any modality, however, acoustic prepulses are the most commonly used.Habituation is a form of non-associative learning. It can also be viewed as a form of sensory filtering, since it reduces the organisms' response to a non-threatening stimulus. Prepulse inhibition (PPI) was originally developed in human neuropsychiatric research as an operational measure for sensory gating 7

α2- and β-adrenoceptors involvement in nortriptyline modulation of auditory sustained attention and impulsivity

“…Averages are calculated for each IRT. None of the drugs used, changed the latency of premature responses at any IRT (unpaired Student's t-test) activation of a startle response, which is evoked by 10 dB louder stimuli (Floody and Kilgard 2007;Dagnino-Subiabre et al 2009), while 80-85-dB sounds as used in our experiment evokes a non-startle response (Valsamis and Schmid 2011). The dependence on NT dose is described by a Yerkes-Dodson inverted Ushaped relationship, consistent with a performance correlating with the phasic release of NE.…”

Chlorovirus ATCV-1 is part of the human oropharyngeal virome and is associated with changes in cognitive functions in humans and mice

“…Also of note were differences in expression of genes in the dopamine pathway (Fig. S2) because perturbation of the dopamine system impairs novel object recognition and PPI in rodents (37,38), as do alterations in the pathway of EIF2 because this factor is central to the control of long-term synaptic plasticity and memory storage (39).…”

Activation of mGluR2/3 receptors in the ventro-rostral prefrontal cortex reverses sensorimotor gating deficits induced by systemic NMDA receptor antagonists

“…The behavioural testing paradigm consisted of the following phases: the acclimation phase, a habituation phase (block 1), and PPI measurement (block 2, see also Valsamis and Schmid, 2011). During the acclimation phase animals were exposed to the chambers and white background noise (65 dB) for 3 min.…”