Alterations in brainstem auditory processing, the acoustic startle response and sensorimotor gating of startle in Wistar audiogenic rats (WAR), an animal model of reflex epilepsies

Author(s)

Siqueira Cunha, Alexandra Olimpio ^[1] ; Moradi, Marzieh ^{[2, 1]} ; de Deus, Junia Lara ^[1] ; Ceballos, Cesar Celis ^[1] ; Moreira Benites, Nikollas ^[1] ; Gama de Barcellos Filho, Procopio Cleber ^[1] ; Cortes de Oliveira, Jose Antonio ^[1] ; Garcia-Cairasco, Norberto ^[1] ; Leao, Ricardo ^[1]

Affiliation

^[1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Physiol, Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Neurosci & Behav Sci, Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: Brain Research; v. 1727, JAN 15 2020.
• Web of Science Citations: 0

Abstract

While acute audiogenic seizures in response to acoustic stimulus appear as an alteration in sensory-motor processing in the brainstem, the repetition of the stimulus leads to the spread of epileptic activity to limbic structures. Here, we investigated whether animals of the Wistar Audiogenic Rat (WAR) strain, genetically selected by inbreeding for seizure susceptibility, would have alterations in their auditory response, assessed by the auditory brainstem responses (ABR) and sensory-motor gating, measured as pre-pulse inhibition (PPI), which could be related to their audiogenic seizures susceptibility or severity. We did not find differences between the amplitudes and latencies of ABR waves in response to clicks for WARs when compared to Wistars. Auditory gain and symmetry between ears were also similar. However, hearing thresholds in response to some tones were lower and amplitudes of wave II were larger in WARs. WARs had smaller acoustic startle reflex amplitudes and the percentages of startle inhibited by an acoustic prepulse were higher for WARs than for Wistars. However, no correlation was found between these alterations and brainstem-dependent seizure severity or limbic seizure frequency during audiogenic kindling. Our data show that while WARs present moderate alterations in primary auditory processing, the sensory motor gating measured in startle/PPI tests appears to be more drastically altered. The observed changes might be correlated with audiogenic seizure susceptibility but not seizures severity. (AU)

• FAPESP's process: 15/22327-7 - Analysis of electrophysiological and morphofunctional properties of neurons in the central nucleus of inferior colliculus related to genesis and spreading of sound-induced convulsive seizures
• Grantee: Alexandra Olimpio Siqueira Cunha
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 16/01607-4 - High intensity sound stimulation and synaptic plasticity
• Grantee: Ricardo Mauricio Xavier Leão
• Support Opportunities: Regular Research Grants