Behavioral evaluation of afferents from the ventral nucleus of the trapezoid body to the first nucleus of the neural circuitry of the auditory startle reflex: the cochlear root nucleus

• Grant number: 13/25737-6
• Support type: Scholarships in Brazil - Master
• Effective date (Start): March 01, 2014
• Effective date (End): May 31, 2015
• Field of knowledge: Biological Sciences - Morphology - Anatomy
• Principal researcher: José de Anchieta de Castro e Horta Júnior
• Grantee: Nicole Orsi Barioni
• Home Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The cochlear root neurons are the first in the central nervous system to receive the acoustic information. They are in connection with sensory integration centers in the brainstem, particularly the pontine caudal nucleus. The cochlear root neurons are related with the fundamental neural circuit of the acoustic startle reflex, together with the spiral ganglion neurons, the pontine reticular nucleus and the spinal cord motoneurons. The acoustic startle reflex shows various modulations such as habituation, sensitization, fear potentiation and prepulse inhibition. The modulations of the acoustic startle reflex are important in clinical diagnostics of psychiatric and neurodegenerative illnesses such as schizophrenia and Parkinson's disease. Startle modulations are promoted by influences from several nuclei on the fundamental neural circuit of the startle reflex. The cochlear root nucleus is the least studied nucleus of this circuit. The origins of the afferents to cochlear root neurons and its neurochemical identity remain unclear. Recently was described a new source of afferents to cochlear root neurons, cholinergic and coming from the ventral nucleus of the trapezoid body. The neurons of this nucleus receive auditory information directly from the inferior colliculus which take part of the auditory pathway and also participates in the neural circuitry responsible for mediating the prepulse inhibition. Therefore, the inferior colliculus may mediate the prepulse inhibition at the cochlear root level via ventral nucleus of the trapezoid body connection, which would be a short and low latency pathway. However, there are no studies on functional aspects of this connection. We intend to study the role of cholinergic projections from the ventral nucleus of the trapezoid body by selective lesion of this nucleus and behavioral assessment of auditory startle reflex and prepulse inhibition.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

TORRES-DA-SILVA, K. R.; DA SILVA, A. V.; BARIONI, N. O.; TESSARIN, G. W. L.; DE OLIVEIRA, J. A.; ERVOLINO, E.; HORTA-JUNIOR, J. A. C.; CASATTI, C. A. Neurochemistry study of spinal cord in non-human primate (Sapajus spp.). EUROPEAN JOURNAL OF HISTOCHEMISTRY, v. 60, n. 3, p. 175-182, 2016. Web of Science Citations: 5.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

BARIONI, Nicole Orsi. Estudo comportamental das aferências do núcleo ventral do corpo trapezóide ao primeiro núcleo do circuito neural do reflexo auditivo de sobressalto : núcleo da raiz coclear. 2015. 91 f. Master's Dissertation - Universidade Estadual Paulista "Júlio de Mesquita Filho" Instituto de Biociências (Campus de Botucatu)..