Loss of the acoustic startle response following neurotoxic lesions of the caudal pontine reticular formation: Possible role of giant neurons

doi:10.1016/0306-4522(92)90231-P

Neuroscience

Volume 49, Issue 3, August 1992, Pages 617-625

https://doi.org/10.1016/0306-4522(92)90231-P Get rights and content

Abstract

The effect of the excitotoxic N-methyl-d-aspartate agonist quinolinic acid in the caudal pontine reticular formation on the acoustic startle response was investigated in rats. Bilateral injections of 90 nmol of quinolinic acid led to large lesions in the reticular formation characterized by the loss of all neurons and a marked reduction or even abolition of the acoustic startle response; 18 nmol of quinolinic acid led to smaller lesions characterized by a selective loss of giant neurons within the caudal pontine reticular formation and a reduction of the startle amplitude. The partial correlation analysis revealed that the reduction of the amplitude of the acoustic startle response can be correlated with the loss of the giant neurons (r = 0.575; d.f.= 29; P < 0.001) but not with the reduction of the number of all neurons (r = 0.207; d.f.= 29; P > 0.2) in the caudal pontine reticular formation. These findings were reconciled with electrophysiological and anatomical data indicating that the giant neurons in the caudal pontine reticular formation receive acoustic input and project to motoneurons of the spinal cord.

It is concluded that the caudal pontine reticular formation is an important element of the startle pathway and that the giant reticulospinal neurons constitute an important part of the sensorimotor interface mediating this response.

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Loss of the acoustic startle response following neurotoxic lesions of the caudal pontine reticular formation: Possible role of giant neurons

Abstract

Physiol. Behav.

Physiol. Behav.

Physiol. Behav.

Physiol. Behav.

Physiol. Behav.

Brain Res.

Brain Res.

Brain Res.

Brain Res.

Brain Res.

Estimation of nuclear population from microtome sections

Anat. Rec.

Reticular formation, central gray and related tegmental nuclei

The mammalian startle response

A primary acoustic startle circuit: lesion and stimulation studies

J. Neurosci.

Role of the Mauthner cell in sensorimotor integration by the brain stem escape network

Brain Behav. Evol.

Actions of neurotransmitters on pontine medial reticular formation neurons of the cat

J. Neurophysiol.

Auditory input to neurons in mesencephalic and rostral pontine reticular formation: an electrophysiological and horseradish peroxidase study in the cat

J. Neurophysiol.